Method and device for drying and / or purifying nitrate esters

Abstract

The present invention relates to a method for drying and / or purifying, preferably drying and purifying, aliphatic or cycloaliphatic nitrate esters (esters of nitric acid), in particular for removing water and volatile and / or volatilizable impurities which are produced particularly during production and / or washing of nitrate esters, and to corresponding uses and to a corresponding apparatus and system for carrying out the method.

Description

[0001] Process and device for drying and / or purifying nitrate esters

[0002] The present invention relates to the technical field of the production and in particular the drying and / or purification of aliphatic and cycloaliphatic nitrate esters (nitric acid esters) for the purpose of providing dry or anhydrous and pure nitrate esters.

[0003] In particular, the present invention relates to a process for drying and / or purifying aliphatic or cycloaliphatic nitrate esters (nitric acid esters), in particular for removing water and volatile impurities arising in particular during the production and / or washing of the nitrate esters.

[0004] Furthermore, the present invention relates to a device for drying and / or purifying aliphatic or cycloaliphatic nitrate esters (nitric acid esters), as well as a production plant for producing aliphatic or cycloaliphatic nitrate esters (nitric acid esters).

[0005] Finally, the present invention relates to the use of an inert gas for drying and / or purification, preferably drying and purification, of aliphatic or cycloaliphatic crude nitrate esters (nitric acid esters) obtained from a manufacturing process.

[0006] Aliphatic or cycloaliphatic organic nitrate esters (nitric acid esters) are reaction products of corresponding aliphatic or cycloaliphatic alcohols and nitric acid. Nitrate esters are generally produced in a continuously operated plant by reacting the alcohol with nitric acid directly or in the presence of sulfuric acid as a catalyst and water-binding agent (e.g., according to the Schmid-Meissner or Biazzi processes, the injector process, the NAB process of Nielsen and Brunnberg, or a modified process according to EP 1 792 891 A1). The nitration of the alcohols, i.e., their conversion to nitrate esters, usually takes place in the liquid phase, either as a pure substance or as a mixture, or in solution in inert, water-immiscible solvents. Organic nitrate esters are primarily used in explosives chemistry (e.g., nitroglycerin, ethylene glycol dinitrate, and many more).), but also from the pharmaceutical industry (e.g., nitrate esters of steroid alcohols, among others) or from the fuel industry, particularly as additives. For example, a well-known and widely used additive in the fuel industry is ethylhexyl nitrate (EHN), which is used as an additive for diesel fuels to increase the cetane number. Other common nitrate esters include pentaerythritol tetranitrate (PETN), glyceryl trinitrate (NGL), and ethylene glycol dinitrate (EGDN).

[0007] The cetane number is a value that describes the ignitability of diesel fuel: The higher the cetane number, the more ignitable the fuel is. First of all, the more unbranched hydrocarbon molecules the fuel contains, the more easily it ignites, which is a desirable behavior, especially in diesel engines.

[0008] Accordingly, a fuel with a lower cetane number tends to make a compression-ignition engine (diesel engine) more difficult to start and may run noisily when cold. Conversely, a fuel with a higher cetane number tends to result in easier cold starts, lower engine noise, and a reduction in white smoke caused by incomplete combustion ("cold smoke").

[0009] There is therefore a general preference for diesel fuels with a high cetane number, which is reinforced by increasingly stringent emissions regulations, as automotive diesel specifications typically specify a minimum cetane number. Accordingly, many diesel fuel formulations contain additives in the form of ignition improvers, also known as cetane boost additives or cetane number improvers, to ensure compliance with these specifications and generally improve the fuel's combustion characteristics.

[0010] The most commonly used ignition enhancer additive for diesel fuels is 2-ethylhexyl nitrate (EHN). It primarily shortens the ignition delay of the fuel to which it is added. Crude nitrate esters obtained from the manufacturing processes mentioned above must undergo a multi-stage washing and additional purification process before their use, e.g., as an ignition enhancer, or before their further processing. This is necessary to remove impurities dissolved or suspended in the crude nitrate esters, such as sulfuric acid, nitric acid, nitrous gases, etc., as well as byproducts from the oxidative degradation of the starting alcohols. This also improves the stability of the nitrate esters, many of which are highly sensitive explosives.

[0011] Generally, washing the crude nitrate esters to remove the dissolved and suspended acids of the nitration mixture and other acidic or other contaminants extractable with the washing agent consists of three steps: an acidic wash, a basic or alkaline wash, and a neutral wash (see, for example, BT Urbanski, Vol. 2, pages 97 ff., especially Figs. 43, 44, 59, and 60, Pergamon Press, Reprint 1985). However, washing the crude nitrate esters directly with, for example, soda solution, i.e., omitting the "acidic wash" step, is also sometimes practiced and is state of the art. Water is typically used as the washing medium. The washing is generally carried out as a liquid-liquid wash with the nitrate ester, which is generally liquid at washing temperature, or as a solution of the same in a suitable solvent.

[0012] When washing the crude nitrate esters in the form of the described liquid-liquid extraction, predominantly only those impurities are washed out which have a high solubility in the washing medium (such as sulfuric acid and nitric acid) or which disproportionate with the water in the aqueous medium to form nitric acid or which form salts with the bases added during the alkaline or basic washing, such as strong acids, in particular sulfuric acid and nitric acid, and medium and weak acids, such as nitrophenols, nitrocresols, nitrobenzoic acids, nitrous acid, acetic acid, oxalic acid, formic acid, carbonic acid, hydrogen cyanide, etc. However, even with regard to these impurities, their removal during washing is not always complete or quantitative, especially when the crude nitrate esters have high loadings of these impurities.It has also been shown that other contaminants, in particular contaminants with unfavorable distribution coefficients in relation to the washing medium or contaminants with weak or lacking acidity or contaminants with a slow conversion rate into substances which do not dissolve in the organic phase, often cannot be completely removed in the wash or in the washing process with one or more steps and / or only with great technical effort.

[0013] Higher water contents in the nitrate esters obtained from the washing process, whether heterogeneously or homogeneously distributed, are generally undesirable because they can negatively impact the nitrate ester product properties. This is particularly reflected in the specifications for the nitrate esters, with the common specification for the water content in ethylhexyl nitrate being set at a maximum of 0.05% water content, because otherwise the product exhibits a cloudiness that is difficult to remove. On the other hand, residual water or moisture, especially in small quantities, is difficult to remove from the nitrate esters.

[0014] Processes are known from the state of the art which, among other things, involve the drying of nitrate esters.

[0015] For example, Chinese patent application CN 1903829 A describes a process for producing and drying isooctyl nitrate. The drying process comprises the following steps: Crude isooctyl nitrate is first separated from water by sedimentation and phase separation; the resulting isooctyl nitrate, still laden with small amounts of water, is then passed over a series of layers or trays of anhydrous sodium sulfate for drying. A disadvantage of this process is that sodium sulfate must be regularly regenerated through thermal treatment, which is a complex process, or, if necessary, completely replaced. Furthermore, sodium sulfate can only remove water from the isooctyl nitrate, but cannot reduce other volatilizable or volatile impurities. Furthermore, the drying performance of sodium sulfate is not sufficiently high to achieve very low water contents in the final product.Furthermore, the process must be carried out in two stages using separate equipment for each process step, which requires considerable effort. The process is also relatively costly and time-consuming. The Chinese patent application CN 1031525 A describes a production process for isooctyl nitrate in which the resulting product is dried under vacuum. While this method can remove volatile or volatilizable impurities, vacuum drying processes are very expensive in terms of equipment and energy consumption and often do not allow for the adequate drying of large quantities of product. Even small amounts of water cannot be easily removed. Furthermore, a significant product loss often occurs due to vacuum drying.

[0016] Finally, Chinese patent CN 101696168 B describes a process for producing isooctyl nitrate in which the resulting product is dried by passing it through columns containing silica gel or molecular sieves. Impurities or water are absorbed from the isooctyl nitrate by the silica gel or molecular sieve. A disadvantage of this method, however, is that the column material must be regularly regenerated or replaced, which is particularly time-consuming and excessively time-, cost-, and labor-intensive, especially for large-volume production. Furthermore, regeneration of the column material usually has to be carried out at high temperatures, which can lead to a fire and / or explosion hazard, especially given the usual presence of residual nitrate esters. This process is therefore also unsuitable for large-scale production.

[0017] The state-of-the-art processes for drying nitrate esters are therefore complex and excessively time-, cost-, and labor-intensive, especially for large-scale production, and often do not produce the desired results. These state-of-the-art processes also do not allow for the removal of volatile contaminants.

[0018] Overall, there is still a need in the prior art for production and, in particular, purification and drying processes for organic, preferably aliphatic and cycloaliphatic, nitrate esters that are efficient in terms of the achievable drying performance and, at the same time, are designed in such a way that the equipment required and the process control and monitoring are as minimal as possible. Against the background of the previously described prior art, the present invention is therefore based on the object of providing a drying and / or purification process for aliphatic or cycloaliphatic organic nitrate esters and a corresponding device or (production) plant, wherein the aforementioned disadvantages of known processes or known devices and (production) plants of the prior art are to be avoided or at least mitigated.

[0019] In particular, the present invention is based on the object of providing a drying and / or purification process for aliphatic or cycloaliphatic organic nitrate esters and a corresponding device or (production) plant, wherein the process or the device and (production) plant in question is / are designed more efficiently with regard to the drying or purification achieved and can be carried out or operated with less effort with regard to process control and equipment compared to the known prior art.

[0020] In a completely surprising way, the applicant has now found that on the basis of the inventive concept underlying the present invention, in particular by means of the process according to the invention for drying and / or purification, preferably drying and purification, of aliphatic or cycloaliphatic nitrate esters (nitric acid esters) as well as the corresponding device or (production) plant, a very efficient and resource-saving treatment concept for nitrate esters can be provided, which equally delivers purified or pure nitrate esters with degrees of drying and / or purity that are in particular significantly lower than according to the prior art, in particular also that water present in the washed crude nitrate esters is removed (iethe washed crude nitrate esters are dried) and at the same time and / or as it were, volatile and / or volatilizable impurities arising in particular during the production of the nitrate esters are removed. To solve the problem described above, the present invention therefore proposes - according to a first aspect of the present invention - a process for drying and / or purifying, preferably drying and purifying, aliphatic or cycloaliphatic nitrate esters (nitric acid esters), in particular for removing water and volatile impurities arising in particular during the production and / or washing of the nitrate esters, according to claim 1. Advantageous developments and refinements of this aspect of the invention are the subject of the relevant auxiliary or subclaims.

[0021] A further subject matter of the present invention—according to a second aspect of the present invention—is a device for drying and / or purifying, preferably a device for drying and purifying, aliphatic or cycloaliphatic nitrate esters (nitric acid esters), in particular for removing water and volatile impurities arising in particular during the production and / or washing of the nitrate esters, preferably by contacting, in particular by flowing through, an inert gas, in particular a device for carrying out the process according to the invention, according to the relevant independent claim. Advantageous further developments and refinements of this aspect of the invention are the subject matter of the relevant subsidiary and dependent claims.

[0022] Furthermore, the present invention—according to a third aspect of the present invention—provides a production plant for producing aliphatic or cycloaliphatic nitrate esters (nitric acid esters) according to the relevant independent claim. Advantageous further developments and refinements of this aspect of the invention are the subject of the relevant subclaims.

[0023] Finally, according to a fourth aspect of the present invention, the subject matter of the present invention is the inventive use according to the relevant independent claims. Advantageous further developments and refinements of this aspect of the invention are the subject matter of the relevant subclaims. It goes without saying that refinements, embodiments, advantages, and the like, which are listed below only for one aspect of the invention in order to avoid repetition, naturally also apply accordingly to the remaining aspects of the invention, without the need for separate mention.

[0024] Furthermore, it goes without saying that the following specifications of values, numbers, and ranges are not to be understood as limiting; it is self-evident to the person skilled in the art that, depending on the individual case or application, deviations from the specified range or specifications may occur without departing from the scope of the present invention.

[0025] In addition, all values ​​or parameters or the like mentioned below can generally be determined using standardized or explicitly specified determination procedures or using determination methods that are familiar to a person skilled in the art.

[0026] Furthermore, with all relative or percentage quantities, particularly those based on weight, mentioned below, it should be noted that these quantities must be selected or combined by the person skilled in the art with regard to the reference system used (e.g., dosage form) in such a way that the total – if necessary, including other components or ingredients or additives or constituents, in particular as defined below – always amounts to 100% or 100% by weight. However, this is self-evident to the person skilled in the art.

[0027] Furthermore, for the description of the present invention, the features of the present invention cited in connection with the specific embodiments, advantages, examples, or the like are also deemed to be disclosed in their combination. Thus, higher-level combinations of individual or multiple features cited for respective embodiments, embodiments, application examples, or the like are also deemed to be disclosed. In particular, for the features characterizing the invention, all possible combinations of these features are deemed to be disclosed, with embodiments of comparable or corresponding preference for the various features being preferred in their combination (e.g., quantities or quantity ranges of the relevant parameters of the same preference, or the like).

[0028] In particular, it also applies that for the information listed below concerning the various parameters of the method according to the invention or the like, which has the same preference or the same level of preference, the respective combinations concerning the various parameters with corresponding preference or preference are also disclosed. Likewise, all other combinations (i.e., combinations based on different preferences or different levels of preference) are also disclosed.

[0029] Having said that, the present invention will now be explained in detail below:

[0030] The present invention - according to a first aspect of the present invention - relates to a process for drying and / or purifying, preferably drying and purifying, aliphatic or cycloaliphatic nitrate esters (nitric acid esters), in particular for removing water and volatile impurities arising in particular during the production and / or washing of the nitrate esters, the process comprising the following process steps:

[0031] (a) first, the crude nitrate esters obtained from a manufacturing process are subjected to washing with a washing medium, followed by separation of the washing medium,

[0032] (b) subsequently, the washed crude nitrate esters obtained in process step (a) are subjected to drying and / or purification, preferably drying and purification, by contacting, in particular by flowing through, an inert gas, in particular such that water present in the washed crude nitrate esters is removed (i.e. the washed crude nitrate esters are dried) and, at the same time and / or simultaneously, volatile impurities arising, in particular, during the production and / or washing of the nitrate esters are removed. Within the scope of the present invention, a particularly efficient, in particular resource-saving and highly effective process for drying and / or purification, in particular drying and purification, of aliphatic or cycloaliphatic organic nitrate esters (nitric acid esters) is provided.

[0033] The high effectiveness of the process according to the invention is expressed in particular in the fact that the process according to the invention can be used to provide particularly high-quality purified or dried nitrate esters, in particular wherein these nitrate esters are characterized by a very high degree of purity and an extremely low proportion of moisture or water that remains in the nitrate esters after carrying out the process according to the invention. The special quality in terms of a particularly high purity and the almost complete absence of moisture or water in the nitrate esters is directly attributable to the process according to the invention, in particular to process step (b) for drying or purifying the nitrate esters by contacting them, in particular by flowing them through, with an inert gas.

[0034] In the context of the present invention, purification means the final removal (i.e. at least substantially complete removal or reduction to a desired minimum, preferably complete removal) of, in particular, volatile impurities or foreign substances from crude nitrate esters which have been obtained from a manufacturing process and have already been subjected to a washing step. The result of the purification or cleaning is purified nitrate esters, i.e. nitrate esters which are free of or freed from foreign substances or impurities and which can therefore also be regarded as pure nitrate esters. The result or objective of the purification in the sense of the present invention is therefore in particular the reduction of the proportion of, in particular, volatile impurities in the nitrate esters, preferably to a proportion of, in particular, volatile impurities in the particularly low ppm range.

[0035] Advantageously, within the scope of the present invention, it is possible to achieve particularly low levels or proportions of, in particular, volatile impurities in the purified nitrate esters, which cannot be achieved in this way with prior art processes, or only with very high and correspondingly impractical effort. The high degree of purity of nitrate esters achievable with the process according to the invention is directly attributable to the special process management within the scope of the present invention.In particular, within the scope of the present invention, nitrate esters are obtained that are so pure that they can be considered essentially free of, in particular, volatile impurities, especially since purified nitrate esters can be produced with a content of, in particular, volatile impurities in a range of, in particular, at most 100 ppm, preferably at most 30 ppm, particularly preferably at most 10 ppm. This is generally not possible with known prior art processes.

[0036] Within the scope of the present invention, on the basis of the process according to the invention, nitrate esters can be obtained which are essentially free of, or freed from, particularly volatile impurities, especially in contrast to processes known or available from the prior art for the purification of nitrate esters.

[0037] In addition, drying in connection with the process according to the invention is to be understood as meaning that traces of moisture or of water remaining in the washed nitrate esters, in particular from the washing medium, are largely or at least substantially completely removed from the nitrate esters obtained by the process according to the invention.

[0038] Advantageously, within the scope of the present invention, it is possible to reduce the proportion of moisture or water in purified or dried nitrate esters to a level or proportion which cannot be achieved with conventional methods or processes known from the prior art or can only be achieved with considerable and accordingly impractical effort.

[0039] Thus, within the scope of the present invention, in particular as a result of the process according to the invention and specifically the process management according to the invention, at least substantially completely dry or completely dry, i.e. freed from moisture or water, for example from the washing medium, and / or free, nitrate esters can be obtained, especially in contrast to processes known from the prior art for drying nitrate esters. In particular, substantially or absolutely dry or substantially completely freed from moisture or water or free within the scope of the present invention means purified or dried nitrate esters with a water content in a range of in particular 0.025 wt. % or less.

[0040] Furthermore, volatile or volatilizable impurities in the context of the present invention are understood to mean substances, materials, or compounds that are volatile or exhibit volatile behavior, especially under the specific process conditions. Volatility is a material property that describes, in particular, its evaporation or tendency to evaporate (i.e., the tendency of a substance to change from the liquid to the gaseous state without reaching the boiling point). In particular, the physical (partition / equilibrium) between the gas phase and the liquid phase, as well as the partial or vapor pressures of the substances, materials, or compounds in question, can play a role or be taken into account.

[0041] Evaporation occurs when the gas phase above or around a liquid is not yet saturated with vapor. The volatility of a substance can be defined, in particular, by its vapor pressure or, within the scope of the present invention, can also be specified in contrast to the vapor pressure of a reference substance.

[0042] The term volatile compounds in the context of the present invention also includes those compounds which are or become volatilizable under the process conditions, i.e. are or become volatile specifically under the specific process conditions, regardless of the volatility of these substances under pure or isolated standard conditions. This can be justified in particular by the fact that in the context of the present invention it is intended to wash or expel volatile impurities from nitrate esters by bringing them into contact with the inert gas. These process conditions are accompanied by a continuous saturation of the gas phase (the inert gas) with liquid, which saturation is kept constant at a comparatively low level, so that the tendency of a substance to volatilize is per se increased under the process conditions of the process according to the invention.It is a significant advantage of the present invention, in particular of the process according to the invention, that purified or dried nitrate esters can be obtained which are characterized by a significantly increased quality with regard to the purity and / or dryness or freedom from moisture and / or water of the nitrate esters compared to previously achievable degrees of drying or purity.

[0043] In particular, the process according to the invention makes it possible to provide purified or pure nitrate esters that have a content of, in particular, volatile impurities in the very low ppm range, in particular of at most 100 ppm, preferably of at most 30 ppm, particularly preferably of at most 10 ppm. This has so far been possible with methods available from the prior art only at extremely high and thus uneconomical expense, or ultimately not at all, especially not in an efficient manner.

[0044] It is also advantageously possible with the process according to the invention to provide dried and / or dry nitrate esters which have a very low proportion of water or moisture, so that within the scope of the present invention at least substantially moisture-free or anhydrous nitrate esters can be provided.

[0045] In particular, the process according to the invention makes it possible to dry nitrate esters to such an extent that moisture or water contents in a range of at most 0.06 wt.%, preferably at most 0.01 wt.%, based on the dried and / or purified nitrate esters, can be achieved.

[0046] Within the scope of the present invention, it can be particularly advantageously achieved that a cloud point below 0 °C is achieved in the dried or dry nitrate esters, which corresponds to a residual moisture content or a moisture and / or water content in the nitrate ester of less than 0.02 wt.%. Nitrate esters with such specifications are characterized, for example, by significantly improved properties when used as ignition improvers in fuel mixtures. This particularly includes an improvement in the ignition properties of a corresponding fuel mixture at low temperatures, approximately in a range of 0 °C or less.The high efficiency of the process according to the invention is advantageously expressed in particular by the fact that, within the scope of the present invention, in particular within the scope of the process according to the invention and specifically due to the specific process control of the process according to the invention, crude nitrate esters which have previously been washed with a washing medium in a washing step can be dried or purified in a manner which requires little equipment by bringing the washed crude nitrate esters into contact with, in particular flowing through, an inert gas. Bringing the crude nitrate esters into contact with, or in particular flowing through, an inert gas allows the crude nitrate esters to be purified or dried using extremely few auxiliaries or process components. This advantageously results in an extremely lean process which, with regard to the process components used in the process according to the invention, is extremely economical.-media. This streamlined, stringent process also has direct advantages in terms of process technology and equipment, as a device and production system can be used that are structurally simplified in their complexity compared to state-of-the-art devices or systems for drying or purifying nitrate esters, thus advantageously achieving increased process reliability and continuity while simultaneously improving product quality.

[0047] Since only very few process components or media (a washing medium in process step (a) and inert gas as drying or purification medium in process step (b)) are necessary within the scope of the process according to the invention, it is also possible to work in a resource-saving manner.

[0048] According to a further particular advantage of the present invention, the process according to the invention also allows recycling or recirculation of the inert gas used in the drying and / or purification step (b). It is therefore advantageously possible within the scope of the present invention to reuse the inert gas in the process according to the invention and in particular to use it again in process step (b) after it has flowed through the nitrate esters to be purified or has come into contact with them. For this purpose, it has proven advantageous if an intermediate drying of the inert gas takes place, which can be integrated into the inventive concept in a straightforward manner and in a stringent process technology manner. It is therefore advantageously possible within the scope of the present invention toto be dried, previously washed crude nitrate esters, to be dried, and to regenerate them in a downstream drying step in such a way that it becomes or is possible to circulate or recycle the inert gas, so that particularly resource-efficient operation can be carried out within the scope of the present invention. Equally, it is advantageous within the scope of the method according to the invention or within the scope of the present invention to also feed moisture or water separated from the inert gas back into the process, in particular to return it to the washing medium of the washing step, so that even within the scope of washing crude nitrate esters obtained from a production process, economic and ecological efficiency can be achieved with regard to the washing medium.

[0049] Thus, the present invention, in particular within the scope of the process according to the invention, not only provides the possibility of obtaining particularly high-quality nitrate esters, which are characterized in particular by very high purity and dryness, but also the possibility of working in a comparatively resource-saving and thus environmentally friendly manner.

[0050] Since the process according to the invention can also be implemented with a comparatively low expenditure on equipment or with devices or production plants that are lean and stringent in terms of process technology, the present invention is characterized by a high efficiency, which is expressed in particular in an uncomplicated handling of the process according to the invention with, at the same time, a high effectiveness of the process according to the invention in the sense of achieving a high purity and dryness of the process product.

[0051] In particular, the present invention provides a purification and drying process for organic, preferably aliphatic and cycloaliphatic, nitrate esters, which is efficient in terms of the achievable drying performance and, at the same time, is designed in such a way that the equipment required and the process control and control are as minimal as possible. Furthermore, within the scope of the present invention, a drying and / or purification process for aliphatic or cycloaliphatic organic nitrate esters and a corresponding device or (production) plant can be provided, wherein the aforementioned disadvantages of known processes or known devices and (production) plants of the prior art are avoided or at least mitigated.

[0052] In particular, within the scope of the present invention, a drying and / or purification process for aliphatic or cycloaliphatic organic nitrate esters and a corresponding device or (production) plant can be provided, wherein the process or the device and (production) plant in question is / are designed more efficiently with regard to the drying or purification achieved and can be carried out or operated with less effort with regard to process control and equipment compared to the known prior art.

[0053] As already explained above, in order to achieve the above-described problem, a process is provided for drying and / or purifying, preferably drying and purifying, aliphatic or cycloaliphatic nitrate esters (nitric acid esters), in particular for removing water and volatile impurities arising in particular during the production and / or washing of the nitrate esters, the process comprising the following process steps:

[0054] (a) first, the crude nitrate esters obtained from a manufacturing process are subjected to washing with a washing medium, followed by separation of the washing medium,

[0055] (b) the washed crude nitrate esters obtained in process step (a) are subsequently subjected to drying and / or purification, preferably drying and purification, by contacting them, in particular by flowing them through, with an inert gas, in particular in such a way that water present in the washed crude nitrate esters is removed (i.e. the washed crude nitrate esters are dried) and, at the same time and / or simultaneously, volatile impurities arising, in particular, during the production and / or washing of the nitrate esters are removed. With regard to the nitrate esters preferably used and / or reacted in the context of the present invention, it has proven useful if the nitrate esters are liquid and / or are in liquid form under standard conditions, in particular at a pressure of 1.013 bar and a relative air humidity of 0% (standard conditions according to DIN 1343, STPD).

[0056] According to the invention, good results are obtained when the nitrate esters are nitrate esters of mono- or polyhydric aliphatic or cycloaliphatic alcohols. In particular, the invention provides that the nitrate esters are selected from (i) nitrate esters of aliphatic or cycloaliphatic alkanols, in particular linear or branched aliphatic or cycloaliphatic alkanols, preferably hexanols, heptanols, octanols, ethylhexyl alcohol, and cyclohexanol; (ii) nitrate esters of aliphatic alkanediols, in particular ethylene glycol and propanediols and their oligomers and polymers, such as ethylene glycol or propanediols, ethylene or propylene triglycol, and polyethylene or polypropylene glycol; (iii) nitrate esters of aliphatic alkanetriols, in particular trimethylolethane, trimethylolpropane, butanetriols, and glycerol; (iv) Nitrate esters of tetra- or polyhydric aliphatic alkanols.

[0057] Advantageously, within the scope of the present invention, a large number of different nitrate esters can be purified or dried in an efficient and effective manner, so that the process according to the invention can be used very flexibly for many different nitrate esters.

[0058] In addition to its applicability for a wide range of nitrate esters, the present invention also advantageously enables the effective and very high removal of a multitude of different, particularly volatile, impurities from these nitrate esters, which generally arise during the production of nitrate esters. The fact that the wide range of impurities, particularly volatile ones, described in more detail below, can be effectively removed from the nitrate esters by means of the process according to the invention once again underlines the advantageous high flexibility and broad application range of the process according to the invention.

[0059] Likewise, the process according to the invention is advantageously characterized in that nitrate esters of a particularly high purity or quality can be obtained, in particular in that the impurities, in particular volatile impurities, which are generally introduced into the nitrate esters during the production and / or washing of the nitrate esters, as defined in more detail below, can be almost completely or largely removed from the nitrate esters as a result of the special process according to the invention.

[0060] The process according to the invention provides particularly good results when the volatile or volatilizable impurities are selected from the group of (i) unreacted and / or partially reacted reactants and / or starting reagents; (ii) nitrated and non-nitrated reaction by-products; (iii) degradation and oxidation products of the products and by-products originating from the nitration; (iv) mineral acids, in particular sulfuric acid, nitric acid and nitrous acid, preferably nitric acid; (v) organic acids, in particular formic acid, acetic acid, oxalic acid, carbonic acid and hydrogen cyanide; (vi) nitrogen bases, in particular ammonia (NH3); (vii) nitrogen oxides, in particular nitrogen monoxide (NO), nitrogen dioxide (NO2) and dinitrogen oxide (N2O) as well as nitrous oxide and other nitrogen oxides (NO X ); (viii) carbon oxides, in particular carbon monoxide (CO) and carbon dioxide (CO2); (ix) solvent and / or washing medium residues.

[0061] It is preferably provided that the volatile or volatilizable impurities to be removed have a higher volatility, in particular a higher vapor pressure and / or a lower boiling point, than the nitrate esters to be purified, in particular based on the vapor pressure of the nitrate esters under standard conditions (pressure of 1.013 bar; air humidity of 0% [standard conditions according to DIN 1343, STPD]) and / or in particular based on the boiling point of the nitrate esters under standard conditions (pressure of 1.013 bar; air humidity of 0% [standard conditions according to DIN 1343, STPD]).

[0062] Particularly advantageously, the volatile or volatilizable contaminants to be removed, especially water, have a vapor pressure that is at least 5 mbar, preferably at least 7.5 mbar, and more preferably at least 10 mbar, higher than the nitrate esters to be purified. Likewise, it has proven effective if the volatile or volatilizable contaminants to be removed have a boiling point that is at least 1 °C, preferably at least 2.5 °C, and more preferably at least 5 °C, lower than the nitrate esters to be purified.

[0063] With regard to the implementation of the process according to the invention, it has proven advantageous with regard to process step (a) if process step (a) and / or the washing are carried out as a liquid-liquid extraction. Within the scope of process step (a) carried out as a liquid-liquid extraction, a large proportion of the water-soluble, particularly volatile, impurities resulting from the production of the nitrate esters can be removed efficiently and with uncomplicated equipment.

[0064] In this sense, process step (a) carried out as a liquid-liquid extraction advantageously contributes to washing out the majority of non-volatile or non-volatilizable impurities from the crude nitrate esters obtained from a manufacturing process, such as salts or residues of inorganic acids or nitrating acid. Thus, process step (a) makes a beneficial contribution to the overall high purity achievable for nitrate esters obtained from the process according to the invention.

[0065] Furthermore, it has proven advantageous for process step (a) if process step (a) comprises an acidic, basic (alkaline) and / or neutral wash, in particular at least one basic (alkaline) and / or neutral wash, preferably an acidic, basic (alkaline) and neutral wash. In this way, water-soluble or inorganic by-products or reactant residues can be largely completely washed out of the crude nitrate esters obtained from the production process within the scope of process step (a).

[0066] Furthermore, it is advantageous if process step (a) and / or the washing is carried out in one or more washing stages, preferably in one, two or three washing stages, more preferably in two or three washing stages; in particular wherein each washing stage comprises one or more washing and / or extraction steps. Such a process procedure additionally contributes to a particularly thorough purification of nitrate esters in the process according to the invention. Within the scope of the present invention, it is further preferably provided that process step (a) and / or the washing is carried out using an aqueous-based washing medium; in particular wherein the aqueous-based washing medium is neutral, acidic or basic (alkaline).In addition to good washing performance, the use of water-based washing media guarantees efficient separation of the washing medium from washed nitrate esters, which remain in particular in the form of an organic phase, while the washing medium forms an aqueous phase that can be easily and precisely separated from the washed crude nitrate ester following the washing step or washing with the washing medium.

[0067] It has proven very effective and therefore advantageous if process step (a) and / or the washing are carried out in at least two, especially three, washing stages. Further advantageously, the washing stages comprise at least one basic (alkaline) washing stage and a final neutral washing stage, preferably comprising a first acidic washing stage, a subsequent second basic (alkaline) washing stage, and a final third neutral washing stage.

[0068] Furthermore, it has proven advantageous within the scope of the process according to the invention if process step (a) and / or the washing, in particular in each washing stage, is carried out in crossflow or counterflow, or in a combination of crossflow and counterflow. This is preferably done with recycling of the washing medium.

[0069] Furthermore, it is preferred according to the invention if, in process step (a), the washing medium is separated by means of a separating device (separator), in particular by means of a static separating device, or by means of a centrifugal separator.

[0070] With regard to process step (b), i.e., the drying and / or purification, preferably drying and purification, of the washed crude nitrate esters, it has proven advantageous within the scope of the present invention if process step (b) is carried out in a drying and / or purification device, preferably a drying and purification device. Preferably, the washed crude nitrate esters obtained in process step (a) are transferred to a drying and / or purification device, preferably a drying and purification device, in process step (b).

[0071] For the drying and / or purification device, it has proven advantageous according to the invention if the drying and / or purification device, preferably drying and purification device, comprises a column, in particular a single-stage or multi-stage column, preferably a packed column, sieve tray column, bubble tray column or falling film column or combinations thereof, and / or a gas / liquid reactor or a stripping device. The aforementioned preferred drying and / or purification devices advantageously allow nitrate esters to be brought into contact with, or in particular to be flowed through, an inert gas in a particularly efficient manner and, from a process engineering perspective, in a manner that is uncomplicated or can be implemented without great effort, as is envisaged in process step (b). Integration of the aforementioned preferred devices into the process according to the invention, in particular also in conjunction with a correspondingly suitable device orProduction plant, thus advantageously allowing simplified or improved process management with regard to process efficiency.

[0072] In the context of the present invention, it has proven advantageous if, in process step (b), the drying and / or purification, preferably drying and purification, is carried out as a continuous or discontinuous, in particular continuous, process.

[0073] Furthermore, it has proven advantageous if in process step (b) the drying and / or purification, preferably drying and purification, is carried out as gas-liquid extraction and / or by means of desorption, in particular as gas-liquid extraction.

[0074] It is a particular and advantageous aspect of the process according to the invention that the drying and / or purification, preferably drying and purification, of washed crude nitrate esters can be carried out as a gas-liquid extraction or by means of desorption, since in particular in this way or as a result thereof the particularly high purity or dryness of purified and / or dried nitrate esters advantageously achieved within the scope of the present invention is achieved. In the context of the present invention, desorption is understood to mean a process in which atoms or molecules of a substance, in particular here in the form of a substance present as an impurity in the washed crude nitrate esters, pass from a liquid in which they are dissolved into the gas phase.In this sense, a gas-liquid extraction in the context of the present invention means an extraction process in which, by bringing a liquid phase into contact with, in particular flowing through, a gas, impurities or foreign substances are dissolved out of this liquid and pass into the gas phase, in particular wherein the impurities or foreign substances are carried out of the liquid by the continuous movement of the gas phase, in particular in the case of flowing through the liquid.

[0075] What is particularly advantageous here is that for nitrate esters, which can tend to form explosive mixtures with air or explosive vapors, such purification processes which involve bringing the nitrate esters into contact with, or in particular flowing through, a gas have not been available to date, particularly since there has not been a process available to date which ensures that no explosive gas-nitrate ester mixtures or nitrate ester vapors are generated during such contacting with, or in particular flowing through, nitrate esters with a gas. In this respect, it is a particular merit of the applicant to have recognized that, particularly when using an inert gas, a gas-liquid extract extraction of nitrate esters ora purification and / or drying of nitrate esters by means of desorption becomes possible, in particular in conjunction with the further preferred process parameters of the process according to the invention, as already explained or as will be given in further detail below.

[0076] According to the applicable aspect, the present invention also particularly comprises such a process for drying and / or purifying, preferably drying and purifying, aliphatic or cycloaliphatic nitrate esters (nitric acid esters), in particular for removing water and volatile and / or volatilizable impurities arising in particular during the production and / or washing of the nitrate esters, in particular as described above, in which the process comprises the following process steps:

[0077] (a) first, the crude nitrate esters obtained from a manufacturing process are subjected to washing with a washing medium, followed by separation of the washing medium, wherein process step (a) and / or the washing is carried out as a liquid-liquid extraction;

[0078] (b) subsequently, the washed crude nitrate esters obtained in process step (a) are subjected to drying and / or purification, preferably drying and purification, by contacting, in particular by flowing through, an inert gas, in particular such that water present in the washed crude nitrate esters is removed (i.e. the washed crude nitrate esters are dried) and, at the same time and / or simultaneously, volatile and / or volatilizable impurities arising in particular during the production and / or washing of the nitrate esters are removed, wherein the drying and / or purification, preferably drying and purification, is carried out as a gas-liquid extraction and / or by desorption, in particular as a gas-liquid extraction; in particular wherein the volatile and / or volatilizable impurities are selected from the group of (i) unreacted and / or partially reacted reactants and / or starting reagents;(ii) nitrated and non-nitrated reaction by-products; (iii) degradation and oxidation products of the products and by-products resulting from nitration; (iv) mineral acids, in particular sulfuric acid, nitric acid and nitrous acid, preferably nitric acid; (v) organic acids, in particular formic acid, acetic acid, oxalic acid, carbonic acid and hydrogen cyanide; (vi) nitrogen bases, in particular ammonia (NH3); (vii) nitrogen oxides, in particular nitrogen monoxide (NO), nitrogen dioxide (NO2) and nitrous oxide (N2O) as well as nitrous oxide and other nitrogen oxides (NO; X); (viii) carbon oxides, in particular carbon monoxide (CO) and carbon dioxide (CO2); (ix) solvent and / or washing medium residues; and / or in particular wherein the volatile and / or volatilizable impurities to be removed have a higher volatility, in particular a higher vapor pressure and / or a lower boiling point, than the nitrate esters to be purified, in particular based on the vapor pressure of the nitrate esters under standard conditions (pressure of 1.013 bar; air humidity of 0% [standard conditions according to DIN 1343, STPD]) and / or in particular based on the boiling point of the nitrate esters under standard conditions (pressure of 1.013 bar; air humidity of 0% [standard conditions according to DIN 1343, STPD]).

[0079] As far as the implementation or design of process step (b) is concerned, it has proven useful within the scope of the present invention if the washed crude nitrate esters obtained in process step (a) are used as such in process step (b) and / or the washed crude nitrate esters obtained in process step (a) are used in concentrated and / or undiluted form in process step (b). Advantageously, within the scope of the present invention, in particular within the scope of the process according to the invention, no additional solvents are required for washed crude nitrate esters in process step (b). In this way, the purified and / or dried, preferably purified and dried, process product, i.e. pure or purified nitrate esters, can be obtained directly from process step (b).

[0080] According to an alternative, less preferred embodiment, however, it is also possible to carry out process step (b) in the presence of an (additional) solvent, in particular an inert solvent (e.g., methylene chloride). In this embodiment, it is possible to remove the (additional) solvent at the same time as carrying out process step (b). Such an embodiment is contemplated if the nitrate esters are already prepared in such a solvent. Such an embodiment is also contemplated if solid nitrate esters are to be dried and / or freed from volatile impurities under standard conditions or standard conditions according to DIN 1343, STPD.

[0081] In this sense, it is preferred within the scope of the present invention if, in process step (b), no (additional) solvent and / or dispersant is added to the washed crude nitrate esters obtained in process step (a) for carrying out drying and / or purification, preferably drying and purification. With regard to the inert gas, it has proven advantageous within the scope of the present invention if, in process step (b), the inert gas is selected and / or designed such that it is non-reactive towards the nitrate esters under the conditions of process step (b). In this way, it is advantageously largely ensured that, within the scope of the process according to the invention, no explosive mixtures of the nitrate esters with the inert gas are produced, so that, in particular, process safety is reliably guaranteed.

[0082] It is preferred according to the invention if in process step (b) the inert gas is selected from the group of nitrogen, oxygen, noble gases, in particular argon, hydrogen, carbon oxides and mixtures thereof, in particular air, preferably from the group of nitrogen, oxygen, noble gases, in particular argon, and mixtures thereof, in particular air, particularly preferably from the group of nitrogen, oxygen and mixtures thereof, in particular air.

[0083] Furthermore, it has proven advantageous if, in process step (b), the washed crude nitrate esters obtained in process step (a) are brought into contact, in particular flowed through, with the inert gas in cross-current and / or countercurrent, preferably in countercurrent.

[0084] In this context, it is particularly preferred if the inert gas is conducted in an upward flow and the nitrate esters are conducted in a downward flow. This particularly preferably takes place in a drying and / or purification device, preferably a drying and purification device, preferably a column, in particular a single- or multi-stage column, preferably a packed column, sieve-tray column, bubble-cap column, or falling-film column, or combinations thereof, and / or in a gas / liquid reactor or in a stripping device. This special process allows particularly efficient mixing and very intensive contact or mass transfer between the inert gas and the nitrate esters to be purified, which advantageously contributes to the high degrees of purity and dryness for purified nitrate esters achievable with the present invention.

[0085] Furthermore, in process step (b), the contacting, in particular flowing through, of the nitrate esters with the inert gas is advantageously carried out in a dispersed distribution, in particular a finely dispersed distribution, of the inert gas in the nitrate esters. This advantageously creates a particularly large contact area between the inert gas and the nitrate esters to be purified. This also contributes to a particularly effective mass transfer between the inert gas and the liquid nitrate ester phase, so that a high degree of desorption of the impurities to be removed, in particular volatile ones, can be achieved, i.e., a high purity of the nitrate esters themselves.

[0086] In this sense, it has proven equally useful within the scope of the present invention if, in process step (b), the inert gas is introduced into the nitrate esters with and / or in a dispersed distribution, in particular a finely dispersed distribution. This is preferably done using nozzles, jet mixers, jet pumps, injectors, lances, sieve trays, and / or fine-pored membranes, preferably using nozzles, jet mixers, and / or fine-pored membranes.

[0087] Furthermore, it is preferably provided according to the invention that in process step (b) the inert gas is used in dry form.

[0088] In the context of the present invention, a dry or dried gas (ie inert gas in dry form) is understood to mean in particular a gas whose dew point is below the temperature at which the process step (b) according to the invention is carried out, in particular wherein the dew point of the dry or dried gas is preferably at least 5 °C, more preferably at least 10 °C, preferably at least 15 °C, below the temperature at which the process step (b) according to the invention is carried out.

[0089] In this context, it has proven particularly useful if the inert gas supplied and / or initially supplied, in particular at the start of process step (b), has a dew point of -20 °C or lower, in particular -30 °C or lower, preferably -35 °C or lower, more preferably -40 °C or lower, and / or a dew point of -80 °C or higher, in particular -65 °C or higher, preferably -55 °C or higher, more preferably -50 °C or higher. The inert gas supplied and / or initially supplied, in particular at the start of process step (b), particularly preferably has a dew point in a range from -20 °C to -80 °C, in particular -30 °C to -65 °C, preferably -35 °C to -55 °C, more preferably -40 °C to -50 °C.

[0090] Inert gases having a dew point in the aforementioned range exhibit, in the context of the process according to the invention, ideal absorption properties for the impurities to be removed from the nitrate esters, in particular volatile ones, or for the moisture or water to be removed.

[0091] Equally preferably, the inert gas has a relative humidity in the range of 0 to 95%, in particular 0 to 90%, preferably 0 to 85%, preferably 0 to 80%. Relative humidities in the aforementioned ranges advantageously ensure that the inert gas has sufficient absorption capacity for moisture or water as well as volatile or volatilizable impurities from the nitrate esters to be purified in the process according to the invention.

[0092] Furthermore, with regard to specific process parameters for process step (b), it has proven useful within the scope of the present invention if, in process step (b), the drying and / or purification, preferably drying and purification, or the bringing into contact, in particular flowing through, with the inert gas is carried out with a volume flow of the inert gas of at least 100 L / h / kg nitrate ester (liters / hour per kg of nitrate ester to be dried and / or freed from volatile impurities) or more, in particular 200 L / h / kg nitrate ester or more, preferably 300 L / h / kg nitrate ester or more, preferably 350 L / h / kg nitrate ester or more, and / or with a volume flow of the inert gas of 600 L / h / kg nitrate ester or less, in particular 500 L / h / kg nitrate ester or less, preferably 450 L / h / kg nitrate ester or less, preferably 425 L / h / kg nitrate ester or less, is carried out.

[0093] Preferably, in process step (b), the drying and / or purification, preferably drying and purification, or the bringing into contact, in particular flowing through, with the inert gas is carried out with a volume flow of the inert gas in a range from 100 L / h / kg nitrate ester to 600 L / h / kg nitrate ester, in particular 200 L / h / kg nitrate ester to 500 L / h / kg nitrate ester, preferably 300 L / h / kg nitrate ester to 450 L / h / kg nitrate ester, preferably 350 L / h / kg nitrate ester to 425 L / h / kg nitrate ester. Furthermore, it has proven advantageous within the scope of the present invention if, in process step (b), the drying and / or purification, preferably drying and purification, orthe contacting, in particular flowing through, with the inert gas is carried out with a residence time of the nitrate esters in the presence of the inert gas of 30 s or more, in particular 1 min or more, preferably 3 min or more, preferably 7 min or more, and / or with a residence time of the nitrate esters in the presence of the inert gas of 20 min or less, in particular 17 min or less, preferably 14 min or less, preferably 12 min or less.

[0094] Advantageously, in process step (b), the drying and / or purification, preferably drying and purification, or bringing into contact, in particular flowing through, with the inert gas is carried out with a residence time of the nitrate esters in the presence of the inert gas in a range from 30 s to 20 min, in particular 1 min to 17 min, preferably 3 min to 14 min, more preferably 7 min to 12 min.

[0095] In the context of the present invention, nitrate esters to be purified therefore advantageously require only a comparatively short residence time in the presence of the inert gas in order to achieve a purification or drying result within the context of the present invention or in particular of the process according to the invention which corresponds to the target parameters preferred for the process according to the invention with regard to purity or dryness of the purified or pure nitrate esters obtained.

[0096] In this sense, within the scope of the present invention, a very efficient and essentially complete or absolute purification or drying of nitrate esters can advantageously be achieved comparatively quickly or within a relatively short time, which has not been possible in this way in the prior art to date.

[0097] In addition, it has proven useful in the context of the present invention if, in process step (b), the drying and / or purification, preferably drying and purification, or the contacting, in particular flowing through, with the inert gas is carried out at temperatures at which the vapor pressure of the nitrate esters is less than 100 mbar, in particular less than 80 mbar, preferably less than 60 mbar, more preferably less than 50 mbar. By means of this preferred process condition, it is further ensured that, in the context of the present invention, in particular in the context of process step (b) of the process according to the invention, no explosive nitrate ester-inert gas mixtures or no explosive nitrate ester vapors can form during the contacting, in particular flowing through, of the nitrate esters with the inert gas.This advantageously ensures a high level of process reliability, which can also be reliably maintained and complied with within the preferred process parameters for the method according to the invention efficiently and without further or special measures.

[0098] It has also proven useful in the context of the present invention if, in process step (b), the drying and / or purification, preferably drying and purification, or the bringing into contact, in particular flowing through, with the inert gas is carried out at temperatures of more than 0 °C, in particular more than 5 °C, preferably more than 7.5 °C, preferably more than 10 °C, and / or at temperatures of less than 60 °C, in particular less than 50 °C, preferably less than 40 °C, preferably less than 35 °C.

[0099] Preferably, in process step (b), the drying and / or purification, preferably drying and purification, or the contacting, in particular flowing through, with the inert gas is carried out at temperatures in a range from 0 °C to 60 °C, in particular 5 °C to 50 °C, preferably 7.5 °C to 35 °C, preferably 10 °C to 30 °C.

[0100] Likewise, it has proven advantageous if, in process step (b), the drying and / or purification, preferably drying and purification, or the bringing into contact, in particular flowing through, with the inert gas is carried out at atmospheric pressure (normal pressure; 1.01325 bar) or in vacuum (negative pressure) or at excess pressure, preferably at atmospheric pressure.

[0101] It is preferred if, in process step (b), the drying and / or purification, preferably drying and purification, or the bringing into contact, in particular flowing through, with the inert gas is carried out at an absolute pressure in the range from 0.1 bar to 3 bar, in particular in the range from 0.3 bar to 1.2 bar, preferably in the range from 0.5 bar to 1.1 bar, particularly preferably at about 1 bar. With regard to the process parameters temperature and pressure, the process according to the invention is therefore advantageous in that it can always be carried out in the range of moderate temperatures and without increased pressure loading, in particular with regard to a cleaning device in which process step (b) is carried out or carried out. This is to be regarded as advantageous in particular with regard to the apparatus and, in this regard, the design outlay for the process and device.At the same time, working in the preferred moderate temperature and pressure ranges makes a valuable contribution to providing a comparatively energy-saving and thus environmentally friendly process.

[0102] According to the invention, it is further preferably provided that the amount of inert gas used in process step (b) is selected and / or adjusted depending on the drying and / or purification conditions, in particular temperature and / or pressure and / or duration of the drying and / or purification and / or type of inert gas, and / or depending on the content and / or type of impurities in the nitrate esters to be purified and / or depending on the desired residual content of, in particular, volatile impurities in the resulting purified nitrate esters.

[0103] In this regard, it has proven particularly useful if the amount of inert gas used in process step (b), based on 1 ton of nitrate ester to be purified and calculated as the volume of the inert gas in standard cubic meters under standard conditions (pressure: 1.013 bar; air humidity: 0%, ie dry inert gas; temperature: 0 °C [standard conditions according to DIN 1343, STPD]), is 0.5 to 500 standard cubic meters, in particular 2 to 200 standard cubic meters, preferably 5 to 100 standard cubic meters, more preferably 8 to 70 standard cubic meters.

[0104] Likewise, it has proven useful within the scope of the present invention if the amount of inert gas used in process step (b), based on 1 ton of nitrate esters to be purified and calculated as the amount and / or weight of the inert gas under standard conditions (pressure: 1.013 bar; air humidity: 0%, ie dry inert gas; temperature of 0 °C [standard conditions according to DIN 1343, STPD]), is 1 to 250 kg, in particular 2 to 140 kg, preferably 5 to 50 kg, more preferably 10 to 40 kg. In the context of the present invention, it is particularly advantageous that the nitrate esters, after drying and / or purification, preferably drying and purification, have a water content of at most 0.06 wt.%, in particular at most 0.03 wt.%, preferably at most 0.02 wt.%, more preferably at most 0.01 wt.%, based on the nitrate esters.

[0105] In particular, within the scope of the present invention, it can preferably be achieved that the nitrate esters after drying and / or purification, preferably drying and purification, have a water content in the range from 0.00001 to 0.06 wt.%, in particular in the range from 0.0001 to 0.03 wt.%, preferably in the range from 0.0005 to 0.02 wt.%, preferably in the range from 0.0005 to 0.01 wt.%, based on the nitrate esters.

[0106] Likewise, within the scope of the present invention, it is advantageously possible to achieve that nitrate esters after drying and / or purification, preferably drying and purification, have a content of impurities, in particular volatile impurities, of at most 100 ppm, in particular of at most 30 ppm, preferably of at most 25 ppm, more preferably of at most 20 ppm, preferably of at most 10 ppm.

[0107] Particularly preferably, the nitrate esters after drying and / or purification, preferably drying and purification, have a content of impurities, in particular volatile impurities, in the range from 0.001 to 100 ppm, in particular in the range from 0.001 to 30 ppm, preferably in the range from 0.001 to 25 ppm, more preferably in the range from 0.002 to 20 ppm, preferably in the range from 0.005 to 10 ppm.

[0108] The present invention thus provides purified and / or dried nitrate esters which have a comparatively very low proportion of, in particular, volatile impurities and / or liquid or moisture and, in this sense, particularly in contrast to nitrate esters obtained by purification or drying processes according to the prior art, can be understood or defined as essentially free of, in particular, volatile impurities and essentially free of water or moisture. In particular, the process according to the invention advantageously makes it possible to provide nitrate esters which reach a cloud point below 0 °C, i.e. have a moisture content of less than 0.02 wt.% moisture or water. Such low moisture levels can be achieved using conventional methods from the prior art only at significantly greater expense and are therefore hardly economical or practicable.Likewise, it is advantageously possible with the present invention to provide nitrate esters which have a proportion of particularly volatile impurities of preferably not more than 10 ppm.

[0109] Overall, the process according to the invention advantageously provides a highly efficient way of drying or purifying nitrate esters, while simultaneously implementing a stringent process that is less complex and thus less prone to errors. Furthermore, the process according to the invention can be implemented in a resource-efficient manner, particularly with regard to the possibility of recycling the process media used, especially the inert gas.

[0110] As far as the inert gas is concerned, in particular with regard to the process section after the inert gas has been passed through the washed crude nitrate esters or has been brought into contact with them and has accordingly absorbed moisture or water, it is preferably provided in this regard within the scope of the present invention that the inert gas after process step (b) and / or after being brought into contact, in particular flowing through, the nitrate esters has a relative humidity and / or relative residual humidity of 50% or more, in particular 65% or more, preferably 75% or more, preferably 80% or more, particularly preferably 90% or more, based on a gas temperature of 20°C to 30°C.

[0111] Within the scope of the process according to the invention, a comparatively high loading of the inert gas used in process step (b) with moisture or water can be achieved, which particularly advantageously contributes to the fact that in process step (b), in particular within relatively short residence times of the nitrate esters in the presence of the inert gas, a very high degree of drying of the nitrate esters can be achieved, as well as a high degree of desorption with respect to or in relation to impurities, in particular volatile ones, contained in the crude nitrate esters to be purified or dried. This aspect once again advantageously highlights the particular efficiency of the process according to the invention.

[0112] Furthermore, with regard to the process control for the process according to the invention, in particular in the context of process step (b), it has proven useful in the context of the present invention if the dried and / or purified, preferably dried and purified, nitrate esters obtained after process step (b) are obtained and / or collected separately from the inert gas.

[0113] In this context, it is particularly provided that no additional separation step is carried out and / or required to separate the dried and / or purified, preferably dried and / or purified, nitrate esters obtained after process step (b) from the inert gas.

[0114] Furthermore, at this stage of the process according to the invention, i.e., in particular after process step (b) has been carried out or completed, it is preferably provided that the inert gas is recycled and / or recirculated after process step (b). The recycling or recirculation of the inert gas after process step (b) takes place in particular after and / or with drying and purification of the inert gas.

[0115] Within the scope of this process control for the process according to the invention, a considerable reduction in the consumption of the process medium can advantageously be achieved, which also increases the cost efficiency of the process and facilitates the recycling or disposal of process chemicals or components.

[0116] In this respect, the possibility of recycling the process medium in process step (b), i.e. the inert gas, within the scope of the present invention represents a significant advantage of the process according to the invention over the prior art.

[0117] In this regard, it has proven advantageous within the scope of the present invention if the inert gas is subjected to a drying and purification treatment after process step (b), in particular by means of a condenser and / or gas scrubber or a combination thereof. Likewise, it has proven advantageous within the scope of the present invention if the inert gas obtained and / or separated after process step (b), in particular the inert gas laden with water or moisture and, in particular, volatile impurities, is transferred to a recycling facility for gas treatment.

[0118] Preferably, there is a temperature gradient between the drying and / or cleaning device in which process step (b) is carried out and the recycling device for treating the inert gas loaded with water or moisture and in particular volatile contaminants.

[0119] The temperature gradient is particularly designed such that a lower temperature is set in the recycling device than in the drying and / or cleaning device or as provided for in the context of carrying out process step (b). Thus, there is preferably a temperature gradient that decreases in the process direction from the drying and / or cleaning device to the recycling device.

[0120] In particular, the temperature gradient between the drying and / or cleaning device and the recycling device is a difference of 5°C or more, in particular 10°C or more, preferably 13°C or more, preferably 15°C or more. In this sense, the temperature during the treatment of the gas is advantageously 5°C or more, in particular 10°C or more, preferably 13°C or more, preferably 15°C or more, lower than that provided for in process step (b).

[0121] It has also proven useful if the temperature difference is 30 °C or less, in particular 25 °C or less, preferably 22 °C or less, preferably 20 °C or less, or if the temperature during the treatment of the gas is 30 °C or less, in particular 25 °C or less, preferably 22 °C or less, preferably 20 °C or less, lower than the scope of process step (b).

[0122] Most preferably, the temperature gradient between the drying and / or cleaning device and the recycling device is therefore a difference in a range from 5 °C to 30 °C, in particular 10 °C to 25 °C, preferably 13 °C to 22 °C, preferably 15 °C to 20 °, or the temperature during the treatment of the gas is therefore advantageously in a range from 5 °C to 30 °C, in particular 10 °C to 25 °C, preferably 13 °C to 22 °C, preferably 15 °C to 20 °C, lower than provided for in process step (b).

[0123] In this context, the inert gas is subjected, in particular, to a treatment to remove water or moisture and, in particular, volatile contaminants. This treatment is preferably carried out by condensation and / or scrubbing, preferably condensation and scrubbing. Furthermore, the treatment is preferably carried out at temperatures lower than the temperature in process step (b).

[0124] To carry out the treatment, in particular by means of condensation and in this regard preferably to set the preferred temperature gradient, a refrigerant, cooling liquid, in particular cold or cooled water, and / or cooling gas, in particular cold or cooled air, can be used, in particular to cool the recycling device in which the treatment of the inert gas takes place.

[0125] Accordingly, it is preferably provided within the scope of the present invention that the recycling device for treating and recycling the gas comprises a condenser and / or gas scrubber or a combination thereof. In particular, the use of a condenser allows the inert gas to be dried quickly and easily in terms of process technology, and thus fed back into the process according to the invention. In particular, the treatment of the gas laden with water or moisture and in particular volatile impurities in a recycling device comprising a condenser, in particular consisting thereof, allows efficient separation of moisture or water from the gas, so that a high degree of purification and in particular drying of the inert gas can be achieved with comparatively little process technology and time expenditure. In this case, the volatile orvolatilizable impurities in the separated moisture or water phase. In this way, it can also be advantageously achieved that, for example, harmful impurities, in particular volatile ones, which are dissolved out of the nitrate esters with the inert gas are captured and neutralized and in any case not released unfiltered into the environment. Accordingly, it has proven advantageous in this context if the treated inert gas is returned to process step (b). The inert gas treated as described above has more than sufficient dryness and purity to be fed back into the process over a large number of process cycles, i.e. recycled, and used again for the purification and drying of crude nitrate esters, so that process medium can be saved and work can be carried out efficiently and in a resource-saving manner.

[0126] Likewise, within the scope of the present invention, it is preferably provided that the condensate resulting from the treatment of the inert gas and / or the resulting scrubbing medium is circulated, particularly after treatment and / or purification. Preferably, the condensate resulting from the treatment of the inert gas is recycled and / or recycled into the scrubbing of process step (a).

[0127] Since, within the scope of the present invention, it is therefore preferably provided to recycle and circulate inert gas from process step (b) and to subject it to drying and / or cleaning prior to recycling, the process according to the invention can be carried out in a resource-saving and economical manner compared to prior art methods and accordingly also efficiently from an economic point of view with regard to used process media.

[0128] This aspect, in addition to the particularly high-quality purified and / or pure nitrate esters obtainable with the process according to the invention, represents a significant advantage of the present invention, particularly given that it is a common goal in the prior art to design large-scale production and purification processes in particular to be ecologically and economically efficient, gentle, and valuable in this sense. This is made possible by the process according to the invention.

[0129] By also being able to recycle condensate or moisture collected from purified inert gas into process step (a), it is also possible within the scope of the present invention to both save scrubbing medium and, in particular, to significantly minimize the slippage of process product, i.e., purified or pure nitrate esters. In particular, the preferred procedure according to the invention allows any fractions of nitrate esters to be purified that may be entrained with the inert gas to be recovered during the drying and purification of the inert gas, for example, by converting them into the condensate phase in the condenser and thus being collected or being scrubbed out in the gas scrubber.Nitrate esters entrained in this way from the gas can then be recycled to the process according to the invention in the washing step (a), whereby the overall loss of product within the scope of the present invention can be significantly minimized.

[0130] In this way, the present invention also allows a significant increase in the absolute yield of purified nitrate esters compared to purification processes for nitrate esters known from the prior art. It should be noted in particular that prior art processes do not allow the purity levels or dryness values ​​for nitrate esters that the present invention allows, and at the same time, they are generally associated with greater product slippage. Therefore, the process according to the invention advantageously offers a significant improvement over the prior art with regard to these two aspects, which has a direct impact on the product yield (particularly essentially quantitative) that can be achieved within the scope of the present invention.

[0131] The present invention according to the applicable aspect also relates to a process for drying and / or purifying, preferably drying and purifying, aliphatic or cycloaliphatic nitrate esters (nitric acid esters), in particular for removing water and volatile and / or volatilizable impurities arising in particular during the production and / or washing of the nitrate esters, in particular a process as described above, which comprises the following process steps:

[0132] (a) first, the crude nitrate esters obtained from a production process are subjected to washing with a washing medium, followed by separation of the washing medium, in particular wherein process step (a) and / or the washing is carried out as a liquid-liquid extraction; (b) subsequently, the washed crude nitrate esters obtained in process step (a) are subjected to drying and / or purification, preferably drying and purification, by contacting, in particular by flowing through, with an inert gas, in particular such that water present in the washed crude nitrate esters is removed (iethe washed crude nitrate esters are dried) and at the same time and / or as it were, volatile and / or volatilizable impurities arising in particular during the production and / or washing of the nitrate esters are removed, in particular wherein the drying and / or purification, preferably drying and purification, is carried out as a gas-liquid extraction and / or by means of desorption, in particular as a gas-liquid extraction; wherein the inert gas is recycled and / or circulated after process step (b), in particular after and / or with drying and purification; in particular wherein the inert gas is subjected to a drying and purification treatment after process step (b), in particular by means of a condenser and / or gas scrubber or a combination thereof; and / or wherein the inert gas obtained and / or separated after process step (b) is mixed, in particular with water orMoisture and in particular volatile impurities are transferred to a device for treating and recycling the gas; in particular wherein the inert gas is subjected to a treatment to remove water or moisture and in particular volatile impurities, preferably by means of condensation and / or scrubbing, preferably condensation and scrubbing, and / or in particular wherein the device for treating and recycling the gas comprises a condenser and / or gas scrubber or a combination thereof; in particular wherein the treated inert gas is recycled to process step (b); and / or in particular wherein the condensate resulting from the treatment of the inert gas and / or the scrubbing medium obtained is circulated, in particular after processing and / or purification, preferably into the scrubbing of process step (a).

[0133] Last but not least, it has proven particularly advantageous for the process according to the invention if the crude nitrate esters are produced by means of an adiabatic or isothermal nitration and / or the production process for the crude nitrate esters includes or is an adiabatic or isothermal nitration. Such production processes demonstrate particularly advantageous compatibility with the drying or purification process according to the invention.

[0134] For further details on the above-described aspect of the invention, reference can also be made to the statements on the other aspects of the invention, whereby these statements apply equally to the present aspect of the invention.

[0135] Furthermore, the present invention - according to a second aspect of the present invention - relates to a device for drying and / or purifying, preferably a device for drying and purifying, aliphatic or cycloaliphatic nitrate esters (nitric acid esters), in particular for removing water and volatile impurities arising in particular during the production and / or washing of the nitrate esters, preferably by bringing them into contact, in particular by flowing through, with an inert gas, in particular a device for carrying out a method according to one of the preceding claims, wherein the device comprises the following devices arranged successively in the process direction:

[0136] - at least one washing device for washing crude nitrate esters obtained from a manufacturing process and / or originating from a production facility with a washing medium with a downstream and / or downstream separation device for separating the washing medium from the washed crude nitrate esters; downstream in the process direction and / or downstream of the washing device

[0137] - at least one cleaning and / or drying device, in particular a column, for drying and / or purifying, in particular drying and purifying, the washed crude nitrate esters obtained from the washing device, wherein the cleaning and / or drying device comprises a first feed means, arranged in particular in an upper region, in particular the column head, of the cleaning and / or drying device, for introducing and / or feeding the washed crude nitrate esters into the cleaning and / or drying device, and a second feed means, arranged in particular in a lower region, in particular the column bottom, of the cleaning and / or drying device, for introducing and / or feeding a dry inert gas into the cleaning and / or drying device, wherein the cleaning and / or drying device comprises means for bringing into contact, in particular for flowing through,the washed crude nitrate esters with the dry inert gas, in particular wherein the means for bringing into contact, in particular for flowing through, are designed such that water present in the washed crude nitrate esters is removed (ie the washed crude nitrate esters are dried) and at the same time and / or as it were, volatile impurities arising in particular during the production and / or washing of the nitrate esters are removed to obtain the dry (dried) nitrate esters freed from, in particular, volatile impurities; in the process direction downstream and / or downstream of the cleaning and / or drying device,

[0138] - at least one recycling device for recycling and / or circulating the inert gas, wherein the recycling device comprises separation means for separating water or moisture and the particularly volatile impurities, in particular a condenser and / or gas scrubber or a combination thereof, in particular wherein the separation means are designed such that water or moistureMoisture and the particularly volatile impurities are separated from the moist inert gas, in particular by means of condensation and / or scrubbing, preferably condensation and scrubbing, to obtain a dry (dried) inert gas freed from, in particular, volatile impurities; in particular wherein the recycling device further comprises a third feed means, arranged in particular between the upper region, in particular the column head, the cleaning and / or drying device and the recycling device, for introducing and / or feeding and / or transporting the moist inert gas, loaded in particular with water and / or the particularly volatile impurities, from the cleaning and / or drying device into the recycling device.In addition to the advantages already described in connection with the method according to the invention, which can equally be applied to the device according to the invention, the device according to the invention for drying or purifying nitrate esters is characterized in particular by the fact that it allows highly efficient drying or purification of nitrate esters within the framework of a lean and stringent process in a system or device that is correspondingly simplified in terms of its complexity. This advantageously contributes to a low susceptibility to errors and malfunctions, as well as easier operation and maintainability of the device according to the invention, as well as to high process stability and reliability, which are accompanied by comparatively high throughputs and processable quantities.

[0139] Likewise, the system according to the invention can be realized in terms of construction and process technology with manageable effort, in particular since the device according to the invention combines devices that are highly compatible and can be efficiently connected using generally available means.

[0140] In this sense, it has proven advantageous within the scope of the present invention for the first supply means to be designed as a connection between the washing device and the cleaning and / or drying device. Equally advantageously, the first supply means is designed as a transport line, in particular as a transport line for connecting the washing device and the cleaning and / or drying device.

[0141] In an analogous manner, it is preferred within the scope of the present invention if the second supply means is designed as a connection between a storage device for the dry inert gas and the cleaning and / or drying device.

[0142] Equally preferably, the second supply means is designed as a transport line, in particular as a transport line connecting a storage device for the dry inert gas and the cleaning and / or drying device. In this sense, the invention also preferably provides for the third supply means to be designed as a connection between the cleaning and / or drying device and the recycling device. Further preferably, the third supply means is designed as a transport line, in particular as a transport line connecting the cleaning and / or drying device and the recycling device.

[0143] Furthermore, with regard to the washing device, it has proven useful within the scope of the present invention if the washing device is designed as a liquid-liquid extraction device.

[0144] Likewise, it is preferably provided that the washing device comprises an acidic washing stage, a basic (alkaline) washing stage and / or a neutral washing stage, in particular at least one basic (alkaline) washing stage and / or neutral washing stage, preferably an acidic, basic (alkaline) and neutral washing stage.

[0145] In addition or alternatively, it has proven advantageous for the washing device to comprise one or more washing stages, preferably one, two, or three washing stages, preferably two or three washing stages. In particular, each washing stage is designed such that it can comprise one or more washing and / or extraction steps.

[0146] Furthermore, it is preferably intended that the washing device be designed such that the washing takes place with an aqueous-based washing medium. In particular, it is preferred that the aqueous-based washing medium be neutral, acidic, or basic (alkaline).

[0147] Furthermore, good results are obtained within the scope of the present invention if the washing device is designed such that the laundry, in particular in each washing stage, is carried out in cross-current or counter-current or in a combination of cross-current and counter-current.

[0148] This preferably takes place with recycling of the washing medium. It is equally preferred if the washing device, particularly in each washing stage, is and / or can be operated in crossflow or counterflow, or in a combination of crossflow and counterflow. This also preferably takes place with recycling of the washing medium.

[0149] Furthermore, it has proven to be advantageous for the device according to the invention if the separation device downstream of the washing device is designed as a separating device (separator), in particular as a static separating device, or as a centrifugal separator.

[0150] Furthermore, with regard to the cleaning and / or drying device, it has proven advantageous within the scope of the present invention if the cleaning and / or drying device, in particular column, comprises a single-stage or multi-stage column, in particular a packed column, sieve tray column, bubble tray column or falling film column or combinations thereof, and / or a gas / liquid reactor or a stripping device.

[0151] In particular, good results are obtained according to the invention when the cleaning and / or drying device, in particular column, is a single-stage or multi-stage column, in particular a packed column, sieve tray column, bubble tray column or falling film column or combinations thereof, and / or a gas / liquid reactor or a stripping device.

[0152] Furthermore, it is preferred within the scope of the present invention if the cleaning and / or drying device, in particular column, is designed such that the drying and / or purification, preferably drying and purification, is carried out as a continuous or discontinuous, in particular continuous, process.

[0153] Furthermore, the cleaning and / or drying device, in particular the column, preferably comprises outlet and / or discharge means for dry (dried) nitrate esters, which have been freed from, in particular, volatile impurities, arranged in particular in the lower region, preferably the column bottom, preferably at the lower region. In this context, it has proven useful if the outlet and / or discharge means is designed as a connection between the cleaning and / or drying device and a collecting and / or collecting device for dry (dried) nitrate esters, which have been freed from, in particular, volatile impurities. Equally preferably, the outlet and / or discharge means is designed as a transport line, in particular designed as a transport line for connecting the cleaning and / or drying device and a collecting and / or collecting device for dry (dried) nitrate esters, which have been freed from, in particular, volatile impurities.

[0154] Preferably, the cleaning and / or drying device, in particular the column, is also designed as a preferably single- or multi-stage packed column, sieve tray column, bubble-cap column, or falling-film column, or combinations thereof, with a column bottom as the lower region. The cleaning and / or drying device preferably has outlet and / or removal means, preferably arranged at the column bottom, for dry nitrate esters freed from, in particular, volatile impurities.

[0155] In this regard, it has proven particularly useful if the outlet and / or discharge means is designed as a connection between the cleaning and / or drying device and a collecting and / or collecting device for dry (dried) nitrate esters, in particular freed from volatile contaminants. Equally preferably, the outlet and / or discharge means is designed as a transport line, in particular as a transport line connecting the cleaning and / or drying device and a collecting and / or collecting device for dry (dried) nitrate esters, in particular freed from volatile contaminants.

[0156] Furthermore, it is proven according to the invention if the cleaning and / or drying device is designed as a gas-liquid extraction device and / or desorption device, in particular as a gas-liquid extraction device.

[0157] According to the invention, it is also preferably provided that the cleaning and / or drying device, in particular the means for bringing into contact, in particular the means for flowing through, the washed crude nitrate esters with the dry inert gas, is / are designed such that the bringing into contact, in particular flowing through, the washed crude nitrate esters obtained from the washing device with the dry inert gas takes place in cross-current and / or countercurrent, preferably in countercurrent.

[0158] In this context, it has proven particularly useful if the cleaning and / or drying device, in particular the means for bringing the washed crude nitrate esters into contact, in particular the means for flowing through, with the dry inert gas, is / are designed in such a way that the dry inert gas is guided in an upward flow and the washed crude nitrate esters are guided in a downward flow.

[0159] Furthermore, it has proven advantageous for the device according to the invention if the recycling device has at least two removal means for dry (dried) inert gas freed from, in particular, volatile impurities and / or water or moisture resulting from the treatment of the inert gas and / or washing liquid with the, in particular, volatile impurities from the moist inert gas, in particular two removal means for dry (dried) inert gas freed from, in particular, volatile impurities and water or moisture resulting from the treatment of the gas and / or washing liquid with the, in particular, volatile impurities from the moist inert gas.

[0160] In this context, it is particularly preferred if the removal means is designed as a direct and / or indirect connection, in particular via the second supply means, between the recycling device and the cleaning and / or drying device. Likewise, it is preferably provided that the removal means is designed as a transport line for dry (dried) inert gas, freed in particular from volatile contaminants, preferably as a transport line for dry (dried) inert gas, freed in particular from volatile contaminants, and is designed for the direct and / or indirect connection, in particular via the second supply means, between the recycling device and the cleaning and / or drying device, in particular such that recycling and / or recirculation of the inert gas takes place.In an analogous manner, it is preferred according to the invention if the discharge means is designed as a connection between the recycling device and the washing device and / or in particular wherein the discharge means is designed as a transport line for water or moisture resulting from the treatment of the inert gas and / or washing liquid with the particularly volatile impurities from the moist inert gas.

[0161] Particularly preferably, the discharge means is designed as a transport line for water or moisture and / or washing liquid resulting from the treatment of the gas with the particularly volatile impurities from the moist inert gas and for connecting the recycling device and the washing device, in particular in such a way that recycling and / or recirculation of water or moisture and / or washing liquid resulting from the treatment of the gas with the particularly volatile impurities from the moist inert gas takes place.

[0162] Further preferably, a temperature gradient also exists between the drying and / or cleaning device and the recycling device for treating the inert gas laden with water or moisture and, in particular, volatile contaminants. The temperature gradient is, in particular, designed such that a lower temperature is set in the recycling device than that provided in the drying and / or cleaning device. Thus, there is preferably a temperature gradient that decreases in the process direction from the drying and / or cleaning device to the recycling device.

[0163] It is further preferred within the scope of the present invention that the recycling device is designed as a condenser and / or gas scrubber or a combination thereof.

[0164] Especially in the case where the recycling device T is designed as a condenser, it has proven useful if the condenser comprises a coolant, cooling liquid, in particular cold or cooled water, and / or cooling gas, in particular cold or cooled air, in particular for cooling the recycling device in which the treatment of the inert gas takes place. Finally, according to the invention, it is preferably provided overall that the above-described device is designed to carry out a method as described above. The device according to the invention is particularly preferably characterized by one or more of the above-described features of the method according to the invention.

[0165] For further details on this aspect of the invention, in particular on the associated advantages and special technical effects, reference can be made to the statements on the method according to the invention, whereby these statements apply equally to the present aspect of the invention.

[0166] Furthermore, the present invention - according to a third aspect of the present invention - relates to a production plant for the production of aliphatic or cycloaliphatic nitrate esters (nitric acid esters), the production plant comprising:

[0167] (i) a nitration device, in particular with one or more reaction vessels (nitration reactors), for carrying out the nitration, in particular for producing aliphatic or cycloaliphatic nitrate esters (nitric acid esters), preferably from mono- or polyhydric aliphatic or cycloaliphatic alcohols, preferably by means of an adiabatic or isothermal nitration;

[0168] (ii) optionally arranged downstream of and / or downstream of the nitration device in the production line, a separation device, in particular a separator, in particular for separating nitrating acid from nitrated crude products (crude nitric acid esters);

[0169] (iii) arranged in the production line downstream and / or downstream of the nitration device and the optionally present separation device, at least one washing device for washing crude nitrate esters obtained from a manufacturing process and / or originating from a production device with a washing medium with a downstream and / or downstream separation device for separating the washing medium from the washed crude nitrate esters; (iv) arranged in the production line downstream and / or downstream of the washing device, at least one cleaning and / or drying device, in particular a column, for drying and / or purifying, in particular drying and purifying, the washed crude nitrate esters obtained from the washing device, wherein the cleaning and / or drying device comprises a, in particular in an upper region, in particular the column head,a first feed means arranged in the cleaning and / or drying device for introducing and / or feeding the washed crude nitrate esters into the cleaning and / or drying device and a second feed means arranged in particular in a lower region, in particular column bottom, of the cleaning and / or drying device for introducing and / or feeding a dry inert gas into the cleaning and / or drying device, wherein the cleaning and / or drying device comprises means for bringing the washed crude nitrate esters into contact, in particular for flowing through, with the dry inert gas, in particular wherein the means for bringing the washed crude nitrate esters into contact, in particular for flowing through, are designed in such a way,that water present in the washed crude nitrate esters is removed (i.e. the washed crude nitrate esters are dried) and at the same time and / or simultaneously, volatile impurities arising in particular during the production and / or washing of the nitrate esters are removed to obtain the dry (dried) nitrate esters freed from, in particular, volatile impurities; downstream in the process direction and / or downstream of the cleaning and / or drying device,

[0170] (v) in the production line downstream and / or downstream of the cleaning and / or drying device, in particular column, at least one recycling device for recycling and / or circulating the inert gas, wherein the recycling device comprises separation means for separating water or moisture and the in particular volatile impurities, in particular a condenser and / or gas scrubber or a combination thereof, in particular wherein the separation means are designed such that water orMoisture and the particularly volatile impurities are separated from the moist inert gas, in particular by means of condensation and / or scrubbing, preferably condensation and scrubbing, to obtain a dry (dried) inert gas freed from, in particular, volatile impurities; in particular wherein the recycling device further comprises a third feed means, arranged in particular between the upper region, in particular the column head, the cleaning and / or drying device and the recycling device, for introducing and / or feeding and / or transporting the moist inert gas, loaded in particular with water and / or the particularly volatile impurities, from the cleaning and / or drying device into the recycling device.

[0171] The production plant according to the invention is essentially characterized by the advantages and special technical features as already described in connection with the method according to the invention and also the device according to the invention. In particular, the special technical features of the device according to the invention are reflected in the production plant according to the present invention and the production plant according to the present invention is advantageously suitable for carrying out and implementing the method according to the invention, as described above, in particular wherein the particularly high efficiency of the method according to the invention in conjunction with the resource-saving implementation of the method according to the invention is significantly due to the arrangement and nature of the facilities included in the production plant according to the invention or is expressed on the basis of these.

[0172] The subject of the present invention according to the applicable aspect is also such a production plant, in particular as described above, which comprises:

[0173] (i) a nitration device, in particular with one or more reaction vessels (nitration reactors), for carrying out the nitration, in particular for producing aliphatic or cycloaliphatic nitrate esters (nitric acid esters), preferably from mono- or polyhydric aliphatic or cycloaliphatic alcohols, preferably by means of an adiabatic or isothermal nitration; (ii) optionally arranged downstream in the production line and / or downstream of the nitration device, a separation device, in particular a separator, in particular for separating nitrating end-acid from nitrated crude products (crude nitric acid esters);

[0174] (iii) arranged in the production line downstream and / or downstream of the nitriding device and the separation device, if present, a device according to the present invention or as described above.

[0175] Preferably, the production plant within the scope of the present invention is designed to carry out the method according to the invention as described above.

[0176] In particular, it is preferred within the scope of the present invention if the production plant according to the invention is characterized by one or more of the features of the method according to the invention and / or the device according to the invention.

[0177] For further details on this aspect of the invention, in particular on the advantages and special technical effects associated therewith, reference can be made to the statements on the preceding aspects of the invention, whereby these statements apply equally to the present aspect of the invention.

[0178] Finally, the present invention - according to a fourth aspect of the present invention - relates to the use of an inert gas for drying and / or purifying, preferably drying and purifying, aliphatic or cycloaliphatic crude nitrate esters (nitric acid esters) obtained from a production process, in particular for removing water and volatile impurities arising in particular during the production and / or washing of the nitrate esters.

[0179] In addition, the present invention according to the applicable aspect relates to the use of an inert gas for drying and / or purifying, preferably drying and purifying, aliphatic or cycloaliphatic crude nitrate esters (nitric acid esters) obtained from a production process, in particular for removing water and volatile and / or volatilizable impurities arising in particular during the production and / or washing of the nitrate esters, by bringing the aliphatic or cycloaliphatic crude nitrate esters into contact, in particular by flowing through them, with the inert gas, in particular in such a way that water present in the washed crude nitrate esters is removed (i.e. the washed crude nitrate esters are dried) and at the same time and / or as it were, volatile and / or volatilizable impurities arising in particular during the production and / or washing of the nitrate esters are removed.

[0180] In the context of the present invention, it has proven particularly useful for the use(s) according to the invention if

[0181] (a) first, the crude nitrate esters obtained from a manufacturing process are subjected to washing with a washing medium, followed by separation of the washing medium, and

[0182] (b) subsequently, the washed crude nitrate esters obtained in this way are subjected to drying and / or purification, preferably drying and purification, by bringing them into contact, in particular by flowing through, with an inert gas, in particular in such a way that water present in the washed crude nitrate esters is removed (ie the washed crude nitrate esters are dried) and at the same time and / or as it were, volatile and / or volatilizable impurities arising in particular during the production and / or washing of the nitrate esters are removed.

[0183] Furthermore, the present invention according to the applicable aspect relates to the use of an inert gas for drying and / or purification, preferably drying and purification, in a process according to the present invention as described above and / or in a device according to the present invention as described above and / or in a production plant according to the present invention as described above.

[0184] Preferably, the use(s) according to the invention are characterized by one or more of the features of the method according to the invention and / or the device according to the invention and / or the production plant according to the invention. For further details on this aspect of the invention, in particular also on the associated advantages and special technical effects, reference can be made to the statements on the other aspects of the invention, whereby these statements apply equally to the present aspect of the invention.

[0185] The present invention is explained in more detail below with reference to figures of preferred embodiments and preferred exemplary embodiments. In connection with the explanation of these preferred exemplary embodiments or embodiments of the present invention, which, however, are in no way limiting with respect to the present invention, further advantages, properties, aspects, and features of the present invention are also presented.

[0186] The single figure, including the following description of the figures, and the following exemplary embodiments serve only to illustrate the present invention, without, however, limiting the present invention thereto.

[0187] In the following description of the preferred embodiments according to the invention shown in the single figure according to Fig.1,

[0188] Fig. 1 is a schematic representation of the design or arrangement of a production plant according to the invention, also comprising a device according to the invention and a schematic representation of the sequence of a method according to the invention, each according to a particular embodiment.

[0189] Figure 1 shows, specifically as a component of a production plant according to the invention, a preferred embodiment of an apparatus according to the invention for drying or purifying aliphatic or cycloaliphatic nitrate esters, in particular for removing water and volatile or volatilizable impurities arising in particular during the production and / or washing of the nitrate esters, or a preferred embodiment of an inventive production plant comprising this apparatus for producing aliphatic or cycloaliphatic nitrate esters or nitric acid esters. In particular, Figure 1 also shows a preferred example of the embodiment of the process according to the invention for drying or purifying aliphatic or cycloaliphatic nitrate esters, in particular for removing water and volatile or volatilizable impurities arising in particular during the production and / or washing of the nitrate esters.

[0190] The production plant according to Figure 1 includes:

[0191] (i) a nitration device PNE, in particular with one or more reaction vessels (nitration reactors), for carrying out the nitration, in particular for producing aliphatic or cycloaliphatic nitrate esters (nitric acid esters), preferably from mono- or polyhydric aliphatic or cycloaliphatic alcohols, preferably by means of an adiabatic or isothermal nitration;

[0192] (ii) not shown in Figure 1, arranged in the production line downstream and / or downstream of the nitration device PNE, a separation device, in particular a separator, in particular for separating nitrating acid from nitrated crude products (crude nitric acid esters);

[0193] (iii) arranged in the production line downstream and / or downstream of the nitration device PNE and the separation device not shown in Figure 1, a washing device W for washing crude nitrate esters NE obtained from a manufacturing process and / or originating from a production device PNE rO h with a washing medium with a downstream and / or downstream separation device for separating the washing medium from the washed crude nitrate esters N Efeucht;

[0194] (iv) arranged in the production line downstream and / or downstream of the washing device W, a cleaning and / or drying device K, in particular a column, for drying and / or purifying, in particular drying and purifying, the washed crude nitrate esters NEfeucht obtained from the washing device W,

[0195] (v) in the production line downstream and / or downstream of the cleaning and / or drying device K, in particular column, a recycling device T for recycling and / or circulating the inert gas TG dry, TG moist. The cleaning and / or drying device K comprises a first feed means 2, arranged in particular in an upper region KK, in particular column head, of the cleaning and / or drying device, for introducing and / or feeding the washed crude nitrate esters N E moist into the cleaning and / or drying device K. Likewise, the cleaning and / or drying device K comprises a second feed means 3, arranged in particular in a lower region KS, in particular column bottom, of the cleaning and / or drying device K, for introducing and / or feeding a dry inert gas TG dry into the cleaning and / or drying device K.

[0196] In addition, the cleaning and / or drying device K also comprises means for bringing the washed crude nitrate esters NE moist into contact, in particular for flowing through, with the dry inert gas TG dry, in particular wherein the means for bringing the washed crude nitrate esters NE moist into contact, in particular for flowing through, are designed such that water present in the washed crude nitrate esters NE moist is removed (i.e. the washed crude nitrate esters are dried and at the same time and / or as it were, volatile and / or volatilizable impurities arising in particular during the production and / or washing of the nitrate esters are removed to obtain the dry (dried) nitrate esters N E dry which are freed from in particular volatile impurities); downstream in the process direction and / or downstream of the cleaning and / or drying device K.

[0197] Furthermore, the recycling device T is provided with separation means for separating water or moisture and, in particular, volatile contaminants, in particular a condenser and / or gas scrubber or a combination thereof. The separation means are particularly designed such that water or moisture and, in particular, volatile contaminants are separated from the moist inert gas TG moist, in particular by means of condensation and / or scrubbing, preferably condensation and scrubbing, to obtain a dry (dried) inert gas TG dry, freed from, in particular, volatile contaminants.

[0198] It is preferably provided that the recycling device T also comprises a third feed means 5, arranged in particular between the upper region KK, in particular the column head, the cleaning and / or drying device K and the recycling device T, for introducing and / or feeding and / or transporting the moist inert gas TGfeucht, which is loaded in particular with water and / or the particularly volatile impurities, from the cleaning and / or drying device K into the recycling device T.

[0199] The preferred production plant according to Figure 1 or the preferred device for drying and / or purifying aliphatic or cycloaliphatic nitrate esters included therein is designed to carry out a process which comprises the following process steps or in particular corresponds to the process according to the invention and comprises the following process steps:

[0200] (a) first, the crude nitrate esters obtained from a manufacturing process are subjected to washing with a washing medium, followed by separation of the washing medium,

[0201] (b) subsequently, the washed crude nitrate esters obtained in process step (a) are subjected to drying and / or purification, preferably drying and purification, by contacting, in particular by flowing through, an inert gas, in particular such that water present in the washed crude nitrate esters is removed (ie the washed crude nitrate esters are dried) and at the same time and / or as it were, volatile and / or volatilizable impurities arising in particular during the production and / or washing of the nitrate esters are removed.

[0202] The crude nitrate esters can preferably be prepared by means of an adiabatic or isothermal nitration, or the preparation process for the crude nitrate esters can preferably comprise or be an adiabatic or isothermal nitration. Particularly preferably, the nitration is carried out according to the disclosures of EP 1 792 891 A1 or in a device suitable according to the disclosures of EP 1 792 891 A1, whereby the content of EP 1 792 891 A1 is hereby expressly incorporated by reference, and its content is fully incorporated into the disclosure of the present application.

[0203] The crude nitrate esters NE obtained from the manufacturing process rO h are then fed via the separation device not shown in Figure 1 into the washing device W for washing the crude nitrate esters NE rO h. In this regard, an initial feed means 1 serves to introduce and / or feed the obtained crude nitrate esters NE rOh into the washing facility W.

[0204] The nitrate esters used in the invention are preferably liquid or in liquid form under standard conditions, in particular at a pressure of 1.013 bar and a relative humidity of 0% (standard conditions according to DIN 1343, STPD). For further details, please refer to the above explanations.

[0205] Particularly preferred nitrate esters are nitrate esters of mono- or polyhydric aliphatic or cycloaliphatic alcohols, or the nitrate esters are selected from (i) nitrate esters of aliphatic or cycloaliphatic alkanols, in particular of linear or branched aliphatic or cycloaliphatic alkanols, preferably of hexanols, heptanols, octanols, ethylhexyl alcohol and cyclohexanol; (ii) nitrate esters of aliphatic alkanediols, in particular of ethylene glycol and propanediols and their oligomers and polymers, such as ethylene glycol or propanediols, ethylene or propylene triglycol and polyethylene or polypropylene glycol; (iii) nitrate esters of aliphatic alkanetriols, in particular of trimethylolethane, trimethylolpropane, butanetriols and glycerol;

[0206] (iv) Nitrate esters of tetra- or polyhydric aliphatic alkanols.

[0207] The volatile and / or volatilizable impurities are preferably selected from the group of (i) unreacted and / or partially reacted reactants and / or starting reagents; (ii) nitrated and non-nitrated reaction by-products; (iii) degradation and oxidation products of the products and by-products originating from the nitration; (iv) mineral acids, in particular sulfuric acid, nitric acid and nitrous acid, preferably nitric acid;

[0208] (v) organic acids, in particular formic acid, acetic acid, oxalic acid, carbonic acid and hydrocyanic acid; (vi) nitrogen bases, in particular ammonia (NH3);

[0209] (vii) nitrogen oxides, in particular nitrogen monoxide (NO), nitrogen dioxide (NO2) and nitrous oxide (N2O) as well as nitrous oxide and other nitrogen oxides (NO X );

[0210] (viii) carbon oxides, in particular carbon monoxide (CO) and carbon dioxide (CO2);

[0211] (ix) Solvent and / or washing medium residues.

[0212] Likewise, the volatile and / or volatilizable impurities to be removed preferably have a higher volatility, in particular a higher vapor pressure and / or a lower boiling point, than the nitrate esters to be purified, in particular based on the vapor pressure of the nitrate esters under standard conditions (pressure of 1.013 bar; air humidity of 0% [standard conditions according to DIN 1343, STPD]) and / or in particular based on the boiling point of the nitrate esters under standard conditions (pressure of 1.013 bar; air humidity of 0% [standard conditions according to DIN 1343, STPD]);In particular, the volatile and / or volatilizable impurities to be removed preferably have a vapor pressure that is at least 5 mbar, preferably at least 7.5 mbar, more preferably at least 10 mbar, higher than the nitrate esters to be purified and / or the volatile and / or volatilizable impurities to be removed preferably have a boiling point that is at least 1 °C, preferably at least 2.5 °C, more preferably at least 5 °C, lower than the nitrate esters to be purified.

[0213] Within the scope of the preferred embodiment of the device or production plant shown in Figure 1, with regard to the process according to the invention, process step (a) and / or the washing is carried out as a liquid-liquid extraction.

[0214] Process step (a) preferably comprises an acidic, basic (alkaline) and / or neutral wash, in particular at least one basic (alkaline) and / or neutral wash, preferably an acidic, basic (alkaline) and neutral wash.

[0215] Equally preferably, process step (a) and / or the washing is carried out in one or more washing stages, preferably in one, two, or three washing stages, preferably in two or three washing stages; in particular wherein each washing stage comprises one or more washing and / or extraction steps. Likewise preferably, process step (a) and / or the washing is carried out with an aqueous-based washing medium; in particular wherein the aqueous-based washing medium is neutral, acidic, or basic (alkaline). Furthermore, process step (a) and / or the washing is preferably carried out in at least two, in particular three, washing stages, in particular wherein the washing stages comprise at least one basic (alkaline) washing stage and a final neutral washing stage, preferably wherein the washing stages comprise a first acidic washing stage, a subsequent second basic (alkaline) washing stage, and a final third neutral washing stage.In this sense, with regard to the production plant or device according to the present invention, in the preferred embodiment according to Figure 1, it is provided that the washing device W is designed as a liquid-liquid extraction device.

[0216] The washing device W preferably comprises an acidic washing stage, a basic (alkaline) washing stage and / or a neutral washing stage, in particular at least one basic (alkaline) washing stage and / or neutral washing stage, preferably an acidic, basic (alkaline) and neutral washing stage. Furthermore, it is preferred if the washing device W comprises one or more washing stages, preferably one, two or three washing stages, preferably two or three washing stages; in particular wherein each washing stage is designed such that it comprises one or more washing and / or extraction steps. Furthermore, the washing device W is preferably designed such that the washing takes place using an aqueous-based washing medium; in particular wherein the aqueous-based washing medium is neutral, acidic or basic (alkaline).

[0217] Furthermore, it has proven useful for the process according to the invention in process step (a) if process step (a) and / or the washing, in particular in each washing stage, is carried out in cross-current or counter-current or in a combination of cross-current and counter-current, preferably with recycling of the washing medium.

[0218] In this regard, the washing device W is advantageously designed such that the laundry, in particular in each washing stage, is carried out in crossflow or counterflow, or in a combination of crossflow and counterflow, preferably with recycling of the washing medium. The washing device W is, in particular in each washing stage, preferably operable in crossflow or counterflow, or in a combination of crossflow and counterflow, and / or can be operated accordingly, preferably with recycling of the washing medium.

[0219] At the conclusion of process step (a), the production plant or device according to Figure 1 is designed for the washing medium to be separated in process step (a) by means of a separating device (separator), in particular a static separating device, or a centrifugal separator. In this sense, the separation device downstream of the washing device W in Figure 1 is designed as a separating device (separator), in particular a static separating device, or as a centrifugal separator.

[0220] The subsequent process step (b) is carried out in the drying and / or cleaning device K. The cleaning and / or drying device K comprises or is in particular a column.

[0221] This preferably comprises a single- or multi-stage column, in particular a packed column, sieve tray column, bubble-cap column, or falling-film column, or combinations thereof. Alternatively, the purification and / or drying device K comprises or is a gas / liquid reactor or a stripping device.

[0222] The washed crude nitrate esters obtained in process step (a) are transferred in process step (b) to the drying and / or cleaning device K of the production plant or device according to Figure 1. For the transfer of the nitrate esters, it is provided that the first feed means 2 is designed as a connection between the washing device W and the cleaning and / or drying device K and / or that the first feed means 2 is designed as a transport line, in particular as a transport line for connecting the washing device W and the cleaning and / or drying device K.

[0223] Likewise, it has proven useful for the further supply means, here in particular the second supply means 3, if this is designed as a connection between a storage device for the dry inert gas TGdry and the cleaning and / or drying device K and / or wherein the second supply means 3 is designed as a transport line, in particular as a transport line for connecting a storage device for the dry inert gas TGdry and the cleaning and / or drying device K.

[0224] For the third feed means 5, it is analogously preferred if the third feed means 5 is designed as a connection between the cleaning and / or drying device K and the recycling device T and / or wherein the third feed means 5 is designed as a transport line, in particular as a transport line for connecting the cleaning and / or drying device K and the recycling device T. Furthermore, with regard to the process control, it has proven useful if, in process step (b), the drying and / or purification, preferably drying and purification, is carried out as a continuous or discontinuous, in particular continuous, process. In the context of Figure 1, the process is designed as a continuous process.Accordingly, the cleaning and / or drying device K, in particular a column, is designed such that the drying and / or purification, preferably drying and purification, is carried out as a continuous or discontinuous, in particular continuous, process. For this purpose, the cleaning and / or drying device K is preferably designed as a gas-liquid extraction device and / or desorption device, in particular as a gas-liquid extraction device. Furthermore, the device or production plant according to the invention is designed to utilize the preferred feed means 2, 3, 5, as described above.

[0225] The contacting, in particular flowing through, of the washed crude nitrate esters obtained in process step (a) with the inert gas takes place in the production plant or device (see Figure 1) in crosscurrent and / or countercurrent, preferably in countercurrent. Furthermore, it is provided for the process according to the invention that in process step (b) the drying and / or purification, preferably drying and purification, is carried out as a gas-liquid extraction and / or by desorption, in particular as a gas-liquid extraction. It has proven advantageous here if the inert gas is conducted in an upward flow and the nitrate esters are conducted in a downward flow.

[0226] Furthermore, good results are obtained if, in process step (b), the nitrate esters are brought into contact, in particular flowed through, with the inert gas in a dispersed distribution, in particular a finely dispersed distribution, in the nitrate esters. Particularly advantageously, in process step (b), the inert gas is introduced into the nitrate esters with and / or in a dispersed distribution, in particular a finely dispersed distribution. For this purpose, the device or production plant advantageously comprises nozzles, jet mixers, jet pumps, injectors, lances, sieve plates, and / or fine-pored membranes, preferably nozzles, jet mixers, and / or fine-pored membranes.

[0227] Furthermore, the inert gas is used in dry form in process step (b). In accordance with the described embodiment of the process, with regard to the device or production plant according to the invention, it is provided that the cleaning and / or drying device K, in particular the means for contacting, in particular the means for flowing through, the washed crude nitrate esters N Efeucht with the dry inert gas TGtrocken, is / are designed such that the contacting, in particular flowing through, of the washed crude nitrate esters N Efeucht obtained from the washing device W with the dry inert gas TGtrocken takes place in cross-current and / or countercurrent, preferably in countercurrent.

[0228] In particular, it is provided that the cleaning and / or drying device K, in particular the means for bringing the washed crude nitrate esters NE moist into contact, in particular the means for flowing through, with the dry inert gas TG dry, is / are designed such that the dry inert gas TG dry is guided in an upward flow and the washed crude nitrate esters N E moist are guided in a downward flow.

[0229] In addition, the production plant or device of Figure 1 is designed such that the dried and / or purified, preferably dried and purified, nitrate esters obtained after process step (b) are obtained and / or collected separately from the inert gas.

[0230] Advantageously, no additional separation step is carried out and / or required to separate the dried and / or purified, preferably dried and / or purified, nitrate esters obtained after process step (b) from the inert gas.

[0231] Also in the sense of the continuous process control, it is accordingly provided for the device according to the invention that the cleaning and / or drying device K, in particular column, comprises outlet and / or discharge means 4 for dry (dried) nitrate esters NEdry, which are freed from in particular volatile impurities, arranged in particular in the lower region KS, preferably the column bottom, preferably at the lower region KS.

[0232] Advantageously, the outlet and / or discharge means 4 is designed as a connection between the cleaning and / or drying device K and a collecting and / or collecting device for dry (dried) nitrate esters NEtrocken which are freed in particular from volatile impurities, and / or the outlet and / or discharge means 4 is designed as a transport line, in particular as a transport line for connecting the cleaning and / or drying device K and a collecting and / or collecting device for dry (dried) nitrate esters NEtrocken which are freed in particular from volatile impurities.

[0233] In the device or production plant according to Figure 1, in process step (b), the washed crude nitrate esters obtained in process step (a) are used as such or in concentrated and / or undiluted form. In this sense, it is therefore preferably provided that in process step (b), no (additional) solvent and / or dispersant is added to the washed crude nitrate esters obtained in process step (a) for drying and / or purification, preferably drying and purification.

[0234] The device or production plant according to Figure 1 is also designed such that in process step (b) the inert gas is selected and / or designed such that it is non-reactive towards the nitrate esters under the conditions of process step (b).

[0235] In this regard, it has proven useful if in process step (b) the inert gas is selected from the group of nitrogen, oxygen, noble gases, in particular argon, hydrogen, carbon oxides and mixtures thereof, in particular air, preferably from the group of nitrogen, oxygen, noble gases, in particular argon, and mixtures thereof, in particular air, particularly preferably from the group of nitrogen, oxygen and mixtures thereof, in particular air.

[0236] Within the scope of the preferred embodiment of the method according to the invention as shown in Figure 1, it is also provided that the inert gas is recycled and / or circulated after method step (b). This step takes place after and / or with drying and purification of the inert gas. Accordingly, the inert gas is subjected to a drying and purification treatment after method step (b), in particular by means of a condenser and / or gas scrubber or a combination thereof. In this regard, the feed means 5, as already explained above, preferably serves as a transport means for feeding moist inert gas from the cleaning and / or drying device K into the recycling device T. In this sense, within the scope of the embodiment of the method according to the invention as shown in Figure 1, it is further provided that the inert gas obtained and / or separated after method step (b) is mixed, in particular with water orInert gas loaded with moisture and especially volatile impurities is transferred to the recycling facility T for gas treatment.

[0237] The recycling device T comprises or is advantageously a condenser and / or gas scrubber, or a combination thereof, in particular a condenser.

[0238] In particular, in the case where the recycling device T is designed as a condenser, it has proven useful if the condenser comprises a refrigerant, cooling liquid, in particular cold or cooled water, and / or cooling gas, in particular cold or cooled air, in particular for cooling the recycling device T in which the treatment of the inert gas takes place.

[0239] There is a temperature gradient between the drying and / or cleaning device K and the recycling device T. The temperature gradient is designed in particular such that a lower temperature is set in the recycling device T than is provided in the drying and / or cleaning device K.

[0240] There is therefore preferably a temperature gradient decreasing in the process direction from the drying and / or cleaning device K to the recycling device T.

[0241] Furthermore, it is provided for the device or production plant in Figure 1 that the recycling device T has two discharge means 6, 7 for dry (dried) inert gas TGdry, which has been freed from volatile impurities in particular, and / or water or moisture resulting from the treatment of the inert gas and / or washing liquid with the volatile impurities in particular from the moist inert gas TGmoist.

[0242] According to Figure 1, the discharge means 6 is designed as an indirect connection, in particular via the second feed means 3, between the recycling device T and the cleaning and / or drying device K. However, a direct design of the discharge means 6 is equally conceivable. In particular, the discharge means 6 is designed as a transport line for dry (dried) inert gas TGdry, which has been freed from volatile impurities in particular, preferably as a transport line for dry (dried) inert gas TGdry, which has been freed from volatile impurities in particular, and in the context of Figure 1 is designed for an indirect connection, in particular via the second feed means 3, between the recycling device T and the cleaning and / or drying device K, in particular such that recycling and / or recirculation of the inert gas TGdry, TGmoist takes place.

[0243] Likewise, the discharge means 7 in the context of Figure 1 is designed as a connection between the recycling device T and the washing device W. In particular, the discharge means 7 is designed as a transport line for water or moisture and / or washing liquid resulting from the treatment of the inert gas with the particularly volatile impurities from the moist inert gas TG moist. The discharge means 7 is designed in particular as a transport line for water or moisture and / or washing liquid resulting from the treatment of the gas with the particularly volatile impurities from the moist inert gas TG moist and for connecting the recycling device T and the washing device W, in particular in such a way that recycling and / or recirculation of water or moisture and / or washing liquid resulting from the treatment of the gas with the particularly volatile impurities from the moist inert gas TG moist takes place.

[0244] With regard to the inert gas, it is first provided that it undergoes a treatment to remove water or moisture and, in particular, volatile contaminants, preferably by means of condensation and / or scrubbing, preferably condensation and scrubbing. Accordingly, it has proven advantageous for the recycling device T to comprise a condenser and / or gas scrubber, or a combination thereof, for treating and recycling the gas.

[0245] The treated inert gas is then returned to process step (b), specifically by transport via the purge means 6. The condensate resulting from the treatment of the inert gas and / or the resulting scrubbing medium are similarly intended to be recycled, particularly after treatment and / or purification. Specifically, the resulting condensate and / or scrubbing medium are recycled into the scrubbing process of process step (a) and / or are transported via the purge means 7.

[0246] Further embodiments, modifications and variations as well as advantages of the present invention will be readily apparent and achievable to a person skilled in the art upon reading the description, without departing from the scope of the present invention.

[0247] The present invention is further illustrated by the following embodiments, without, however, limiting the present invention thereto.

[0248] List of reference symbols:

[0249] PNE nitriding facility

[0250] NEroh Crude nitrate ester

[0251] W Washing facility

[0252] N Ewet washed crude nitrate esters

[0253] K Cleaning and / or drying device

[0254] KK upper area of ​​the cleaning and / or drying device

[0255] KS lower area of ​​the cleaning and / or drying device

[0256] T Recycling facility

[0257] N Edry dry or dried and particularly free from volatile

[0258] Nitrate esters freed from impurities

[0259] TGdry dry or dried and particularly free of volatile

[0260] Inert gas freed from impurities

[0261] TGfeucht moist inert gas loaded with volatile impurities

[0262] 1 Feeding means for introducing and / or feeding the obtained crude nitrate esters N Eroh into the washing device W

[0263] 2 Feeding means for introducing and / or feeding the washed crude nitrate esters N Efeucht into the cleaning and / or drying device K

[0264] 3 Feeding means for introducing and / or supplying a dry inert gas TGdry into the cleaning and / or drying device K

[0265] 4 Laxatives for dry (dried) and freed from volatile impurities in particular Nitrate esters N Etrocken

[0266] 5 Feeding means for introducing and / or supplying and / or transporting the moist inert gas TG moist, particularly loaded with water and / or volatile contaminants, from the cleaning and / or drying device K into the recycling device T

[0267] 6 Laxatives for dry (dried) and freed from especially volatile impurities inert gas TGdry

[0268] 7 Laxative for water or moisture resulting from the treatment of the inert gas and / or washing liquid with the particularly volatile impurities from the moist inert gas TGfeucht Examples of implementation

[0269] 1. Purification and drying of 2-ethylhexyl nitrate by the process according to the invention

[0270] In a conventional production process for nitrate esters according to the prior art according to Example 1 of EP 1 792 891 A1, 1000 mL of 2-ethylhexyl nitrate (EHN) are produced.

[0271] The crude nitrate ester obtained in this way is subsequently subjected to drying and purification according to the invention to remove water or moisture and volatile or volatilizable impurities arising during the production and washing of the nitrate esters, wherein an apparatus according to the invention and a process according to the invention are used as shown in the single figure, as already described in detail above.

[0272] For this purpose, the crude nitrate ester originating from the production process, after separation of the nitrating acid, which still contains significant amounts of water or moisture and of volatile or volatilizable impurities arising during the production and washing of the nitrate esters, is washed at approximately 30 °C in a multi-stage washing device (three stages: acidic, subsequent basic or alkaline and final neutral wash with aqueous washing medium) and separated from the washing medium in each case.

[0273] The washed crude nitrate ester has a water content of 0.056% (by weight) and exhibits a significant turbidity upon cooling due to this water content. Furthermore, the washed crude nitrate ester contains various volatile or volatilizable impurities (CO2 at 31 ppm; NO and NO2 at 15 ppm; HNO3 at 10 ppm; NH3 at 120 ppm; volatile organic compounds such as formic acid at 13 ppm). The total content of volatile or volatilizable impurities before carrying out the process according to the invention is thus 189 ppm.

[0274] The washed crude nitrate ester is transferred to a cleaning and drying device according to the present invention (column according to the single figure representation with column bottom and column head; supply of the dry inert gas via column bottom and supply of the crude nitrate ester via column head via respective supply lines) and there flows through a fine-pored ceramic membrane with 400 L / h of dry inert gas in the form of dry air (dew point approx. -40°C) (countercurrent; finely dispersed gas flow).

[0275] The temperature in the cleaning and drying device is approximately 20 °C, and the pressure in this device corresponds to atmospheric pressure. The amount of inert gas used, based on 1 ton of nitrate ester to be purified and calculated as the volume of inert gas in standard cubic meters under standard conditions (pressure: 1.013 bar; air humidity: 0%, i.e., dry inert gas; temperature: 0 °C [standard conditions according to DIN 1343, STPD]), is approximately 50 standard cubic meters.

[0276] The water content of washed crude nitrate esters, which is initially 0.056% (weight percent) before inert gas introduction, is checked after 1 min, 2 min, 5 min and 10 min.

[0277] After 1 minute of flowing through the nitrate esters to be cleaned or dried, the water content is already 0.045%, after 2 minutes it is 0.030%, after 5 minutes it is 0.018%, and after 10 minutes it is 0.003%. The EHN, initially cloudy due to the production process, clears into a completely clear liquid after just one minute of treatment, which remains completely clear throughout the rest of the process.

[0278] In contrast, the water content of conventionally produced and state-of-the-art purified 2-ethylhexyl nitrates is generally around 0.05%.

[0279] Within the scope of the process according to the invention or by means of the drying and cleaning devices according to the invention, nitrate esters can be provided that contain significantly less water or are free of water and are purer than those of the prior art or conventional production and cleaning processes and devices.

[0280] The EHN obtained from the process according to the invention was further analyzed for levels of volatile or volatilizable impurities. This confirmed that the dried and purified EHN obtained was virtually free of undesirable impurities or accompanying substances within the scope of detection. Specifically, the levels of the following impurities were minimized as listed below: CCh reduction from 31 ppm to 1 ppm; NO and NO2 reduction from 15 ppm to below 1 ppm; HNOs reduction from 10 ppm to 2 ppm; NHs reduction from 120 ppm to below 1 ppm; volatile organic compounds (e.g., formic acid) reduction from 13 ppm to 2 ppm. In addition to a significant reduction in water content, the process according to the invention can also achieve a far-reaching reduction in volatile or volatilizable impurities that can be introduced into the crude nitrate ester during nitrate ester production.

[0281] Furthermore, the process is controlled in such a way that the vapor pressures of nitrate esters are always kept low, preventing the formation of explosive mixtures of nitrate ester vapor and gas at any time. This provides both a highly efficient and extremely safe process.

[0282] The inert gas in the form of air, which has absorbed the water or moisture and the volatile or volatilizable impurities from the product during the process, is conveyed from the cleaning and drying device via a corresponding supply or transport line to a recycling facility with a gas scrubber and condenser. There, the gas scrubber removes the volatile or volatilizable impurities, and then the water is removed by condensation in a cooler. The dry air thus obtained is then reused to dry washed crude nitrate esters or recycled.

[0283] The resulting condensate, together with traces of entrained EHN and separated undesired by-products, is returned to the washing device, which is located upstream of the cleaning and drying device, and there is incorporated into the process according to the invention or neutralized.

[0284] The process according to the invention is particularly advantageous and economical: The air or inert gas used for drying and purification is circulated in a (closed) circuit. This eliminates environmental and exhaust emissions. The condensate produced at the cooler, which separates the transported water, can be easily recycled into the production process (product wash), especially if it contains small amounts of product (EHN). This reduces or prevents any EHN slippage.

[0285] The procedure described above is also repeated with other inert gases (nitrogen and argon). Comparable results are obtained. 2. Purification and drying of pentyl nitrate (amyl nitrate) according to the process of the invention

[0286] Crude pentyl nitrate (amyl nitrate) is purified and dried in a similar manner using the inventive process described above for EHN. Comparable results are obtained.

[0287] 3. Comparative example: Treatment of 2-ethylhexyl nitrate according to the state of the art

[0288] In a conventional production process for nitrate esters according to the prior art according to Example 1 of EP 1 792 891 A1, 1000 mL of 2-ethylhexyl nitrate (EHN) are produced.

[0289] After separating the nitrating acid, the crude nitrate ester is washed at approximately 30 °C as described in Example 1 and separated from the washing medium. The resulting washed crude nitrate ester is passed at a rate of 20 mL / min through a cooling apparatus consisting of a 2 m long stainless steel tube with an inner diameter of 3 mm, placed in a thermostatic bath with a controlled temperature of -5 °C. In a receiver vessel, in which the washed and cooled EHN ester is collected, clearly visible water droplets are separated. These droplets are separated using a coalescer made of stainless steel mesh.

[0290] The initial water content of the washed crude nitrate esters is 0.056%. After drying by cooling and using a coalescer, the water content of the nitrate esters obtained from this process is still 0.028%. The cloud point of the dried EHN nitrate esters upon cooling can therefore only be reduced to approximately 11 °C.

[0291] In contrast to the process according to the invention, a less dry product is obtained, the cloud point of which is also comparatively high, ie in cold regions, crystallization of water can occur during transport of the corresponding esters, which can negatively affect the product quality.

[0292] Furthermore, the process according to the comparative example is significantly more energy-intensive due to the required intensive cooling, while simultaneously being less effective. The separate and downstream, but necessary, water separation using a coalescer represents an additional and complex work step compared to the process according to the invention (which, in contrast, is significantly more efficient and effective).

[0293] Also, in contrast to the process according to the invention, the content of volatile or volatilizable impurities cannot be significantly reduced (total content of volatile or volatilizable impurities after carrying out the process of Example 3: > 160 ppm).

Claims

Patent claims:

1. A process for drying and / or purifying, preferably drying and purifying, aliphatic or cycloaliphatic nitrate esters (nitric acid esters), in particular for removing water and volatile impurities arising in particular during the production and / or washing of the nitrate esters, the process comprising the following process steps: (a) first, the crude nitrate esters obtained from a manufacturing process are subjected to washing with a washing medium, followed by separation of the washing medium, (b) subsequently, the washed crude nitrate esters obtained in process step (a) are subjected to drying and / or purification, preferably drying and purification, by contacting, in particular by flowing through, an inert gas, in particular such that water present in the washed crude nitrate esters is removed and, at the same time and / or simultaneously, volatile impurities arising in particular during the production and / or washing of the nitrate esters are removed.

2. The process according to claim 1, wherein the nitrate esters are liquid and / or are in liquid form under standard conditions, in particular at a pressure of 1.013 bar and a relative humidity of 0% (standard conditions according to DIN 1343, STPD); and / or wherein the nitrate esters are nitrate esters of mono- or polyhydric aliphatic or cycloaliphatic alcohols; and / or wherein the nitrate esters are selected from (i) nitrate esters of aliphatic or cycloaliphatic alkanols, in particular of linear or branched aliphatic or cycloaliphatic alkanols, preferably of hexanols, heptanols, octanols, ethylhexyl alcohol and cyclohexanol; (ii) Nitrate esters of aliphatic alkanediols, in particular of ethylene glycol and propanediols and their oligomers and polymers, such as ethylene glycol or propanediols, ethylene or propylene triglycol and polyethylene or Polypropylene glycol; (iii) nitrate esters of aliphatic alkanetriols, in particular trimethylolethane, trimethylolpropane, butanetriols and glycerol; (iv) nitrate esters of tetra- or polyhydric aliphatic alkanols.

3. The process according to claim 1 or claim 2, wherein the volatile impurities are selected from the group of (i) unreacted and / or partially reacted reactants and / or starting reagents; (ii) nitrated and non-nitrated reaction by-products; (iii) degradation and oxidation products of the products and by-products originating from the nitration; (iv) mineral acids, in particular sulfuric acid, nitric acid and nitrous acid, preferably nitric acid; (v) organic acids, in particular formic acid, acetic acid, oxalic acid, carbonic acid and hydrogen cyanide; (vi) nitrogen bases, in particular ammonia (NH3); (vii) nitrogen oxides, in particular nitrogen monoxide (NO), nitrogen dioxide (NO2) and dinitrogen oxide (N2O) as well as nitrous oxide and other nitrogen oxides (NO X); (viii) carbon oxides, in particular carbon monoxide (CO) and carbon dioxide (CO2); (ix) solvent and / or washing medium residues; and / or wherein the volatiles to be removed have a higher volatility, in particular a higher vapor pressure and / or a lower boiling point, than the nitrate esters to be purified, in particular based on the vapor pressure of the nitrate esters under standard conditions (pressure of 1.013 bar; air humidity of 0% [standard conditions according to DIN 1343, STPD]) and / or in particular based on the boiling point of the nitrate esters under standard conditions (pressure of 1.013 bar; air humidity of 0% [standard conditions according to DIN 1343, STPD]);in particular wherein the volatiles to be removed have a vapor pressure that is at least 5 mbar, preferably at least 7.5 mbar, more preferably at least 10 mbar, higher than the nitrate esters to be purified and / or in particular wherein the volatiles to be removed have a boiling point that is at least 1 °C, preferably at least 2.5 °C, more preferably at least 5 °C, lower than the nitrate esters to be purified.; 4. A process according to any one of the preceding claims, wherein process step (a) and / or the washing is carried out as a liquid-liquid extraction; and / or wherein process step (a) comprises an acidic, basic (alkaline) and / or neutral wash, in particular at least one basic (alkaline) and / or neutral wash, preferably an acidic, basic (alkaline) and neutral wash; and / or wherein process step (a) and / or the wash is carried out in one or more washing stages, preferably in one, two or three washing stages, preferably in two or three washing stages; in particular wherein each washing stage comprises one or more washing and / or extraction steps; and / or wherein process step (a) and / or the wash is carried out with an aqueous-based washing medium; in particular wherein the aqueous-based washing medium is neutral, acidic or basic (alkaline).

5. Process according to one of the preceding claims, wherein process step (a) and / or the washing is carried out in at least two, in particular three, washing stages, in particular wherein the washing stages comprise at least one basic (alkaline) washing stage and a final neutral washing stage, preferably wherein the washing stages comprise a first acidic washing stage, a subsequent second basic (alkaline) washing stage and a final third neutral washing stage.

6. Process according to one of the preceding claims, wherein process step (a) and / or the washing, in particular in each washing stage, is carried out in cross-current or counter-current or in a combination of cross-current and counter-current, preferably with recycling of the washing medium.

7. Method according to one of the preceding claims, wherein in method step (a) the separation of the washing medium takes place by means of a separating device (separator), in particular by means of a static separating device, or by means of a centrifugal separator.

8. The process according to any one of the preceding claims, wherein process step (b) is carried out in a drying and / or purification device, preferably a drying and purification device; in particular wherein the washed crude nitrate esters obtained in process step (a) are transferred in process step (b) to a drying and / or purification device, preferably a drying and purification device; and / or in particular wherein the drying and / or purification device, preferably a drying and purification device, comprises a column, in particular a single-stage or multi-stage column, preferably a packed column, a sieve tray column, a bubble-cap tray column or a falling-film column or combinations thereof, and / or a gas / liquid reactor or a stripping device.

9. Process according to one of the preceding claims, wherein in process step (b) the drying and / or purification, preferably drying and purification, is carried out as a continuous or discontinuous, in particular continuous, process.

10. The process according to any one of the preceding claims, wherein in process step (b) the drying and / or purification, preferably drying and purification, is carried out as gas-liquid extraction and / or by means of desorption, in particular as gas-liquid extraction.

11. A process for drying and / or purifying, preferably drying and purifying, aliphatic or cycloaliphatic nitrate esters (nitric acid esters), in particular for removing water and volatile impurities arising in particular during the production and / or washing of the nitrate esters, in particular a process according to any one of the preceding claims, wherein the process comprises the following process steps: (a) first, the crude nitrate esters obtained from a manufacturing process are subjected to washing with a washing medium, followed by separation of the washing medium, wherein process step (a) and / or the washing is carried out as a liquid-liquid extraction; (b) the washed crude nitrate esters obtained in process step (a) are subsequently subjected to drying and / or purification, preferably drying and purification, by contacting, in particular by flowing through, an inert gas, in particular such that water present in the washed crude nitrate esters is removed and, at the same time and / or simultaneously, volatile impurities arising in particular during the production and / or washing of the nitrate esters are removed, wherein the drying and / or purification, preferably drying and purification, is carried out as a gas-liquid extraction and / or by desorption, in particular as a gas-liquid extraction; in particular wherein the volatile impurities are selected from the group of (i) unreacted and / or partially reacted reactants and / or starting reagents; (ii) nitrated and non-nitrated reaction by-products;(iii) degradation and oxidation products of the products and by-products resulting from nitration; (iv) mineral acids, in particular sulfuric acid, nitric acid and nitrous acid, preferably nitric acid; (v) organic acids, in particular formic acid, acetic acid, oxalic acid, carbonic acid and hydrogen cyanide; (vi) nitrogen bases, in particular ammonia (NH3); (vii) nitrogen oxides, in particular nitrogen monoxide (NO), nitrogen dioxide (NO2) and nitrous oxide (N2O) as well as nitrous oxide and other nitrogen oxides (NO; X); (viii) carbon oxides, in particular carbon monoxide (CO) and carbon dioxide (CO2); (ix) solvent and / or washing medium residues; and / or in particular wherein the volatile impurities to be removed have a higher volatility, in particular a higher vapor pressure and / or a lower boiling point, than the nitrate esters to be purified, in particular based on the vapor pressure of the nitrate esters under standard conditions (pressure of 1,013 bar; air humidity of 0% [standard conditions according to DIN 1343, STPD]) and / or in particular based on the Boiling point of the nitrate esters at standard conditions (pressure of 1,013 bar; Humidity of 0% [standard conditions according to DIN 1343, STPD]).

12. Process according to one of the preceding claims, wherein in process step (b) the washed crude nitrate esters obtained in process step (a) are used as such and / or wherein in process step (b) the washed crude nitrate esters obtained in process step (a) are used in concentrated and / or undiluted form; and / or wherein in process step (b) no (additional) solvent and / or dispersant is added to the washed crude nitrate esters obtained in process step (a) for carrying out drying and / or purification, preferably drying and purification.

13. Process according to one of the preceding claims, wherein in process step (b) the inert gas is selected and / or designed such that it is non-reactive towards the nitrate esters under the conditions of process step (b); and / or wherein in process step (b) the inert gas is selected from the group consisting of nitrogen, oxygen, noble gases, in particular argon, hydrogen, carbon oxides and mixtures thereof, in particular air, preferably from the group consisting of nitrogen, oxygen, noble gases, in particular argon, and mixtures thereof, in particular air, particularly preferably from the group consisting of nitrogen, oxygen and mixtures thereof, in particular air.

14. Process according to one of the preceding claims, wherein in process step (b) the contacting, in particular flowing through, of the washed crude nitrate esters obtained in process step (a) with the inert gas takes place in cross-current and / or countercurrent, preferably in countercurrent; in particular wherein the inert gas is conducted in an upward flow and the nitrate esters are conducted in a downward flow; in particular in a drying and / or purification device, preferably a drying and purification device, preferably a column, in particular a single-stage or multi-stage column, preferably a packed column, sieve tray column, Bubble cap or falling film column or combinations thereof and / or in a gas / liquid reactor or in a stripping device.

15. The process according to any one of the preceding claims, wherein in process step (b) the contacting, in particular flowing through, of the nitrate esters with the inert gas in a dispersed distribution, in particular a finely dispersed distribution, of the inert gas in the nitrate esters takes place and / or is carried out; and / or wherein in process step (b) the inert gas is introduced into the nitrate esters with and / or in a dispersed distribution, in particular a finely dispersed distribution, preferably by means of nozzles, jet mixers, jet pumps, injectors, lances, sieve plates and / or fine-pored membranes, preferably by means of nozzles, jet mixers and / or fine-pored membranes.

16. The process according to any one of the preceding claims, wherein in process step (b) the inert gas is used in dry form; in particular wherein the inert gas in dry form has a dew point which is below the temperature at which process step (b) according to the invention is carried out; in particular wherein the dew point is preferably at least 5°C, more preferably at least 10°C, preferably at least 15°C, below the temperature at which process step (b) according to the invention is carried out; and / or in particular wherein the inert gas supplied and / or initially supplied, in particular at the start of process step (b), has a dew point of -20°C or lower, in particular -30°C or lower, preferably -35°C or lower, preferably -40°C or lower, and / or a dew point of -80°C or higher, in particular -65°C or higher, preferably -55°C or higher, preferably -50°C or higher;and / or in particular wherein the inert gas supplied and / or initially supplied, in particular at the beginning of process step (b), has a dew point in a range from -20 °C to -80 °C, in particular -30 °C to -65 °C, preferably -35 °C to -55 °C, more preferably -40 °C to -50 °C; and / or; in particular wherein the inert gas supplied and / or initially supplied in particular at the beginning of process step (b) has a relative humidity in the range from 0 to 95%, in particular 0 to 90%, preferably 0 to 85%, preferably 0 to 80%.

17. The process according to any one of the preceding claims, wherein in process step (b) the drying and / or purification, preferably drying and purification, or the bringing into contact, in particular flowing through, with the inert gas is carried out with a volume flow of the inert gas of 100 L / h / kg nitrate ester (litres / hour per kg of nitrate ester to be dried and / or freed from volatile impurities) or more, in particular 200 L / h / kg nitrate ester or more, preferably 300 L / h / kg nitrate ester or more, preferably 350 L / h / kg nitrate ester or more, and / or with a volume flow of the inert gas of 600 L / h / kg nitrate ester or less, in particular 500 L / h / kg nitrate ester or less, preferably 450 L / h / kg nitrate ester or less, preferably 425 L / h / kg nitrate ester or less; and / or wherein in process step (b) the drying and / or purification, preferably drying and purification, orthe bringing into contact, in particular flowing through, with the inert gas is carried out with a volume flow of the inert gas in a range from 100 L / h / kg nitrate ester to 600 L / h / kg nitrate ester, in particular 200 L / h / kg nitrate ester to 500 L / h / kg nitrate ester, preferably 300 L / h / kg nitrate ester to 450 L / h / kg nitrate ester, preferably 350 L / h / kg nitrate ester to 425 L / h / kg nitrate ester.

18. The process according to any one of the preceding claims, wherein in process step (b) the drying and / or purification, preferably drying and purification, or the contacting, in particular flowing through, with the inert gas is carried out with a residence time of the nitrate esters in the presence of the inert gas of 30 s or more, in particular 1 min or more, preferably 3 min or more, preferably 7 min or more, and / or with a residence time of the nitrate esters in the presence of the inert gas of 20 min or less, in particular 17 min or less, preferably 14 min or less, preferably 12 min or less; and / or wherein in process step (b) the drying and / or purification, preferably drying and purification, or the contacting, in particular flowing through, with the inert gas is carried out with a residence time of the nitrate esters in the presence of the inert gas in a range from 30 s to 20 min, in particular 1 min to 17 min, preferably 3 min to 14 min, more preferably 7 min to 12 min.

19. The process according to any one of the preceding claims, wherein in process step (b) the drying and / or purification, preferably drying and purification, or the bringing into contact, in particular flowing through, with the inert gas is carried out at temperatures at which the vapor pressure of the nitrate esters is less than 100 mbar, in particular less than 80 mbar, preferably less than 60 mbar, more preferably less than 50 mbar, and / or wherein in process step (b) the drying and / or purification, preferably drying and purification, orthe contacting, in particular flowing through, with the inert gas is carried out at temperatures of more than 0 °C, in particular more than 5 °C, preferably more than 7.5 °C, more preferably more than 10 °C, and / or at temperatures of less than 60 °C, in particular less than 50 °C, preferably less than 40 °C, more preferably less than 35 °C; and / or wherein in process step (b) the drying and / or purification, preferably drying and purification, or the contacting, in particular flowing through, with the inert gas is carried out at temperatures in a range from 0 °C to 60 °C, in particular 5 °C to 50 °C, preferably 7.5 °C to 35 °C, more preferably 10 °C to 30 °C.

20. The method according to any one of the preceding claims, wherein in process step (b) the drying and / or purification, preferably drying and purification, or the contacting, in particular flowing through, with the inert gas is carried out at atmospheric pressure (normal pressure; 1.01325 bar) or in vacuum (negative pressure) or at overpressure, preferably at atmospheric pressure, and / or wherein in process step (b) the drying and / or purification, preferably drying and purification, or bringing into contact, in particular flowing through, with the inert gas at an absolute pressure in the range from 0.1 bar to 3 bar, in particular in the range from 0.3 bar to 1.2 bar, preferably in the range from 0.5 bar to 1.1 bar, particularly preferably at about 1 bar.

21. Process according to one of the preceding claims, wherein the amount of inert gas used in process step (b) is selected and / or adjusted depending on the drying and / or purification conditions, in particular temperature and / or pressure and / or duration of the drying and / or purification and / or type of inert gas, and / or depending on the content and / or type of volatile impurities in the nitrate esters to be purified and / or depending on the desired residual content of volatile impurities in the resulting purified nitrate esters; and / or wherein the amount of inert gas used in process step (b), based on 1 ton of nitrate esters to be purified and calculated as the volume of the inert gas in standard cubic meters under standard conditions (pressure: 1.013 bar; air humidity: 0%, iedry inert gas; temperature: 0 °C [standard conditions according to DIN 1343, STPD]), 0.5 to 500 standard cubic meters, in particular 2 to 200 standard cubic meters, preferably 5 to 100 standard cubic meters, more preferably 8 to 70 standard cubic meters, and / or wherein the amount of inert gas used in process step (b), based on 1 ton of nitrate ester to be purified and calculated as the amount and / or weight of the inert gas under standard conditions (pressure: 1.013 bar; air humidity: 0%, ie dry inert gas; temperature of 0 °C [standard conditions according to DIN 1343, STPD]), 1 to 250 kg, in particular. 2 to 140 kg, preferably 5 to 50 kg, preferably 10 to 40 kg.

22. Process according to one of the preceding claims, wherein the nitrate esters after drying and / or purification, preferably drying and purification, have a water content of at most 0.06 wt.%, in particular at most 0.03 wt.%, preferably at most 0.02 wt.%, more preferably at most 0.01 wt.%, based on the nitrate esters; and / or wherein the nitrate esters after drying and / or purification, preferably drying and purification, have a water content in the range of 0.00001 to 0.06 wt.%, in particular in the range of 0.0001 to 0.03 wt.%, preferably in the range of 0.0005 to 0.02 wt.%, more preferably in the range of 0.0005 to 0.01 wt.%, based on the nitrate esters.

23. The process according to any one of the preceding claims, wherein the nitrate esters, after drying and / or purification, preferably drying and purification, have a content of volatile impurities of at most 100 ppm, in particular of at most 30 ppm, preferably of at most 25 ppm, more preferably of at most 20 ppm, more preferably of at most 10 ppm; and / or wherein the nitrate esters, after drying and / or purification, preferably drying and purification, have a content of volatile impurities in the range from 0.001 to 100 ppm, in particular in the range from 0.001 to 30 ppm, preferably in the range from 0.001 to 25 ppm, more preferably in the range from 0.002 to 20 ppm, preferably in the range from 0.005 to 10 ppm.

24. Process according to one of the preceding claims, wherein the inert gas after process step (b) and / or after contacting, in particular flowing through, the nitrate ester has a relative humidity and / or relative residual humidity of 50% or more, in particular 65% by weight or more, preferably 75% or more, more preferably 80% or more, particularly preferably 90% or more, based on a gas temperature of 20°C to 30°C.

25. A process according to any one of the preceding claims, wherein the dried and / or purified, preferably dried and purified, nitrate esters obtained after process step (b) are obtained and / or collected separately from the inert gas; in particular wherein no additional separation step is required to separate the dried and / or purified, preferably dried and / or purified nitrate ester from the inert gas is carried out and / or required.

26. A process according to any one of the preceding claims, wherein the inert gas is recycled and / or circulated after process step (b), in particular after and / or with drying and purification; in particular wherein the inert gas is subjected to a drying and purification treatment after process step (b), in particular by means of a condenser and / or gas scrubber or a combination thereof.

27. A process according to any one of the preceding claims, wherein the inert gas obtained and / or separated after process step (b), in particular the inert gas laden with water or moisture and volatile impurities, is transferred to a recycling device for treating the gas; in particular wherein the inert gas is subjected to a treatment to separate water or moisture and the volatile impurities, preferably by means of condensation and / or scrubbing, preferably condensation and scrubbing, and / or in particular wherein the recycling device for treating and recycling the gas comprises a condenser and / or gas scrubber or a combination thereof.

28. The process according to claim 27, wherein the treated inert gas is recycled to process step (b); and / or wherein the condensate resulting from the treatment of the inert gas and / or the scrubbing medium obtained is circulated, in particular after treatment and / or purification, preferably recycled and / or recycled into the scrubbing of process step (a).

29. Process for drying and / or purifying, preferably drying and purifying, aliphatic or cycloaliphatic nitrate esters (nitric acid esters), in particular for removing water and in particular during the production and / or washing of the nitrate esters, volatile impurities, in particular a process according to one of the preceding claims, wherein the process comprises the following process steps: (a) first, the crude nitrate esters obtained from a manufacturing process are subjected to washing with a washing medium, followed by separation of the washing medium, in particular wherein process step (a) and / or the washing is carried out as a liquid-liquid extraction; (b) the washed crude nitrate esters obtained in process step (a) are subsequently subjected to drying and / or purification, preferably drying and purification, by contacting, in particular by flowing through, an inert gas, in particular such that water present in the washed crude nitrate esters is removed and, at the same time and / or simultaneously, volatile impurities arising in particular during the production and / or washing of the nitrate esters are removed, in particular wherein the drying and / or purification, preferably drying and purification, is carried out as a gas-liquid extraction and / or by desorption, in particular as a gas-liquid extraction; wherein the inert gas is recycled and / or circulated after process step (b), in particular after and / or during drying and purification;in particular wherein the inert gas is subjected to a drying and purification treatment after process step (b), in particular by means of a condenser and / or gas scrubber or a combination thereof; and / or wherein the inert gas obtained and / or separated after process step (b), in particular inert gas laden with water or moisture and volatile impurities, is transferred to a device for treating and recycling the gas; in particular wherein the inert gas is subjected to a treatment to remove water or moisture and volatile impurities, preferably by means of condensation and / or scrubbing, preferably condensation and scrubbing, and / or in particular wherein the device for treating and; Recycling of the gas comprises a condenser and / or gas scrubber or a combination thereof; in particular wherein the treated inert gas is recycled to process step (b); and / or in particular wherein the condensate resulting from the treatment of the inert gas and / or the scrubbing medium obtained is circulated, in particular after processing and / or purification, preferably into the scrubbing of process step (a).

30. A process according to any one of the preceding claims, wherein the crude nitrate esters are prepared by means of an adiabatic or isothermal nitration and / or the preparation process for the crude nitrate esters comprises or is an adiabatic or isothermal nitration.

31. Apparatus for drying and / or purifying, preferably apparatus for drying and purifying, aliphatic or cycloaliphatic nitrate esters (nitric acid esters), in particular for removing water and volatile impurities arising in particular during the production and / or washing of the nitrate esters, preferably by bringing them into contact, in particular by flowing through, with an inert gas (TG), in particular apparatus for carrying out a process according to one of the preceding claims, wherein the apparatus comprises the following devices (W, K, T) arranged successively in the process direction: - at least one washing device (W) for washing crude nitrate esters (NE) obtained from a manufacturing process and / or originating from a production facility (PNE) rOh) with a washing medium with a downstream and / or downstream separation device for separating the washing medium from the washed crude nitrate esters (NEfeucht); downstream in the process direction and / or downstream of the washing device (W) at least one cleaning and / or drying device (K), in particular a column, for drying and / or purifying, in particular drying and purifying, the washed crude nitrate esters (NE moist) obtained from the washing device (W), wherein the cleaning and / or drying device (K) comprises a first feed means (2), arranged in particular in an upper region (KK), in particular the column head, of the cleaning and / or drying device, for introducing and / or feeding the washed crude nitrate esters (N E moist) into the cleaning and / or drying device (K), and a second feed means (3), arranged in particular in a lower region (KS), in particular the column bottom, of the cleaning and / or drying device (K), for introducing and / or feeding a dry inert gas (TG dry) into the cleaning and / or drying device (K), wherein the cleaning and / or drying device (K) comprises means for bringing into contact,in particular for flowing through the washed crude nitrate esters (NE moist) with the dry inert gas (TG dry), in particular wherein the means for bringing into contact, in particular for flowing through, are designed such that water present in the washed crude nitrate esters (NE moist) is removed and, at the same time and / or simultaneously, volatile impurities arising, in particular, during the production and / or washing of the nitrate esters, are removed to obtain the dry (dried) nitrate esters (N E dry) freed from volatile impurities; downstream in the process direction and / or downstream of the cleaning and / or drying device (K), at least one recycling device (T) for recycling and / or recirculating the inert gas (TG dry, TG dry), wherein the recycling device (T) comprises separation means for separating water or moisture and the volatile impurities,in particular a condenser and / or gas scrubber or a combination thereof, in particular wherein the separation means are designed such that water or moisture and the volatile impurities are separated from the moist inert gas (TG moist), in particular by means of condensation and / or scrubbing, preferably condensation and, Wash, to obtain a dry (dried) inert gas (TG dry) freed from volatile impurities; in particular wherein the recycling device (T) further comprises a third feed means (5), arranged in particular between the upper region (KK), in particular the column head, the cleaning and / or drying device (K) and the recycling device (T), for introducing and / or feeding and / or transporting the moist inert gas (TG moist), in particular laden with water and / or the volatile impurities, from the cleaning and / or drying device (K) into the recycling device (T).

32. Device according to one of the preceding claims, wherein the first feed means (2) is designed as a connection between the washing device (W) and the cleaning and / or drying device (K) and / or wherein the first feed means (2) is designed as a transport line, in particular as a transport line for connecting the washing device (W) and the cleaning and / or drying device (K).

33. Device according to one of the preceding claims, wherein the second supply means (3) is designed as a connection between a storage device for the dry inert gas (TGdry) and the cleaning and / or drying device (K) and / or wherein the second supply means (3) is designed as a transport line, in particular as a transport line for connecting a storage device for the dry inert gas (TGdry) and the cleaning and / or drying device (K).

34. Device according to one of the preceding claims, wherein the third feed means (5) is designed as a connection between the cleaning and / or drying device (K) and the recycling device (T) and / or wherein the third feed means (5) is designed as a transport line, in particular as a transport line for connecting the cleaning and / or drying device (K) and the recycling device (T).

35. Device according to one of the preceding claims, wherein the washing device (W) is designed as a liquid-liquid extraction device; and / or wherein the washing device (W) comprises an acidic washing stage, a basic (alkaline) washing stage and / or a neutral washing stage, in particular at least one basic (alkaline) washing stage and / or neutral washing stage, preferably an acidic, basic (alkaline) and neutral washing stage; and / or wherein the washing device (W) comprises one or more washing stages, preferably one, two or three washing stages, preferably two or three washing stages; in particular wherein each washing stage is designed such that it comprises one or more washing and / or extraction steps; and / or wherein the washing device (W) is designed such that the washing takes place with an aqueous-based washing medium; in particular wherein the aqueous-based washing medium is neutral, acidic or basic (alkaline).

36. Device according to one of the preceding claims, wherein the washing device (W) is designed such that the washing, in particular in each washing stage, is carried out in crossflow or counterflow or in a combination of crossflow and counterflow, preferably with recycling of the washing medium; and / or wherein the washing device (W), in particular in each washing stage, is and / or can be operated in crossflow or counterflow or in a combination of crossflow and counterflow, preferably with recycling of the washing medium.

37. Device according to one of the preceding claims, wherein the separation device downstream of the washing device (W) is designed as a separating device (separator), in particular as a static separating device, or as a centrifugal separator.

38. Device according to one of the preceding claims, wherein the cleaning and / or drying device (K), in particular column, comprises a single-stage or multi-stage column, in particular a packed column, sieve tray column, bubble tray column or falling film column or combinations thereof, and / or a gas / liquid reactor or a stripping device.

39. Device according to one of the preceding claims, wherein the cleaning and / or drying device (K), in particular column, is a single-stage or multi-stage column, in particular a packed column, sieve tray column, bubble tray column or falling film column or combinations thereof, and / or a gas / liquid reactor or a stripping device.

40. Device according to one of the preceding claims, wherein the cleaning and / or drying device (K), in particular column, is designed such that the drying and / or purification, preferably drying and purification, is carried out as a continuous or discontinuous, in particular continuous, process.

41. Device according to one of the preceding claims, wherein the cleaning and / or drying device (K), in particular column, comprises outlet and / or discharge means (4) for dry (dried) nitrate esters (N Etrocken ) freed from volatile impurities, in particular in the lower region (KS), preferably the column bottom, preferably at the lower region (KS);in particular wherein the outlet and / or discharge means (4) is designed as a connection between the cleaning and / or drying device (K) and a collecting and / or collecting device for dry (dried) nitrate esters (NEdry) freed from volatile impurities and / or wherein the outlet and / or discharge means (4) is designed as a transport line, in particular as a transport line for connecting the cleaning and / or drying device (K) and a collecting and / or collecting device for dry (dried) nitrate esters (NEdry) freed from volatile impurities.

42. Device according to one of the preceding claims, wherein the cleaning and / or drying device (K), in particular column, is designed as a preferably single- or multi-stage packed column, sieve tray column, bubble tray column or falling film column or combinations thereof with a column bottom (KS) as the lower region, in particular wherein the cleaning and / or drying device (K) has outlet and / or discharge means (4) for dry (dried) nitrate esters (NEdry) freed from volatile impurities, preferably arranged at the column bottom (KS);in particular wherein the outlet and / or discharge means (4) is designed as a connection between the cleaning and / or drying device (K) and a collecting and / or collecting device for dry (dried) nitrate esters (NEdry) freed from volatile impurities and / or wherein the outlet and / or discharge means (4) is designed as a transport line, in particular as a transport line for connecting the cleaning and / or drying device (K) and a collecting and / or collecting device for dry (dried) nitrate esters (NEdry) freed from volatile impurities.

43. Device according to one of the preceding claims, wherein the cleaning and / or drying device (K) is designed as a gas-liquid extraction device and / or desorption device, in particular as a gas-liquid extraction device.

44. Device according to one of the preceding claims, wherein the cleaning and / or drying device (K), in particular the means for bringing the washed crude nitrate esters (NE moist) into contact, in particular the means for flowing through, with the dry inert gas (TG dry), is / are designed such that the contacting, in particular flowing through, of the washed crude nitrate esters (NE moist) obtained from the washing device (W) with the dry inert gas (TG dry) takes place in cross-current and / or countercurrent, preferably in countercurrent; in particular wherein the cleaning and / or drying device (K), in particular the means for bringing the washed crude nitrate esters (NE moist) into contact, in particular the means for flowing through, with the dry inert gas (TG dry), is / are designed in such a way that the dry inert gas (TG dry) is / are guided upwards and the washed crude nitrate esters (N E moist) are guided downwards.

45. Device according to one of the preceding claims, wherein the recycling device (T) has at least two discharge means (6, 7) for dry (dried) inert gas (TGdry) freed from volatile impurities and / or water or moisture resulting from the treatment of the inert gas and / or washing liquid with the impurities from the moist inert gas (TGwet), in particular two discharge means (6, 7) for dry (dried) inert gas (TGdry) freed from volatile impurities and water or moisture resulting from the treatment of the gas and / or washing liquid with the impurities from the moist inert gas (TGwet);in particular wherein the discharge means (6) is designed as a direct and / or indirect connection, in particular via the second feed means (3), of the recycling device (T) and the cleaning and / or drying device (K) and / or in particular wherein the discharge means (6) is designed as a transport line for dry (dried) inert gas (TGdry) freed from volatile impurities, preferably as a transport line for dry (dried) inert gas (TGdry) freed from volatile impurities and is designed for the direct and / or indirect connection, in particular via the second feed means (3), of the recycling device (T) and the cleaning and / or drying device (K), in particular such that a recycling and / or recirculation of the inert gas (TGdry, TGwet) takes place;and / or in particular wherein the discharge means (7) is designed as a connection between the recycling device (T) and the washing device (W) and / or in particular wherein the discharge means (7) is designed as a transport line for water or moisture resulting from the treatment of the inert gas and / or washing liquid with the volatile impurities from the moist inert gas (TGfeucht), in particular as a transport line for water or moisture resulting from the treatment of the gas and / or washing liquid with the volatile impurities from the moist inert gas (TGfeucht) and for connecting the; Recycling device (T) and the washing device (W), in particular such that recycling and / or circulation of water or moisture resulting from the treatment of the gas and / or washing liquid with the volatile impurities from the moist inert gas (TG moist) takes place.

46. Device according to one of the preceding claims, wherein the device is designed to carry out a method according to one of the preceding method claims.

47. Device according to one of the preceding claims, characterized by one or more of the features of the method claims (claims 1 to 30).

48. Production plant for the production of aliphatic or cycloaliphatic nitrate esters (nitric acid esters), the production plant comprising: (i) a nitration device (PNE), in particular with one or more reaction vessels (nitration reactors), for carrying out the nitration, in particular for producing aliphatic or cycloaliphatic nitrate esters (nitric acid esters), preferably from mono- or polyhydric aliphatic or cycloaliphatic alcohols, preferably by means of an adiabatic or isothermal nitration; (ii) optionally arranged in the production line downstream and / or downstream of the nitration device (PNE), a separation device, in particular a separator, in particular for separating nitrating acid from nitrated crude products (crude nitric acid esters); (iii) arranged in the production line downstream and / or downstream of the nitration device (PNE) and the optionally present separation device, at least one washing device (W) for washing crude nitrate esters (NE) obtained from a manufacturing process and / or originating from a production device (PNE) rO h) with a washing medium with a downstream and / or downstream separation device for separating the washing medium from the washed crude nitrate esters (N Efeucht); (iv) arranged in the production line downstream and / or downstream of the washing device (W), at least one cleaning and / or drying device (K), in particular a column, for drying and / or purifying, in particular drying and purifying, the washed crude nitrate esters (NE moist) obtained from the washing device (W), wherein the cleaning and / or drying device (K) comprises a first feed means (2), arranged in particular in an upper region (KK), in particular the column head, of the cleaning and / or drying device, for introducing and / or feeding the washed crude nitrate esters (N E moist) into the cleaning and / or drying device (K), and a first feed means (2), arranged in particular in a lower region (KS), in particular the column bottom,the cleaning and / or drying device (K) comprises a second supply means (3) for introducing and / or supplying a dry inert gas (TGdry) into the cleaning and / or drying device (K), wherein the cleaning and / or drying device (K) comprises means for bringing the washed crude nitrate esters (NEdry) into contact, in particular for flowing through, with the dry inert gas (TGdry), in particular wherein the means for bringing them into contact, in particular for flowing through, are designed in such a way,that water present in the washed crude nitrate esters (N Efeucht) is removed and, at the same time and / or simultaneously, volatile impurities arising in particular during the production and / or washing of the nitrate esters are removed to obtain the dry (dried) nitrate esters (N Etrocken) freed from volatile impurities; downstream in the process direction and / or downstream of the cleaning and / or drying device (K), (v) in the production line downstream and / or downstream of the cleaning and / or drying device (K), in particular column, at least one recycling device (T) for recycling and / or circulating the inert gas (TG dry, TG moist), wherein the recycling device (T) comprises separation means for separating water or moisture and the volatile impurities, in particular a condenser and / or gas scrubber or a A combination thereof, in particular wherein the separation means are designed such that water or moisture and the volatile impurities are separated from the moist inert gas (TG moist), in particular by means of condensation and / or scrubbing, preferably condensation and scrubbing, to obtain a dry (dried) inert gas (TG dry) freed from volatile impurities; in particular wherein the recycling device (T) also comprises a third feed means (5), arranged in particular between the upper region (KK), in particular the column head, the cleaning and / or drying device (K) and the recycling device (T), for introducing and / or feeding and / or transporting the moist inert gas (TG moist), in particular laden with water and / or the volatile impurities, from the cleaning and / or drying device (K) into the recycling device (T).

49. Production plant for the production of aliphatic or cycloaliphatic nitrate esters (nitric acid esters), in particular production plant according to claim 48, wherein the production plant comprises: (i) a nitration device (PNE), in particular with one or more reaction vessels (nitration reactors), for carrying out the nitration, in particular for producing aliphatic or cycloaliphatic nitrate esters (nitric acid esters), preferably from mono- or polyhydric aliphatic or cycloaliphatic alcohols, preferably by means of an adiabatic or isothermal nitration; (ii) optionally arranged in the production line downstream and / or downstream of the nitration device (PNE), a separation device, in particular a separator, in particular for separating nitrating acid from nitrated crude products (crude nitric acid esters); (iii) arranged in the production line downstream and / or downstream of the nitriding device (PNE) and the optionally present separation device, a device according to one of the preceding claims (claims 31 to 47).

50. Production plant according to claim 48 or claim 49, wherein the production plant is designed to carry out a method according to one of the preceding method claims (claims 1 to 30).

51. Production plant according to one of the preceding claims, characterized by one or more of the features of the method claims (claims 1 to 30) and / or the device claims (claims 31 to 47).

52. Use of an inert gas for drying and / or purifying, preferably drying and purifying, crude aliphatic or cycloaliphatic nitrate esters (nitric acid esters) obtained from a manufacturing process, in particular for removing water and volatile impurities arising in particular during the manufacturing and / or washing of the nitrate esters.

53. Use of an inert gas for drying and / or purification, preferably drying and purification, of Production process obtained from aliphatic or cycloaliphatic crude nitrate esters (nitric acid esters), in particular for removing water and volatile impurities arising in particular during production and / or washing of the nitrate esters, by bringing the aliphatic or cycloaliphatic crude nitrate esters into contact, in particular by flowing through, with the inert gas, in particular in such a way that water present in the washed crude nitrate esters is removed and at the same time and / or as it were, volatile impurities arising in particular during production and / or washing of the nitrate esters are removed.

54. Use according to claim 52 or claim 53, wherein (a) first, the crude nitrate esters obtained from a manufacturing process are subjected to washing with a washing medium, followed by separation of the washing medium, and (b) the washed crude nitrate esters obtained in this way are subsequently subjected to drying and / or purification, preferably drying and purification, by bringing them into contact, in particular by flowing through, with an inert gas, in particular in such a way that water present in the washed crude nitrate esters is removed and, at the same time and / or simultaneously, volatile impurities arising in particular during the production and / or washing of the nitrate esters are removed.

55. Use of an inert gas for drying and / or purification, preferably drying and purification, in a process according to one of the preceding process claims and / or in a device according to one of the preceding device claims and / or in a production plant according to one of the preceding plant claims.

56. Use according to one of the preceding claims, characterized by one or more of the features of the method claims (claims 1 to 30) and / or the device claims (claims 31 to 47) and / or the production plant claims (claims 48 to 51).

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