Method and apparatus for drying and / or purifying nitrate esters

Abstract

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, especially those arising during the production and / or washing of the nitrate esters, wherein the process comprises the following process steps: (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; (b) subsequently, the washed crude nitrate esters obtained in process step (a) are subjected to drying and / or purification, preferably drying and purification, by contact, in particular by flowing, with an inert gas, in particular such thatthat water present in the washed crude nitrate esters is removed and, at the same time and / or in the same way, volatile impurities arising in particular during the production and / or washing of the nitrate esters are removed.

Description

The present invention relates to the technical field of the production and in particular the drying and / or (re-)purification of aliphatic and cycloaliphatic nitrate esters (nitric acid esters) for the purpose of providing dry or anhydrous and pure nitrate esters. In particular, the present invention relates to a process for drying and / or purifying aliphatic or cycloaliphatic nitrate esters (nitric acid esters), especially for removing water and volatile impurities, particularly those arising during the production and / or washing of the nitrate esters. 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 manufacturing aliphatic or cycloaliphatic nitrate esters (nitric acid esters). 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. Aliphatic and cycloaliphatic organic nitrate esters (nitric acid esters) are reaction products of corresponding aliphatic and cycloaliphatic alcohols and nitric acid. Nitrate esters are generally produced in a continuous plant by reacting the alcohol with nitric acid, either 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 Nielsen and Brunnberg NAB process, 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, as a mixture, or in solution in inert, water-immiscible solvents. Organic nitrate esters are primarily known from the explosives industry (e.g., nitroglycerin, ethylene glycol dinitrate, etc.), but also from the pharmaceutical industry (e.g., nitrate esters of steroid alcohols, etc.) and 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 to increase the cetane number of diesel fuels. Other common nitrate esters include pentaerythritol tetranitrate (PETN), glyceryl trinitrate (NGL), and ethylene glycol dinitrate (EGDN). The cetane number is a value that describes the ignitability of diesel fuel: the higher the cetane number, the more readily the fuel ignites. The more unbranched hydrocarbon molecules the fuel contains, the more readily it ignites, which is a desirable characteristic, especially in diesel engines. Fuel with a lower cetane number tends to make a compression-ignition engine (diesel engine) more difficult to start and may run noisier when cold. Conversely, fuel with a higher cetane number tends to lead to easier cold starts, lower engine noise, and a reduction in white smoke ("cold smoke") caused by incomplete combustion. 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 stipulate a minimum cetane number. Accordingly, many diesel fuel compositions 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 properties. The most commonly used ignition enhancer additive for diesel fuels is probably 2-ethylhexyl nitrate (EHN). It primarily reduces the ignition delay of the fuel to which it is added. Crude nitrate esters obtained from the aforementioned manufacturing processes must undergo a multi-stage washing and additional purification process before their use, e.g., as ignition enhancers, or before further processing. This is necessary to remove impurities dissolved or suspended in the crude nitrate esters, such as sulfuric acid, nitric acid, nitrose gases, etc., as well as byproducts from the oxidative degradation of the starting alcohols. This also improves the stability of the nitrate esters, which are largely highly sensitive explosives. Generally, the washing of crude nitrate esters to remove dissolved and suspended acids from the nitrating mixture and other acidic or otherwise extractable impurities consists of three steps: an acidic wash, a basic or alkaline wash, and a neutral wash (see, e.g., BT Urbanski, Vol. 2, pp. 97 ff., especially Figs. 43, 44, 59, and 60, Pergamon Press, Reprint 1985). However, washing the crude nitrate esters directly with, for example, a soda solution, i.e., omitting the acidic wash step, is also sometimes practiced and is considered state of the art. Water is usually used as the washing medium. The washing is generally carried out as a liquid-liquid wash with the nitrate esters, which are generally liquid at washing temperature, or as a solution of the same in a suitable solvent. When washing crude nitrate esters using the described liquid-liquid extraction process, primarily only those impurities are washed out that have high solubility in the washing medium (such as sulfuric acid and nitric acid), or that disproportionate with water to form nitric acid in the aqueous medium, or that form salts with the bases added during alkaline or basic washing, such as strong acids, especially sulfuric acid and nitric acid, and medium-strength 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 concentrations of these impurities. It has also been shown that other impurities, in particular impurities with unfavorable distribution coefficients in relation to the washing medium, or impurities with weak or no acidity, or impurities with a slow conversion rate into substances that do not dissolve in the organ phase, often cannot be completely removed in the washing process in one or more steps and / or only with great technical effort. Higher water contents in the nitrate esters obtained from the washing process, whether heterogeneously or homogeneously distributed, are generally undesirable because they can negatively affect the properties of the nitrate ester product. This is reflected in the specification data for nitrate esters, with the common specification for the water content in ethylhexyl nitrate being set at a maximum of 0.05%, because otherwise the product exhibits a turbidity 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. Methods are known from the prior art which, among other things, involve the drying of nitrate esters. For example, Chinese patent application CN 1903829 A describes a process for the production and drying of isooctyl nitrate. The drying process comprises the following steps: Raw isooctyl nitrate is first separated from water by sedimentation and phase separation; the resulting isooctyl nitrate, still containing small amounts of water, is then passed over a series of layers or trays of anhydrous sodium sulfate for drying. A disadvantage of the process is that sodium sulfate must be regularly and costly regenerated by thermal treatment or, if necessary, completely replaced. Furthermore, sodium sulfate can only remove water from the isooctyl nitrate; it cannot reduce other volatile impurities. In addition, the drying capacity of sodium sulfate is not high enough to achieve very low water contents in the final product.Furthermore, the process must be carried out in two stages using separate apparatus for each stage, which entails considerable effort. The process is also relatively expensive and time-consuming. The German patent application EP 1 792 891 A1 relates to a process for the production of nitric acid esters of monohydric alcohols, wherein a monohydric alcohol or a mixture of monohydric alcohols is reacted with nitric acid in the presence of sulfuric acid. In the synthesis of the nitric acid ester of 2-ethylhexan-1-ol according to the examples, a washing step with water is carried out after the reaction. After the three-stage washing with water (acidic wash), alkali (basic wash), and water (neutral wash), a product is obtained with a content of 99.5% of the nitric acid ester, which still contains 0.4% impurities, mainly 2-ethylhexan-1-ol and other by-products. US patent 4,327,184 A relates to a device for removing or extracting alcohol from a fermentation broth using a carrier gas. The carrier gas is recycled and can be dried by condensation. Chinese patent application CN 1031525 A describes a manufacturing process for isooctyl nitrate in which the resulting product is dried under vacuum. While this method can remove volatile or volatile impurities, vacuum drying processes are very complex in terms of equipment and energy consumption, and often do not allow for the adequate drying of large quantities of product. Small amounts of water cannot be easily removed either. Furthermore, vacuum drying often results in a significant loss of product. Finally, Chinese patent CN 101696168 B describes a process for producing isooctyl nitrate in which the resulting product is dried by passing it over columns containing silica gel or a molecular sieve. Impurities and water are absorbed from the isooctyl nitrate by the silica gel or molecular sieve. However, a disadvantage of this method is that the column material must be regularly regenerated or replaced, which is particularly complex and excessively time-consuming, costly, and labor-intensive for large-scale production. Furthermore, column regeneration usually requires high temperatures, which, especially given the common presence of residual nitrate esters, can lead to a fire and / or explosion hazard. Therefore, this method is also unsuitable for large-scale industrial production. The methods known from the prior art for drying nitrate esters are therefore particularly complex and excessively time-consuming, costly, and labor-intensive for large-scale production, and often do not lead to the desired results. Furthermore, these prior art methods do not allow for the removal of volatile impurities. Overall, the state of the art still shows a need for manufacturing and, in particular, purification and drying processes for organic, preferably aliphatic and cycloaliphatic nitrate esters, which are efficient with regard to the achievable drying performance and at the same time designed in such a way that as little equipment effort as possible and little effort with regard to process control is required. Against the background of the prior art described above, the present invention is therefore based on the objective of providing a drying and / or purification process for aliphatic or cycloaliphatic organic nitrate esters and a corresponding device or (production) plant, whereby the aforementioned disadvantages of known processes or known devices and (production) plants of the prior art are to be avoided or at least mitigated. In particular, the present invention is based on the objective 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 apparatus compared to the known prior art. In a completely unexpected manner, the applicant has now discovered that, based on the inventive concept underlying the present invention, in particular by means of the inventive process for drying and / or purifying, preferably drying and purifying, aliphatic or cycloaliphatic nitrate esters (nitric acid esters) and the corresponding apparatus or (production) plant, a very efficient and resource-saving treatment concept for nitrate esters can be provided, which yields equally purified or pure nitrate esters with degrees of drying and / or purity that are, in particular, significantly lower than those of the prior art, and especially that water present in the washed crude nitrate esters is removed (i.e.,(the washed crude nitrate esters are dried) and simultaneously and / or in particular during the production of the nitrate esters, volatile and / or volatilizable impurities are removed. To solve the problem described above, the present invention proposes – according to a first aspect of the present invention – a method 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, especially those arising during the production and / or washing of the nitrate esters, according to claim 1. Advantageous further developments and embodiments of this aspect of the invention are the subject of the corresponding dependent claims. A further object 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, especially those arising during the production and / or washing of the nitrate esters, preferably by contacting, in particular by flowing, an inert gas, in particular a device for carrying out the process according to the inventive method, according to the corresponding independent claim. Advantageous further developments and embodiments of this aspect of the invention are the subject of the corresponding dependent and subclaims. Furthermore, according to a third aspect of the present invention, a production plant for the manufacture of aliphatic or cycloaliphatic nitrate esters (nitric acid esters) is related to the independent claim. Advantageous further developments and embodiments of this aspect of the invention are the subject of the dependent claims. Finally, the subject matter of the present invention – according to a fourth aspect of the present invention – is the use according to the invention as described in the relevant independent claims. Advantageous further developments and embodiments of this aspect of the invention are the subject matter of the relevant dependent claims. It goes without saying that any embodiments, designs, advantages and the like, which are listed below for the purpose of avoiding repetition only with regard to one aspect of the invention, naturally also apply to the other aspects of the invention without the need for separate mention. 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 deviations from the specified range or specifications are possible in individual cases or depending on the application, without leaving the scope of the present invention. Furthermore, it should be noted that all values ​​or parameters mentioned below, or the like, can generally be determined using standardized or explicitly specified determination methods, or using determination methods that are generally familiar to those skilled in the field. Furthermore, it should be noted that for all relative or percentage-based quantity specifications mentioned below, especially those related to weight, these specifications must be selected or combined by a person skilled in the art in such a way that the total always results in 100% or 100% by weight, possibly including further components, ingredients, additives, or constituents, particularly as defined below. This is self-evident to a person skilled in the art. Furthermore, for the purposes of describing the present invention, the features of the present invention cited in connection with specific embodiments, configurations, advantages, examples, or the like are also considered disclosed in combination. Thus, higher-order combinations of individual or multiple features cited for specific embodiments, configurations, application examples, or the like are also considered disclosed. In particular, with regard to the features characterizing the invention, all possible combinations of these features shall be deemed disclosed, with embodiments of comparable or corresponding preference of the various features in their combination being preferred (e.g. quantities or quantity ranges of the relevant parameters of the same preference or the like). It is particularly important to note that for the following information relating to the various parameters of the inventive method or the like, all combinations of the same preference or level of preference, including those relating to the different parameters, are also disclosed. Likewise, all other combinations (i.e., combinations based on different preferences or levels of preference) are also disclosed. Having stated the above, the present invention will now be explained in detail below: The subject matter of the present invention – according to a first aspect of the present invention – is a method 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, volatile impurities that arise during the production and / or washing of the nitrate esters, wherein the method comprises the following process steps: (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; (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,subjected to 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 simultaneously and / or similarly, volatile impurities arising in the production and / or washing of the nitrate esters are removed. Within the scope of the present invention, a particularly efficient, especially 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. The high efficiency of the process according to the invention is particularly evident in the fact that it can produce exceptionally high-quality purified or dried nitrate esters, especially those characterized by a very high degree of purity and an extremely low moisture or water content remaining after the process. This exceptional quality, in terms of particularly high purity and near-complete absence of moisture or water in the nitrate esters, is directly attributable to the process according to the invention, particularly to process step (b) for drying or purifying the nitrate esters by contacting, and especially by flowing, an inert gas through them. Within the scope 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 obtained from a manufacturing process and which have already undergone a washing step. The result of the purification is purified nitrate esters, i.e., free of foreign substances or impurities, which can thus also be considered pure nitrate esters. The result or objective of the purification within the meaning 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 low ppm range. It is therefore advantageous within the scope of the present invention to achieve particularly low levels or proportions of especially volatile impurities in the purified nitrate esters, which cannot be achieved in this way with methods known from the prior art, 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 specific process parameters within the scope of the present invention. In particular, the present invention yields nitrate esters of such purity that they can be considered essentially free of impurities, especially volatile ones, particularly since purified nitrate esters with a concentration of impurities, especially volatile ones, in the range of at most 100 ppm, preferably at most 30 ppm, and most preferably at most 10 ppm, can be produced. This is generally not possible with known processes of the prior art. Within the scope of the present invention, nitrate esters that are essentially free of volatile impurities can be obtained on the basis of the inventive method, especially in contrast to methods known from the prior art or available for the purification of nitrate esters. Furthermore, drying in connection with the inventive process means that traces of moisture or, in particular, of water remaining in the washed nitrate esters from the washing medium are largely or at least substantially completely removed from the nitrate esters obtained with the inventive process. 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 that cannot be achieved with conventional methods or processes known from the prior art, or only with considerable and therefore impractical effort. Thus, within the scope of the present invention, and in particular as a result of the inventive method and especially the inventive process flow, at least substantially completely dry nitrate esters, i.e., nitrate esters free of moisture or water, for example from the washing medium, can be obtained, especially in contrast to methods for drying nitrate esters known from the prior art. In particular, "substantially dry" or "absolutely dry" or "free of moisture or water" within the scope of the present invention refers to nitrate esters purified or dried with a water content in the range of, in particular, 0.025 wt.% or less. Furthermore, volatile or volatilizable impurities within the scope of the present invention are understood to be substances or compounds that are volatile or exhibit volatile behavior, particularly under the specific process conditions. Volatility is a material property that describes, in particular, evaporation or the tendency to evaporate (i.e., the tendency of a substance to change from the liquid to the gaseous state without reaching its boiling point). The physical (distribution) equilibrium between the gas and liquid phases, as well as the partial or vapor pressures of the substances or compounds in question, can also play a role or be considered in this context. 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, also by contrasting it with the vapor pressure of a reference substance. Within the scope of the present invention, the term "volatile compounds" also includes compounds that become or are volatile under the process conditions, i.e., specifically those that are or become volatile under the specific process conditions, irrespective of the volatility of these substances under pure or isolated standard conditions. This is particularly justified by the fact that, within the scope of the present invention, it is provided that volatile impurities are washed or driven off from nitrate esters by contact with the inert gas. These process conditions are associated with a continuous or constant saturation of the gas phase (the inert gas) with liquid at a comparatively low level, so that the tendency of a substance to volatile under the process conditions of the process according to the invention is inherently increased. A significant advantage of the present invention, and in particular of the inventive method, is that purified or dried nitrate esters can be obtained which are characterized by a significantly improved quality with regard to purity and / or dryness or freedom from moisture and / or water of the nitrate esters compared to previously achievable degrees of dryness or purity. In particular, the process according to the invention makes it possible to provide purified or pure nitrate esters containing a proportion of impurities, especially volatile ones, in the very low ppm range, particularly at most 100 ppm, preferably at most 30 ppm, and most preferably at most 10 ppm. With methods available from the prior art, this has so far only been possible with extremely high and therefore uneconomical effort, or ultimately not at all, and certainly not in an efficient manner. It is also advantageously possible with the method 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. In particular, the inventive method makes it possible to dry nitrate esters to such an extent that moisture or water contents in the 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. Within the scope of the present invention, it can be particularly advantageous to achieve a cloud point below 0 °C in the dried nitrate esters, which corresponds to a residual moisture content or a proportion of moisture and / or water 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 involves an improvement in the ignition properties of a corresponding fuel mixture at low temperatures, for example in the range of 0 °C or below. 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, especially within the scope of the process according to the invention and specifically due to the specific process flow of the process according to the invention, drying or purification of crude nitrate esters previously washed with a washing medium in a washing step can be carried out in a manner requiring little equipment, by bringing the washed crude nitrate esters into contact with an inert gas, in particular by flowing through it. Bringing the crude nitrate esters into contact with, or in particular by flowing through it, an inert gas allows for purification or drying of the crude nitrate esters using very few auxiliary materials or process components. This advantageously results in an extremely streamlined process with regard to the process components used in the process according to the invention.-media is a streamlined process reduced in complexity. This lean, rigorous process design also has a direct advantage in terms of process engineering and equipment, as it allows the use of a device and a production plant that are structurally simpler in complexity compared to prior art devices and plants for drying or purifying nitrate esters. This advantageously results in increased process reliability and continuity while simultaneously improving product quality. Furthermore, since the process according to the invention requires only very few process components or media (a washing medium in process step (a) and inert gas as a drying or purification medium in process step (b)), resource-saving work can be carried out. According to a further, particular advantage of the present invention, the process according to the invention also allows for the recycling or recirculation of the inert gas used in the drying and / or purification step (b). Within the scope of the present invention, it is therefore advantageously possible to reuse the inert gas in the process according to the invention after it has flowed through or come into contact with the nitrate esters to be purified, and in particular to use it again in process step (b). For this purpose, it has proven advantageous to carry out an intermediate drying of the inert gas, which can be integrated into the concept according to the invention in a straightforward manner from an equipment perspective and in a process-technical manner. It is therefore advantageous within the scope of the present invention to dry and regenerate inert gas that has absorbed moisture or water from the previously washed crude nitrate esters to be purified or dried in a downstream drying step, thus enabling the inert gas to be recirculated or recycled. This allows for particularly resource-efficient operation within the scope of the present invention. Likewise, it is advantageous within the scope of the inventive process to also feed moisture or water separated from the inert gas back into the process, in particular back into the washing medium of the washing step. This allows for economically and ecologically efficient operation, even with regard to the washing medium, when washing crude nitrate esters obtained from a manufacturing process. The present invention, particularly within the framework of the inventive method, thus provides not only 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-efficient and therefore environmentally friendly manner. Furthermore, since the process according to the invention can be implemented with comparatively little equipment or with process-related lean and stringent devices or production plants, the present invention is characterized by high efficiency, which is expressed in particular in the uncomplicated handling of the process according to the invention while simultaneously achieving high effectiveness of the process according to the invention in terms of achieving a high purity and dryness of the process product. In particular, the present invention provides a cleaning and drying process for organic, preferably aliphatic and cycloaliphatic nitrate esters, which is efficient with regard to the achievable drying performance and at the same time is designed in such a way that as little equipment effort as possible and little effort with regard to process control is required. 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, whereby the aforementioned disadvantages of known processes or known devices and (production) plants of the prior art are avoided or at least mitigated. 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 apparatus compared to the known prior art. As previously explained, to solve the problem described above, 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 during the production and / or washing of the nitrate esters, is provided, wherein the process comprises the following process steps: (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; (b) subsequently, the washed crude nitrate esters obtained in process step (a) are subjected to drying and / or purification, preferably drying and purification, by contact, in particular by flowing, an inert gas, in particular such that...that water present in the washed crude nitrate esters is removed (i.e., the washed crude nitrate esters are dried) and simultaneously and / or similarly, 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 converted within the scope of the present invention, it has proven advantageous if the nitrate esters are liquid and / 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). 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, according to the invention, the nitrate esters are selected from (i) nitrate esters of aliphatic or cycloaliphatic alkanols, especially linear or branched aliphatic or cycloaliphatic alkanols, preferably hexanols, heptanols, octanols, ethylhexyl alcohol, and cyclohexanol; (ii) nitrate esters of aliphatic alkanediols, especially 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, especially trimethyl olethane, trimethylolpropane, butanetriols, and glycerol. (iv) Nitrate esters of tetravalent or polyvalent aliphatic alkanols. Advantageously, within the scope of the present invention, a large number of different nitrate esters can be efficiently and effectively purified or dried, so that the inventive method is very flexible and can be used for many different nitrate esters. In addition to its applicability to a wide range of nitrate esters, the present invention also advantageously enables the effective and highly effective removal of a large number of different, particularly volatile, impurities that generally arise during the production of nitrate esters. The fact that the inventive method can effectively remove the wide range of impurities, particularly volatile ones, described in more detail below, from the nitrate esters further underscores the advantageous high flexibility and broad applicability of the inventive method. Likewise, the process according to the invention is advantageously characterized by the fact that nitrate esters of a particularly high purity or quality can be obtained, in particular by the fact that the impurities, especially volatile ones, which are generally introduced into the nitrate esters during their production and / or washing, 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. The process according to the invention yields particularly good results when the volatile or volatilizable impurities are selected from the group consisting of (i) unreacted and / or partially reacted starting materials 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) nitrogenous bases, in particular ammonia (NH3); (vii) nitrogen oxides, in particular nitric oxide (NO), nitrogen dioxide (NO2) and dinitrogen oxide (N2O) as well as nitroses and other nitrogen oxides (NOx); (viii) carbon oxides, in particular carbon monoxide (CO) and carbon dioxide (CO2); (ix) solvent and / or washing medium residues. 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, especially with regard to the vapor pressure of the nitrate esters under standard conditions (pressure of 1.013 bar; humidity of 0% [standard conditions according to DIN 1343, STPD]) and / or especially with regard to the boiling point of the nitrate esters under standard conditions (pressure of 1.013 bar; humidity of 0% [standard conditions according to DIN 1343, STPD]). Particularly advantageous is that the volatile or volatilizable impurities to be removed, especially water, have a vapor pressure at least 5 mbar, preferably at least 7.5 mbar, preferably at least 10 mbar, higher than that of the nitrate esters to be purified. It has also proven advantageous if the volatile or volatilizable impurities to be removed have a boiling point that is at least 1 °C, preferably at least 2.5 °C, preferably at least 5 °C lower than that of the nitrate esters to be purified. Regarding the implementation of the process according to the invention, it has proven advantageous with respect to process step (a) if process step (a) and / or the washing are carried out as liquid-liquid extraction. In process step (a) carried out as liquid-liquid extraction, a large proportion of the water-soluble, and in particular volatile, impurities resulting from the production of the nitrate esters can be efficiently and easily removed from them. In this sense, a process step (a) carried out as a liquid-liquid extraction advantageously contributes to washing out the majority of non-volatile or non-volatile 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 an advantageous contribution to the overall high purity achievable for nitrate esters obtained from the process according to the invention. Furthermore, for process step (a), it has proven advantageous 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, the removal of water-soluble or inorganic by-products or reactant residues from the crude nitrate esters obtained from the manufacturing process can be achieved almost completely within the scope of process step (a). 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, and 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 configuration additionally contributes to a particularly thorough purification of nitrate esters within the framework of 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 with an aqueous-based washing medium; in particular, wherein the aqueous-based washing medium is neutral, acidic, or basic (alkaline). Besides good washing performance, the use of aqueous-based washing media guarantees efficient separation of the washing medium from the 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 after the washing step or the washing with the washing medium. It has proven to be very effective and therefore advantageous if process step (a) and / or the washing is carried out in at least two, in particular three, washing stages. Furthermore, the washing stages advantageously comprise at least one basic (alkaline) washing stage and a final neutral washing stage, preferably wherein the washing stages include a first acidic washing stage, a subsequent second basic (alkaline) washing stage, and a final third neutral washing stage. Furthermore, it has proven advantageous within the framework of the inventive process if process step (a) and / or the washing, particularly in each washing stage, is carried out in cross-flow or counter-flow or in a combination of cross-flow and counter-flow. Preferably, this is done with recycling of the washing medium. Furthermore, according to the invention, it is preferred if in process step (a) the separation of the washing medium is carried out by means of a separating device (separator), in particular by means of a static separating device, or by means of a centrifugal separator. As regards 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 cleaning device, preferably a drying and cleaning device. Preferably, the washed crude nitrate esters obtained in process step (a) are transferred in process step (b) to a drying and / or cleaning device, preferably a drying and cleaning device. According to the invention, the drying and / or cleaning device has proven advantageous if it comprises, preferably a drying and cleaning device, a column, in particular a single- or multi-stage column, preferably a packed column, screen tray column, bubble-cap 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 cleaning devices advantageously allow, in a particularly efficient manner and in a process engineering perspective, the contact or, in particular, the flow of nitrate esters with an inert gas, as provided for in process step (b). Integration of the aforementioned preferred devices into the process according to the invention, especially also in conjunction with a suitably appropriate apparatus or...The production plant thus advantageously allows for a simplified or, with regard to process efficiency, improved process control. Within the scope 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. 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. A particular and advantageous aspect of the process according to the invention is that the drying and / or purification, preferably drying and purification, of washed crude nitrate esters can be carried out by 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 be a process in which atoms or molecules of a substance, particularly in this case in the form of an impurity present in the washed crude nitrate esters, pass from a liquid in which they are dissolved into the gas phase. In this sense, gas-liquid extraction within the context of the present invention refers to an extraction process in which impurities or foreign substances are dissolved from a liquid phase and pass into the gas phase by contacting, in particular by flowing, a gas through a liquid phase, and in particular, the impurities or foreign substances are carried out of the liquid by the continuous movement of the gas phase, especially in the case of flowing through the liquid. A particular advantage here is that for nitrate esters, which can tend to form explosive mixtures with air or explosive vapors, such purification processes, which involve contacting or, in particular, flowing the nitrate esters through a gas, were not previously available, especially since no process existed that ensured that no explosive gas-nitrate ester mixtures or nitrate ester vapors were generated during such contact or, in particular, flowing of a gas through nitrate esters. In this respect, it is a particular merit of the applicant to have recognized that, especially when using an inert gas, a gas-liquid extract of nitrate esters or...Purification and / or drying of nitrate esters by means of desorption becomes possible, particularly in combination with the other preferred process parameters of the process according to the invention, as already described or further detailed below. According to the applicable aspect, the present invention also includes in particular 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, especially those arising during the production and / or washing of the nitrate esters, in particular as described above, wherein the process comprises the following process steps: (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, wherein process step (a) and / or the washing is carried out as 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 contact, 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 simultaneously and / or as well, in particular during the production and / or washing of the nitrate esters, volatile and / or volatilizable impurities are removed, wherein the drying and / or purification, preferably drying and purification, is carried out as gas-liquid extraction and / or by desorption, in particular as gas-liquid extraction; in particular wherein the volatile and / or volatilizable impurities are selected from the group consisting of (i) unreacted and / or partially reacted starting materials and / or precursor 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) nitrogenous bases, in particular ammonia (NH3); (vii) nitrogen oxides, in particular nitric oxide (NO), nitrogen dioxide (NO2) and dinitrogen oxide (N2O) as well as nitrose and other nitrogen oxides (NOx); (viii) carbon oxides, in particular carbon monoxide (CO) and carbon dioxide (CO2); (ix) solvent and / or washing medium residues; and / or in particular where 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 with respect to the vapor pressure of the nitrate esters under standard conditions (pressure of 1.013 bar; humidity of 0% [standard conditions according to DIN 1343, STPD]) and / or in particular with respect to the boiling point of the nitrate esters under standard conditions (pressure of 1.013 bar; humidity of 0% [standard conditions according to DIN 1343, STPD]). Regarding the execution and design of process step (b), it has proven advantageous within the scope of the present invention to use the washed crude nitrate esters obtained in process step (a) as such in process step (b), and / or to use the washed crude nitrate esters obtained in process step (a) in concentrated and / or undiluted form in process step (b). Advantageously, within the scope of the present invention, and particularly within the scope of the process according to the invention, no additional solvents for washed crude nitrate esters are required 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). According to an alternative, less preferred embodiment, 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, the (additional) solvent can be removed during process step (b). Such an embodiment is suitable if the nitrate esters are already produced in such a solvent. This embodiment is also suitable if solid nitrate esters are to be dried and / or freed from volatile impurities under standard conditions according to DIN 1343, STPD. 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 the purpose of carrying out drying and / or purification, preferably drying and purification. Regarding 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 configured such that it is non-reactive towards the nitrate esters under the conditions of process step (b). In this way, it is advantageously ensured to a large extent that no explosive mixtures of the nitrate esters with the inert gas are generated within the scope of the process according to the invention, thus reliably guaranteeing process safety in particular. According to the invention, it is preferred if 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 their mixtures, in particular air, preferably from the group consisting of nitrogen, oxygen, noble gases, in particular argon, and their mixtures, in particular air, particularly preferably from the group consisting of nitrogen, oxygen and their mixtures, in particular air. Furthermore, it has proven advantageous if, in process step (b), the contacting, in particular the flowing, of the washed crude nitrate esters obtained in process step (a) with the inert gas is carried out in cross-current and / or counter-current flow, preferably in counter-current flow. In this context, it is particularly preferred if the inert gas flows upwards and the nitrate esters flow downwards. This is particularly preferably carried out in a drying and / or purification unit, preferably a drying and purification unit, preferably a column, in particular a single- or multi-stage column, preferably a packed column, screen 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 specific process allows for 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 achievable for purified nitrate esters with the present invention. Furthermore, in process step (b), the contacting, in particular the flowing through, of the nitrate esters with the inert gas is advantageously carried out in a dispersed distribution, particularly a finely dispersed distribution, of the inert gas within the nitrate esters. In this way, a particularly large contact area between the inert gas and the nitrate esters to be purified is advantageously generated. This additionally contributes to a particularly effective mass transfer between the inert gas and the liquid nitrate ester phase, so that a high degree of desorption with respect to the impurities to be removed, especially volatile ones, can be achieved, i.e., a high purity of the nitrate esters themselves. In this sense, it has proven equally advantageous within the scope of the present invention if, in process step (b), the inert gas is introduced into the nitrate ester with and / or in a dispersed distribution, in particular a finely dispersed distribution. This is preferably done by means of nozzles, jet mixers, jet pumps, injectors, lances, sieve trays and / or fine-pored membranes. Furthermore, according to the invention, it is preferably provided that in process step (b) the inert gas is used in dry form. In the context of the present invention, a dry or dried gas (i.e., inert gas in dry form) is understood to be, 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, and more preferably at least 15 °C, below the temperature at which the process step (b) according to the invention is carried out. In this context, it has proven particularly advantageous if the inert gas supplied and / or initially supplied, especially at the beginning 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. Particularly preferably, the inert gas supplied and / or initially supplied, especially at the beginning of process step (b), has a dew point in a range of -20 °C to -80 °C, in particular -30 °C to -65 °C, preferably -35 °C to -55 °C, preferably -40 °C to -50 °C. Inert gases having a dew point in the aforementioned range exhibit ideal absorption properties for the impurities, especially volatile impurities, moisture, or water to be removed from the nitrate esters, within the framework of the inventive process. Equally preferably, the inert gas has a relative humidity in the range of 0 to 95%, particularly 0 to 90%, preferably 0 to 85%, and more 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, within the framework of the process according to the invention. With regard to specific process parameters for process step (b), 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, or the contacting, in particular flowing, with the inert gas is carried out with a volume flow rate 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 rate 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. becomes. Preferably in process step (b) the drying and / or purification, preferably drying and purification, or the contacting, in particular flowing, with the inert gas is carried out with a volume flow of the inert gas in a range of 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, or the contacting, in particular flowing, 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. Advantageously, in process step (b) the drying and / or purification, preferably drying and purification, or the contacting, in particular flowing, 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 of 30 s to 20 min, in particular 1 min to 17 min, preferably 3 min to 14 min, preferably 7 min to 12 min. Within the scope 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 scope of the present invention, or in particular the inventive method, which corresponds to the target parameters preferred for the inventive method with regard to the purity or dryness of the purified or pure nitrate esters obtained. In this sense, the present invention advantageously enables a very efficient and essentially complete or absolute purification or drying of nitrate esters to be achieved relatively quickly or within a relatively short time, which has not been possible in this way in the prior art. Furthermore, within the scope of the present invention, it has proven advantageous if, in process step (b), the drying and / or purification, preferably both drying and purification, or the contact, in particular the flow 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, and more preferably less than 50 mbar. This preferred process condition further ensures that, within the scope of the present invention, and particularly within process step (b) of the process according to the invention, no explosive nitrate ester-inert gas mixtures or explosive nitrate ester vapors can form during the contact, in particular the flow through, of the nitrate esters with the inert gas.This advantageously ensures a high level of process reliability, which can also be maintained efficiently and reliably within the preferred process parameters for the inventive method without further or special measures. In the context of the present invention, it has also proven advantageous if, in process step (b), the drying and / or purification, preferably drying and purification, or the contacting, in particular flowing, with the inert gas is carried out at temperatures above 0 °C, in particular above 5 °C, preferably above 7.5 °C, preferably above 10 °C, and / or at temperatures below 60 °C, in particular below 50 °C, preferably below 40 °C, preferably below 35 °C. Preferably in process step (b) the drying and / or purification, preferably drying and purification, or the contacting, in particular flowing, with the inert gas is carried out at temperatures in a range of 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. Likewise, it has proven advantageous if, in process step (b), the drying and / or purification, preferably drying and purification, or the contacting, in particular flowing, with the inert gas is carried out at atmospheric pressure (normal pressure; 1.01325 bar) or in a vacuum (negative pressure) or at overpressure, preferably at atmospheric pressure. It is preferred that in process step (b) the drying and / or purification, preferably drying and purification, or the contacting, in particular flowing, with the inert gas is carried out at an absolute pressure in the range of 0.1 bar to 3 bar, in particular in the range of 0.3 bar to 1.2 bar, preferably in the range of 0.5 bar to 1.1 bar, particularly preferably at about 1 bar. With regard to the process parameters temperature and pressure, the method according to the invention is advantageously characterized by the fact that it can always be operated in the range of moderate temperatures and without increased pressure load, particularly with respect to a cleaning device in which process step (b) is carried out. This is particularly advantageous with regard to the equipment and design effort required for the method and device. Likewise, operating in the preferred moderate temperature and pressure ranges makes a valuable contribution to providing a comparatively energy-saving and thus environmentally friendly process. 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 particularly volatile impurities in the resulting purified nitrate esters. In this regard, it has proven particularly advantageous if the quantity of inert gas used in process step (b), based on 1 tonne 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; humidity: 0%, i.e., 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, preferably 8 to 70 standard cubic meters. Likewise, within the scope of the present invention, it has proven advantageous if the quantity of inert gas used in process step (b), based on 1 tonne of nitrate ester to be purified and calculated as the quantity and / or weight of the inert gas under standard conditions (pressure: 1.013 bar; humidity: 0%, i.e., 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, preferably 10 to 40 kg. Advantageously, within the scope of the present invention, it is achieved in particular 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.%, preferably at most 0.01 wt.%, based on the nitrate esters. 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 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.%, preferably in the range of 0.0005 to 0.01 wt.%, based on the nitrate esters. 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, in particular volatile, impurities of at most 100 ppm, in particular at most 30 ppm, preferably at most 25 ppm, more preferably at most 20 ppm, preferably at most 10 ppm. Particularly preferably, the nitrate esters, after drying and / or purification, preferably drying and purification, have a content of, in particular volatile, impurities in the range of 0.001 to 100 ppm, particularly in the range of 0.001 to 30 ppm, preferably in the range of 0.001 to 25 ppm, more preferably in the range of 0.002 to 20 ppm, preferably in the range of 0.005 to 10 ppm. 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 which, in this sense, especially in contrast to nitrate esters obtained by purification or drying processes according to the prior art, can be understood or defined as being essentially free of, in particular, volatile impurities and essentially free of water or moisture. In particular, the method according to the invention makes it advantageously possible to provide nitrate esters that achieve a cloud point below 0 °C, i.e., a moisture content of less than 0.02 wt% moisture or water. Such low moisture levels can only be achieved with conventional methods from the prior art at a significantly higher cost and are therefore hardly economical or practical. Likewise, the present invention makes it advantageously possible to provide nitrate esters that contain a proportion of impurities, particularly volatile ones, preferably no more than 10 ppm. Overall, the process according to the invention advantageously provides a highly efficient method for drying or purifying nitrate esters, while simultaneously realizing a streamlined process that is reduced in complexity and thus susceptibility 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. As regards the inert gas, particularly in relation to the process step after the inert gas has been passed through or brought into contact with the washed crude nitrate esters and has accordingly absorbed moisture or water, it is preferably provided 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 moisture of 50% or more, in particular 65% or more, preferably 75% or more, preferably 80% or more, and particularly preferably 90% or more, based on a gas temperature of 20°C to 30°C. Within the framework 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 is particularly advantageous in that a very high degree of drying of the nitrate esters can be achieved in process step (b), especially within relatively short residence times of the nitrate esters in the presence of the inert gas, as well as a high degree of desorption with respect to, or in relation to, the volatile impurities contained in the crude nitrate esters to be purified or dried. This aspect further highlights the particular efficiency of the process according to the invention. With further regard to the process for the process according to the invention, in particular within the scope of process step (b), it has proven advantageous within the scope of the present invention if the dried and / or purified, preferably dried and purified, nitrate esters obtained after process step (b) are obtained separately and / or separated from the inert gas and / or collected. In this context, it is particularly intended 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 according to process step (b) from the inert gas. Furthermore, at this stage of the process according to the invention, i.e., in particular after the execution of process step (b) has been carried out or completed, it is preferably provided that the inert gas after process step (b) is recycled and / or recirculated. The recycling or recirculation of the inert gas after process step (b) is carried out in particular after and / or during drying and purification of the inert gas. Within the framework of this process control for the inventive method, a significant reduction in the consumption of the process medium can advantageously be achieved, which also increases the cost efficiency of the method and facilitates the utilization or disposal of process chemicals or components. In this respect, the possibility that, within the scope of the present invention, the process medium can be recycled in process step (b), i.e., the inert gas, represents a significant advantage of the process according to the invention compared to the prior art. In this respect, 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, within the scope of the present invention, it has proven advantageous if the inert gas obtained and / or separated according to process step (b), in particular inert gas loaded with water or moisture and especially volatile impurities, is transferred to a recycling device for the treatment of the gas. Preferably, there is a temperature gradient between the drying and / or cleaning unit in which process step (b) is carried out and the recycling unit for treating the inert gas loaded with water or moisture and, in particular, volatile impurities. The temperature gradient is designed such that the recycling unit operates at a lower temperature than the drying and / or cleaning unit or as provided for in process step (b). Preferably, there is a temperature gradient decreasing in the process direction from the drying and / or cleaning unit to the recycling unit. In particular, the temperature gradient between the drying and / or cleaning unit and the recycling unit 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 therefore 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). It has also proven advantageous 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 within the limits of process step (b). The temperature gradient between the drying and / or cleaning device and the recycling device is therefore particularly preferably a difference in the range of 5 °C to 30 °C, in particular 10 °C to 25 °C, preferably 13 °C to 22 °C, preferably 15 °C to 20 °C, or the temperature during the treatment of the gas is therefore advantageously in the range of 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). In this context, the inert gas is subjected in particular to treatment to remove water or moisture and, especially, volatile impurities. This treatment is preferably carried out by means of condensation and / or scrubbing, more preferably condensation and scrubbing. Furthermore, the treatment is preferably carried out at temperatures lower than the temperature in process step (b). To carry out the treatment, in particular by means of condensation and preferably to adjust 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, especially for cooling the recycling device in which the treatment of the inert gas takes place. 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 for the rapid drying of the inert gas in a time-efficient and process-technically uncomplicated manner, and thus its reintroduction into the process according to the invention. In particular, the treatment of the gas laden with water or moisture and especially volatile impurities in a recycling device comprising, and especially consisting of, a condenser enables the efficient separation of moisture or water from the gas, so that a high degree of purification and, in particular, a high degree of drying of the inert gas can be achieved with comparatively little process-technical and time expenditure. Advantageously, the volatile or...Volatile impurities in the separated moisture or water phase. In this way, it can also be advantageously achieved that, for example, harmful impurities, especially volatile ones, dissolved from the nitrate esters by 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 to recycle the treated inert gas in process step (b). The inert gas treated as described above exhibits more than sufficient dryness and purity to be reintroduced into the process, i.e., recycled, over a multitude of process cycles and reused for the purification and drying of crude nitrate esters, thus saving process medium and enabling efficient and resource-conserving operation. Similarly, 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 washing medium obtained is recycled, particularly after processing and / or purification. Preferably, the condensate resulting from the treatment of the inert gas is recycled and / or fed back into the washing process of step (a). By preferably providing, within the scope of the present invention, to recycle and recirculate 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 perspective with regard to consumed process media. This aspect, in addition to the particularly high-quality purified and / or pure nitrate esters accessible with the process according to the invention, represents a significant advantage of the present invention, especially given that it is a common endeavor in the prior art to design large-scale production and purification processes in an ecologically and economically efficient, gentle, and therefore valuable manner. This is made possible by the process according to the invention. Furthermore, by allowing condensate or moisture collected from purified inert gas to be recycled back into process step (a), the present invention makes it possible to both save on washing medium and, in particular, to significantly minimize the slip of process product, i.e., purified or pure nitrate esters. In particular, the preferred method according to the invention allows for the recovery of fractions of nitrate esters to be purified that may be entrained with the inert gas during the drying and purification of the inert gas, for example, by allowing them to pass into the condensate phase in the condenser and thus be collected, or by washing them out in the gas scrubber.Nitrate esters released from the gas in this way can then be added back to the process according to the invention during washing step (a), thereby significantly minimizing the overall loss of product within the scope of the present invention. In this way, the present invention also allows for a significant increase in the absolute yield of purified nitrate esters compared to prior art purification processes for nitrate esters. It is particularly important to consider that prior art processes do not achieve the purity levels or dryness values ​​for nitrate esters that the present invention permits and, at the same time, 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 directly affects the product yield achievable within the scope of the present invention (especially in a substantially quantitative way). The present invention, according to the applicable aspect, further 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, in particular, volatile and / or volatilizable impurities that arise during the production and / or washing of the nitrate esters, in particular a process as described above, which comprises the following process steps: (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 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 contact, 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 simultaneously and / or similarly, in particular during the production and / or washing of the nitrate esters, volatile and / or volatilizable impurities are removed, in particular wherein the drying and / or purification, preferably drying and purification, is carried out as gas-liquid extraction and / or by desorption, in particular as gas-liquid extraction; wherein the inert gas is recycled and / or recirculated 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 loaded with water or moisture and in particular volatile impurities, is transferred to a device for the treatment and recycling of the gas; in particular wherein the inert gas is subjected to a treatment for the removal of water or moisture and in particular volatile impurities, preferably by means of condensation and / or scrubbing, more preferably condensation and scrubbing, and / or in particular wherein the device for the treatment and recycling of the gas comprises a condenser and / or gas scrubber or a combination thereof; in particular wherein the treated inert gas is returned to process step (b);and / or in particular wherein the condensate resulting from the treatment of the inert gas and / or the washing medium obtained is recycled, in particular after preparation and / or purification, preferably into the washing of process step (a).; Last but not least, the process according to the invention has proven particularly advantageous when the crude nitrate esters are produced by means of adiabatic or isothermal nitration and / or the production process for the crude nitrate esters includes or is adiabatic or isothermal nitration. Such production processes exhibit particularly advantageous compatibility with the drying and purification process according to the invention. For further details on the invention aspect described above, reference can also be made to the explanations of the other invention aspects, these explanations applying equally to the present invention aspect. Furthermore, the 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, especially those arising during the production and / or washing of the nitrate esters, preferably by contacting, in particular by flowing, 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:comprising, in the process direction, successive units: - at least one washing unit for washing crude nitrate esters obtained from a manufacturing process and / or originating from a production facility with a washing medium, comprising a downstream and / or downstream separation unit for separating the washing medium from the washed crude nitrate esters; downstream and / or downstream of the washing unit in the process direction - at least one cleaning and / or drying unit, in particular a column, for drying and / or purification, in particular drying and purification, of the washed crude nitrate esters obtained from the washing unit, wherein the cleaning and / or drying unit comprises, in particular in an upper region, in particular a column head,The cleaning and / or drying device comprises a first feeding means for introducing and / or feeding the washed crude nitrate esters into the cleaning and / or drying device, and a second feeding means, arranged in a lower area, particularly the column sump, 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 contacting, in particular for flowing through, the washed crude nitrate esters with the dry inert gas, in particular wherein the means for contacting, in particular for flowing through, are designed such thatthat water present in the washed crude nitrate esters is removed (i.e., the washed crude nitrate esters are dried) and simultaneously and / or similarly, volatile impurities arising in particular during the production and / or washing of the nitrate esters are removed, while obtaining dry (dried) nitrate esters free of volatile impurities in particular; downstream in the process direction and / or following the cleaning and / or drying equipment, at least one recycling device for recycling and / or recirculating the inert gas, wherein the recycling device comprises separators for separating water or moisture and the volatile impurities in particular, in particular a condenser and / or gas scrubber or a combination thereof, in particular wherein the separators are designed in such a way thatthat water or moisture and, in particular, volatile impurities are separated from the moist inert gas, especially by means of condensation and / or scrubbing, preferably condensation and scrubbing, to obtain a dry (dried) inert gas free of, in particular, volatile impurities; in particular, wherein the recycling device also comprises a third feed means, arranged in particular between the upper area, in particular the column head, the cleaning and / or drying device and the recycling device, for introducing and / or supplying and / or transporting the moist inert gas, loaded in particular with water and / or the, in particular, volatile impurities, from the cleaning and / or drying device to the recycling device. In addition to the advantages already described in connection with the method according to the invention, which can likewise be transferred to the device according to the invention, the device according to the invention for drying or purifying nitrate esters is particularly distinguished by the fact that it allows for highly efficient drying or purification of nitrate esters within the framework of a process-engineered, streamlined, and rigorously designed process in a correspondingly simplified system or device with regard to its complexity. This advantageously contributes to low susceptibility to errors or malfunctions, as well as simplified operation and maintenance of the device according to the invention, and also to high process stability and safety, which are accompanied by comparatively high throughputs and achievable quantities. Likewise, the system according to the invention can be implemented constructively and / or process-technically with manageable effort, in particular since the device according to the invention combines such devices that are highly compatible and can be efficiently connected with generally available means. In this sense, it has proven advantageous within the scope of the present invention if the first feeding means is configured as a connection between the washing device and the cleaning and / or drying device. It is equally advantageous if the first feeding means is configured as a transport line, in particular as a transport line for connecting the washing device and the cleaning and / or drying device. Similarly, within the scope of the present invention, it is preferred 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. Equally preferably, the second supply means is designed as a transport line, in particular as a transport line for connecting a storage device for the dry inert gas and the cleaning and / or drying device. In accordance with the invention, it is also preferably provided that the third feed means is designed as a connection between the cleaning and / or drying unit and the recycling unit. More preferably, the third feed means is designed as a transport line, in particular as a transport line for connecting the cleaning and / or drying unit and the recycling unit. Furthermore, with regard to the washing device, it has proven advantageous within the scope of the present invention if the washing device is designed as a liquid-liquid extraction device. 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. In addition or as an alternative, it has proven advantageous for the washing system to comprise one or more washing stages, preferably one, two, or three washing stages. In particular, each washing stage is designed to include one or more washing and / or extraction cycles. Furthermore, it is preferably intended that the washing device is designed such that the washing is carried out with a water-based washing medium. In particular, it is preferred that the water-based washing medium is neutral, acidic, or basic (alkaline). Furthermore, good results are obtained within the scope of the present invention if the washing device is designed such that the washing, in particular in each washing stage, is carried out in cross-flow or counter-flow or in a combination of cross-flow and counter-flow. Preferably, this is done by recycling the washing medium. It is equally preferred if the washing device, particularly in each washing stage, can be operated in cross-flow or counter-flow or in a combination of cross-flow and counter-flow. This is also preferably done with recycling of the washing medium. Furthermore, it has proven 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. Furthermore, with regard to the cleaning and / or drying equipment, it has proven advantageous within the scope of the present invention if the cleaning and / or drying equipment, in particular a column, comprises a single- or multi-stage column, in particular a packed column, sieve tray column, bubble-cap tray column or falling film column or combinations thereof, and / or a gas / liquid reactor or a stripping device. In particular, good results are obtained according to the invention if the cleaning and / or drying device, in particular column, is a single- or multi-stage column, in particular a packed column, sieve tray column, bubble-cap tray column or falling film column or combinations thereof, and / or a gas / liquid reactor or a stripping device. Furthermore, within the scope of the present invention, it is preferred 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. Furthermore preferably, the cleaning and / or drying device, in particular column, especially in the lower area, preferably the column sump, preferably arranged in the lower area, includes outlet and / or discharge means for dry (dried) nitrate esters freed from volatile impurities. In this context, it has proven advantageous if the outlet and / or discharge medium is configured as a connection between the cleaning and / or drying unit and a collection and / or holding unit for dry (dried) nitrate esters free of volatile impurities. Equally preferred is the outlet and / or discharge medium configured as a transport line, particularly as a transport line connecting the cleaning and / or drying unit and a collection and / or holding unit for dry (dried) nitrate esters free of volatile impurities. Preferably, the purification and / or drying device, in particular the column, is designed as a preferably single- or multi-stage packed column, sieve tray column, bubble-cap tray column, or falling film column, or combinations thereof, with a column sump as the lower section. Preferably, the purification and / or drying device includes outlet and / or discharge means for dry nitrate esters, preferably free of volatile impurities, arranged at the column sump. In this regard, it has proven particularly advantageous if the outlet and / or discharge medium is designed as a connection between the cleaning and / or drying unit and a collection and / or holding unit for dry (dried) nitrate esters free of, in particular, volatile impurities. It is equally preferred that the outlet and / or discharge medium be designed as a transport line, in particular as a transport line connecting the cleaning and / or drying unit and a collection and / or holding unit for dry (dried) nitrate esters free of, in particular, volatile impurities. Furthermore, it will prove advantageous 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. According to the invention, it is also preferably provided that the cleaning and / or drying device, in particular the means for contacting, in particular the means for flowing through, the washed crude nitrate esters with the dry inert gas, is / are designed such that the contacting, in particular flowing through, of the washed crude nitrate esters obtained from the washing device with the dry inert gas takes place in cross-current and / or counter-current flow, preferably in counter-current flow. In this context, it has proven particularly advantageous if the cleaning and / or drying equipment, in particular the means for contacting, in particular the means for flowing, the washed crude nitrate esters with the dry inert gas, is / are designed in such a way that the dry inert gas is guided upwards and the washed crude nitrate esters are guided downwards. Furthermore, it has proven advantageous for the device according to the invention if the recycling device has at least two discharge agents 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 containing the volatile impurities from the moist inert gas, in particular two discharge agents 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 containing the volatile impurities from the moist inert gas. In this context, it is particularly preferred if the discharge agent is designed as a direct and / or indirect connection, especially via the second feed agent, between the recycling device and the cleaning and / or drying device. It is also preferably provided that the discharge agent is designed as a transport line for dry (dried) inert gas free of volatile impurities, and preferably as a transport line for dry (dried) inert gas free of volatile impurities, and is designed for the direct and / or indirect connection, especially via the second feed agent, 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. Similarly, according to the invention, it is preferred if the laxative is designed as a connection between the recycling device and the washing device and / or, in particular, if the laxative is designed as a transport line for water or moisture resulting from the treatment of the inert gas and / or washing liquid containing the particularly volatile impurities from the moist inert gas. The discharge agent is particularly preferably designed as a transport line for water or moisture and / or washing liquid resulting from the treatment of the gas, containing in particular volatile impurities from the moist inert gas, and for connecting the recycling device and the washing device, in particular such that recycling and / or recirculation of water or moisture and / or washing liquid resulting from the treatment of the gas, containing in particular volatile impurities from the moist inert gas, takes place. Preferably, a temperature gradient also exists between the drying and / or cleaning unit and the recycling unit for treating the inert gas laden with water or moisture and, in particular, volatile impurities. The temperature gradient is specifically designed such that a lower temperature is set in the recycling unit than in the drying and / or cleaning unit. Thus, there is preferably a temperature gradient decreasing in the process direction from the drying and / or cleaning unit to the recycling unit. 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. Especially in the case where the recycling device T is designed as a condenser, it has proven advantageous if the condenser comprises a refrigerant, cooling liquid, in particular cold or cooled water, and / or cooling gas, in particular cold or cooled air, especially for cooling the recycling device in which the treatment of the inert gas takes place. According to the invention, it is generally preferred that the device described above is configured for carrying out a method as previously illustrated. The device according to the invention is particularly preferably characterized by one or more of the features of the method described above. 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 descriptions of the method according to the invention, these descriptions applying equally to the present aspect of the invention. Furthermore, according to a third aspect of the present invention, a production plant for the manufacture of aliphatic or cycloaliphatic nitrate esters (nitric acid esters) comprises: (i) a nitration unit, in particular with one or more reaction vessels (nitration reactors), for carrying out the nitration, in particular for the manufacture of 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 and / or following the nitration unit in the production line, a separation unit, in particular a separator (separator).in particular for the separation of nitrating acid from nitrated crude products (crude nitrate esters); (iii) arranged downstream and / or downstream of the nitration unit and any separation unit present in the production line, at least one washing unit for washing crude nitrate esters obtained from a manufacturing process and / or originating from a production unit with a washing medium, comprising a downstream and / or downstream separation unit for separating the washing medium from the washed crude nitrate esters; (iv) arranged downstream and / or downstream of the washing unit in the production line, at least one purification and / or drying unit, in particular a column, for drying and / or purification, in particular drying and purification, of the washed crude nitrate esters obtained from the washing unit,wherein the cleaning and / or drying device comprises a first feed means, arranged in particular in an upper region, in particular 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 column sump, 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 with, in particular for flowing through, the dry inert gas, in particular wherein the means for bringing into contact with, in particular for flowing through, the washed crude nitrate esters are designed such thatthat water present in the washed crude nitrate esters is removed (i.e., the washed crude nitrate esters are dried) and simultaneously and / or similarly, in particular during the production and / or washing of the nitrate esters, volatile impurities arising therefrom are removed, while obtaining dry (dried) nitrate esters free of volatile impurities; downstream in the process direction and / or following the cleaning and / or drying equipment, (v) downstream in the production line and / or following the cleaning and / or drying equipment, in particular a column, at least one recycling device for recycling and / or recirculating the inert gas, wherein the recycling device comprises separators 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 separating means are designed such that water or moisture 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 free of particularly volatile impurities; in particular, wherein the recycling device also comprises a third feed means, in particular arranged between the upper area, in particular column head, the cleaning and / or drying device and the recycling device, for introducing and / or feeding and / or transporting the moist inert gas, in particular loaded with water and / or the particularly volatile impurities, from the cleaning and / or drying device to the recycling device. The production plant according to the invention is characterized essentially by the advantages and technical features already described in connection with the inventive method and the inventive apparatus. In particular, the technical features of the inventive apparatus are reflected in the production plant according to the present invention, and the production plant according to the present invention is advantageously suited for carrying out the inventive method as described above, especially since the particularly high efficiency of the inventive method, in conjunction with its resource-saving implementation, is primarily due to the arrangement and design of the equipment included in the inventive production plant. The subject matter of the present invention, according to the applicable aspect, is also such a production plant, in particular as described above, which comprises: (i) a nitration unit, in particular with one or more reaction vessels (nitration reactors), for carrying out the nitration, in particular for the production of 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 and / or following the nitration unit in the production line, a separation unit, 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 following the nitriding unit and any separation unit present, a device according to the present invention or as described above.; Preferably, the production plant within the scope of the present invention is designed to carry out the inventive method as described above. In particular, within the scope of the present invention, it is preferred if the production plant according to the invention is characterized by one or more of the features of the method and / or the device according to the invention. 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 explanations of the preceding aspects of the invention, these explanations applying equally to the present aspect of the invention. Finally, the subject of the present invention – according to a fourth aspect of the present invention – is 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, in particular for the removal of water and of volatile impurities, in particular, which arise during the manufacture and / or washing of the nitrate esters. Furthermore, 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, in particular for the removal of water and of volatile and / or volatilizable impurities, especially those arising during the production and / or washing of the nitrate esters, by bringing the aliphatic or cycloaliphatic crude nitrate esters into contact with the inert gas, especially by flowing through it, in particular such that water present in the washed crude nitrate esters is removed (i.e., the washed crude nitrate esters are dried) and simultaneously and / or similarly, volatile and / or volatilizable impurities arising during the production and / or washing of the nitrate esters are removed. Within the scope of the present invention, it has proven particularly advantageous for the use(s) according to the invention if (a) the crude nitrate esters obtained from a manufacturing process are first subjected to washing with a washing medium, followed by separation of the washing medium, and (b) subsequently the washed crude nitrate esters obtained in this way are subjected to drying and / or purification, preferably drying and purification, by contact, 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 simultaneously and / or similarly, volatile and / or volatilizable impurities arising in the manufacture and / or washing of the nitrate esters are removed. Furthermore, the present invention relates to the use of an inert gas for drying and / or purification, preferably drying and purification, in a process as previously described according to the present invention and / or in a device as previously described according to the present invention and / or in a production plant as previously described according to the present invention. Preferably, for the use(s) according to the invention, it is provided that these are characterized by one or more of the features of the method and / or the device and / or the production plant according to the invention. 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 explanations of the other aspects of the invention, these explanations applying equally to the present aspect of the invention. The present invention will now be explained in more detail with reference to figures of preferred embodiments and preferred exemplary embodiments. In connection with the explanation of these preferred exemplary embodiments, which are in no way limiting with respect to the present invention, further advantages, properties, aspects, and features of the present invention will also be presented. The single figure, including the following figure description and the following embodiments, serve only to illustrate the present invention, without limiting the present invention thereto. In the following description of the preferred embodiments shown in the single figure representation according to Fig. 1, Fig. 1 shows a schematic representation of the design or arrangement of a production plant according to the invention, also comprising a device according to the invention as well as a schematic representation of the process of a method according to the invention, each according to a particular embodiment. Fig. 1 shows, specifically as part of a production plant according to the invention, a preferred embodiment of a device according to the invention for drying or purifying aliphatic or cycloaliphatic nitrate esters, in particular for removing water and volatile or volatilizable impurities, especially those arising during the production and / or washing of the nitrate esters, or a preferred embodiment of a production plant according to the invention comprising this device for the production of aliphatic or cycloaliphatic nitrate esters or nitric acid esters. In particular, Fig. 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, especially those arising during the production and / or washing of the nitrate esters.The production plant according to Fig. 1 comprises: (i) a nitration unit PNE, in particular with one or more reaction vessels (nitration reactors), for carrying out the nitration, in particular for the production of aliphatic or cycloaliphatic nitrate esters (nitric acid esters), preferably from mono- or polyhydric aliphatic or cycloaliphatic alcohols, preferably by means of adiabatic or isothermal nitration; (ii) not shown in Fig. 1, arranged downstream and / or downstream of the nitration unit PNE in the production line, a separation unit, in particular a separator, in particular for separating nitrating acid from nitrated crude products (crude nitric acid esters); (iii) arranged downstream and / or downstream of the nitration unit PNE and the nitration unit shown in Fig. 1 in the production line, a separator, in particular for separating nitrating acid from nitrated crude products (crude nitric acid esters);(1) a washing device W for washing crude nitrate esters NEroh obtained from a manufacturing process and / or from a production facility PNE, with a washing medium and a downstream and / or downstream separation device for separating the washing medium from the washed crude nitrate esters NEfeucht; (iv) arranged downstream and / or downstream of the washing device W in the production line, a cleaning and / or drying device K, in particular a column, for drying and / or purification, in particular drying and purification, of the washed crude nitrate esters NEfeucht obtained from the washing device W; (v) arranged downstream and / or downstream of the cleaning and / or drying device K, in particular a column, in the production line, a recycling device T for recycling and / or recirculation of the inert gas TGtrocken, TGfeucht. The cleaning and / or drying device K comprises a first feed element 2, arranged in particular in an upper region KK, especially the column head, of the cleaning and / or drying device, for introducing and / or feeding the washed crude nitrate esters NE (moist) into the cleaning and / or drying device K. Likewise, the cleaning and / or drying device K comprises a second feed element 3, arranged in particular in a lower region KS, especially the column sump, 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. Furthermore, the cleaning and / or drying device K also includes means for contacting, 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 contacting, 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 simultaneously and / or similarly, in particular during the production and / or washing of the nitrate esters, volatile and / or volatilizable impurities arising therefrom are removed, while obtaining the dry (dried) nitrate esters NE (dry) free of volatile impurities in particular; downstream in the process direction and / or downstream of the cleaning and / or drying device K). Furthermore, the recycling device T is provided to include separating means for the removal of water or moisture and, in particular, volatile impurities, specifically a condenser and / or gas scrubber or a combination thereof. The separating means are designed such that water or moisture and, in particular, volatile impurities are removed from the moist inert gas TGfeucht, in particular by means of condensation and / or scrubbing, preferably condensation and scrubbing, to obtain a dry inert gas TGtrocken free of, in particular, volatile impurities. It is preferably provided that the recycling device T also comprises a third feed means 5, arranged in particular between the upper area KK, in particular 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, loaded in particular with water and / or the volatile impurities, from the cleaning and / or drying device K into the recycling device T. The preferred production plant according to Fig. 1, or the preferred device included therein for drying and / or purifying aliphatic or cycloaliphatic nitrate esters, is designed to carry out a process comprising the following process steps, or in particular, the process according to the invention, which includes 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 contact, 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 simultaneously and / or similarly, volatile and / or volatilizable impurities that arise in the production and / or washing of the nitrate esters are removed. The production of the crude nitrate esters can preferably be carried out by means of adiabatic or isothermal nitration, or the production process for the crude nitrate esters can preferably include or comprise an adiabatic or isothermal nitration. The nitration is particularly preferably carried out according to the specifications of EP 1 792 891 A1 or in a device suitable according to the specifications of EP 1 792 891 A1, wherein the content of EP 1 792 891 A1 is hereby expressly referenced and its content is fully incorporated into the disclosure of the present application. The crude nitrate esters NEroh obtained from the manufacturing process are subsequently transferred via the separation device (not shown in Fig. 1) to the washing device W for washing the crude nitrate esters NEroh. For this purpose, an initial feed medium 1 serves to introduce and / or feed the obtained crude nitrate esters NEroh into the washing device W. The nitrate esters used according to 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, reference is made to the above explanations. Particularly preferred are the 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 alcanetriols, in particular of trimethyl olethane, trimethylolpropane, butanetriols and glycerol; (iv) nitrate esters of tetra- or polyhydric aliphatic alkanols. The volatile and / or volatilizable impurities are preferably selected from the group consisting of (i) unreacted and / or partially reacted starting materials and / or precursor 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) nitrogenous bases, in particular ammonia (NH3); (vii) nitrogen oxides, in particular nitric oxide (NO), nitrogen dioxide (NO2) and dinitrogen oxide (N2O) as well as nitroses and other nitrogen oxides (NOx); (viii) carbon oxides, in particular carbon monoxide (CO) and carbon dioxide (CO2); (ix) solvent and / or washing medium residues. 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, especially with respect to the vapor pressure of the nitrate esters under standard conditions (pressure of 1.013 bar; humidity of 0% [standard conditions according to DIN 1343, STPD]) and / or especially with respect to the boiling point of the nitrate esters under standard conditions (pressure of 1.013 bar; 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 at least 5 mbar, preferably at least 7.5 mbar, 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 at least 1 °C, preferably at least 2.5 °C, preferably at least 5 °C lower than the nitrate esters to be purified. In the preferred embodiment of the device or production plant shown in Fig. 1, the process step (a) and / or the washing is carried out as liquid-liquid extraction with regard to the process according to the invention. Preferably, 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. 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, more preferably in two or three washing stages; in particular, wherein each washing stage comprises one or more washing and / or extraction cycles. It is also preferably preferred that 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 preferably, 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. In this sense, with regard to the production plant or device according to the present invention, in the preferred embodiment according to Fig. 1, it is provided that the washing device W is designed as a liquid-liquid extraction device. Preferably, 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. Furthermore, it is preferred that the washing device W comprises one or more washing stages, preferably one, two, or three washing stages, more preferably two or three washing stages; in particular, wherein each washing stage is configured to include one or more washing and / or extraction cycles. Moreover, the washing device W is preferably configured such that the washing is carried out with an aqueous washing medium; in particular, wherein the aqueous washing medium is neutral, acidic, or basic (alkaline). Furthermore, it has proven advantageous for the inventive process in process step (a) if process step (a) and / or the washing, in particular in each washing stage, is carried out in cross-flow or counter-flow or in a combination of cross-flow and counter-flow, preferably with recycling of the washing medium. In this respect, the washing device W is advantageously designed such that the washing, particularly in each washing stage, is carried out in cross-flow or counter-flow or in a combination of cross-flow and counter-flow, preferably with recycling of the washing medium. The washing device W is, particularly in each washing stage, preferably operable in cross-flow or counter-flow or in a combination of cross-flow and counter-flow and / or can be operated accordingly, preferably with recycling of the washing medium. At the conclusion of process step (a), the production plant or device according to Fig. 1 is provided for such that the washing medium is separated in process step (a) by means of a separating device (separator), in particular by means of a static separator, or by means of a centrifugal separator. In this sense, the separation device downstream of the washing unit W in Fig. 1 is designed as a separating device (separator), in particular as a static separator, or as a centrifugal separator. The subsequent process step (b) is carried out in the drying and / or cleaning unit K. The cleaning and / or drying unit K comprises, or is in particular a column. 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. The washed crude nitrate esters obtained in process step (a) are transferred in process step (b) to the drying and / or cleaning unit K of the production plant or device according to Fig. 1. For the transfer of the nitrate esters, it is provided that the first feed element 2 is designed as a connection between the washing unit W and the cleaning and / or drying unit K and / or that the first feed element 2 is designed as a transport line, in particular as a transport line for connecting the washing unit W and the cleaning and / or drying unit K. Likewise, for the further supply means, in particular the second supply means 3, it has proven effective if this is designed as a connection between a storage device for the dry inert gas TGtrocken 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 TGtrocken and the cleaning and / or drying device K. For the third feeding means 5, it is analogously preferred if the third feeding 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 feeding 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. With regard to the process flow, it has proven advantageous if, in process step (b), the drying and / or purification, preferably both drying and purification, is carried out as a continuous or batch process, particularly a continuous one. In the context of Fig. 1, the process is designed as a continuous process. Accordingly, the cleaning and / or drying unit K, in particular a column, is configured such that the drying and / or purification, preferably both drying and purification, is carried out as a continuous or batch process, particularly a continuous one. For this purpose, the cleaning and / or drying unit K is preferably configured as a gas-liquid extraction unit and / or desorption unit, in particular a gas-liquid extraction unit. Furthermore, for the device according to the invention, the following is also required:The production plant is designed to utilize the preferred feeding means 2, 3, 5, as previously described. The contact, in particular the flow, of the washed crude nitrate esters obtained in process step (a) with the inert gas takes place in the production plant or apparatus according to Fig. 1 in cross-current and / or counter-current flow, preferably in counter-current flow. Furthermore, the process according to the invention provides that in process step (b) the drying and / or purification, preferably drying and purification, is carried out by gas-liquid extraction and / or by desorption, in particular by gas-liquid extraction. It has proven advantageous if the inert gas is guided upwards and the nitrate esters downwards. Furthermore, good results are obtained if, in process step (b), the contact, in particular the flow, of the nitrate ester with the inert gas is carried out in a dispersed distribution, particularly a finely dispersed distribution, within the nitrate esters. It is particularly advantageous if, in process step (b), the inert gas is introduced into the nitrate esters in a dispersed distribution, particularly a finely dispersed distribution. For this purpose, the apparatus or production plant advantageously comprises nozzles, jet mixers, jet pumps, injectors, lances, sieve trays, and / or fine-pored membranes. Furthermore, the inert gas is used in dry form in process step (b). In accordance with the described embodiment of the method, it is provided with regard to the device or production plant according to the invention 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 NE (moist) 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-flow and / or counter-flow, preferably in counter-flow. In particular, it is provided that the cleaning and / or drying device K, in particular the means for contacting, in particular the means for flowing, the washed crude nitrate esters NE moist with the dry inert gas TG dry, is / are designed such that the dry inert gas TG dry is guided upwards and the washed crude nitrate esters NE moist are guided downwards. Furthermore, the production plant or device of Fig. 1 is designed such that the dried and / or purified, preferably dried and purified, nitrate esters obtained after process step (b) are obtained separately and / or separated from the inert gas and / or collected. Advantageously, no additional separation step is provided to separate the dried and / or purified, preferably dried and / or purified, nitrate esters obtained after process step (b) from the inert gas. In the interest of continuous process operation, the device according to the invention is accordingly provided that the cleaning and / or drying device K, in particular column, in particular in the lower region KS, preferably the column sump, preferably at the lower region KS, comprises outlet and / or discharge means 4 for dry (dried) nitrate esters NE dry free of particularly volatile impurities. Advantageously, the outlet and / or discharge agent 4 is designed as a connection between the cleaning and / or drying device K and a collection and / or receiving device for dry (dried) nitrate esters NE dry, free from volatile impurities in particular, and / or the outlet and / or discharge agent 4 is designed as a transport line, in particular as a transport line for connecting the cleaning and / or drying device K and a collection and / or receiving device for dry (dried) nitrate esters NE dry, free from volatile impurities in particular. In the apparatus or production plant according to Fig. 1, the washed crude nitrate esters obtained in process step (a) are used as such, or in concentrated and / or undiluted form, in process step (b). In this sense, it is therefore preferably provided that no (additional) solvent and / or dispersant is added to the washed crude nitrate esters obtained in process step (a) in process step (b) for the purpose of drying and / or purification, preferably drying and purification. The device or production plant according to Fig. 1 is also designed such that in process step (b) the inert gas is selected and / or designed in such a way that it is non-reactive towards the nitrate esters under the conditions of process step (b). In this regard, it has proven advantageous if, 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 their mixtures, in particular air, preferably from the group consisting of nitrogen, oxygen, noble gases, in particular argon, and their mixtures, in particular air, particularly preferably from the group consisting of nitrogen, oxygen and their mixtures, in particular air. In the preferred embodiment of the inventive process according to Fig. 1, it is further provided that the inert gas is recycled and / or recirculated after process step (b). This step takes place after and / or during drying and purification of the inert gas. Accordingly, after process step (b), the inert gas is subjected to a drying and purification treatment, in particular by means of a condenser and / or gas scrubber or a combination thereof. In this respect, the feeder 5, as already described above, preferably serves as a transport means for supplying moist inert gas from the purification and / or drying unit K to the recycling unit T. In this sense, within the framework of the implementation of the inventive method according to Fig. 1, it is further provided that the inert gas obtained and / or separated after process step (b), in particular inert gas loaded with water or moisture and in particular volatile impurities, is transferred to the recycling device T for treatment of the gas. The recycling device T comprises, or in particular advantageously includes, a condenser and / or gas scrubber, or a combination thereof, in particular a condenser. In particular, if the recycling device T is designed as a condenser, it has proven advantageous if the condenser comprises a refrigerant, cooling liquid, in particular cold or cooled water, and / or cooling gas, in particular cold or cooled air, especially for cooling the recycling device T in which the treatment of the inert gas takes place. There is a temperature gradient between the drying and / or cleaning unit K and the recycling unit T. The temperature gradient is designed such that a lower temperature is set in the recycling unit T than is provided for in the drying and / or cleaning unit K. Preferably, there is a temperature gradient decreasing in the process direction from the drying and / or cleaning unit K to the recycling unit T. Furthermore, the device or production plant in Fig. 1 is provided to have two discharge agents 6, 7 for dry (dried) inert gas TG dry, free of particularly volatile impurities, and / or water or moisture resulting from the treatment of the inert gas and / or washing liquid containing the particularly volatile impurities from the moist inert gas TG moist. The laxative 6 is designed as shown in Fig. 1 as an indirect connection between the recycling device T and the cleaning and / or drying device K, in particular via the second feed device 3. However, a direct design of the laxative 6 is also conceivable. In particular, the discharge agent 6 is designed as a transport line for dry (dried) inert gas TG dry free of volatile impurities, preferably as a transport line for dry (dried) inert gas TG dry free of volatile impurities, and within the framework of Fig. 1 designed for the indirect connection of the recycling device T and the cleaning and / or drying device K, in particular via the second feed agent 3, in particular such that recycling and / or recirculation of the inert gas TG dry, TG moist takes place. Similarly, the discharge medium 7 in Fig. 1 is designed as a connection between the recycling unit T and the washing unit W. In particular, the discharge medium 7 is designed as a transport line for water or moisture and / or washing liquid resulting from the treatment of the inert gas, containing the volatile impurities from the moist inert gas TGfeucht. The discharge medium 7 is designed specifically as a transport line for water or moisture and / or washing liquid resulting from the treatment of the gas, containing the volatile impurities from the moist inert gas TGfeucht, and for connecting the recycling unit T and the washing unit W, in particular such that recycling and / or recirculation of the water or moisture and / or washing liquid resulting from the treatment of the gas, containing the volatile impurities from the moist inert gas TGfeucht, takes place. With regard to the inert gas, it is initially provided that it undergoes treatment to remove water or moisture and, in particular, volatile impurities, preferably by means of condensation and / or scrubbing, more preferably condensation and scrubbing. Accordingly, it has proven advantageous if the recycling device T for the treatment and recycling of the gas comprises a condenser and / or gas scrubber or a combination thereof. The treated inert gas is then recycled in process step (b), specifically by means of transport via the laxative 6. The condensate resulting from the treatment of the inert gas and / or the washing medium obtained is also intended to be recirculated, particularly after processing and / or purification. Specifically, the resulting condensate and / or washing medium obtained is recycled into the washing process of step (a) and / or conveyed via the discharge agent 7. Further embodiments, modifications and variations as well as advantages of the present invention are readily apparent and achievable for the person skilled in the art when reading the description, without leaving the scope of the present invention. The present invention is further illustrated by the following exemplary embodiments, without, however, limiting the present invention to these. Reference symbol list: P N Nitrating unit N Raw nitrate ester W Washing unit N Moist-washed raw nitrate esters K Cleaning and / or drying unit KK Upper area of ​​the cleaning and / or drying unit KS Lower area of ​​the cleaning and / or drying unit T Recycling unit N Dry nitrate esters, dried and freed from volatile impurities T Dry inert gas, dried and freed from volatile impurities T Moist inert gas, loaded with volatile impurities 1 Feeding agent for introducing and / or feeding the obtained raw nitrate esters N Raw into the washing unit W 2 Feeding agent for introducing and / or feeding the washed raw nitrate esters N Moist into the cleaning and / or drying unit K 3 Feeding agent for introducing and / or feeding a dry inert gas T Dry into the cleaning and / or drying unit K 4 Deferral agentfor dry (dried) nitrate esters free of volatile impurities NE dry5 Feeding agent for introducing and / or feeding and / or transporting the moist inert gas TG moist, loaded in particular with water and / or the volatile impurities, from the cleaning and / or drying unit K to the recycling unit T 6 Removal agent for dry (dried) inert gas free of volatile impurities TG dry 7 Removal agent for water or moisture and / or washing liquid resulting from the treatment of the inert gas with the volatile impurities from the moist inert gas TG moist Examples of implementation 1. Purification and drying of 2-ethylhexyl nitrate according to the inventive process In a conventional production process for nitrate esters according to the state of the art as shown in Example 1 of EP 1 792 891 A1, 1000 mL of 2-ethylhexyl nitrate (EHN) are produced. 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 that arise during the production and washing of the nitrate esters, wherein an apparatus and a process according to the invention are used in accordance with the single figure shown, as already described in detail above. For this purpose, the crude nitrate ester from the production process, after separation of the nitrating acid, which still contains significant amounts of water or moisture and 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 unit (three stages: acidic, subsequent basic or alkaline and final neutral washing with aqueous washing medium) and separated from the washing medium at each stage. The washed crude nitrate ester has a water content of 0.056% (by weight) and exhibits a distinct turbidity upon cooling due to this water content. Furthermore, the washed crude nitrate ester contains various volatile and 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 and volatilizable impurities before carrying out the process according to the invention is therefore 189 ppm. The washed crude nitrate ester is transferred to a purification and drying device according to the present invention (column according to the single figure showing the column sump and column head; supply of the dry inert gas via the column sump and supply of the crude nitrate ester via the column head via the respective feed lines) and is then subjected to a flow of 400 L / h of dry inert gas in the form of dry air (dew point approx. -40°C) through a fine-pored ceramic membrane (countercurrent flow; finely dispersed gas flow). The temperature in the cleaning and drying unit is approximately 20 °C, and the pressure in this unit corresponds to atmospheric pressure. The quantity of inert gas used, based on 1 tonne 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; humidity: 0%, i.e., dry inert gas; temperature: 0 °C [standard conditions according to DIN 1343, STPD]), is approximately 50 standard cubic meters. The water content of washed crude nitrate esters, initially at 0.056% (by weight) before inert gas injection, is checked after 1 min, 2 min, 5 min and 10 min. After 1 minute of flow 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%. Furthermore, the EHN, which is initially cloudy due to the production process, clarifies into a completely clear liquid after just one minute of treatment, and remains completely clear throughout the rest of the process. In contrast, the water content of conventionally produced and state-of-the-art purified 2-ethylhexyl nitrates is generally around 0.05%. Within the framework of the inventive method or by means of inventive drying and cleaning devices, significantly lower-water or water-free and purer nitrate esters can be provided compared to the prior art or conventional manufacturing and cleaning methods and devices. The EHN obtained from the process according to the invention was further analyzed for volatile and volatilizable impurities. This analysis confirmed that the dried and purified EHN obtained is virtually free of undesirable impurities and accompanying substances within the limits of detection. Specifically, the levels of the following impurities were minimized as follows: CO2 reduction from 31 ppm to 1 ppm; NO and NO2 reduction from 15 ppm to below 1 ppm; HNO3 reduction from 10 ppm to 2 ppm; NH3 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 substantial reduction of volatile or volatilizable impurities that can be introduced into the crude nitrate ester during nitrate ester production. Furthermore, the process is controlled in such a way that the vapor pressures of nitrate esters are always kept low, so that explosive mixtures of nitrate ester vapor and gas can never form. Thus, a highly efficient and a very safe process is provided. The inert gas, in the form of air, which has absorbed water, moisture, and volatile impurities from the product during the process, is conveyed from the cleaning and drying unit via a suitable supply or transport line to a recycling unit with a gas scrubber and condenser. There, the gas scrubber removes the volatile impurities, and subsequently, a condenser removes the water. The resulting dry air is then reused for drying washed crude nitrate esters or recirculated (recycled). The resulting condensate, together with traces of entrained EHN and separated unwanted by-products, is returned to the washing unit, which is located upstream of the cleaning and drying unit, and is incorporated into the process according to the invention or neutralized there. 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 loop according to the invention. This eliminates environmental and exhaust emissions. The condensate collected at the cooler, which separates the transported water, can be easily returned to the production process (product washing), especially if it contains small amounts of product (EHN); this reduces or prevents any potential EHN slippage. The procedure described above is repeated with other inert gases (nitrogen and argon). Comparable results are obtained. 2. Purification and drying of pentyl nitrate (amyl nitrate) according to the inventive process Crude pentyl nitrate (amyl nitrate) is purified and dried in a corresponding manner according to the previously described process for EHN. Comparable results are obtained. 3. Comparative example: State-of-the-art treatment of 2-ethylhexyl nitrate In a conventional production process for nitrate esters according to the state of the art as shown in Example 1 of EP 1 792 891 A1, 1000 mL of 2-ethylhexyl nitrate (EHN) are produced. After removal of the nitrating acid according to Example 1, the crude nitrate ester is washed at approximately 30 °C and separated from the washing medium. The resulting washed crude nitrate ester is passed through a cooling apparatus at a rate of 20 mL / min. This cooling apparatus consists of a 2 m long stainless steel tube with an inner diameter of 3 mm and is located in a thermostatic bath at a controlled temperature of -5 °C. Water droplets are clearly visible in a receiving vessel in which the washed and cooled EHN ester is collected. These droplets are removed by a coalescer made of stainless steel mesh. 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 EHN nitrate esters dried in this way can therefore only be lowered to approximately 11 °C upon cooling. In contrast to the process according to the invention, a less dry product is obtained, whose cloud point is also comparatively high, i.e., in cold regions, water crystallization can occur during the transport of corresponding esters, which can negatively affect the product quality. Furthermore, the method according to the comparative example is significantly more energy-intensive due to the required strong cooling, while simultaneously being less effective. Furthermore, the separate and subsequent, but necessary, water separation using a coalescer represents an additional and complex step compared to the inventive method (which, in contrast, is significantly more efficient and effective). Furthermore, 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

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, especially those arising during the production and / or washing of the nitrate esters, wherein the process comprises the following process steps: (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; (b) subsequently, the washed crude nitrate esters obtained in process step (a) are subjected to drying and / or purification, preferably drying and purification, by contact, in particular by flowing, with an inert gas, in particular such thatthat water present in the washed crude nitrate esters is removed and, at the same time and / or in the same way, volatile impurities arising in particular during the production and / or washing of the nitrate esters are removed. The method of claim 1, wherein the nitrate esters are liquid 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 of trimethylolethane, trimethylolpropane, butanetriols and glycerol; (iv) Nitrate esters of tetrahydric or polyhydric aliphatic alkanols.; The process according to claim 1 or claim 2, wherein the volatile impurities are selected from the group consisting of (i) unreacted and / or partially reacted starting materials 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) nitrogenous bases, in particular ammonia (NH3); (vii) nitrogen oxides, in particular nitric oxide (NO), nitrogen dioxide (NO2) and nitrous oxide (N2O) as well as nitrose and other nitrogen oxides (NOx); (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 with respect to the vapor pressure of the nitrate esters under standard conditions (pressure of 1.013 bar; humidity of 0% [standard conditions according to DIN 1343, STPD]) and / or in particular with respect to the boiling point of the nitrate esters under standard conditions (pressure of 1.013 bar; humidity of 0% [standard conditions according to DIN 1343, STPD]); in particular wherein the volatiles to be removed have a vapor pressure at least 5 mbar, preferably at least 7.5 mbar, 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 at least 1 °C, preferably at least 2.5 °C, preferably at least 5 °C lower than the nitrate esters to be purified. A method according to any one of the preceding claims, wherein process step (a) and / or the washing is carried out as 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 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; and / or wherein 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). Method according to one of the preceding claims, wherein the 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. Method according to one of the preceding claims, wherein the method step (a) and / or the washing, in particular in each washing stage, is carried out in cross-flow or counter-flow or in a combination of cross-flow and counter-flow, preferably with recycling of the washing medium. Method according to one of the preceding claims, wherein in method step (a) the separation of the washing medium is carried out by means of a separating device (separator), in particular by means of a static separating device, or by means of a centrifugal separator. A method according to any of the preceding claims, wherein process step (b) is carried out in a drying and / or cleaning unit, preferably a drying and cleaning unit; in particular, wherein the washed crude nitrate esters obtained in process step (a) are transferred in process step (b) to a drying and / or cleaning unit, preferably a drying and cleaning unit; and / or in particular, wherein the drying and / or cleaning unit, preferably a drying and cleaning unit, preferably comprises a column, in particular a single- 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. Method 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. Method 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 gas-liquid extraction and / or by means of desorption, in particular as gas-liquid extraction. A method 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, especially those arising during the production and / or washing of the nitrate esters, in particular a method according to one of the preceding claims, wherein the method comprises the following process steps: (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, wherein process step (a) and / or the washing is carried out as 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 contact, in particular by flowing through, an inert gas, in particular such that water present in the washed crude nitrate esters is removed and volatile impurities arising during the production and / or washing of the nitrate esters are removed simultaneously and / or in the same way, in particular, the drying and / or purification, preferably drying and purification, is carried out by gas-liquid extraction and / or by desorption, in particular by gas-liquid extraction; in particular, wherein the volatile impurities are selected from the group consisting of (i) unreacted and / or partially reacted starting materials 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 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 nitric oxide (NO), nitrogen dioxide (NO2) and dinitrogen oxide (N2O) as well as nitrose and other nitrogen oxides (NOx); (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 with respect to the vapor pressure of the nitrate esters under standard conditions (pressure of 1.013 bar;humidity of 0% [standard conditions according to DIN 1343, STPD]) and / or in particular with regard to the boiling point of the nitrate testers under standard conditions (pressure of 1.013 bar; humidity of 0% [standard conditions according to DIN 1343, STPD]).; A method according to any 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 the purpose of carrying out drying and / or purification, preferably drying and purification. A method according to any of the preceding claims, wherein in process step (b) the inert gas is selected and / or configured 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. A method according to one of the preceding claims, wherein in process step (b) the contact, in particular flow, of the washed crude nitrate esters obtained in process step (a) with the inert gas is carried out in a transverse and / or countercurrent flow, preferably in a countercurrent flow; in particular wherein the inert gas is guided upwards and the nitrate esters are guided downwards; in particular in a drying and / or cleaning device, preferably a drying and cleaning 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. A method according to one of the preceding claims, wherein in process step (b) the contacting, in particular flowing, of the nitrate ester with the inert gas in a dispersed distribution, in particular a finely dispersed distribution, of the inert gas in the nitrate ester is carried out and / or is performed; and / or wherein in process step (b) the inert gas is introduced into the nitrate ester 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 trays and / or fine-pored membranes, preferably by means of nozzles, jet mixers and / or fine-pored membranes. A method according to any 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, more 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, in particular at the beginning of process step (b), and / or initially supplied, has a dew point of -20 °C or lower, in particular -30 °C or lower, more 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, more preferably -55 °C or higher, more preferably -50 °C or higher;and / or, in particular, wherein the inert gas supplied, especially at the beginning of process step (b), and / or initially supplied, has a dew point in the range of -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, especially at the beginning of process step (b), and / or initially supplied, has a relative humidity in the range of 0 to 95%, in particular 0 to 90%, more preferably 0 to 85%, more preferably 0 to 80%. A method according to 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, with the inert gas is carried out with a volume flow rate of the inert gas of 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 rate 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, respectively.The contact, in particular the flow, with the inert gas is carried out with a volume flow rate of the inert gas in a range of 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. A method according to any of the preceding claims, wherein in process step (b) the drying and / or purification, preferably drying and purification, or contact, in particular flow, 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 contact, in particular flow, with the inert gas is carried out with the inert gas.The contact, in particular the flow, with the inert gas is carried out with a residence time of the nitrate ester in the presence of the inert gas in a range of 30 s to 20 min, in particular 1 min to 17 min, preferably 3 min to 14 min, preferably 7 min to 12 min. A method according to one of the preceding claims, wherein in process step (b) the drying and / or purification, preferably drying and purification, or contacting, in particular flowing, 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, preferably less than 50 mbar, and / or ...the contact, in particular the flow, with the inert gas is carried out at temperatures above 0 °C, in particular above 5 °C, preferably above 7.5 °C, preferably above 10 °C, and / or at temperatures below 60 °C, in particular below 50 °C, preferably below 40 °C, preferably below 35 °C; and / or wherein in process step (b) the drying and / or purification, preferably drying and purification, or the contact, in particular the flow, with the inert gas is carried out at temperatures in a range of 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. A method according to 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, with the inert gas is carried out at atmospheric pressure (normal pressure; 1.01325 bar) or in a vacuum (negative pressure) or at positive pressure, preferably at atmospheric pressure, and / or wherein in process step (b) the drying and / or purification, preferably drying and purification, or the contacting, in particular flowing, with the inert gas is carried out at an absolute pressure in the range of 0.1 bar to 3 bar, in particular in the range of 0.3 bar to 1.2 bar, preferably in the range of 0.5 bar to 1.1 bar, particularly preferably at about 1 bar. A method according to any 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 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) is calculated per tonne of nitrate esters to be purified and as the volume of the inert gas in standard cubic meters under standard conditions (pressure: 1.013 bar; relative humidity: 0%, i.e.,dry 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, preferably 8 to 70 standard cubic meters, and / or wherein the quantity of inert gas used in process step (b), based on 1 tonne of nitrate ester to be purified and calculated as the quantity and / or weight of the inert gas under standard conditions (pressure: 1.013 bar; humidity: 0%, i.e., 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, preferably 10 to 40 kg. A method according to any 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.%, 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.%, preferably in the range of 0.0005 to 0.01 wt.%, based on the nitrate esters. A method according to any of the preceding claims, wherein the nitrate esters, after drying and / or purification, preferably drying and purification, have a volatile impurity content of at most 100 ppm, in particular at most 30 ppm, preferably at most 25 ppm, more preferably at most 20 ppm, more preferably at most 10 ppm; and / or wherein the nitrate esters, after drying and / or purification, preferably drying and purification, have a volatile impurity content in the range of 0.001 to 100 ppm, in particular in the range of 0.001 to 30 ppm, more preferably in the range of 0.001 to 25 ppm, more preferably in the range of 0.002 to 20 ppm, more preferably in the range of 0.005 to 10 ppm. Method according to one of the preceding claims, wherein the inert gas after process step (b) and / or after contact, in particular flowing through, the nitrate ester has a relative humidity and / or relative residual moisture of 50% or more, in particular 65% by weight 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. A method according to any of the preceding claims, wherein the dried and / or purified, preferably dried and purified, nitrate esters obtained after process step (b) are obtained separately and / or separated from the inert gas and / or collected; in particular, wherein 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. Method according to one of the preceding claims, wherein the inert gas is recycled and / or recirculated after process step (b), in particular after and / or under 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. A method according to any of the preceding claims, wherein the inert gas obtained and / or separated according to process step (b), in particular inert gas loaded with water or moisture and volatile impurities, is transferred to a recycling device for treatment of the gas; in particular wherein the inert gas is subjected to treatment for the removal of water or moisture and the volatile impurities, preferably by means of condensation and / or scrubbing, more preferably condensation and scrubbing, and / or in particular wherein the recycling device for treatment and recycling of the gas comprises a condenser and / or gas scrubber or a combination thereof. The method of claim 27, wherein the treated inert gas is recycled in process step (b); and / or wherein the condensate resulting from the treatment of the inert gas and / or the washing medium obtained is recycled, in particular after processing and / or purification, preferably into the washing of process step (a). A method 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, especially those arising during the production and / or washing of the nitrate esters, in particular a method according to one of the preceding claims, wherein the method comprises the following process steps: (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 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 contact, in particular by flowing through, an inert gas, in particular such that water present in the washed crude nitrate esters is removed and volatile impurities arising 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 gas-liquid extraction and / or by desorption, in particular as gas-liquid extraction; wherein the inert gas is recycled and / or recirculated 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 loaded 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 for the removal of water or moisture and volatile impurities, preferably by means of condensation and / or scrubbing, more 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 returned to process step (b);and / or in particular wherein the condensate resulting from the treatment of the inert gas and / or the washing medium obtained is recycled, in particular after preparation and / or purification, preferably into the washing of process step (a).; Method according to any of the preceding claims, wherein the crude nitrate esters are produced by means of adiabatic or isothermal nitration and / or the production process for the crude nitrate esters comprises or is adiabatic or isothermal nitration. 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, especially those arising during the production and / or washing of the nitrate esters, preferably by contacting, in particular by flowing, an inert gas (TG), in particular a device for carrying out a method according to one of the preceding claims, wherein the device comprises the following, successive arrangements in the process direction (W, K,T) comprises: - at least one washing unit (W) for washing crude nitrate esters (NEroh) obtained from a manufacturing process and / or originating from a production facility (PNE) with a washing medium, including a downstream and / or downstream separation unit for separating the washing medium from the washed crude nitrate esters (NEfeucht); downstream and / or downstream of the washing unit (W) in the process direction - at least one cleaning and / or drying unit (K), in particular a column, for drying and / or purification, in particular drying and purification, of the washed crude nitrate esters (NEfeucht) obtained from the washing unit (W), wherein the cleaning and / or drying unit (K) includes a column head, in particular in an upper region (KK), in particular in a column head,The cleaning and / or drying device (K) comprises a first feed means (2) for introducing and / or feeding the washed crude nitrate esters (NE wet) into the cleaning and / or drying device (K), and a second feed means (3) arranged in a lower region (KS), in particular the column sump, 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 contacting, in particular for flowing through, the washed crude nitrate esters (NE wet) with the dry inert gas (TG dry), in particular wherein the means for contacting, in particular for flowing through, are designed such thatthat water present in the washed crude nitrate esters (NE wet) is removed and simultaneously and / or similarly, volatile impurities arising in particular during the production and / or washing of the nitrate esters are removed, while obtaining the dry (dried) nitrate esters (NE dry) free of volatile impurities; downstream in the process direction and / or following the cleaning and / or drying unit (K) - at least one recycling unit (T) for recycling and / or recirculating the inert gas (TG dry, TG wet), wherein the recycling unit (T) comprises separators 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 separators are designed such that water or moisture and the volatile impurities are removed from the moist inert gas (TG wet),in particular by means of condensation and / or washing, preferably condensation and washing, to obtain a dry (dried) inert gas (TG dry) free of volatile impurities; in particular wherein the recycling device (T) further comprises a third feed means (5) arranged in particular between the upper area (KK), in particular 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 loaded with water and / or the volatile impurities, from the cleaning and / or drying device (K) to the recycling device (T). 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). 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 (TGtrocken) 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 (TGtrocken) and the cleaning and / or drying device (K). 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). Device according to one of the preceding claims, wherein the washing device (W) is configured 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, more preferably two or three washing stages; in particular wherein each washing stage is configured to comprise one or more washing and / or extraction cycles; and / or wherein the washing device (W) is configured to carry out the washing with an aqueous-based washing medium; in particular wherein the aqueous-based washing medium is neutral, acidic or basic (alkaline). 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 cross-flow or counter-flow or in a combination of cross-flow and counter-flow, preferably with recycling of the washing medium; and / or, wherein the washing device (W), in particular in each washing stage, is operable and / or can be operated in cross-flow or counter-flow or in a combination of cross-flow and counter-flow, preferably with recycling of the washing medium. Device according to one of the preceding claims, wherein the separating 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. Device according to one of the preceding claims, wherein the cleaning and / or drying device (K), in particular a column, comprises a single- or multi-stage column, in particular a packed column, sieve tray column, bubble-cap tray column or falling film column or combinations thereof, and / or a gas / liquid reactor or a stripping device. Device according to one of the preceding claims, wherein the cleaning and / or drying device (K), in particular column, is a single- or multi-stage column, in particular a packed column, sieve tray column, bubble-cap tray column or falling film column or combinations thereof, and / or a gas / liquid reactor or a stripping device. 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. Device according to one of the preceding claims, wherein the cleaning and / or drying device (K), in particular column, in particular in the lower region (KS), preferably the column sump, preferably comprises outlet and / or discharge means (4) arranged in the lower region (KS) for dry (dried) and volatile impurity-free nitrate esters (NEdry);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 collection and / or receiving 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 collection and / or receiving device for dry (dried) nitrate esters (NEdry) freed from volatile impurities.; 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, bubble-cap tray or falling film column or combinations thereof with a column sump (KS) as the lower region, in particular wherein the cleaning and / or drying device (K) preferably has outlet and / or discharge means (4) arranged at the column sump (KS) for dry (dried) and volatile impurity-free nitrate esters (NEdry);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 collection and / or receiving 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 collection and / or receiving device for dry (dried) nitrate esters (NEdry) freed from volatile impurities.; 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. Device according to one of the preceding claims, wherein 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 (NEmoist) with the dry inert gas (TGdry), is / are designed such that the contacting, in particular flowing through, of the washed crude nitrate esters (NEmoist) obtained from the washing device (W) with the dry inert gas (TGdry) takes place in cross-current and / or counter-current flow, preferably in counter-current flow; in particular wherein 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 (NEmoist) with the dry inert gas (TGdry), is / are designed such that the dry inert gas (TGdry) is guided upwards and the washed crude nitrate esters (NEmoist) are guided downwards. Device according to one of the preceding claims, wherein the recycling device (T) comprises at least two discharge agents (6, 7) for dry (dried) inert gas (TG dry) free of volatile impurities and / or water or moisture resulting from the treatment of the inert gas and / or washing liquid containing the impurities from the moist inert gas (TG moist), in particular two discharge agents (6, 7) for dry (dried) inert gas (TG dry) free of volatile impurities and water or moisture resulting from the treatment of the gas and / or washing liquid containing the impurities from the moist inert gas (TG moist);in particular wherein the discharge means (6) is designed as a direct and / or indirect connection, in particular via the second feed means (3), between 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) and volatile impurities-free inert gas (TG dry), preferably as a transport line for dry (dried) and volatile impurities-free inert gas (TG dry) and for the direct and / or 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 (TG dry, TG moist) takes place;and / or in particular wherein the discharge medium (7) is configured as a connection between the recycling device (T) and the washing device (W) and / or in particular wherein the discharge medium (7) is configured as a transport line for water or moisture and / or washing liquid resulting from the treatment of the inert gas with the volatile impurities from the moist inert gas (TGfeucht), in particular as a transport line for water or moisture and / or washing liquid resulting from the treatment of the gas with the volatile impurities from the moist inert gas (TGfeucht) and is configured to connect the recycling device (T) and the washing device (W), in particular such that recycling and / or recirculation of water or moisture and / or washing liquid resulting from the treatment of the gas with the volatile impurities from the moist inert gas (TGfeucht) takes place.; Device according to one of the preceding claims, wherein the device is configured to carry out a method according to one of the preceding method claims. Device according to one of the preceding claims, characterized by one or more of the features of the method claims (claims 1 to 30). Production plant for the manufacture of aliphatic or cycloaliphatic nitrate esters (nitric acid esters), wherein the production plant comprises: (i) a nitration unit (PNE), in particular with one or more reaction vessels (nitration reactors), for carrying out the nitration, in particular for the manufacture of 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 and / or following the nitration unit (PNE) in the production line, a separation device, in particular a separator (separator),in particular for the separation of nitrating acid from nitrated crude products (crude nitrate esters); (iii) arranged downstream and / or downstream of the nitration unit (PNE) and any separation unit present in the production line, at least one washing unit (W) for washing crude nitrate esters (NEroh) obtained from a manufacturing process and / or originating from a production unit (PNE) with a washing medium, with a downstream and / or downstream separation unit for separating the washing medium from the washed crude nitrate esters (NEfeucht); (iv) arranged downstream and / or downstream of the washing unit (W) in the production line, at least one purification and / or drying unit (K), in particular a column, for drying and / or purification, in particular drying and purification, of the washed crude nitrate esters (NEfeucht) obtained from the washing unit (W),wherein the cleaning and / or drying device (K) comprises a first feed means (2) arranged 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 (NE wet) into the cleaning and / or drying device (K), and a second feed means (3) arranged in a lower region (KS), in particular column sump, 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 contacting, in particular for flowing through, the washed crude nitrate esters (NE wet) with the dry inert gas (TG dry), in particular wherein the means for contacting, in particular for flowing through, are configured such thatthat water present in the washed crude nitrate esters (NE wet) is removed and simultaneously and / or similarly, in particular during the production and / or washing of the nitrate esters, volatile impurities arising while obtaining dry (dried) nitrate esters (NE dry) free of volatile impurities are removed; downstream in the process direction and / or downstream of the cleaning and / or drying unit (K), (v) downstream in the production line and / or downstream of the cleaning and / or drying unit (K), in particular a column, at least one recycling unit (T) for recycling and / or recirculating the inert gas (TG dry, TG wet), wherein the recycling unit (T) comprises separators 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 separating means are designed such that water or moisture and the volatile impurities are separated from the moist inert gas (TGmoist), in particular by means of condensation and / or washing, preferably condensation and washing, to obtain a dry (dried) inert gas (TGdry) free of volatile impurities; in particular wherein the recycling device (T) also comprises a third feed means (5) arranged in particular between the upper area (KK), in particular 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 (TGmoist), in particular loaded with water and / or the volatile impurities, from the cleaning and / or drying device (K) to the recycling device (T). Production plant for the manufacture of aliphatic or cycloaliphatic nitrate esters (nitric acid esters), in particular a production plant according to claim 48, wherein the production plant comprises: (i) a nitration unit (PNE), in particular with one or more reaction vessels (nitration reactors), for carrying out the nitration, in particular for the manufacture of 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 and / or following the nitration unit (PNE) in the production line, a separation unit, 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 following the nitriding unit (PNE) and the separating unit that may be present, a device according to any of the preceding claims (claims 31 to 47).; Production plant according to claim 48 or claim 49, wherein the production plant is configured to carry out a process according to one of the preceding process claims (claims 1 to 30). 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 apparatus claims (claims 31 to 47). 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, in particular for the removal of water and of volatile impurities, especially those arising during the production and / or washing of the nitrate esters. 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, in particular for the removal of water and of volatile impurities, especially those arising during the production and / or washing of the nitrate esters, by contacting, in particular by flowing, the aliphatic or cycloaliphatic crude nitrate esters with the inert gas, in particular such that water present in the washed crude nitrate esters is removed and, at the same time and / or in the same way, volatile impurities, especially those arising during the production and / or washing of the nitrate esters, are removed. Use according to claim 52 or claim 53, wherein (a) the crude nitrate esters obtained from a manufacturing process are first subjected to washing with a washing medium, followed by separation of the washing medium, and (b) subsequently the washed crude nitrate esters obtained in this way are subjected to drying and / or purification, preferably drying and purification, by contact, in particular by flowing through, an inert gas, in particular such that water present in the washed crude nitrate esters is removed and volatile impurities arising in the manufacture and / or washing of the nitrate esters are removed simultaneously and / or in the same way. 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. Use according to any of the preceding claims, characterized by one or more of the features of the method claims (claims 1 to 30) and / or the apparatus claims (claims 31 to 47) and / or the production plant claims (claims 48 to 51).

Images