Method and device for the separation of strongly adsorbent materials for the suppression of the adsorption effect in purification plants

Abstract

Process for the separation of strongly adsorbent materials for the elimination of odors and for the suppression of the adsorption effect in regenerative exhaust air purification plants by separation of functional groups and / or partial oxidation into non-adsorbent or weakly adsorbent materials as well as into non-adsorbent or weakly odorous materials, characterized in that a waste gas containing these materials is brought into intensive contact, at a temperature of 200°C to 450°C, with a substance or a mixture of substances having a large internal and / or external surface area. Figure 1

Description

Title of the invention: Method and device for the separation of strongly adsorbent materials for the suppression of the adsorption effect in purification plants

[0001] The invention relates to a method and a device for the separation of adsorbent materials for the suppression of the adsorption effect in regenerative stale air purification plants. State of the art

[0002] Regeneration of stale gas or stale air means the removal of harmful components from the gas phase. The terms stale gas and stale air are used unequally.

[0003] Waste gas cleaning is the removal of harmful components from air and waste gases. For the removal of solid and liquid components contained in the waste gas, dust removal, aerosol separation and flue gas cleaning processes are used. For gaseous components, but also for solid, liquid or droplet-like components, absorption, adsorption, catalytic cleaning, thermal cleaning, post-combustion, etc. processes can be applied, depending on the chemical and physical characteristics of the components. The skilled person will be aware of the details of these processes as well as the fact that these processes sometimes overlap and are sometimes used in combination with each other. For this reason, some aspects of these are presented briefly below, insofar as they are of interest or may be of interest with regard to the background of the invention.

[0004] Adsorption processes are used both for the purification of industrial waste gases and in domestic technology, for example in extractor hoods. By depositing porous adsorbents on the inner surface, harmful air components, in particular hydrocarbons, are removed from the waste gas to be purified. For this purpose, for example, fixed-bed, moving-bed, rotor, fluidized-bed and entrained-flow adsorbers can be used. Thus, for example, it is known to extract volatile organic hydrocarbon compounds (VOCs) from a low-concentration waste air flow and to convey the adsorbed solvents in a subsequent high-concentration waste air flow to the further treatment.

[0005] Chemical air purification plants use, for example, absorption scrubbers to separate different materials contained in the stale air. Depending on Henry's constant, temperature, pressure and transport acceleration by a continuation of the chemical reaction in the liquid phase, eff efficiencies of 95% up to >99% can be achieved; and for this reason, scrubbers are suitable for the separation of, for example, HCl, NH3, HF, NOX, formaldehyde, H2S, SO2, SF6, mercaptans, amines, ketones, alcohols.

[0006] Non-aqueous washing agents having low vapor pressure, such as biodiesel, anthracene, amines, Genosorb® or ionic liquids are also known, which are better suited for certain compounds and under certain conditions.

[0007] Thermal stale air purification plants are often used when biological and chemical stale air purification processes cannot be implemented effectively. Thermal processes include recuperative thermal oxidation,

[0008] regenerative thermal oxidation and catalytic oxidation.

[0009] Special aspects must be taken into account when eliminating odors. Instead of talking about cleaning stale gas, we should rather talk here about cleaning stale air.

[0010] Odor emissions regularly cause significant nuisance to neighborhoods. Their elimination or reduction is even required by law in many countries.

[0011] and is the subject of numerous bilateral and multilateral treaties.

[0012] Odors often result from a mixture of materials containing up to several hundred individual materials. For this reason, odors are also referred to as a sum effect of a plurality of individual materials, each of which is laden with an odor.

[0013] Several hundred individual materials and gases having the most diverse concentrations and characteristics can contribute to an odor and can contain water-soluble or non-water-soluble materials, organic or inorganic materials, etc.

[0014] For the reduction of odor emissions, scrubbers, bio-scrubbers, bio-filters, adsorbers, chemical scrubbers or thermal installations are used, all of which are subject to fundamental problems since they do not capture the aforementioned sum effect in a general way and, thus, cannot eliminate it either.

[0015] This sum effect is, among other things, the result of odor intensity, i.e. the intensity of the odor sensation that is triggered by olfactory stimulation. Odor intensity increases in general, when the concentration of the odorant increases. Odors are received by the human nose which contributes, together with the other sensory organs, to the sensation of considering such odor emissions as significant and thus as harmful effects on the environment. Furthermore, i.e. in addition to odor intensity, the sum effect is related to hedonic (it smells good, bad, neutral) and the distribution of effects depending on the time of day and the season. The strength of an odor is therefore essentially determined by three measurement values, namely by the concentration of the odorant, by the intensity of the odor and the hedonic effect of the odor.

[0016] It is therefore due to this complexity that the pollutant air purification technologies known from the state of the art often fail to significantly reduce or even eliminate odor emissions with their plurality of presentation forms, so that, regularly, the state of the art is only rarely able to offer, with the known modeling of calculations of the process technology, pollutant air purification systems suitable for general use.

[0017] Based on these disadvantages of the state of the art, it is an object of the present invention to provide a method and a device for cleaning polluted air from odor emissions, which can be implemented or used universally, which is economical and which only requires low temperatures.

[0018] These aspects are solved with a method according to claim 1 and with a device according to claim 6. Preferred embodiments are disclosed in the dependent claims. Summary of the invention

[0019] The invention relates to a method and a device for the separation of strongly adsorbent materials for the suppression of the adsorption effect in regenerative exhaust air purification plants, which occurs due to the fact that, according to the regenerative principle, the heat exchange medium comes into contact, alternately, with uncleaned exhaust gas and cleaned exhaust gas, the temperature of the cleaned exhaust gas being, due to the thermal efficiency coefficient of, usually, 95 to 97%, 23 to 40 °C higher than that of the uncleaned exhaust gas and, thus, in the first process step of the regenerative heat exchange, strongly adsorbent materials adsorb on the large surface thereof, in particular at the cold end thereof and, thus, on the side of the exhaust gas inlet, and in the second process step, they are desorbed from there, together with the cleaned exhaust gas more hot,and arrive in an unpurified manner in the chimney or in the environment.

[0020] According to the invention, a substance or a mixture of substances having a large inner surface is used, which can be realized, for example, in the form of bulk material or as a layer applied as a washcoat on a ceramic honeycomb support, and is brought into intense contact with the stale gas at a preferential temperature of 200 to 450 °C, whereby the strongly adsorbent materials, whether due to their polarity, their molecular weight, their low volatility or their possibility of forming hydrogen bonds, are transformed, by separation of functional groups and / or partial oxidation, into non-adsorbent materials or adsorbents to a significantly lesser degree.

[0021] The required temperature is either already provided by the temperature of the stale gas or is reached, according to the device described here, using a regenerative or recovery heat exchanger, the energy input necessary for this coming entirely or partially from the separation or partial oxidation reaction and, where appropriate, the remainder coming from external energy, whatever its form.

[0022] Organic materials possibly deposited over time in the heat exchanger can be completely oxidized, from time to time, by baking or pyrolysis by raising the temperature to 400 to 450°C.

[0023] According to one aspect, there is provided a method for the separation of strongly adsorbent materials for the removal of odors and for the suppression of the adsorption effect in stale air regeneration plants by separation of functional groups and / or partial oxidation in non-adsorbent or less adsorbent materials and in materials carrying little or no odor, characterized in that a stale gas containing these substances is brought into intensive contact, at a temperature of 200°C to 450°C, with a substance or mixture of substances having a large internal surface area and / or a large external surface area.

[0024] According to one embodiment, the substance, or mixture of substances, having a large inner surface and / or a large outer surface is provided with a layer formed as a bulk material or with a layer applied as a washcoat on a ceramic honeycomb body.

[0025] According to one embodiment, the substance used, or the mixture of substances, having a large interior surface area and / or a large exterior surface area preferably consists of extremely porous aluminum oxide, titanium oxide, or mixtures thereof.

[0026] According to one embodiment, the substance used, or the mixture of substances, having a large inner surface and / or a large outer surface is extruded into a honeycomb body, preferably from extremely porous aluminum oxide, titanium oxide, or powder mixtures together with clayton or other extrudable materials, fired and used for the purposes cited.

[0027] According to one embodiment, the temperature required for the separation or partial oxidation of the highly adsorbent materials in the stale gas is reached by the release of energy during the partial oxidation or is made available partially or entirely by external energy.

[0028] According to one embodiment, in the case of use of a recuperative heat exchanger, the latter can be brought to 400°C - 500°C by means of varying the cycle time to free it by pyrolysis from any organic deposits.

[0029] According to one aspect, there is provided a device for the separation of strongly adsorbent materials for the suppression of the adsorption effect in waste gas purification plants, characterized in that, in this device, the waste gas containing strongly adsorbent materials is brought into intensive contact at a temperature preferably of 200 °C to 450 °C, with a substance or a mixture of substances having a large internal surface, which makes it possible to modify the strongly adsorbent substances by separation of functional groups and / or partial oxidation in such a way that they no longer adsorb or adsorb much less.

[0030] According to one embodiment, the substance used is in the form of a bulk material or a layer applied as a washcoat on a ceramic honeycomb body or as an extruded honeycomb body.

[0031] According to one embodiment, the temperature required for separation and partial oxidation is achieved by heat displacement using a regenerative or recuperative heat exchanger, the residual energy contribution required for this being able to come from partial oxidation or from energy supplied from outside, regardless of the form.

[0032] According to one embodiment, the recuperative heat exchanger may be a fixed bed, ceramic honeycomb bed, fluidized bed, or rotating or cyclone heat exchanger.

[0033] According to one embodiment, the recuperative heat exchanger can be brought to 400°C to 450°C by varying the cycle time to free it, by pyrolysis, from any organic deposits.

[0034] Description of the embodiments

[0035] The following findings and contexts form part of the basis of the invention:

[0036] Individual substances causing odor emission include, to a large extent, high-boiling compounds. These pose a problem for the purification efficiency of, for example, an RTO (regenerative thermal oxidation) plant, since they cannot be sufficiently reduced by it.

[0037] Tests by the applicant with such an RTO installation have shown that, especially when the concentrations of the odorous substances are low and when they are high-boiling point compounds, it may happen that, instead of an expected purification efficiency of 99.8% that the applicant obtains for his non-ad- With the triple-bed system he uses, he only achieves a maximum of 30% to 40% for such odorous substances. Even a value of 40% is low when compared to the 99.8% stale gas cleaning achieved for the usual substances to be cleaned. In this case, it is no longer justified to use a high-investment cost stale air cleaning solution for the reduction of odorous substances, even if the RTO system is the most robust form and is also one of the most efficient and cost-effective systems for stale gas cleaning.

[0038] This also includes the fact that, especially with regard to odorous substances which are used in the aroma industry or in the manufacture of perfumes etc., but which also include other unpleasant odors such as those from rendering or slaughterhouses, these are most often strongly adsorbing substances which produce their effect already at low concentrations, i.e. which have a very low odor threshold, and which can therefore be harmful even at low concentrations.

[0039] Likewise, in the present invention, it is taken into account that odorous substances rarely contain hydrocarbons in such a high concentration that their combustion in itself already provides a significant calorific value. That is, heating would have to be added during the intended removal of odorous substances in order to obtain the required combustion temperature. This greatly increases the energy requirement, when one thinks of the usual temperature ranges for such purification processes, which are approximately 600 °C to 900 °C and above.

[0040] For this reason, the applicant has designed the method and the device in such a way that additional heating can be limited to low values, so that the method can be carried out at the lowest possible temperature. Furthermore, with this method, a lowering of high boiling points or a high adsorption tendency of the chemical compounds concerned can be achieved.

[0041] For this reason, a complete oxidation of the chemical compound concerned during the purification process is not necessarily necessary, but the purification process is designed in such a way that the odor can be eliminated or in any case greatly reduced.

[0042] For this purpose, the adsorption or adsorption capacity of the chemical compound concerned is reduced, which is achieved by separation of its functional groups and / or by partial oxidation, which is explained below in more detail.

[0043] Since the chemical compounds additionally have a high boiling point, the compounds responsible for the emission of odors are first, as it were, divided into smaller parts by the separation of functional groups that cause the high boiling point, and / or they are subjected to partial oxidation.

[0044] As an example, the known alcohol group can be mentioned, since this can form hydrogen bonds that greatly increase the boiling point. By separating only the OH group from the compound, this is sufficient for the boiling point to drop significantly and significant adsorption to no longer occur.

[0045] Preferably, a compound is separated only at the most unstable location, and two individual molecules are produced.

[0046] Alternatively, a functional group may be modified or separated. Thus, in general, the odor is already eliminated. The compound does not need to be separated completely.

[0047] With this method, surface-active substances, i.e. substances having a large inner surface area, are used. Preferred are special forms of aluminum oxide or titanium oxide, the latter being particularly preferred since it is acid-resistant.

[0048] With surface-active substances, i.e. substances with a large inner surface area, for example aluminium oxide or titanium oxide or mixtures thereof, it is possible to separate compounds essentially also at low temperatures between 200°C and 400°C.

[0049] At 400 °C, many compounds can already be completely oxidized. When it comes to thermally stable compounds, it is rather carbon that remains, but which can be completely oxidized, to give CO2, by an occasional baking at 450 °C.

[0050] The aim is to carry out the purification at the lowest possible temperature, where there is no carbonization yet, in order to be able to satisfy the lowest possible energy requirements.

[0051] With odor applications, it is rarely the case - as already mentioned - that these stale gases have a high energy content. Thus, when heating to only 200 °C to 300 °C is required, instead of 800 °C for example, this constitutes an enormous advantage due to the energy savings. This is an essential aspect of the invention.

[0052] The invention offers two possibilities for this:

[0053] The method and the device can be implemented or used on their own, i.e. autonomously and independently of other purification methods or other devices. The chemical substance, or chemical substances, or respectively the gas, from the odor emission is purified / are purified to such a degree that the desired goal is completely or essentially achieved, that the odor emission is completely or essentially eliminated. The part of the gas which is therefore not purified may contain residues of hydrocarbons, carbon monoxide CO and others but can nevertheless be considered satisfactory with regard to the desired reduction of the odor emission.

[0054] When the total concentration of the unseparated part of the gas, i.e. approximately the unpurified part of hydrocarbons, carbon monoxide, is so low that it is below an emission limit value set for example by law, this technology used autonomously and independently, constitutes, for this reason alone, an effective possibility. In addition, the odor is reduced or eliminated.

[0055] On the other hand, the aforementioned system, first and independent, can be used as a pre-purification step. For example, the method and the device can be placed before an RTO installation or a rotor concentrator in order to destroy precisely the high-boiling compounds, so that they can no longer constitute a hindrance in the subsequent purification. This ensures that there is no further impairment of the purification efficiency in the following purification step.

[0056] If these odorous substances are pre-separated in such a way that substances without a high boiling point result or these substances lose their high boiling point characteristic, the substances remaining after this purification phase can then be completely separated in an RTO plant. This provides the advantage that the RTO plant can purify everything that is fed to its combustion chamber. Complete combustion is carried out, resulting in CO2 and water. Thus, only a pre-purification is required, by means of which the high boiling point substances are converted into substances without a high boiling point. This is precisely what the present invention achieves. The high boiling point substances are separated or modified to such an extent that they no longer have a high boiling point.

[0057] Thus, the invention can be used independently of any other exhaust gas or exhaust air cleaning plant, for example an RTO plant, solely for removing odorous substances. As a result, a stand-alone system is created. On the other hand, the invention can also be part of an integrated exhaust air cleaning with several processes in series.

[0058] The invention is therefore configured, according to the explanations given above, to separate odorous substances using its method and its device.

[0059] Odorous substances have functional groups and are often strongly adsorbent substances.

[0060] To separate means to break the bond. A molecule consists, for example, of several atoms which are linked together by bonds. In the invention, a bond is broken. Thus, from one molecule, two or more molecules are produced. The molecules thus produced no longer constitute the same compounds.

[0061] Adsorbent substances are known to those skilled in the art.

[0062] Adsorbent substances include, for example, ammonia or phenol. It is on these that the following explanations must be addressed "pars pro toto" for all odor-emitting substances. Both substances are intensely odorous substances to which the invention relates in the same way, although they are very different in their boiling characteristics. The invention is therefore able to achieve a reduction in olfactory discomfort also for such different substances.

[0063] Phenol is a so-called high-boiling substance since it boils at only 181°C. Furthermore, phenol is strongly adsorbent since two other effects are important, namely the polarity of a bond, on the one hand; the more polarized a chemical substance is, the more adsorbent it is; this is even more valid, when the substance can form hydrogen bonds, i.e. includes an OH group such as phenol. On the other hand, phenol is an aromatic alcohol; due to its aromatic nucleus, the electrons are delocalized; this exerts an influence on the OH bond. For this reason, phenol is strongly adsorbent.

[0064] Usually, in an RTO plant with a triple-bed system, a purification efficiency of at least 98% is still achieved for a substance with a molecular weight such as that of phenol or with a boiling point of the order of 180 °C to 200 °C. However, for phenol, when the raw gas temperature is very low, i.e., for example, below 50 °C, the purification efficiency drops to approximately 90%; at a raw gas temperature of 100 °C, a purification efficiency of approximately 95% is still achieved, but it is almost impossible to achieve a higher purification efficiency. Thus, in this example case of phenol, even with a triple-bed RTO plant, a purification efficiency of a maximum of approximately 95% is achieved, whereas, in relation to the boiling point, 98% should be achievable. But phenol is strongly adsorbent since it is a polar-bonded substance with high volatility.

[0065] The skilled person will obviously know that, apart from the mentioned aspects of the high boiling point characteristic, charge distribution and volatility also play a role. This is best measured by means of the evaporation coefficient. The evaporation coefficient of a molecule is most often indicated in comparison with another molecule; then the time factor is included, which is indicated as a number. It goes without saying that for different substances, different number values ​​must be taken into account; the faster a substance evaporates, the higher its evaporation coefficient.

[0066] On the other hand, the skilled person also knows that substances with a high boiling point should evaporate slowly at a low temperature or have a low vapor pressure and are nevertheless very volatile and can evaporate quickly; starting from the boiling point or vapor pressure alone, one could not This is not to be expected, but it can result from high volatility. This is all related to the surface tension and the shape of the molecule, i.e. whether the molecule has a spherical shape or is an elongated molecule.

[0067] Ammonia, also mentioned above, is a toxic gas with a strong odor. The reduction of NH3 is often made mandatory by various laws (see BImSchG (Bundes-Immissionsschutzgesetz; Federal Emission Protection Act), TA-Luft (Technische Anleitung zur Reinhaltung der Luft; Technical Instructions on Air Quality Control), GIRL (Geruchsimmissions-Richtlinie; Odor Emissions Directive)). Ammonia is readily soluble in water. Ammonia is, in principle, not a high-boiling substance. Ammonia has a boiling point well below 0 °C and is therefore, at room temperature, a gas; despite this, ammonia adsorbs on surfaces. If ammonia is to be scrubbed, for example in an RTO plant, the scrubbing effect depends on whether the exhaust gas is dry or wet; dry ammonia hardly adsorbs.

[0068] With a polluted gas, such as exists in mechanical biological waste treatment plants, due to the heat exchanger, the ceramic surface is always moist by the humidity of the polluted gas. In the lower zone where it is cold, water vapor is sufficient which adsorbs on the ceramic, and in the adsorbed water, ammonia goes into solution or ammonia binds to the adsorbed water. But even then, only a purification efficiency of 95% is achieved for ammonia instead of the targeted purification efficiency of 99.8%. This is due to the good solubility of ammonia in water as well as the polarity.

[0069] Similarly, dust deposits can adsorb other substances and aerosol deposits can absorb other substances and can thus lead to a significantly higher adsorption / desorption efficiency.

[0070] The above explanations therefore show that and why traditional installations for purifying stale gas or stale air only achieve limited results in reducing or eliminating odor emissions. All this is solved by the present invention which, however - as the example of ammonia shows - is not limited to compounds having a high boiling point.

[0071] With regard to the reduction or elimination of olfactory discomfort by separation, the following should be mentioned:

[0072] Most substances that emit an odor include a functional group.

[0073] This functional group can be one of hundreds of different groups such as, for example, an aromatic nucleus (-aryl group) or it is an alcohol group (-OH group) or a carbonic acid group (-COOH group) or a thiol group. (-SH group) or it is a primary, secondary or tertiary amine (-NH2, -NHR or -NHR1R2 group) which is linked to a hydrocarbon structure.

[0074] When separating such a functional group from a molecule at low temperature, it resembles a catalytic reaction, with the essential difference that precious metal or Cu-Mn catalysts would have a higher purification capacity at the beginning, but they can be poisoned very quickly since they are very sensitive, for example, compared to larger molecules, hydrothermal aging, sulfur or halogen compounds and a plurality of inorganic elements such as heavy metals, phosphorus, sodium, potassium, arsenic, lead, mercury and many others.

[0075] Poisoning does not occur or does not occur irreversibly when using, already mentioned briefly above, substances or mixtures of substances such as aluminum oxide or titanium oxide, since each of these substances is very inert. TiO2 is not sulfated by SO3 either.

[0076] However, for the separation of functional groups, slightly higher temperatures are required than with a precious metal catalyst. Nevertheless, the temperature can be kept relatively low, since many compounds can be separated already at low temperatures such as, for example, 200 °C.

[0077] 200°C to 300°C are sufficient for most applications. At temperatures up to 450 °C, the separation of its functional groups, carried out according to the invention, into non-adsorbing substances or substances that adsorb to a significantly lower degree, occurs for practically every chemical substance.

[0078] In most cases, this is accompanied by partial oxidation.

[0079] This means that complete oxidation is not necessarily sought since separation or partial oxidation is sufficient for odor suppression and / or reduction of the adsorption tendency. Frequent products resulting from separation are short-chain hydrocarbons and carbon monoxide.

[0080] When the process is used as pre-purification, the remaining hydrocarbons and carbon monoxide can be removed, for example, in a subsequent RTO plant, in a known conventional manner.

[0081] If, on the other hand, the process is applied as a stand-alone system and independent of other purification plants, in a very large number of cases, the concentrations of remaining hydrocarbons and carbon monoxide will be so low that, after this separation, no emission problem persists in relation to its remaining values, and that, in any case, the odor is reduced, or even completely eliminated.

[0082] Thus, the separation of functional groups from the chemical or molecule for high boiling materials means that the boiling point drops because at least two smaller molecules are produced.

[0083] Similarly, the initial functional group also does not retain its initial shape since it is also modified during separation. And the polarity and adsorption tendency also change.

[0084] The method means that, regardless of whether high-boiling or non-high-boiling odor-causing materials are concerned, for almost every chemical material, the separation of its functional groups carried out according to the invention leads to non-adsorbing or significantly less adsorbing substances.

[0085] It is sufficient that the strong adsorption effect is eliminated, regardless of the types and quantities of the parts created.

[0086] The catalytic effect in the mentioned temperature range of 200 °C to 450 °C is achieved by the large surface area which is a combination of an inner surface with an outer surface. To these extremely stable compounds having a large surface area belong the mentioned aluminum oxide and titanium oxide which are also known as catalyst supports, since, due to their inert character and their large inner surface area, they are used as supports for precious metal or for metal oxide catalysts. Obviously, the invention is not limited to this.

[0087] Each compound in this sense is to be taken into account. Thus, compounds from the groups of silicate ceramics, magnesium oxide, zirconium oxide, zirconium oxide reinforced aluminum oxide, aluminum titanate, titanium dioxides, silicon oxides, carbides, nitrides are to be taken into account, to name but a few examples. But fiber ceramic composite materials and metal matrix compounds will be taken into account by the person skilled in the art.

[0088] The skilled person knows that all catalytic installations are used to convert hydrocarbons, during the purification of polluted air, generally >99.9%, into CO2 and water. For the purposes of the present invention, this is not necessary at all. For this reason, it is not necessary to use precious metal catalysts or other oxidation catalysts, which could also do this, albeit with a short lifetime. Instead, robust substances, or mixtures of substances, i.e. materials with a large surface area, will be used. These materials may not give complete oxidation but at most give a few internal bond breaks. But this is sufficient as long as the odor is eliminated or when the odor has been transformed from a very unpleasant odor to a bearable odor. An essential aspect is then that the adsorbent characteristics are eliminated.

[0089] Known installations for cleaning stale gas or stale air, such as RTO installations, do not have the high cleaning efficiency for adsorbent materials. Alternatively, an RTO system could also be used for odor removal. When adsorbent materials are involved, the cleaning efficiencies can drop by up to 40%. Especially in this case, it is advantageous to have a pre-cleaning system according to the invention, with which, among other things, the high-boiling compounds are separated, so that they are no longer high-boiling compounds. Then, the remaining materials can be fed to the RTO system to achieve the high cleaning efficiency relating to this part.

[0090] According to the invention, a substance, or a mixture of substances, having a large inner surface area and / or a large outer surface area is used.

[0091] This can be done in the form of a bulk substance or a layer applied as a washcoat on a ceramic honeycomb body, the odor-emitting material being brought into intensive contact with the substance at a temperature of 200°C to 450°C, whereby the strongly adsorbing substances, by separation of functional groups and / or partial oxidation, are transformed into non-adsorbing or significantly less adsorbing substances, whether due to their polarity, molecular weight, low volatility or their possibility of forming hydrogen bonds. By this, the desired effects of reducing or eliminating odor emission and lowering the adsorption tendency occur.

[0092] The mixture of substances has a large inner surface area and / or a large outer surface area, which can be achieved by the aluminum oxide or titanium oxide cited as an example.

[0093] A mixture of substances within the meaning of the invention is a composition of two or more substances which do not form a bond with each other. There is no reaction between the substances. As a synonymous term, the term mixing can be used.

[0094] There may also be a preparation.

[0095] The mixture of substances is presented either as a deposit of bulk material or as a washcoat on a monolithic support having a honeycomb structure.

[0096] The substances in this mixture have a large internal surface area.

[0097] A large internal surface area is defined as a substance having a surface area of ​​significantly more than 10 to 20 m2 per gram. Large internal surfaces have, for example, a surface area of ​​100 to 1000 m2 per gram.

[0098] The inner surface is given by the fact that the substance has porous structures. It is in these structures that adsorbent and / or high-boiling substances can penetrate or diffuse.

[0099] The molecules can react on the surface of the porous structure of the substance and they are then separated.

[0100] When reactions need to be accelerated, a particularly large total surface area is required. This is most easily achieved by providing a large internal surface area. This results in a large surface area in a small space.

[0101] According to an alternative embodiment, for a substance not having a large interior surface area, the exterior surface area can be enlarged.

[0102] This can be achieved by shredding or grinding a substance. By this, the larger surface area of ​​the resulting particles is made usable.

[0103] Another embodiment of the invention may be a system with small pellets by which a large surface area is also obtained. Here, a pellet structure can be used, since with the help of the small pellets, a large outer surface area is obtained in addition to the inner surface area.

[0104] A desired goal is then that both the inner surface and the outer surface are as large as possible.

[0105] Yet another embodiment of the invention is based on the following idea: In order to make the process more dust resistant, given the use of such substances, it is preferred to use a honeycomb structure and to apply the substance in the form of a washcoat coating.

[0106] This results in a structure of honeycomb bodies which are provided with a coating.

[0107] The honeycomb body then has a large outer surface. Inside the honeycomb body, the surfaces of the inner channels of the honeycomb body are to be added to the surface. By means of the honeycomb body, a large outer surface and a large inner surface can be obtained. An enlargement of the material inner surface and, in addition, an enlargement of the outer surface by the ceramic support (honeycomb body) are obtained inside it.

[0108] When using, for example, a ceramic honeycomb having dimensions of 150 x 150 x 300 mm with 60 x 60 channels, this results in an external surface area of ​​1000 square meters per cubic meter. This result is to be multiplied by the internal surface area of ​​the washcoat.

[0109] When the washcoat has 200 m2 per gram and when there are about 100 g per element, this gives 147 elements per cubic meter. This results in 2.8 million m2 of surface area per cubic meter of ceramic honeycomb.

[0110] The honeycomb body is preferably to be used only together with the washcoat.

[0111] The manufacture of honeycomb from pure titanium oxide or pure aluminum oxide is not possible on a large industrial scale; however, one could extrude, for example, mixtures of clayton and aluminum or titanium oxide powders.

[0112] The passages in the honeycomb body do not get clogged so much by the dust, since in the honeycomb body there is mainly a laminar flow. Depending on whether or not there is dust in the stale gas, the corresponding geometry can be chosen.

[0113] Furthermore, it is considered appropriate to use activated carbon honeycombs. For this purpose, clayton is mixed with activated carbon and is extruded.

[0114] A honeycomb can also be made of any material other than the aluminum and titanium oxides mentioned as examples.

[0115] According to the invention, it is not strictly necessary to have a ceramic honeycomb as the basic body which is then coated. It is also possible to produce a paint from the metals mentioned, without coating.

[0116] With or without a honeycomb body, the aim is to obtain, by selecting the mixture, with a large internal or external surface, a composition of materials which allows the explained separation of functional groups.

[0117] Although all the details of the physical and chemical processes of the separation of functional groups are not yet fully elucidated, the applicant starts from the following contexts:

[0118] The enlargement of the surface is necessary, since the gas, the odorous substance, must find a path through the structures. When using substances of the kind described above, the gas can pass or diffuse through the numerous interstices between the pellets, the honeycombs, the porous structures of the substances, i.e. their channels, between the phases etc.

[0119] This goes from bottom to top or side to side, left to right, or top to bottom.

[0120] The flow of odor-laden gas diffuses or passes through the mixture and its interstices or channels of all kinds.

[0121] At the temperature described above, fusion is very strong. When a molecule passes through the mixture, it does not stay on this path, because of the thermal movement. The molecule is jostled in one direction and the other and slides all the time in one of the interstices or channels and "gets lost" there.

[0122] The molecule enters the channels and at some point touches the surface of the mixture. The molecule hits an active surface. On this active surface, the molecule is briefly immobilized and separation is carried out.

[0123] Therefore, separation is initiated when these molecule parts pass through the channels or interstices of the mixture. The molecule impacts the solid matter of the substance material.

[0124] The molecules do not just collide. Rather, they are absorbed into active areas of the solid matter of the substance material.

[0125] In this context, by way of example, reference is made to the reaction of the molecule, for example R-OH with an oxygen molecule O2: a molecule in the stale gas is retained by the surface, then, by a reaction with O2, a RH and H2O as well as a free radical O can be formed, the latter reacting with another R-OH to give RH and H2O. The reaction is thus completed. The rest again results from the bonding location.

[0126] The separated molecule that adsorbs less strongly and has lost, reduced or changed its odor, returns to the stale gas flow and continues to circulate. This is then the separated molecule.

[0127] The separated molecule can react again with the surface of the mixture and can be separated again.

[0128] In this way, the functional groups are separated from the molecules. The odorous part of the molecule is therefore separated.

[0129] For example, when separating thiols, two molecules are formed: the alkyl residue which binds with the H radical of the -SH group, and SO2 which is formed from the S of the -SH group and O2. SO2 has a significantly higher odor threshold than a thiol. Therefore, the odor concentration is greatly reduced when converting thiols to SO2 and an alkane.

[0130] The mechanism at its base can be explained as for catalysis. In order to arrive from starting materials to products, a reaction path can be followed. The starting materials can have a lower or higher energy level than the products, and we therefore speak of an endothermic or exothermic reaction. When the starting materials and the products are stable, the transition state is always higher than the higher energy level of the two.

[0131] A catalyst can then make possible a new reaction path with a significantly lower energetic transition state by stabilizing the latter.

[0132] By providing a large inner surface and / or a large outer surface, a second reaction path is possible which only requires a significantly lower activation energy. By this, the bond is already separated at a significantly lower temperature. Brief description of the drawings

[0133] The invention will be described below with reference to the following exemplary embodiment to which it is obviously not limited.

[0134] Represented are:

[0135] [Fig-1]: the device for implementing the process for regenerative thermal oxidation (RTO) in the form of a turret,

[0136] [Fig.2]: the device for implementing the process with a recuperative heat exchanger and

[0137] [Fig.3]: a device for implementing the process for the regenerative purification of stale gas with two heat exchangers arranged next to each other and a central heating system for the supply of thermal energy. Example of realization

[0138] [Fig.l] shows a device for the regenerative purification of stale gas, with a flow of stale gas 1.

[0139] [Fig.l] comprises two heat exchangers 2 in the middle of which a substance 4 is shown. The substance 4 is preferably in the form of a bulk material or as a ceramic honeycomb support 9.

[0140] Between each of the heat exchangers 2 and the substance 4, a respective heater 10 is provided to provide thermal energy.

[0141] In [Fig.l], a conduit system 11 is provided.

[0142] The stale gas of the stale gas stream 1 is introduced into the conduit system 11 by a pump 12.

[0143] According to a top view in [Fig.l], a respective valve 13 is arranged on the upper face and respectively on the lower face of the conduits 11.

[0144] Alternately, in accordance with arrows 13 and 14, the stale gas 1 is transported, according to arrow 13, towards the valve 15 of the conduit 11.

[0145] The same is valid, correspondingly, for the stale gas which is transported in the conduit 11, following the arrow 14, towards the valve 16.

[0146] The stale gas is conveyed, via the valve 15, to the upper heat exchanger 2; 17.1.

[0147] In relation to this, alternately, the stale gas 1 is conveyed, following the arrow 14, to the valve 2; 16.

[0148] Via the valve 2; 16, the stale gas 2 is introduced into the heat exchanger 2; 18.

[0149] Starting from the respective valve 15; 16, the stale gas is introduced into the associated heat exchanger 2; 17.

[0150] The adsorbent substance contained in the stale gas is adsorbed on the exchangers 2; 17 and 2; 18.

[0151] The stale gas adsorbent substance 1 is adsorbed on the respective stale gas inlet 7 side of the respective heat exchanger 17; 18.

[0152] On the respective waste gas outlet sides of the heat exchangers 17; 18, after the waste gas has exited through the waste gas outlet sides 8 of the heat exchangers 17; 18, thermal energy 3 is fed, by the respective heaters 10, via the corresponding waste gas flow 1, to the waste gas adsorbent substance 1.

[0153] Following the heat conveyance, the stale gas 1 is introduced into a substance 4 which has a large interior surface 5, the substance 4 being a mixture of substances having a large interior surface.

[0154] Substance 4 is preferably maintained in the form of a bulk material.

[0155] Substance 4 can also be arranged

[0156] in a ceramic honeycomb support.

[0157] Alternatively, the substance may also be a quantity of pellets.

[0158] Further, the substance may also be a ceramic honeycomb support to which a washcoat coating is applied.

[0159] Alternatively, the substance may also be extruded, in a mixture with clayton, in the form of a honeycomb.

[0160] The adsorbent material contained in the stale gas 1 comes into contact with substance material inside the substance 4 in substance channels 19.

[0161] When the adsorbent material comes into contact with the material of substance 4, the adsorbent material separates functional groups.

[0162] Upon contact of the adsorbent material with the material of substance 4, the adsorbent material is at least partially oxidized.

[0163] The purified gas 20, purified in the heat exchangers 17; 18 and in the channels 19 of the substance 4, is released into the atmosphere.

[0164] [Fig.2] shows the device for implementing the method with a recuperative heat exchanger 21 which comprises a path 22 for purified gas as well as a path 23 for stale gas.

[0165] In [Fig.2], the stale gas 1 is conveyed to the path 23 for stale gas, using the pump 12 via the conduit 11.

[0166] The stale gas 1 is conveyed to the substance 4 via another conduit 11 in which the heater 10 is arranged.

[0167] With regard to the substance 4, reference is made to the corresponding paragraphs in relation to [Fig.l]. Correspondingly to [Fig.l], the substance 4 is preferably arranged in a bulk depot 9 and comprises the substance channels 19.

[0168] The stale gas 1 purified using the substance is introduced, via the conduit 11, into the path 22 for purified gas and is released into the atmosphere in the form of purified gas 20.

[0169] In [Fig.3], the stale gas 1 is conveyed to the heat exchangers 17 and 18 via the pump 12 and the conduits 11.

[0170] In the channels 11 carrying stale gas, valves 15 are shown.

[0171] The two heat exchangers 17 and 18 each comprise an individual stale gas inlet side 7 through which the unpurified stale gas is introduced into the heat exchangers 17; 18.

[0172] According to a top view in [Fig.3], a substance 4 is adjacent to the respective stale gas outlet side 8 of the heat exchangers 17; 18.

[0173] With respect to structure and function, the two substances 4 correspond to the two substances 4 described in connection with [Fig.l].

[0174] In the representation of [Fig.3], the heater 10 is arranged approximately in the middle between the two substances 4. The heater 10 supplies thermal energy 3 to the two substances 4 of [Fig.3].

[0175] As in [Fig.l], the two heat exchangers 17; 18 and the corresponding substances 4 are supplied with the stale gas 1.

[0176] After the finished purification of the stale gas 1 by the heat exchangers 17; 18 and the substances 4, the purified gas 20 is released into the atmosphere. Example 1

[0177] This example concerns a pilot test that was carried out by the applicant and is related to the manufacture of food and here with different flavors obtained from yeast extracts. The flavors are used, for example, for soup packs. These flavors make the soup taste like meat. In reality, there is yeast protein in the soups modified in taste by a Maillard reaction, not meat. Yeasts are inexpensive protein-rich substances that can be modified, by the Maillard reaction, into thousands of different tastes and at the same time form odor-active substances with a low odor threshold.

[0178] The applicant has initiated a pilot test and has seen that, precisely when the concentrations are so low and when it comes to high-boiling compounds, it cannot be ruled out that, when reducing odorous substances, an efficiency of between approximately 30% and at most approximately 40% can be achieved instead of the usual purification efficiency of 99.8% achieved for non-adsorbent materials with triple-bed systems of the RTO plant.

[0179] Example 2: Odour-laden waste gas from the odorant / flavouring industry, large volume flows of up to several hundred thousand Nm3 / h with a low load of harmful substances of a few mg / Nm3, for example 10 to 50 mg / Nm3 but with 105 to 106 GE / m3.

[0180] Example 3: Pollutant-laden exhaust gas from tire manufacturing, for which, due to carcinogenicity and mutagenicity as well as the harmful effect on fruit, lower emission threshold values ​​are to be set than for TOC in general, the pollutant gas also having a volume flow of up to several hundred thousand Nm3 / h and TOC concentrations of only 100 to 500 mg / Nm3. Reference numbers

[0181] 1 stale gas

[0182] 2 heat exchanger

[0183] 3 thermal energy

[0184] 4 substance

[0185] 5 inner surface of the substance

[0186] 6 medium

[0187] 7 stale gas inlet side

[0188] 8 stale gas outlet side

[0189] 9 bulk material

[0190] 10 heating

[0191] 11 conduit

[0192] 12 pump

[0193] 13 arrow (up)

[0194] 14 arrow (down)

[0195] 15 valve (top)

[0196] 16 valve (bottom)

[0197] 17 heat exchanger (top)

[0198] 18 heat exchanger (bottom)

[0199] 19 substance channel

[0200] 20 purified gas

[0201] 21 heat exchanger

[0202] 22 path for purified gas

[0203] 23 path for stale gas

Claims

Claims

1. A method for separating strongly adsorbent materials for odor removal and for suppressing the adsorption effect in exhaust air regeneration plants by separation of functional groups and / or partial oxidation into non-adsorbent or less adsorbent materials and into materials carrying little or no odor, in which an exhaust gas containing these materials is brought into intensive contact, at a temperature of 200°C to 450°C, with a substance or a mixture of substances having an inner and / or outer substance surface area of ​​more than 10 m2 per gram, characterized in that the temperature required for the separation or partial oxidation of the strongly adsorbent materials in the exhaust gas is reached by the release of energy during the partial oxidation.

2. Method according to claim 1, characterized in that the substance, or mixture of substances, having an inner and / or outer substance surface area greater than 10 m2 per gram is provided with a layer formed as bulk material or a layer applied as a washcoat on a ceramic honeycomb body.

3. A method according to claim 1, characterized in that the substance used, or the mixture of substances, having an inner and / or outer substance surface area greater than 10 m2 per gram consists of extremely porous aluminum oxide, titanium oxide, or mixtures thereof.

4. A method according to claim 1, characterized in that the substance used, or mixture of substances, having an inner and / or outer substance surface area greater than 10 m2 per gram is extruded into honeycomb bodies, preferably from highly porous aluminum oxide, titanium oxide or powder mixtures together with clayton or other extrudable materials, fired and used for the purposes cited.

5. A method according to claim 1, characterized in that the temperature required for the separation or partial oxidation of the strongly adsorbent materials in the waste gas is provided by- initially by external energy.

6. Method according to claim 1, characterized in that, in the case of use of a recuperative heat exchanger, the latter can be brought to 400°C - 500° by means of the variation of the cycle time to free it by pyrolysis of any organic deposits.

7. Device for the separation of strongly adsorbent materials for the suppression of the adsorption effect in exhaust gas cleaning plants, in which the exhaust gas containing strongly adsorbent materials is brought into intensive contact at a temperature preferably of 200 °C to 450 °C with a substance or a mixture of substances having an inner substance surface area greater than 10 m2 per gram, whereby the strongly adsorbent substances can be modified by separation of functional groups and / or partial oxidation in such a way that they no longer adsorb or adsorb much less, characterized in that the temperature required for the separation and partial oxidation is reached by heat displacement using a regenerative or recuperative heat exchanger, the residual energy contribution required for this coming from the partial oxidation.

8. Device according to claim 7, characterized in that the substance used is in the form of bulk material or a layer applied as a washcoat on a ceramic honeycomb body or as an extruded honeycomb body.

9. Device according to claim 7, characterized in that the temperature required for separation and partial oxidation is achieved by heat displacement using a regenerative or recuperative heat exchanger, the residual energy contribution required for this being able to come from energy supplied from outside.

10. Device according to claim 9, characterized in that the recuperative heat exchanger can be a fixed bed, ceramic honeycomb bed, fluidized bed, or rotating or cyclone heat exchanger.

11. Device according to claim 9 characterized in that the recovery heat exchanger can be brought to 400°C to 450°C by varying the cycle time to free it, by pyrolysis, from any organic deposits.

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