EP2558194A2 - Use of granulated natural minerals as gas adsorbents for removing gaseous pollutant components - Google Patents

Abstract

The invention relates to the use of a granulated mineral or mineral agglomerate which contains naturally occurring smectite-rich clays and/or bentonites having a proportion of swellable three-sheet silicates and/or naturally occurring nanohalloysites, where the granulated mineral or mineral agglomerate has not been chemically treated and is free of additives, as gas adsorbent for removing ozone, siloxanes, formaldehyde, mercaptans, hydrocarbons and organic amines from waste air/offgas, natural gas and gaseous energy carriers.

Description

 Use of natural mineral granules as a gas adsorber for the removal of gaseous pollutant components

The invention relates to the use of natural mineral granules as Gasadsorber for the removal of gaseous pollutant components such as ozone, siloxanes, formaldehyde, mercaptans, organic amines and hydrocarbons from exhaust air / natural gas or liquids.

In exhaust air / exhaust gas, the pollution with these gaseous pollutant components can be in the range of more than 0.1 ppm to 1000 ppm and thus pollute the environment or be harmful to the process.

This is how z. As in plasma technology processes that operate under atmospheric pressure and with oxygen or air, ozone as a process gas or as a by-product, which must be respected, especially in interiors in a possible exposure of the limit of 0.1 ppm s.

In the energetic utilization of landfill gas, especially hydrogen sulfide and Siloxangehalte are disturbing process technology, as during combustion in the combined heat and power plant (CHP) adverse effects (oil consumption, engine damage) are to be obtained. For example, mercaptans, which are used to odor city gas / natural gas and liquid gas, have been found to be extremely disruptive in fuel cell technology, as they can significantly limit the functionality and life of components.

Formaldehyde is often detected as a gaseous pollutant component during heating and combustion processes and as space outgassing when using certain building materials. State of the art

Siloxanes, formaldehyde, hydrocarbons, organic amines and mercaptans as well as other gaseous sulfur compounds are known in the prior art from the exhaust air and gas streams by means of the synthetically produced molecular sieves, natural zeolites and activated carbon products, which are also possibly modified, used as adsorbents eliminated.

The use of zeolites and molecular sieves is described in the patents US 2006 108262A, US 2006 024217A, US 2002 170436A, US 6319484A, KR 2001 0037128A, EP 1005895A, US 6579347B, US 6296823B, US

2007 129236A, WO 07029807A, JP 2007 021363A, US 5417947A, DE 4012982A and US 2008 0156190A. In the patents US 5460792A, US 52238899A, US 6319440B, DE 401334A, DE 4003668A, US 4689054A, EP 0045865A, EP 0893128A, JP 55157314A, CN 101327400A, CN 201108793Y, US

2008 179177A, CN 101199913A, US 2007 012185A, US 2005 031504A, US 2003 190270A, JP 2000 084406A, JP 2000 000425A, JP 11309204A and US 6332916B describes the use of activated carbon, optionally in granulated or metal-doped form.

Further, the patents JP 2003 126234A, CN 1834542A and US

2009 136405A the use of photocatalytic titanium dioxide, the patent US 2007 151452A the use of granulated porous glass, the patent EP 0908224A the use of carbon nanoparticles, the patent US 5914455A the use of activated aluminum, the patent US 6524535A the use of Mica / Mica flakes, the patents EP 0103144A and DE 4233478A the use of silica gel or hydrophobic silica and the patent US 2001 005981A the use of iron hydroxides and calcined diatomaceous earth or the document DE 4012982A the use of diatomaceous earth in the fixation of gaseous pollutants of the above Composition of exhaust air room air and gas flows.

WO 2009/125004 describes hailoysites and smectites as novel unmodified gas adsorber granules for the treatment of raw biogas with the aim of removing hydrogen sulfide and ammonia without the possibility of use for fixing siloxanes, hydrocarbons, ozone, organic amines, Formaldehyde and mercaptans is given. Removal of ozone from exhaust air / exhaust gas

The most commonly used process for residual ozone destruction is the catalytic destruction of ozone. Catalyst-damaging gases from the process as well as aerosols can considerably limit the effect of residual ozone killers or are at the expense of the service life, so that additionally suitable cleaning methods have to be used.

From DE 4326121A1 and EP 0747110A1 a method for the protection of catalysts for the purification of the exhaust gases of internal combustion engines from catalyst poisons (eg phosphorus, sulfur, arsenic, lead, mercury and organosilicon compounds) is known in which the Poisons are filtered out by adsorption on an adsorber. The adsorber is arranged either between the engine outlet and the catalyst inlet or in the fuel gas before entering the engine.

In V. Congress on Engine Combustion Processes, Essen 2001: Reports on Energy and Process Engineering, Series Heft 2011.1, A. Leperertz (ed.), Erlangen 2001, p. 591-600, the combination of a low-temperature plasma with suitable catalysts for the plasma catalytic lysis of NO _x described. The investigations examined the combinations of non-thermal plasma and modifications of A1 ₂ 0 ₃ .

In DE 19828904A1, such a combination is provided with a catalyst which contains a nitrogen compound with nitrogen in a negative oxidation state (ammonia-laden or nitride-containing). The catalyst is cyclically subjected to regeneration.

In DE 10211810A1, the exhaust air stream is initially passed over an adsorber / catalyst to reduce organic and inorganic pollutants from exhaust gases. The adsorber / catalyst is a solid in the form of granules or chippings with high absorption capacity for the pollutants.

After loading, the influx of exhaust air is interrupted and the adsorber / catalyst operated in a separate circulatory system - together with a plasma generator - to the degradation of pollutants. In the circulation, the reactive species generated in the plasma are transported via the adsorber / catalyst. lysator thereby degrading the bound pollutants to form water and carbon monoxide. The oxygen necessary for the oxidation is added in the form of air, pure oxygen or ozone.

In this process, the reaction products are part of the circulatory system and ozone is only consumed until the pollutants are degraded.

According to this process, when the cleaned exhaust air is released, either an excess of ozone or the concentration is below the limits from the outset.

In DE 10158970A1, it is provided to produce oxidizing agent with a plasma generator (eg by dielectrically impeded discharge) and to pass it via an adsorbent agent for adsorbing oxidizable substances. The adsorbed substances are oxidatively degraded. For residual ozone, a destruction agent is furthermore provided, where the air streams are passed to a destruction agent for catalytic degradation after flowing through the adsorbent.

DE 10225492A1 describes the catalytic oxidation of air pollutants with ozone and a cobalt-aluminum mixed oxide.

According to DE 19801840A1, in the case of plasma-chemical exhaust air purification, it is also known to use catalysts for separating ozone which split the ozone originating from the plasma into atomic oxygen, which then reacts with the pollutant. Such a system can be arranged in the outflow of a plasma reactor, and an adsorbent (activated carbon, silica gel) can be admixed with the catalyst, usually free of noble metal with oxides of the metals Fe, Mn or Cu.

For the removal of residual ozone from a water purification plant with ozone, EP 0277843A2 has proposed a zeolite in various configurations as an ozone adsorber.

US 2008 / 0017590A1 proposes for industrial processes the use of adsorbers for separating ozone from a gas stream with oxygen, which consist of silica gel, silicon-rich mordenite or Y zeolite. The disadvantage is that these are synthetic mineral products whose production is costly. Also known are special forms of plasma reactors in which pellets with catalytic properties are introduced in the gas space or parts thereof. In the patent US 699830B1, for example, a system for various pollutants and also for the adsorption of ozone has been put under protection. As active materials, aluminum, metal oxide catalysts, ferroelectric materials, and ceramic materials are provided.

The use of activated carbon as part of an exhaust air purification process is described for example in DE 102004053030A1.

In the method and the corresponding apparatus, various forms of discharge configurations for plasma generation are proposed in combination with a downstream activated carbon filter.

The activated carbon is consumed. Activated carbon is also applicable only at low ozone concentrations, as it may cause inflammation at higher concentrations.

In summary, it can be stated that the resources used are depleted or that their function is impaired by harmful gas components. Overall, a greater effort arises. In some cases, the materials themselves are relatively expensive - for example, in catalytic processes or activated carbon. Furthermore, the disposal or the regeneration of o zonbeladenen adsorber z. T. very expensive.

The state of the art of regeneration of adsorbers are thermal desorption, microwave desorption and displacement desorption (with water vapor).

During the thermal desorption, a targeted heating of the adsorber takes place. The disadvantage is an increased expenditure of energy in order to achieve the high desorption temperatures (for example in the range of 200 ° C. to 300 ° C., in some cases considerably higher temperatures are required). The strong heating of the adsorber in turn has a negative impact on the life. Because of the required thermal stability of the adsorber materials their selection is limited.

The microwave desorption also aims at a corresponding heating of the material. In addition to mentioned problems, the cost is relatively high, as well as means for shielding are required.

Displacement desorption with water vapor also has the disadvantage of increased energy expenditure. The water vapor must also be removed again. It is not known to what extent a similar effect can be achieved with other gases.

Also mentioned above is the removal of oxidizable substances (VOCs, organic particles) by oxidants which are used for the regeneration of adsorber materials (DE 10158970A1). The oxidizing agents can be generated with the aid of a plasma generator, in particular via a dielectrically impeded discharge. This process, when loaded with pollutants, is virtually an indirect regeneration of the adsorber materials. This only works for oxidizable pollutants and additional a source for the production of a suitable oxidant is required.

A similar process is proposed in DE 10158970A1, where oxidants are produced with a dielectric barrier discharge and adsorber means are disposed on either an electrode or the dielectric.

A method of concentrating toluene is described in IEEE Trans. Ind. Appl. Appl. Vol. 45, no. 1, pp. 10 -15, Jan. / Feb. 2009 ,; T. Kuroki et al. ; "Regeneration of Honeycomb Zeolites by Nonthermal Plasma Desorption of Toluene" presented. Required is a honeycomb structure in which the plasma is generated.

Elimination of siloxanes from landfill and sewage sludge biogases

In the prior art, siloxanes are removed from gas streams using silica gel, zeolites and activated carbon products or by modified mineral gas additives, which are prepared by acid activation or heat treatment in the range from 110 to 1000 ° C., and in the specifications GB 2396315, JP 02083016A, US Pat. JP 2005 040703A and DE 4220950A1, US 2008 179177A, US 2007 0068386 and US 7393381.

Hydrophobized silica gel has a 10 times higher loading capacity as activated carbon for siloxanes, but is significantly more expensive than activated carbon products. Jong Kuk Kim et al. : "Adsorption of siloxane con- tained in landfill using clay mineral". - Journ. Korean Indust. and Engin. Chemistry 17 (2006), 465-470 describe a good siloxane adsorption to the four-layer silicate vermiculite (3.8 g / g vermiculite) and recommend this mineral product for the substitution of activated carbon.

The adsorber granules used hitherto have the following disadvantageous effects:

Flammability, limited reactivity (activated carbon products),

 high production costs (hydrophobized silica gel, synthetic zeolites, acid activation or temperature treatment),

 limited functionality due to low adsorption performance / lifetime.

Removal of mercaptans from natural gas, town gas and LPG

The desulphurisation of city gas and natural gas aims at target values of <5 ppm for sulfur compounds. Synthetic zeolites (US Pat. No. 6,579,347, US Pat. No. 3,864,452), mixtures of zinc oxide and zeolites (US Pat. No. 4,717,552), cadmium-exchanged zeolites (US Pat. No. 4,358,297) and activated carbon, activated aluminum and silica gel, if appropriate also as mixtures, have proven to be effective adsorber materials (US 7211128, US 7449049, US 4830733).

Furthermore, US Pat. No. 4,690,806 describes synthetic AI-based spinels as good adsorbents.

Gas processing for fuel cell technology requires sulfur levels of <1 ppm due to the risk of poisoning catalysts contained in the reformers and the fuel cell.

According to the prior art, activated carbon / zeolites (DE 10347139B4), activated carbon and metal oxides, such as ZnO (DE 10115220A1), zinc oxides (AT 407100B), alumina pellets (US 6294276B1), lead acetate or silver (EP 1926169, EP 2168912) and Sepiolites and / or mi with activated carbon, zeolites, silica gel, diatomaceous earth, which may also be impregnated with metal ions (Co, Mn, Cu, Fe, Cr, Ni) (EP 1501913 Bl) used. In particular, the lifetime and functionality of MCFC and SOFC fuel cells (MCFC = "Molten Carbonate Fuel Cell" = high temperature fuel cell, SOFC = "Solid Oxide Fuel Cell" = solid oxide fuel cell) is determined by the effective removal of sulfur compounds.

These adsorbent materials used so far are usually very expensive, z. T. little environmentally friendly (zinc, lead) and z. T. as problematic in terms of their ability to regenerate.

Adsorption of formaldehyde from gaseous media

Due to the carcinogenicity of formaldehyde, various limits have been established for formaldehyde concentrations, and various methods for fixing formaldehyde from exhaust gases, air streams, and indoor air have been developed. Polymer-based adsorbers are described in EP 1155728 and US 4067854, the company DOW Chemical markets the product DOWEX OPTIPORE V493.

Furthermore, it was demonstrated that biomass (bacteria, moss, cellulose, wool) binds formaldehyde (CN 101327405, US 6332961).

Aktivkohleadsorber, z. T. with KJ or KOH doping, are described in US 4824577, US 5714126 and US 2007 0012 185. With regard to the effectiveness of activated carbon adsorbents for formaldehyde fixation, Chao-Heng Tseng et. al., and demonstrated that activated carbon adsorbents have low efficiency (3.3- 28.6% fixation) over photocatalytic or ozone-based treatments (Proc. of the Air and Waste Management Assoc, 98th Annud Conference, Paper 457, Minneapolis 2005 ).

US Pat. No. 6,316,521 and EP 1103274 describe the fixation of formaldehyde on adsorber mixtures of activated alumina and potassium permanganate.

S. WANG et. al inform about the use of titanium dioxide nanoparticles for the catalytic decomposition of formaldehyde and the much better Effectiveness of this Process on Activated Carbon Adsorbents ("Mechanism Analysis of Indoor Formaldehyde Decomposition by Nano-Titanium Oxide" in: Proc. Bioinformatics and Biomedical Engineering, Shanghai 2008, pp. 3304-3306).

Zeolites, e.g. T. also shown from mixtures of hydrophilic and hydrophobized zeolites are described in the patents US 6396823 and CN 101314101. Furthermore, the use of various metal catalysts or platinum or palladium-doped zeolites is prior art (GB 2252968A).

The use of the mineral sepiolite for the adsorption of formaldehyde is also known from technical information (Primary Information Service, Uliagaram, Chennai-India), where it is found that sepiolytic adsorbents have a 10-fold higher efficiency in the fixation of formaldehyde over activated carbon products exhibit. In summary, the adverse effects of the previously applied filter materials and methods for fixing formaldehyde from gas or air streams can be characterized as follows: T. low efficiency (eg activated carbon filter) and

 high costs (synthesis products, metal catalysts).

Elimination of hydrocarbons from exhaust air / exhaust gas

A material that is very commonly used as an adsorber in a variety of devices for removing hydrocarbon contaminants from fluid media, and the like. a. Exhaust gases used is activated carbon. For example, the US Pat. No. 7,719,957 describes the use of activated carbon in a filter device, which, for. B. can be connected to a Tokar to gases generated during a surgical operation, such as carbon monoxide or gas contamination consisting of smoke u. a. Particles, hydrocarbon vapors u. a. to bind organic odors.

In addition, however, other materials such as zeolites or clays, which have a large inner surface or in which substances can be stored due to a layer structure, are able to retain gases by adsorption.

In US 2965687 organoclays for the adsorption of aromatic Hydrocarbons, benzene, cyclohexane and xylene used. Here quaternary alkyl ammonium coated diatomaceous earth and bentonites / montmorillonites are described as adsorber, which are desorbed after loading by heating.

EP 2168656 claims that adsorbers can be used to first bind organic molecules such as ethers, aldehydes, ketones, alcohols and amines from the vapor phase over an aqueous solution (from fermentation processes). The adsorber used are silicon dioxide, bentonites, silicates, clays, hydrocalcites, aluminum silicates, oxide powders, mica, glass, aluminates, clinoptilolites, gismondines, quartz, activated carbon, bone charcoal, polystyrene, polyurethane, polyacrylamide, polymethacrylate, polyoxygenate 1 p yr i di n and preferably zeolites used. In a second step, the organic molecules are desorbed by heating and then condensed by cooling.

In WO 2008 110820 an adsorber is claimed, which is designed as a hollow fiber after thermal treatment. For the adsorption ceramic materials such. For example, alumina, bentonite, silica, hydroxyapatite or mixtures thereof. The advantages are a high selectivity for u. a. for VOCs ("Volatile Organic Compounds") and greenhouse gases.

Bentonite is also used in column chromatography (microadsorption columns), e.g. For example, in WO 2007 030847 a packing material is proposed which has a carrier with a large, inner surface such. B. contains bentonite.

In US 6352578 an air purification filter is described in which u. a. acid-activated bentonites or other activated clays impregnated with various inorganic substances, in particular sulfates, are used to obtain a high efficiency adsorbent for toluene and phthalates.

In WO 2007 060429 a reactor is described in which clays such. As bentonite, used as a slurry dispersed to remove VOC Kontamina- tions from large volumes of air. These favorable properties of the clays are based on complex binding mechanisms, including van der Waals interactions, ligand binding and covalent bonds, and adsorption due to the hydrophobicity of the clays. As a preliminary An organophilization with quaternary ammonium compounds was carried out.

In EP 414095 a method for exhaust gas removal is presented which u. a. works with an adsorption filter containing as adsorbent both activated carbon, silica gel and bentonite and biomass (peat, compost) as a mixture components. This should be organic pollutants such as hydrocarbons and halogenated HCs such as alkanes, aldehydes, ketones, aromatics, esters, turpentine or alcohols or mixtures of these can be eliminated.

Finally, DE 69107739 discloses a method of removing hydrocarbon compounds from air and water using bentonite in colloidal form.

According to the prior art, the following disadvantages arise in the case of the mineral adsorbers used hitherto: the processes for treating the mineral adsorbers, in particular the swellable phyllosilicates (bentonite, montmorillonite) by alkylammonium ion occupancies, acid activation and sulphate doping, are cost-intensive,

 thermal reactivation processes lead to premature loss of reactivity in multiple treatments as a result of treatment at temperatures> 100 ° C,

 Adsorbers that work on the basis of biomass mineral mixtures are flammable.

task

The object of the invention results directly from the above description of the prior art adhering problems or disadvantages.

The object of the invention is therefore to provide effective and cost-effective ways of treating exhaust gases, exhaust air and pollutant-containing gases. In particular, residual ozone, siloxanes, sulfur-containing gaseous compounds such as mercaptans, formaldehyde, hydrocarbons and organic amines from gas streams and exhaust air are fixed.

The cleaning should be carried out up to residual concentrations of <0.1 ppm of gaseous pollutants.

Furthermore, the regeneration should be effective and the lifetime long. Non-combustibility is also required.

Inventive solution

The object of the invention is defined by the main claim use of a mineral granules, the naturally occurring smektitreiche clays / bentonites with a proportion of swellable Dreischichtsilikate of at least 50% by weight and / or naturally occurring nano-halloysites with a Halloysitanteil (7A or 10A type) of contains at least 50% by weight, dissolved as a gas adsorber for the removal of ozone, siloxanes, formaldehyde, mercaptans, hydrocarbons and organic amines from exhaust air / exhaust gas, natural gas, gaseous fuels and liquefied gas.

For the inventive use suitable mineral granules based on naturally occurring smektitreichen clays / bentonites with a proportion of swellable three-layer silicates and / or naturally occurring nano-halloysites are described in WO 2009 / 125004A2.

Advantageous and / or preferred embodiments are the subject of the dependent claims.

Surprisingly, it has been shown that natural nanoporous Hailoysites and swellable three-layer silicates without any chemical treatment (eg acid activation or impregnation or addition of alkali compounds) and / or treatment (annealing) at higher temperatures (> 110 ° C) in the form of gaseous mineral granules gaseous Contain pollutants compounds such as ozone, sulfur-containing components (eg., Mercaptans), siloxanes, formaldehyde, hydrocarbons and organic amines very effective or fix and thus represent an effective alternative to previously used filter materials.

For the production of the mineral granules used according to the invention as gas adsorbers Nulate conventional processing methods (drying, preferably up to 50 ° C, breaking, fractionation, granulation, extrusion) and / - or a low-temperature plasma-technological treatment for surface modification of the adsorber granules are used. The preparation can also be carried out by build-up granulation of powder material or spray drying.

The lifetime of the mineral granules used according to the invention as a gas adsorber in the filter system is long and the mineral granules are also not combustible.

In regeneration experiments, it has furthermore been found that the laden mineral granules used according to the invention as gas adsorbers can be reactivated by short-term injection of oxygen or air into the filter system in which they are contained as component. Furthermore, the regeneration of clay minerals used according to the invention as a gas adsorber can also take place in an air-flow system in which low-temperature plasma is generated in the granule interstices and in the pores. Other gases such as nitrogen or argon can be used in the plasma regeneration. The regeneration can also take place in a continuously operating rotary adsorber.

Detailed description of the invention and embodiments

The invention relates to the use of a mineral granulate or agglomerate comprising naturally occurring smectite-rich clays and / or bentonites with a proportion of swellable three-layer silicates of at least 50% by weight and / or naturally occurring nano-halloysites having a halide content (7A or 10A). The mineral granulate or agglomerate has not been physically or chemically treated and is free from additives, as a gas adsorber for removing ozone, siloxanes, formaldehyde, mercaptans, hydrocarbons and organic amines from exhaust air, natural gas and gaseous fuels.

According to one embodiment of the invention, the mineral granules or - agglomerate on a particle size range of 0, 1 to 10 mm for good gas permeability. Advantageously, grain bands of 0, 1 to 5 mm or from 1 to 5 mm

According to a further embodiment of the invention, the swellable three-layer silicates have a specific surface area of 100 to 800 m ² / g and a cation exchange capacity of at least 50 meq / 100g.

According to a further embodiment of the invention, the smectite-rich clays / bentonites have a montmorillonite content of at least 75% by weight, advantageously of at least 50% by weight.

According to a further embodiment of the invention, the hailoysites have a nanopore volume of up to 30%.

figure description

Show it:

Fig. 1: The filter effect of bentonite granules

Fig. 2: A long-term measurement with Halloysitgranulat

3: The filter properties of smectite-rich clay granules

Fig. 4: The filtering effect of halloysite at higher ozone concentration Fig. 5: The desorption of methane from halloysite as a function of temperature

 FIG. 6: The fixing of formaldehyde from waste air / waste gas streams to the mineral adsorber used according to the invention

 FIGS. 7 to 10: The adsorption of dimethylamine on the mineral adsorber used according to the invention

Removal of ozone from exhaust air / exhaust gas

The inventive use of defined in the main claim mineral granules as Gasadsorber results in an effective and cost-effective component of the plasma technology treatment of ozone-containing gases / exhaust air. Residual ozone contents of <0.1 ppm in the gases by selected mineral adsorbers, which are only broken, dried (up to a maximum of 50 ° C.) and fractionated (gas-permeable granules), have been obtained by means of physisorption and / or catalytic reaction , Furthermore, the regeneration of the loaded mineral granules can be carried out effectively and inexpensively.

The mineral granules used according to the invention as gas adsorbers for the removal of ozone are characterized in that naturally occurring mineral raw materials in granular form - without any additives and chemical treatments - are used. The mineral granules used according to the invention preferably consist of natural ones Halloysites, bentonites or smektitreichen clays and are prepared by drying to 50 ° C, breaking and fractionation. Particularly preferred for good gas permeability is the grain band 0.5 - 10 mm.

According to a preferred embodiment of the invention, mineral granules with minimum contents of 7A and / or 10A-type halloysites of more than 50% by weight and / or swellable three-layer silicates of more than 50% by mass are used according to the invention as gas adsorbers.

The mineral granules used according to the invention as gas adsorbers serve as constituents / fillers of technical components and systems for the treatment / purification of, for example, ozone-containing gas and exhaust air streams. They eliminate both excess ozone and the maximum amount of ozone generated from ozone-forming processes, so that the natural ozone level in rooms is not exceeded.

The mineral granules used according to the invention as gas adsorbers for the removal of, for example, ozone are also characterized in that an energy input by means of low-temperature plasma takes place in granule clearances and pores of the adsorber.

example 1

Adsorption of ozone

For the experimental investigations, a cartridge was used, which could be filled with various adsorbent materials. On one side of the cartridge ozone-enriched air was flowed in and on the other side via a sensor the ozone concentration was measured.

The required ozone was generated with a laboratory ozonizer. In this a dielectrically impeded discharge is operated. Concentration measurements were made with a commercial instrument using the principle of UV absorption.

The materials were tested under conditions suitable for use in plasma technological processes. The typical natural environmental exposure to ozone is in the range 0.02-0.05 ppm. The samples were mixed with air and an ozone concentration of about one Magnitude (it was in the experiments (see Fig. 1 - 4) ozone concentrations of 0.25 ppm, 0.17 ppm, 0.16 ppm and 1.3 ppm set as initial values) higher, rinsed through. In the examples experiments are presented to the following used mineral materials:

Bentonite, of the type Bavarian bentonite, Landshut

 Halloysite in front of the Dunino type, Poland

 smectite-rich clay of the type clay Friedland, Mecklenburg-Vorpommern

FIG. 1 shows an example of the filter effect of bentonite. The initial concentration of ozone was in the range of 0.25 ppm. Shown is the initial concentration of ozone and the effect on the passage of the ozone-enriched air stream through a cartridge with the filter granules bentonite (stratification 2.5 cm, diameter 5 cm). The ozone concentration drops to about 0.03 ppm. This corresponds approximately to the ozone content in the experimental room.

Measurements with the halloysite granules are shown in FIG. The ozone concentration was monitored over a period of 20 h. For comparison, the starting concentrations were also measured at three different times.

An experiment with the smectite-rich clay granules is shown in FIG. Again, a good filtering effect is observed.

A test with a higher initial ozone concentration is shown in FIG. 4 for the adsorbent material Halloysite.

At this higher concentration, the measured ozone levels above the granules are in the same range as before measurements.

In the examples, the effect of the different materials used according to the invention was demonstrated. The best filter properties were the halloysite granules. Bentonite and SF (a smectite-rich clay) also showed low ozone levels, making these materials suitable for ozone binding in technological processes.

In the case of the plasma regeneration, in particular reactors with granulate beds are provided. The device can also take the form of a be constructed of continuous rotary adsorber. Example 2:

Landfill gas processing

Sulfur compounds (motor oil poison) and siloxanes are undesirable admixtures in landfill / sewage sludge gases, as they affect the BHK engines (CHP = cogeneration) in their function up to the destruction at high Siloxanbelastung.

A landfill gas was treated under the following conditions:

 Landfill gas from the central landfill Emscherbruch, North Rhine-Westphalia

 average flow rate: 124 1 / h (via bypass system)

 Mineral Adsorber Medium: Halloysite granules (2 - 4 mm), capacity: 1.5 l

Duration of the experiment: 55 days

Results obtained: Table 1

 Time raw gas (untreated) gas after filter

 (Days) Silox. Content Sulfur Water Content Silox. Content Sulfur Water Temp.

salary

(mg m ³ ) (mg / m ³ ) (mg / m ³ ) (mg / m ³ )

1 12.6 146 0.35 0.0

2 n.b. n.d. 0.45 0.0

3 n.b. n.d. 0.34 0.0

10 n.b. n.d. 0.00 0.0

13 10.5 170 0, 16 0.0

17 n.b. n.d. 0.33 0.0

23 13.8 175 1, 82 0.0

31 n.b. 280 n.b. 0.0

41 n.b. 224 n.b. 0.0

43 n.b. 224 n.b. 0.0

55 n.b. 308 n.b. 42.0

Usual fluctuation ranges from long-term observation:

organosilicon. Compounds: 10-20 mg / m ³

Hydrogen sulfide: 140-300 mg / m ³

Under the given experimental conditions, the service life of the selected mineral adsorber granulate was about 50 days for hydrogen sulfide and about 20 days for siloxanes, whereby with respect to siloxane a depletion of 10 to 30 times with respect to the raw gas contamination could be achieved.

Example 3

Treatment of liquefied petroleum gas for the operation of fuel cells

Instead of filter cartridges filled with synthetic zeolites or with metal catalysts for the relevant gas treatment, tests were carried out with fillings of halloysite granules (2-4 mm) in order to effectively remove the residual sulfur content in the liquefied petroleum gas. The following parameters were applied:

Filling quantity of HNT granules (HNT = "Hailoysite Nanotubes"): 9 kg

 Propane (technical, Fa. Air Liquide)

 Flow rate: 2.5 1 / min

Rotameter after filter cartridge (150 1 / h), bypass (gas mouse: 0.7 1 / min) Measurement methodology: gas chromatography, H ₂ S sensor (Severin)

Measurement results :

Table 2

Locality / gas composition before / after IMineraladsorber

 Time of gas measurement. Gas components measured values (concentrations)

 In front of filter cartridge PropaneVEthananteil 99, 1 Vol-% /> 1 Vol .-%

(Start of measurement) Total i- and n-butane <1% by volume

 Hydrogen sulfide 2 ppm

Total sulfur 3.3 mg / m ³

 After filter cartridge PropanVEthan- u. Air content 96.0% by volume /> 1% by volume

(after 4h gas flow) total i- and n-butane <1% by volume

 Hydrogen sulfide 0.0 ppm

Total sulfur 0.46 mg / m ³

 After filter cartridge propane / ethane i 1 98.6% by volume / <1% by volume

(after 72h gas flow) Total i- and n-butane <I vol.%

 Hydrogen sulfide 0.0 ppm

Total sulfur 0.45 mg / m ³

 After filter cartridge propane / ethane 93.0% by volume

 (after 144h gas flow) Total i- and n-butane 6% by volume

 Hydrogen sulfide 0.0 ppm

Total sulfur 0, 19 mg / m ³

Without consideration event. Nitrogen content variations

The total sulfur content also includes the sulfur compounds (eg mercaptans) used for the odorization of industrial gases, with a reduction of 7 to 17 times the initial value during the test period compared with the total sulfur output concentration of 3.3 mg / m ³ has been. Example 4

Formaldehydfixierunq

A laboratory test with the following experimental parameters: Granule type: Halloysite

 Granule distribution: 0.7 - 1.4 mm

 Granule mass: 0.97 g

Volume flow CH ₂ 0 / N ₂ mixture: 176 ml / min

Initial concentration CH ₂ 0: lOOppm yielded the following adsorption result for the pollutant formaldehyde (CH ₂ O) used on the mineral granulate (halloysite) used according to the invention, see FIG. 6. The measurement result shows that the pollutant was retained in the given test system for 56 min. This shows an effective fixation of formaldehyde from exhaust air / exhaust gas streams at the mineral adsorber used in the invention. On breakthrough (56 min), 1.3 mg of CH ₂ O were fixed per gram of adsorbent. After a further 194 minutes, 3.8 mg of CH ₂ O were bound per gram of adsorbent.

Example 5

Adsorption of methane

At a biogas plant biogas was branched off in a bypass system in front of the engine of a combined heat and power plant and passed through a filter module.

The filter module consisted of three stacked filters, each with three chambers, each chamber having a volume of 5.301 dm ³ . With the help of a gas pump, the gas flow was evenly conducted over all filter columns. The filter columns were filled with halloysite.

After a period of six weeks, the mineral adsorber material was taken out and the methane adsorbed thereon was released again by means of thermode sorption. The methane was detected semi-quantitatively using a mass spectrometer based on the mass number 13 (for CH ₃ ⁺ ). The heating rate of the Thermodesorptiongerätes was 20 K / min. The measurement was started at 22 ° C and terminated at 1000 ° C. In Figure 5, the release of methane is initially seen above 350 ° C and then significantly above 520 ° C. The maximum of the release is 620 ° C.

Example 6

Adsorption of dimethylamine

To check the adsorption properties of amines, a gas mixture of dimethylamine C2H ₇ N was selected with a concentration of 92 ppm and nitrogen as a carrier gas. The experiments were each carried out with 6 g of granules at a flow rate with a volume flow of 150 ml / min.

FIG. 7 shows a comparison of the FTIR spectra of dimethylamine when passing through a bypass and the adsorbent P2, a bentonite, after 60 minutes. It can be seen that dimethylamine is adsorbed by P2.

FIG. 8 shows the associated time course of concentration of dimethylamine after flow through the mineral adsorbent P2. It is achieved a complete adsorption of the pollutant for the entire period considered.

FIG. 9 shows an example of the temporal concentration course of dimethylamine after flowing through the mineral adsorbent P5, a halloysite. In turn, a complete adsorption of the pollutant is achieved for the entire considered period.

FIG. 10 shows the time course of concentration of dimethylamine after flow through the mineral adsorbent P4, a zeolite. Again, a complete adsorption is observed.

Claims

claims

1. Use of a mineral granulate or agglomerate, the naturally occurring smektitreiche clays and / or bentonites with a share of swellable three-layer silicates of at least 50% by weight and / or naturally occurring nano-halloysites with a Halloysitanteil (7A or 10A type) of at least 50th % Mass fraction, wherein the mineral granulate or agglomerate has not been chemically treated and is free of additives, as a gas adsorber for the removal of ozone, siloxanes, formaldehyde, mercaptans, hydrocarbons and organic amines from exhaust air, natural gas and gaseous energy sources.

2. Use according to claim 1, wherein the mineral granules or agglomerate has a particle size range of 0.1 to 10 mm for good gas permeability.

3. Use according to claim 2, wherein the mineral granules or agglomerate has a particle size range of 0.1 to 5 mm.

4. Use according to claim 3, wherein the mineral granules or agglomerate has a particle size of 1 to 5 mm.

5. Use according to one of the preceding claims, wherein the swellable three-layer silicates have a specific surface area of 100 to 800 m ² / and a cation exchange capacity of at least 50 meq / 100 g.

6. Use according to one of the preceding claims, wherein the smectite-rich clays / bentonites have a montmorillonite content of at least 75 wt. -I.

7. Use according to claim 6, wherein the smektitreichen clays / bentonites have a montmorillonite content of at least 50 wt .-%.

8. Use according to one of the preceding claims, wherein the Hailoysite have a Nanoporenvolumen of up to 30%.