EP3701191B1 - Method for purifying a raw gas stream and purification device - Google Patents

Description

The present invention relates to the field of raw gas cleaning. In particular, the present invention relates to the purification of raw gas containing water vapor and carrying organic impurities, in particular exhaust steam, for eliminating odors and/or converting exhaust gases. Furthermore, the present invention relates to a cleaning device for carrying out a raw gas/vapor vapor cleaning method.

The raw gas cleaning can be carried out in particular to eliminate odors using thermal systems, for example regenerative thermal oxidation systems. However, this usually requires a high level of energy expenditure in order to maintain the system temperatures required for thermal raw gas cleaning. This high energy expenditure is mostly due to the fact that a separation process is often carried out first in order to separate water with, for example, organic dust, in particular fat, oil and/or protein particles, from the raw gas. As a result, oxidizable substances with a considerable calorific value are lost from the raw gas stream fed to the thermal plant for raw gas cleaning, which reduces the efficiency of the thermal conversion. In addition, the substances occurring during the separation process have to be post-treated in a complex manner and/or disposed of specifically as hazardous waste. If, on the other hand, a separation process for the pre-treatment of the raw gas is not carried out, adhesions, blockages or other deposits can occur on a heat transfer material (heat exchanger material, heat storage material) during the course of the thermal conversion, which can greatly reduce the operating life of the system and/or significantly increase the maintenance effort .

The release of Mark Peckham et al., "Exhaust gas fuel reforming", Joint project with Johnson Matthey, Ford Motor Company, University of Birmingham, 23 February 2015, XP055669323 , discloses an internal combustion engine with a fuel reformer.

The present invention is based on the object of providing a method for cleaning a steam-containing raw gas stream, in particular exhaust steam with organic impurities, which can be carried out simply and cost-effectively.

According to the invention, this object is achieved by a method according to claim 1 .

The organic impurities contained in the raw gas stream preferably react with the water vapor contained in the raw gas stream without the supply of oxygen.

The contaminants are or include in particular liquid contaminants and/or solid contaminants and/or gaseous contaminants.

Because the raw gas stream is first reformed in the method according to the invention and only then thermally converted by supplying oxidizer, preferably air, fresh air, ambient air, oxygen-containing exhaust air, process exhaust air, etc., a calorific value contained in the raw gas stream can preferably be used in the oxidation and thus enable fuel-saving or otherwise energy-saving thermal raw gas cleaning. In addition, such a method is preferably comparatively simple and inexpensive because a preceding deposition step can be dispensed with.

It can be provided that the clean gas flow is fed to a heat exchanger, in particular a condenser, and that by means of the heat exchanger, in particular by means of the condenser, in the clean gas flow contained water vapor is condensed. In this way, in particular, a volume and/or volumetric flow of the clean gas flow in the clean gas discharge can be reduced, as a result of which an energy-efficient flow through the cleaning device can ultimately be obtained.

The chemical reaction in the reforming area is preferably an allothermal and/or hydrothermal gasification. A water-gas shift reaction, preferably in the first flow space, can be advantageous for the energy requirements of steam reforming.

As an alternative or in addition to this, it can be provided that the chemical reaction in the oxidation area is a reaction with supporting energy and/or an autothermal oxidation. The water vapor of the steam-containing raw gas stream is preferably used as a gasification medium, particularly in the reforming area. A reaction with supporting energy is preferably a combustion.

The process can preferably be carried out with any thermal regenerative exhaust air cleaning system (TRA). In particular, the solution according to the invention can be implemented not only with the exemplary embodiments of a cleaning device shown in the attached figures, but rather also with numerous variants thereof.

For example, linearly arranged regenerator chambers can be provided as flow spaces. Furthermore, rotating systems can be provided, in particular rotary valve devices according to EP 0 548 630 A1 . The process can also preferably be carried out on oxidizers such as the product “ ^Vocsidizer® ” from MEGTEC SYSTEMS, INC. according to the WO 01/88436 A1 be performed. Furthermore, the method can preferably also be carried out on one of those systems be provided, which are disclosed in one or more of the following publications:
WO 01/59367 A1 , AU2001-232509A1 , WO 1995/024590 A1 , EP 1 906 088 B1 .

According to the invention, the method is carried out by means of a cleaning device which comprises a plurality of flow chambers, with a first of the flow chambers at least temporarily forming the reforming area and with a second of the flow chambers at least temporarily forming a heat storage area to which the clean gas flow is fed.

Furthermore, it can be provided that the cleaning device comprises at least a third flow chamber, which at least temporarily forms a preheating area, to which the oxidant flow is fed for preheating it, before the oxidant flow is fed to the oxidation area.

According to the invention, the raw gas stream and/or the clean gas stream and/or the oxidizer stream is fed cyclically/alternately to different flow spaces so that the flow spaces alternately form the reforming area and/or the heat storage area and/or the preheating area.

The flow spaces are preferably flowed through in different directions, depending on whether the respective flow space forms a reforming area or a heat storage area.

In particular, a main flow direction in a flow space when it forms a reforming area is opposite to a main flow direction in the same flow space when it forms the heat storage area.

The flow spaces are preferably alternately heated and cooled, in particular heated by means of the clean gas stream and/or cooled by means of the raw gas stream and/or the oxidizer stream.

The flow paths are switched cyclically/alternately and/or preferably based on the energetic balance of the heat storage areas, as is the case, for example, from the patent specification EP 1 906 088 B1 (also known as the XtraBalance ^® process).

The flow spaces are preferably provided with a heat storage material, for example at least partially filled with a heat storage material.

The thermal storage material is or preferably comprises a composite of various ceramic materials (e.g. material known by the trademark ^XtraComb® ). “Composition” is preferably also to be understood as meaning a layering of storage elements, storage bodies or storage blocks, the storage elements, storage bodies or storage blocks being inhomogeneous, for example in planes or in layers, in particular in the vertical composition or stacking.

The heat storage material can in particular comprise or be formed from densely fired and/or smooth and/or highly porous and/or coated with a catalyst material and/or ceramic storage material. Furthermore, the heat storage material can preferably be a composition of densely fired storage material and/or smooth Storage material and/or highly porous storage material and/or storage material coated with a catalyst material and/or ceramic storage material.

It can be favorable if the raw gas stream has an oxidizer content, in particular an oxygen content, of less than 5% by volume, in particular less than 3% by volume, preferably less than 1% by volume.

The raw gas flow is, in particular, exhaust steam.

The raw gas stream is preferably saturated with steam.

The raw gas stream is preferably fed to the reforming area without the addition of further media. In particular, preferably no gas stream containing oxidizer is fed to the raw gas stream before the raw gas stream is fed to the reforming area.

In the reforming area, the raw gas stream is preferably heated to at least approximately 600°C, in particular to at least approximately 750°C, for example to at least approximately 800°C, particularly preferably to at least 850°C.

Provision can be made for the raw gas flow in the reforming area and/or the clean gas flow in a heat storage area and/or the oxidant flow in a preheating area to be routed through a respective heat storage unit of a heat storage device, with one or more or all of the heat storage units being guided in particular by ceramic flow bodies, for example molded ceramic flow bodies , are formed or include such.

The preferably porous surfaces of the ceramic flow bodies are particularly effective as an acceleration factor for allothermal and/or hydrothermal gasification.

The heat storage units preferably have catalytic materials, for example a catalytic coating and/or catalytically active components.

The catalytic effect preferably always relates to the reforming of the raw gas stream.

Provision can be made for the raw gas stream to be heated before being fed to the reforming area and/or the oxidizer stream to be heated before and/or after being fed to a preheating area by means of a heat exchanger and/or a heating device.

It can be favorable if a heating device is or includes a burner, for example a gas and/or oil burner. Alternatively or additionally, the heating device can also comprise an electrical heating device, for example an infrared heater, a resistance heater and/or the like. The heat can be transferred to the raw gas stream and/or the oxidizer stream directly by supplying a fuel gas stream or indirectly via a heat exchanger.

In particular, provision can be made for the raw gas stream and/or the oxidizer stream to be heated to at least approximately 90 °C, for example at least approximately 95 °C, preferably at least approximately 100 °C, in particular to prevent water from condensing in the area of the cleaning device, in particular the thermal exhaust air cleaning system.

It can be advantageous if the clean gas flow is first fed to a heat storage area and then to a downstream heat exchanger, with the clean gas flow being cooled by the heat exchanger in particular to such an extent that condensate forms and heat that is initially still contained in the clean gas flow is thereby transferred to the heat exchanger and/or otherwise made usable. Advantageous for the energy requirement for conveying the raw gas and clean gas flow is preferably the reduction of the clean gas volume flow by condensing out the water vapor contained. In particular, it can preferably be provided that a negative pressure below the ambient pressure is created in the condenser, as a result of which the energy requirement for conveying the raw gas and clean gas flow for the raw gas cleaning is reduced.

It can be advantageous if the oxidizer flow is fed past the reforming area and/or independently of a flow path of the raw gas flow to the oxidation area.

In particular, the oxidizer stream is preferably fed to the oxidation region through a flow space that is separate from the flow space that forms the reforming region.

In one embodiment of the invention, it can be provided that the mass flow and/or the volume flow of the oxidizer flow is controlled and/or regulated as a function of a mass flow and/or volume flow of the raw gas flow and/or as a function of an oxygen content in the outflowing clean gas flow. In particular, the control and/or regulation takes place in such a way that a predetermined oxidant content and/or a predetermined temperature are achieved in the oxidation area and/or in a clean gas discharge.

The impurities contained in the raw gas stream, in particular organic compounds, are broken down and converted in the reforming area, in particular by steam reforming. A reformed raw gas stream that can be obtained in this way comprises gaseous oxidizable and/or organic substances, for example hydrogen, methane and/or carbon monoxide.

In particular, steam reforming takes place on a porous and/or ceramic surface of heat storage units in at least one flow space.

Any oxidizer still contained in the raw gas stream, in particular oxygen, can be used to supply part of the energy required for the steam reforming, in particular by partial oxidation of hydrocarbons, which produces carbon monoxide, for example. For example, further energy for the steam reforming, in particular the steam reforming in the first flow space, can preferably be supplied by means of a subsequent water-gas shift reaction.

A major part of the activation energy required for steam reforming is preferably supplied by heat storage material and/or a heat exchanger in the reforming area. In particular, the energy is made available by means of the heat storage units in the flow spaces, which have been previously heated for this purpose, in particular by heat transfer from the clean gas flow. Provision of energy from steam reforming and/or the water-gas shift reaction is also advantageous.

In particular, two, three or more than three flow chambers can be provided in the method.

At least one flow chamber is preferably always flushed by means of the oxidizer flow.

At least one flow space, preferably heat storage material contained therein, is preferably always heated by means of the clean gas flow.

The heat of the heat storage material contained or provided in at least one flow space is preferably used by means of the raw gas flow.

In the oxidation area, organic components of the raw gas stream preferably react with the oxidizer from the oxidizer stream. The proportion of water vapor and the reduced oxygen content compared to the ambient air ensure that thermal nitrogen oxide formation is minimized. Heat storage material with a reaction-accelerating effect is preferably provided in the heat storage area, to which the clean gas stream is preferably fed. This surface-enlarging heat storage material preferably enables post-oxidation in particular in the upper heat storage area of the flow chambers in order to convert and/or render harmless residual impurities still contained in the clean gas flow, in particular substances that have not been completely oxidized.

Heat removed from the clean gas flow by means of a heat exchanger can be used in particular to preheat process exhaust air and/or ambient air, in particular before it is fed in as an oxidant flow. Any condensate that occurs here is preferably returned to a production process.

The invention is based on the further object of providing a cleaning device for cleaning a raw gas stream, which is of simple construction and can be operated cost-effectively.

According to the invention, this object is achieved by a cleaning device according to claim 14 .

The cleaning device according to the invention is particularly suitable for carrying out the method according to the invention.

The cleaning device preferably has one or more of the features and/or advantages described in connection with the method according to the invention.

Furthermore, the method according to the invention can have one or more of the features and/or advantages described in connection with the cleaning device according to the invention.

The cleaning device preferably comprises a heat exchanger which is arranged in particular in the clean gas discharge and which is in particular a condenser. Water vapor contained in the clean gas flow can preferably be condensed by means of the heat exchanger, in particular by means of the condenser. In this way, in particular, a volume and/or volumetric flow of the clean gas flow in the clean gas discharge can be reduced, as a result of which an energy-efficient flow through the cleaning device can ultimately be obtained. A negative pressure below the ambient pressure can preferably be generated in the heat exchanger, in particular in the condenser, as a result of which the energy requirement for conveying the raw gas and clean gas flow for the raw gas cleaning can be reduced.

According to the invention, the cleaning device comprises a plurality of flow chambers, which are in particular provided with heat storage material, and a control device, wherein the cleaning device can be switched to different operating modes by means of the control device.

In a first cleaning mode, the raw gas flow can be fed to at least a first of the flow spaces by means of the raw gas feed and the clean gas flow can be removed from at least a second of the flow spaces by means of a clean gas discharge. This mode preferably runs cyclically recurring, in particular with all, but at least with at least two, flow spaces.

Furthermore, it can be provided that the cleaning device can be set into further operating modes, for example a second or third or fourth cleaning mode, in which further flow spaces are provided for the passage of the raw gas flow and/or the clean gas flow.

At least one third flow space is preferably flushed in at least one cleaning mode. This at least one third flow chamber, to which the oxidant flow, in particular a fresh air flow, process exhaust air flow and/or process gas flow, can be fed, preferably contains a preheating device, in particular for heating the oxidant flow before this oxidant flow is fed to the heat storage area upstream of the oxidation area.

In particular, the purification device comprises or forms a regenerative thermal oxidizer (RTO).

It can be advantageous if the cleaning device comprises a plurality of flow spaces through which the raw gas flow, the clean gas flow and/or the oxidizer flow can flow, the flow spaces each comprising a heat storage unit.

One or more or all of the heat storage units preferably have a layered structure made of different, temperature-resistant solid materials, in particular different heat storage materials.

As an alternative or in addition to this, one or more or all of the heat storage units can have one or more flow layers for influencing the inflow, throughflow or outflow of gas.

For example, a layered structure made of different heat storage materials and/or flow materials is provided.

Provision can be made for a first layer to be formed from a densely fired ceramic material. In this way, in particular, penetration of moisture into the material, which can lead to the spread of odors, salt formation and blocking of the storage material, can be avoided.

At least one second layer is preferably formed from alumina porcelain or similar storage material, wherein this alumina porcelain or similar material can have a higher bulk density compared to the material of the first layer. As a result, preferably a larger amount of energy can be stored in this second layer.

For example, a third layer preferably comprises a mullite material, preferably porous mullite material. This mullite material preferably has a reaction-accelerating effect, which can result in particular from an increase in surface area and traces of metals in the material.

A bed of turbulence-generating materials, for example saddle bodies and/or balls, is provided as the fourth layer, whereby an optimized inflow of the reformed raw gas flow to the oxidation area and thus an optimized oxidation in the oxidation area can be achieved. Furthermore, this bed preferably makes it possible to equalize the inflow of the clean gas flow space and leads to a uniform release of energy to the heat storage material located therein.

In alternative embodiments of the layer structure, additional layers can also be provided or individual layers mentioned can be omitted.

Further preferred features and/or advantages of the invention are the subject of the following description and the graphic representation of exemplary embodiments.

Fig. 1

eine schematische Darstellung einer ersten Ausführungsform einer Reinigungsvorrichtung zur Reinigung von wasserdampfhaltigem Rohgas, welches organische Verunreinigungen aufweist, mit einer Regelung des Sauerstoffgehaltes im Reingasstrom;

Fig. 2

eine der Fig. 1 entsprechende schematische Darstellung der Reinigungsvorrichtung in einem Reinigungs- und Spülmodus;

Fig. 3

eine der Fig. 1 entsprechende schematische Darstellung der Reinigungsvorrichtung im Reinigungsmodus; und

Fig. 4

einen schematischen Schnitt durch den Aufbau einer Wärmespeichereinheit einer Wärmespeichervorrichtung der Reinigungsvorrichtung.

In the drawings show:

1

a schematic representation of a first embodiment of a cleaning device for cleaning steam-containing raw gas, which has organic impurities, with a control of the oxygen content in the clean gas stream;

2

one of the 1 corresponding schematic representation of the cleaning device in a cleaning and rinsing mode;

3

one of the 1 corresponding schematic representation of the cleaning device in the cleaning mode; and

4

a schematic section through the structure of a heat storage unit of a heat storage device of the cleaning device.

Identical or functionally equivalent elements are provided with the same reference symbols in all figures.

one in the Figures 1 to 4 The cleaning device shown, denoted as a whole by 100, is used in particular for cleaning raw gas.

The cleaning device 100 is particularly suitable for cleaning exhaust steam, which is also known as fumes or vapours.

The cleaning device 100 includes in particular a regenerative thermal oxidation device 102 for the thermal conversion of odorous substances and other contaminants in the exhaust steam.

The cleaning device 100 preferably comprises a reforming area 104, a heat storage area 106 and a preheating area 108.

The raw gas to be cleaned can be fed to the reforming area 104 by means of a raw gas feed 110 of the cleaning device 100 .

Oxidant and/or scavenging gas can preferably be supplied to the preheating area 108 via an oxidizer supply 112 and/or a scavenging gas supply 114 .

Furthermore, a clean gas discharge 116 of the cleaning device 100 is preferably provided, via which clean gas generated from the raw gas can be discharged.

The clean gas outlet 116 is thus in particular an exhaust gas outlet 118 of the cleaning device 100.

The clean gas discharge 116 in particular adjoins the heat storage area 106 or includes it.

A plurality of heat exchangers 120 of the cleaning device 100 are preferably used to heat or cool gas flows in order ultimately to optimize the energy efficiency of the cleaning device 100 .

In addition, a heat storage device 122 of the cleaning device 100 is preferably provided, by means of which the heat generated in the cleaning device 100 can be temporarily stored and used again for optimized operation of the cleaning device 100 .

For this purpose, the heat storage device 122 comprises, in particular, a plurality of heat storage units 124.

The cleaning device 100 includes an oxidation area 126 which adjoins the reforming area 104 and the preheating area 108 and which in particular opens into the heat storage area 106 .

At the in the Figures 1 to 4 illustrated embodiment of the cleaning device 100, the reforming area 104, the preheating area 108 and the heat storage area 106 are not stationary, but are formed by different flow chambers 128 of the cleaning device 100, depending on the locations of the supply of raw gas and oxidizer and depending on the removal of clean gas.

Each flow space 128 includes a heat storage unit 124 of the heat storage device 122, so that the flow space 128 is dependent heat can be supplied from the respective gas supply or gas discharge or heat can be removed therefrom.

One or more optional heating devices of the cleaning device 100 can contribute to optimizing the operation of the cleaning device 100 in addition to the heat storage device 122 and/or in addition to the heat exchangers 120 .

How in particular from a comparison of 2 and 3 shows, the flow chambers 128 are flowed through in different directions depending on the respective operating mode (cleaning mode) of the cleaning device 100 .

For optimized utilization and/or heat transfer, the heat storage units 124 in the flow spaces 128 are preferably provided with a layered structure.

As 4 can be seen, in particular an optimization for the supply and passage of raw gas can be provided. In particular, a first layer 130a is provided for this purpose, which is formed, for example, from a densely fired ceramic material.

A second layer 130b adjoining the first layer 130a is preferably made of alumina porcelain or a similar ceramic material and has a higher density than the material of the first layer 130a. As a result, an area with a high heat storage capacity can be created.

A third layer 130c adjoining the second layer 130b comprises, for example, a mullite material which has a reaction-accelerating effect and contributes to the optimization of reaction-kinetic processes within the flow space 128 .

Finally, a fourth layer 130d adjoining the third layer 130c preferably serves to optimize the inflow to the oxidation region 126 adjoining the heat storage unit 124. For this purpose, the fourth layer 130d has, for example, a bed of a turbulence-generating material, for example saddle bodies.

At the in 4 flow of raw gas through the heat storage unit 124 shown, the heat storage unit 124 serves as a reforming region 104 of the cleaning device 100.

If the same heat storage unit 124 or a structurally identical further heat storage unit 124 is used as the heat storage area 106, the direction of flow is reversed.

The cleaning device 100 preferably comprises an oxidizer sensor 140, in particular for the detection of oxygen, which controls or regulates the volume flow of the oxidizer supplied via the oxidizer feed 112 by means of a control unit 141.

A common switchover unit or two individual switchover units 115 are preferably used for brief flushing of the oxidizer.

The in the Figures 1 to 4 The illustrated embodiment of the cleaning device 100 preferably works as follows:
A raw gas in the form of exhaust steam, for example, is routed via the raw gas feed line 110 to a first flow space 128a, which forms the reforming region 104.

A heat storage unit 124 is arranged in this first flow space 128a, for example in accordance with FIG 4 Schematically illustrated embodiment.

This heat storage unit 124 was charged with heat before the raw gas was fed in, so that the raw gas now fed in is heated by means of the heat storage unit 124 . In particular, a temperature of at least about 750°C, for example at least 800°C, is achieved.

At these high temperatures, the components of the raw gas are broken down, so that a reformed raw gas, for example water gas, results in particular from hydrocarbons and water. In particular, long-chain hydrocarbons and low-volatile hydrocarbons are largely converted into methane, carbon monoxide, hydrogen and other easily combustible substances.

The raw gas has a very low oxygen content of less than 5 vol .

In particular, the entire raw gas stream that was passed through the reforming area 104 is fed to the oxidation area 126 as a reformed raw gas stream.

In the oxidation region 126, the reformed raw gas flow encounters an oxidant-containing gas flow, in particular an oxidant flow.

The oxidizer flow is in particular air or an air mixture or an oxidizer-containing, in particular oxygen-containing, process gas.

The oxidizer stream is fed via the oxidizer feed 112 to a third flow space 128c. Care is taken here that the temperature of the oxidizer stream is at least approximately 100° C. or more, for example at least 100° C., preferably at least approximately 110° C. In this way, an undesired condensation of water can preferably be avoided.

The oxidizer stream can be heated by means of an optional heating device and/or one or more heat exchangers 120 . This is preferably a preheating.

The oxidizer stream is only heated to a desired temperature in the flow space 128c in order to be able to feed it to the oxidation region 126 . The target temperature of the oxidizer stream is preferably at least 750°C, for example at least approximately 800°C, in particular approximately 850°C.

This heating to the target temperature is achieved in the flow space 128 in particular in that the third flow space 128c also has a heat storage unit 124, for example in accordance with in 4 illustrated embodiment. This heat storage unit 124 is preferably heated prior to the introduction of the oxidizer stream, for example using the clean gas stream.

The oxidizer stream preferably has an oxygen content of at least about 15% by volume, for example at least about 18% by volume, preferably about 21% by volume.

The merging of the heated, reformed raw gas stream with the heated oxidizer stream in the oxidation region 126 leads to oxidation of the combustible components of the reformed raw gas stream in the oxidation region 126, which in particular hydrocarbons, carbon monoxide and Hydrogen are oxidized from the reformed raw gas stream, in particular to carbon dioxide and water.

As a result, a clean gas stream is ultimately obtainable, which is discharged from the oxidation region 126 through a second flow space 128b forming the heat storage region 106 .

In the heat storage area 106, the clean gas flow gives off at least part of its heat to the heat storage unit 124 arranged in the second flow space 128b. This heat storage unit 124 is preferably a heat storage unit 124 in accordance with FIG 4 illustrated embodiment.

After flowing through the second flow space 128b forming the heat storage area 106 , the clean gas is discharged via the clean gas outlet 116 . By means of an optional heat exchanger 120, the amount of heat still remaining in the clean gas can preferably be at least partially removed from the clean gas flow and thus made usable elsewhere.

The cleaning operation of the cleaning device 100 described above (for example according to 1 , which in particular represents normal operation) can preferably be maintained until the amounts of heat stored in the heat storage units 124 of the first and third flow chambers 128a, 128c are no longer sufficient for heating the raw gas stream and/or the oxidizer stream or for a sufficient reaction in the reforming area 104 are sufficient. The time of switching is preferably determined by measuring, calculating or otherwise determining the energy content in the flow spaces, in particular by carrying out an energy comparison of the flow spaces using a control module, for example the XtraBalance control module.

If sufficient heating is no longer possible, the cleaning device 100 is preferably put into a rinsing mode by means of a control device 115 (see FIG 2 ), in which ambient air is briefly supplied to the third flow space 128c, for example by means of a flushing gas supply 114 . Raw gas and flushing gas are supplied to the first flow space 128a and/or clean gas is supplied to the second flow space 128b. In particular, the flushing gas, which is ambient air, for example, is used to clean the heat storage units 124 in order ultimately to avoid an undesired emission of odorous substances or harmful gases in the event of a subsequent flow reversal.

After the flushing process, the raw gas is no longer fed to the first flow space 128a but, for example, to the second flow space 128b, which then consequently no longer forms the heat storage area 106 but now the reforming area 104 (see 3 ).

The heat accumulator unit 124 arranged in the second flow space 128b was finally heated up beforehand due to the supply of the clean gas flow and thus now forms a sufficient heat source for carrying out the reforming process for reforming the raw gas flow.

The first flow space 128a, which previously formed the reforming area 104, now accordingly forms the scavenging area 108, so that the clean gas flow generated in the oxidation area 126 is now discharged via the third flow space 128c.

The heat storage unit 124 arranged in the third flow space 128c is thereby heated and thus prepared for later use as a reforming area 104 or also as a preheating area 108 .

Next to the in the 2 and 3 illustrated operating modes of the cleaning device 100 numerous other operating modes can be implemented. In particular, the in the 1 , 2 and 3 the third flow space 128c forming the preheating area 108 is used at regular intervals to discharge/remove the clean gas (see 3 ) and thereby prepared for reuse as a preheating area 108 or as a reforming area 104.

The oxidant feed 112 is controlled in particular as a function of an oxygen content in the clean gas stream. In particular, the oxidizer quantity, in particular the oxidizer volume flow and/or the oxidizer mass flow, is preferably controlled and/or regulated in such a way that reliable oxidation of the substances contained in the reformed raw gas flow in the oxidation region 126 results. The corresponding regulation can, for example, be temperature-dependent, oxygen-dependent or also dependent on a composition of the clean gas flow. In addition, of course, numerous other controlled variables and/or controlled variables are conceivable.

Due to the fact that in the described cleaning device 100 a reformed raw gas stream is generated from a raw gas stream before it is chemically reacted with an oxidizer, the cleaning device 100 can be operated in a particularly simple and cost-efficient manner. In addition, additional devices such as separators and scrubbers can be avoided.

In a further development it can also be provided that the clean gas stream is fed to a condenser, in particular to a heat exchanger 120 which is arranged in the clean gas outlet 116 and is designed as a condenser. The volume of the clean gas flow can preferably be reduced as a result, in particular by the water vapor contained in the clean gas flow being condensed out. in the A negative pressure below the ambient pressure can thus preferably be generated in the condenser, as a result of which the energy requirement for conveying the raw gas and clean gas flow for the raw gas cleaning can be reduced.

Claims (17)

1. Method for purifying a organically contaminated raw gas stream containing water vapor, wherein the method comprises the following:

   - feeding the raw gas stream to a reforming region (104) in which the contaminants in the raw gas stream react chemically with the water vapor in the raw gas stream, as a result of which a reformed raw gas stream which contains oxidizable and/or organic gas substances is obtained;

   - feeding the reformed raw gas stream and an oxidizing agent stream to an oxidation region (126) in which the oxidizable and/or organic gas substances of the reformed raw gas stream react chemically with the oxidizing agent of the oxidizing agent stream, as a result of which a purified gas stream is obtained, wherein the purification device (100) comprises a plurality of flow chambers (128), a raw gas feed line (110) and a control device, wherein the purification device (100) is switched to different operating modes by means of the control device,

   wherein in a first purification mode:
   the raw gas stream is fed to at least a first of the flow chambers (128a) by means of the raw gas feed line (110) and the purified gas stream is discharged from at least a second of the flow chambers (128b) by means of a purified gas discharge line (116); and

   wherein in a second purification mode:
   the raw gas stream is fed to the at least one second flow chamber (128b) by means of the raw gas feed line (110) and the purified gas stream is discharged from the at least one first flow chamber (128a) by means of the purified gas discharge line (116).
2. Method according to claim 1, wherein the chemical reaction in the reforming region (104) is allothermal and/or hydrothermal gasification and/or the chemical reaction in the oxidation region (126) is a reaction with an external source of energy and/or autothermal oxidation.
3. Method according to either claim 1 or claim 2, wherein the first of the flow chambers (128a) at least temporarily forms the reforming region (104) and the second of the flow chambers (128b) at least temporarily forms a heat storage region (106) to which the purified gas stream is fed.
4. Method according to claim 3, wherein the purification device (100) comprises at least one third flow chamber (128c) which at least temporarily forms a preheating region (108) to which the oxidizing agent stream can be fed for preheating before the oxidizing agent stream is fed to the oxidation region (126).
5. Method according to either claim 3 or claim 4, wherein the raw gas stream and/or the purified gas stream and/or the oxidizing agent stream is fed alternately to different flow chambers (128) in each case such that the flow chambers (128) each alternately form the reforming region (104) and/or the heat storage region (106) and/or the preheating region (108).
6. Method according to any of claims 1 to 5, wherein the raw gas stream has an oxidizing agent content, in particular oxygen content, of less than 5 vol.%, in particular less than 3 vol.%, preferably less than 1 vol.%.
7. Method according to any of claims 1 to 6, wherein the raw gas stream is heated to at least approximately 800°C, in particular at least approximately 900°C, in the reforming region (104).
8. Method according to any of claims 1 to 7, wherein the raw gas stream in the reforming region (104) and/or the purified gas stream in a heat storage region (106) and/or the oxidizing agent stream in a preheating region (108) are guided through a relevant heat storage unit (124) of a heat storage device (122), wherein one or more or all of the heat storage units (124) are formed in particular by ceramic flow bodies or comprise such.
9. Method according to any of claims 1 to 8, wherein the raw gas stream is heated before it is fed to the reforming region (104) and/or the oxidizing agent stream is heated before and/or after it is fed to a preheating region (108) by means of a heat exchanger (120) and/or a heating device.
10. Method according to any of claims 1 to 9, wherein the purified gas stream is first fed to a heat storage region (106) and then to a downstream heat exchanger (120), wherein the purified gas stream is cooled by means of the heat exchanger (120) in particular to such an extent that condensate forms and as a result heat which is initially still contained in the purified gas stream is transferred to the heat exchanger (120) and/or made usable in other ways.
11. Method according to any of claims 1 to 10, wherein the oxidizing agent stream is fed, bypassing the reforming region (104) and/or independently of a flow path of the raw gas stream, to the oxidation region (126).
12. Method according to any of claims 1 to 11, wherein the mass flow and/or the volumetric flow of the oxidizing agent stream are controlled in an open and/or closed loop

    - depending on a mass flow and/or volumetric flow of the raw gas stream and/or

    - depending on a degree of contamination in the raw gas stream and/or

    - depending on a calorific value of the raw gas stream and/or

    - depending on an oxygen content in the purified gas stream,

    in particular such that a predefined oxygen/oxidizing agent content and/or a predefined temperature are achieved in the oxidation region (126) and/or in a purified gas discharge line (116).
13. Method according to any of claims 1 to 12, wherein the purified gas stream is fed to a heat exchanger (120), in particular a condenser, and the water vapor in the purified gas stream is condensed by means of the heat exchanger (120), in particular by means of the condenser.
14. Purification device (100) for purifying a raw gas stream containing water vapor,
    wherein the purification device (100) comprises the following:

    - a raw gas feed line (110) for feeding the raw gas stream to a reforming region (104) of the purification device (100), in which region the contaminants in the raw gas stream react chemically with the water vapor in the raw gas stream, as a result of which a reformed raw gas stream which contains oxidizable and/or organic gas substances can be obtained; and

    - an oxidizing agent feed line (112) for feeding an oxidizing agent stream to an oxidation region (126) of the purification device (100), in which region the oxidizable and/or organic gas substances of the reformed raw gas stream react chemically with the oxidizing agent of the oxidizing agent stream, as a result of which a purified gas stream can be obtained, wherein the purification device (100) comprises a plurality of flow chambers (128) and a control device, wherein the purification device (100) can be switched to different operating modes by means of the control device,

    wherein in a first purification mode:
    the raw gas stream can be fed to at least a first of the flow chambers (128a) by means of the raw gas feed line (110) and the purified gas stream can be discharged from at least a second of the flow chambers (128b) by means of a purified gas discharge line (116); and

    wherein in a second purification mode:
    the raw gas stream can be fed to the at least one second flow chamber (128b) by means of the raw gas feed line (110) and the purified gas stream can be discharged from the at least one first flow chamber (128a) by means of the purified gas discharge line (116).
15. Purification device (100) according to claim 14, wherein the plurality of flow chambers (128) of the purification device (100) are provided with heat storage material.
16. Purification device (100) according to either claim 14 or claim 15, wherein the purification device (100) comprises a plurality of flow chambers (128) through which the raw gas stream, the purified gas stream and/or the oxidizing agent stream can flow, wherein the flow chambers (128) each comprise a heat storage unit (124), wherein one or more or all of the heat storage units (124) have a layered structure consisting of different materials, in particular different heat storage materials.
17. Purification device (100) according to any of claims 14 to 16, wherein the purification device (100) comprises a heat exchanger (120) which is arranged in the purified gas discharge line (116) and is designed as a condenser and by means of which water vapor in the purified gas stream can be condensed such that in particular a volume and/or volumetric flow of the purified gas stream in the purified gas discharge line can be reduced.

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