EP3309240A1 - Method and device for gasification of biomass - Google Patents

Abstract

The invention relates to a method (10) for the gasification of biomass (B) and to a device (11) arranged therefor. The process takes place in at least three stages (12, 12i, 12ii, 13, 14). In a first process stage (12), in one embodiment, biogenic residue (biomass) may be supplied to a heating zone (ZE) to dry the biomass (B) and allow the volatiles to escape to produce a pyrolysis gas (PY) therefrom. The pyrolysis gas (PY) is fed to an oxidation zone (ZO) where it is substoichiometrically oxidized to produce a crude gas (R). The coke-like, carbonaceous residue (RK) which is produced in the heating zone (ZE) is partially gasified together with the raw gas (R) in a second process stage (13) in a gasification zone (ZV). The heating zone (ZE) can be heated indirectly. The gasification zone (ZV) can also be heated indirectly. The heating zone (ZE) and the oxidation zone (ZO) are preferably separate from each other in separate chambers (23, 24). The gasification produces activated carbon (AK) and a hot process gas (PH). The inventive method (10) includes or the device (11) is adapted to a certain amount of activated carbon of a minimum of 0.02 kilograms to a maximum of 0.1 kilograms per kilogram of supplied biomass (water and ash free, waf), from the the activated carbon in the gasification zone (ZV) has arisen, and the hot product gas (PH) in a third process stage (14) in a cooling zone (ZK), for example, at most 50 ° C to cool. Preferably, the device is set up or includes the method that the activated carbon (AK) and the hot process gas (PH) are cooled together in such a way that the temperature of the process gas (PH) in the cooling zone (CC) during co-cooling with the activated carbon (AK) remains above a lower limit temperature which is greater than the dew point temperature of the product gas (PH). The adsorption process taking place during the co-cooling of activated carbon (AK) and product gas (PH) causes tar to accumulate in the cooling zone during cooling from the hot process gas (PH) on the activated carbon (AK). As a result, after the third process stage (14), a clean gas (PR, PA) is obtained, which is essentially free of tar. The tar-enriched activated carbon (AK) can be at least partially burned to heat the heating zone (ZE) and / or the gasification zone (ZV).

Description

The invention relates to a method and a device for gasification of biomass. By biomass is meant any carbonaceous biogenic mass such as wood waste, crop waste, grass clippings, digestate, sewage sludge or the like.

Decentralized small plants with a throughput of less than 200 kg of biomass per hour are used in practice, for example at farms or in the municipal sector, in order to prevent the transport of the biomass and the residues and to be able to use the waste heat on site. The acceptance of such systems in the market is still missing today. A major reason for this is the tar, which arises in the pyrolysis and gasification of biomass. The tar has so far been consuming to remove and usually requires a high level of maintenance for the plants. If the gas produced in the gasification is then to be used in a combined heat and power plant, it is even necessary to completely remove the tar from the product gas produced. Not only the maintenance but also the purchase of such equipment is expensive.

A method and apparatus for gasification of biomass using a DC gasifier is out DE 10 2008 043 131 A1 known. To avoid the tar charge of the product gas, there is proposed a one-stage process with the aid of the DC gasifier, wherein fuel is supplied to the gasification chamber against gravity. In the reduction zone, above the oxidation zone formed a stationary fluidized bed. This is intended to avoid the critical channel formation known in fixed-bed gasifiers in the region of the reduction zone and in this way reduce the tar charge of the product gas. However, the production of such a fluidized bed requires limiting the gasification to certain biogenic residues or particle sizes, since otherwise a stable fluidized bed can not be achieved.

EP 1 436 364 B1 describes a device with a reaction chamber in which the supply of biomass takes place laterally. In the reaction chamber, the tar-containing gases may condense on the closed lid. This allows either the removal of the condensed tar from the reaction chamber or the return of the tar in the reaction zones within the reduction chamber. This should increase the overall efficiency. A similar device also describes EP 2 522 707 A2 , There is also an aftertreatment unit available, with the residue as completely as possible mineralized and "white ash" to be generated.

Another solution for biomass gasification is in DE 20 2009 008 671 U1 described. There, a direct current carburetor with a pyrolysis chamber and a carburetor is proposed. In the oxidation zone of the gasifier, the tar-containing pyrolysis gas is burned at 1200 ° C. Demensprechend very high temperatures in the oxidation zone are required.

EP 2 636 720 A1 describes a process in which a synthesis gas is produced by steam reforming from biomass. This requires very large heating surfaces for indirect heating. In gasifier tubes or carburettor spirals is to be moved by moving paddle a fluidized bed be generated. The synthesis gas is then purified in a carbon filter in a countercurrent process and cools down as well.

DE 198 46 805 A1 describes a method and apparatus for gasification and combustion of biomass. In the process, pyrolysis gas and coke are produced in a degassing furnace, which is fed to a gasification reactor in which the coke is partially gasified to form activated carbon. The activated carbon is removed via a conveyor from the combustion chamber and transported in a filter outside the combustion chamber. The product gas resulting from the process is removed separately from the activated carbon from the gasification reactor and cooled in a heat exchanger. Subsequently, the cooled product gas is passed through the filter filled with the activated carbon. In the process, pollutants should remain in the activated carbon.

Starting from this prior art, it can be regarded as an object of the present invention to provide a method and an apparatus for the gasification of biomass, which processes a wide variety of biogenic residues regardless of the particle size and can produce a low-tarry product gas economically.

This object is achieved by a method having the features of claim 1 and a device having the features of claim 13.

In the method according to the invention, the product gas from the biomass, which is supplied to a device for gasification of biomass, for example according to claim 13, generated in at least three process stages. In a first process stage, a raw gas and a carbonaceous residue are produced from the supplied biomass.

For this purpose, the biomass is oxidized substoichiometrically, for example in an oxidation zone by supplying an oxygen-containing gas, in particular air. The oxygen-containing gas to be supplied may be preheated for this purpose. In the substoichiometric oxidation, the raw gas and a coke-like, carbonaceous residue.

In a modification of the method, in the first stage of the process, the biomass supplied is dried in a first sub-stage in a heating zone and / or heated in such a way that the volatile components escape from the biomass, forming a pyrolysis gas and the carbonaceous residue. Drying and pyrolysis can be carried out in a common heating zone. Alternatively, the drying of the biomass and the pyrolysis can be carried out in separate zones. In a second sub-stage, the pyrolysis gas from the first stage in an oxidation zone is substoichiometrically oxidized by supplying the oxygen-containing gas, whereby the crude gas is formed.

The inventive method includes that carbonaceous residue and the raw gas from the first stage in a second stage of the process are partially gasified such that activated carbon is formed. In this case, preferably up to a maximum of 75% and more preferably up to a maximum of 60 to 65% of the carbonaceous residue in the gasification zone gasified. The temperature in the gasification zone may be at least 800 ° C and at most 1000 ° C in one embodiment. In the gasification zone, a hot product gas and activated carbon is produced.

In the third process stage are in a cooling zone the hot product gas and at least part of the activated carbon cooled together. An adsorption process takes place in which the tar from the hot product gas attaches to the activated carbon. Thus, the tar is removed from the hot product gas and the product gas provided subsequent to the third stage of the process is tar lean or substantially free of tar constituents. The inventive method includes that a certain amount of the activated carbon produced in the gasification zone and the hot product gas, to which the supplied biomass has led, fed to the cooling zone and cooled together in the cooling zone, so that an adsorption process takes place during cooling, in which the specific amount of activated carbon is enriched during the cooling by tar from the hot product gas.

The specific amount of activated carbon has a mass mAK2, which is from a minimum of 2% to a maximum of 10% of the mass mBwaf of the biomass supplied based on the reference level water and ash-free (waf). For example, per kilogram of biomass supplied, based on the reference state, water and ash-free 0.05 kg of activated carbon are conveyed into the cooling zone for co-cooling with the resulting product gas. For example, if a mass flow of biomass mBroh is fed to the device, the biomass will typically include water and minerals. The mass flow mBroh fed biomass therefore corresponds to a mass flow mBwaf of biomass in the state of reference water and ash-free, which is usually smaller than the mass flow mBroh. At a constant mass flow of fed biomass a certain mass flow mAK2 activated carbon is conveyed from the gasification zone into the cooling zone, wherein the determined mass flow mAK2 at least 2% and at most 10% of the mass flow mBwaf the biomass based on the reference state is water and ash-free: $$\mathrm{mAK}2=0.02...0.1\mathrm{mBwaf}\mathrm{,}$$

In order to achieve that only a certain amount of activated carbon is supplied together with the product gas to the cooling zone and cooled there together with the product gas, the process for gasification of biomass can be controlled or regulated, for example, such that only generates the specific amount of activated carbon in the gasification zone becomes. Alternatively or additionally, excess activated carbon can be diverted from the gasification zone and / or between the gasification zone and the cooling zone.

In the event of a change in demand for pure product gas, for example a load change of a motor fed therewith, the time delay must be considered, with which increasing or decreasing the supply of biomass at the input of the device for adjusting the demand for product gas increased or decreased Production of activated carbon in the gasification reactor leads. Therefore, the amount of activated carbon to be branched off is determined by the amount of biomass from which the instantaneous activated carbon and the instantaneous hot product gas are produced.

With the aid of this method or a corresponding device which provides the method steps, it is possible economically and simply to produce a tar-poor product gas in the biomass gasification. By co-cooling at least a portion of the activated carbon and the hot teerbehafteten product gas, the tar does not or only in insignificant amounts from the wall of the chamber, in which the teerbehaftete hot product gas and the part of the activated carbon are cooled together. Rather, the specific amount of activated carbon takes the tar from the hot product gas during the cooling down. An expensive cleaning of the chamber of the tar is therefore rarely or not at all necessary.

The temperature at which the product gas is cooled in the cooling zone is for example at most 50 ° C. The cleaning becomes particularly efficient if the product gas and the determined amount of the activated carbon in the third stage of the process for the adsorption process in the cooling zone together are not cooled below a limit temperature which is greater than the dew point temperature of the product gas. In this way, a high loading capacity of the activated carbon remains usable. Preferably, the lower limit temperature of at least 10 to a maximum of 20 Kelvin is greater than the dew point temperature of the product gas.

The product gas purified by the adsorption process may be supplied as fuel to a device such as a gas turbine or a gas engine. Preferably, the mass flow of supplied biomass is adjusted in proportion to the power requirement of the device to be fed with purified product gas. The particular mass flow of activated carbon supplied from the gasification zone of the cooling zone, which has arisen from the proportionally increased or decreased amount of supplied biomass, is preferably adjusted proportionally.

It is also advantageous if the gasification is carried out under an increased pressure relative to ambient pressure. For example, at a pressure in the range of about 5 bar. The generated cooled product gas can then be used without intermediate compression in gas turbines or supercharged engines. To achieve this, the at least one reaction chamber can be placed under a corresponding pressure. For example, the oxygen-containing Gas (for example, air) are introduced via a compressor or other suitable compression unit under pressure in the at least one reaction chamber. By carrying out the process under increased pressure, it is also possible to increase the loading capacity of the activated carbon.

Preferably, the gasification of the biomass is carried out in a stepped process. For example, an at least two-stage process is obtained if the heating for drying and pyrolysis on the one hand and the processing of the resulting pyrolysis gas and the carbonaceous residue by means of oxidation and / or gasification on the other hand carried out in separate chambers. It is particularly preferred, for example, if the heating zone for drying and / or pyrolysis on the one hand and the oxidation zone on the other hand are arranged in separate chambers. If the heating of the biomass and / or the release of the volatiles from the biomass for producing the pyrolysis gas on the one hand and the stoichiometric oxidation on the other hand carried out in a stepped process in separate zones, the desired temperature in the oxidation zone can be largely independent of the size of the piece Biomass and the moisture of the biomass are reached and adjusted. A three-stage process is obtained if, in addition, the substoichiometric oxidation on the one hand and the gasification of the carbonaceous residue on the other hand carried out in separate zones in separate chambers.

It is preferred if the temperature in the oxidation zone is less than the ash softening point or the ash melting point of the ashes of the carbonaceous residue. It is advantageous if the temperature in the oxidation zone is as close as possible to the ash softening point or ash melting point. For example, the substoichiometric oxidation is carried out at a temperature of a minimum of 1000 ° C to a maximum of 1200 ° C.

In some embodiments, the calorific value of the product gas is between 1.5 and 2 kWh per cubic meter. The cold gas efficiency of the process may be more than 80%.

With this method, all types and sizes of biogenic residues can be gasified as biomass. The formation of a fluidized bed is eliminated. There is no polluted wastewater. The tar removal is from the product gas is economically possible even for small plants, since neither high investment costs in the tar removal are required and also the operation does not require a high level of maintenance.

The process according to the invention can work with a mixed form of autothermal and allothermal gasification. The temperature in the oxidation zone is set in one embodiment by the amount and preferably also by the temperature of the supplied oxygen-containing gas. This allows gas production to be adapted to demand without affecting the temperature in the gasification zone. The temperature in the gasification zone can be adjusted by indirect heating with a heater. Alternatively or additionally, the heat for the gasification zone is provided by heat input from the oxidation zone, for example by partially oxidized carbonaceous residue and / or pyrolysis gas there.

For indirect heating of the gasification zone in one embodiment requires less than 10% of the energy content of the biomass supplied. Compared to a purely allothermal gasification therefore smaller heating surfaces can be provided in the gasification zone.

The activated carbon and the hot product gas are preferably cooled in the cooling zone by indirect cooling. The cooled product gas, which can also be referred to as pure gas, can be fed to a filter and / or dust separator unit following the cooling zone in order to reduce the dust load of the product gas. The filter can be fed with activated carbon, which diverted before the cooling zone as excess activated carbon and therefore not cooled together with the teerbehafteten product gas. For the fine cleaning, a cleaning device with swap bodies for the activated carbon can be used, as it is known per se.

It is preferred if activated carbon resulting from the process, at least the part with the tar adsorbed thereon from the third process stage, is combusted in a reactor which was previously used in the third process stage for cooling the product gas and the activated carbon. Preferably, the exhaust gas of the combustion is used to heat the heating zone. The overall efficiency is thereby increased. The fuel for a reactor for generating the heat to dry or release the volatiles of the biomass during pyrolysis need not be supplied separately, but automatically accrues.

The gasification zone can be heated by the heat of a reactor. This can be done in particular by the indirect heating of a gasification zone having reaction chamber or the reaction chamber portion in which the gasification zone is present. As fuel for the reactor, in one embodiment, the activated carbon removed after cooling from the cooling zone can be used.

During the combustion of the activated carbon in the reactor, it may be advantageous to increase the surface area of the activated carbon before it is fed to the burner, for example by grinding or grinding the activated carbon after removal from the cooling zone. By one or more of the measures mentioned, the efficiency of the method or the device can be further increased.

It is also advantageous to use an exhaust gas produced in the combustion in the reactor for preheating the oxygen-containing gas before it is fed into the oxidation zone.

The apparatus according to the invention for gasification of biomass with which an embodiment of the method according to the invention can be carried out has at least one first chamber in which a heating zone for the biomass is provided. In the heating zone, the biomass can be dried and / or pyrolyzed. The apparatus may provide a heating zone with separate sub-zones for drying and pyrolysis. The subzones may be arranged, for example, in mutually separate first chambers of the device. The apparatus has a feeder which is adapted to feed the biomass to the heating zone to produce pyrolysis gas and carbonaceous residue. The apparatus further includes at least one second chamber providing an oxidation zone for the oxidation of the pyrolysis gas and a gasification zone for the gasification of the carbonaceous residue. The device may comprise separate second chambers, so that the oxidation zone and the gasification zone are provided in separate chambers. The second chamber or chambers with the oxidation zone and the gasification zone are preferably separate from the first chamber with the heating zone, so that the heating zone on the one hand and the oxidation zone and the gasification zone on the other hand are separated from each other. The device has a gas supply device, which is set up to supply an oxygen-containing gas, for example air, to the oxidation zone in an amount such that the pyrolysis gas present in the oxidation zone undergoes substoichiometric oxidation, whereby a crude gas is produced. The amount of oxygen-containing gas supplied and the biomass supplied can be used to adjust the production of the product gas to the demand. The apparatus comprises a conveying means adapted to convey the pyroles gas from the heating zone into the oxidation zone and the raw gas from the oxidation zone to the gasification zone and adapted to convey the carbonaceous residue from the heating zone to the gasification zone. The conveyor operates, for example, with at least one conveyor and / or by means of the prevailing weight. The apparatus further comprises a heating means adapted to adjust the temperature in the gasification zone so as to partially gasify the carbonaceous residue, optionally with gas constituents of the raw gas fed thereto into the gasification zone, whereby activated carbon and a hot product gas arise. The heating means may be a heater for, for example, indirect, heating the gasification zone. Alternatively or additionally comes as heating means, for example, heat input from the oxidation zone in question. The by the exothermic substoichiometric oxidation of pyrolysis gas and optionally also of carbonaceous Residual material in the oxidation zone resulting heat can be from the oxidation zone in the gasification zone, for example by heat radiation and / or by the hot raw gas or the heated carbonaceous residue, registered.

The product gas produced by the gasification is still teerbehaftet. The device is therefore adapted to provide a certain amount - for example a certain mass flow - of the activated carbon from the gasification zone and the product gas from the gasification zone in a cooling zone of the device. For example, the device is adapted to convey a certain amount of the activated carbon and the hot product gas with a conveying means from the gasification zone into a cooling zone. The conveyor has, for example, a conveyor and / or works by means of the prevailing weight. The specific amount of activated carbon has a mass of at least 2% to a maximum of 10% of the mass of biomass (mwaf) supplied, based on the reference state, water-free and ash-free, from which the activated carbon and the hot product gas are produced. The specific amount has, for example, a mass of 5% of the mass mwaf of the biomass supplied based on the reference state water and ash-free.

If, for example, a mass flow mBroh is fed to biomass to the device, this corresponds to a mass flow mBwaf of biomass based on the reference state without water and ash, which as a rule is smaller than mBroh, since the biomass fed to the device is generally water and ash ( Minerals). In the apparatus, a mass flow of activated carbon mAK in the gasification zone is produced from the mass flow mBroh. The device is adapted to supply a certain amount of activated carbon in the form of a specific mass flow mAK2 the cooling zone. Namely, a certain amount of activated carbon with a mass flow mAK2 of at least 2% to a maximum of 10% of the mass flow of biomass based on the water and ash-free reference state of the cooling zone supplied. The device is in the event of a change in demand for pure product gas, for example, at a load change of the gas engine fed thereto, set up to determine the amount to be conveyed to the cooling zone activated carbon according to the amount of biomass (waf), which led to the activated carbon produced as explained in the description of the procedure.

By way of example, the device can be set up to convey only a specific quantity, for example a specific mass flow, into the cooling zone such that the device controls the process, for example by means of a process control device, so that only a specific mass flow mAK2 of activated carbon from the region between minimum 2 % mBwaf up to a maximum of 10% mBwaf in the gasification zone. Alternatively or additionally, the device may, for example, have a branching device, which is set up to branch off excess activated carbon upstream of the cooling zone, so that the excess activated carbon is not conveyed into the cooling zone.

The apparatus further comprises a cooling device having a cooling chamber for co-cooling the diverted particular amount of activated carbon and the product gas. The cooling device is configured to co-cool the particular branched amount of activated carbon and the hot product gas in the cooling zone that provides the cooling chamber such that an adsorption process takes place during cooling in the cooling zone, wherein the activated carbon during cooling by tar from the hot product gas is enriched.

Since the specific amount of activated carbon and the hot product gas are cooled together in the cooling chamber and it comes to the adsorption of the tar contained in the product gas to the activated carbon during cooling, the tar is not at all or only a negligible proportion of the wall of the Cooling chamber of the cooling device from. Consequently, the cooling chamber does not need to be cleaned consuming. It is thus even a unmanned operation of the device possible.

In one embodiment, the device has a common reaction chamber for oxidation and gasification. The promotion of the raw gas and the carbonaceous residue from the oxidation zone in the gasification zone takes place at least supported by the weight force substantially in the vertical direction. Likewise, the transport of the hot product gas and the activated carbon from the gasification zone into the cooling zone can at least be assisted by the weight force. It is preferable to arrange the oxidation zone and the gasification zone in one chamber and the cooling zone in a separate chamber separate therefrom. To convey the substances between the chambers and / or within the chambers, appropriate conveying means such as augers or the like may be present.

Preferably, the oxidation and gasification zones on the one hand and the cooling zone on the other hand are separated from each other. By arranging the zones in separate chambers, the apparatus is arranged to perform a stepped process.

It is preferred, when the device is set up, to gasify the biomass at ambient pressure to be able to carry out increased pressure. For example, to an input of the device for supplying biomass, an outlet of the device for discharging the purified product gas and / or an output of the device for discharging ash each sluices are arranged, which are arranged so the device between input and output or To operate outlet at elevated pressure relative to ambient pressure.

• Figur 1 ein Blockschaltbild eines Ausführungsbeispiels des erfindungsgemäßen Verfahrens bzw. der erfindungsgemäßen Vorrichtung.
• Figur 2 ein Blockschaltbild eines weiteren Ausführungsbeispiels des erfindungsgemäßen Verfahrens bzw. der erfindungsgemäßen Vorrichtung,
• Figur 3 ein Ausführungsbeispiel der Vorrichtung mit einer gesonderten Erhitzungskammer zur Trocknung und Pyrolyse und einer gemeinsamen Reaktionskammer für eine Oxidationszone und eine Vergasungszone sowie einer separaten Kühlzone in einer gesonderten Kühlkammer.

Advantageous embodiments of the method and the device will become apparent from the dependent claims, the description and the drawings. Hereinafter, preferred embodiments of the invention will be explained in detail with reference to the accompanying drawings. Show it:

• FIG. 1 a block diagram of an embodiment of the method according to the invention or the device according to the invention.
• FIG. 2 a block diagram of another embodiment of the method and the device according to the invention,
• FIG. 3 An embodiment of the device with a separate heating chamber for drying and pyrolysis and a common reaction chamber for an oxidation zone and a gasification zone and a separate cooling zone in a separate cooling chamber.

Of the FIG. 1 schematically a block diagram of an embodiment of the invention is illustrated. The block diagram shows a method 10 or a device 11 for gasifying a biomass B. The method essentially has three successive process stages 12, 13, 14. In a first process stage 12, the biomass B is supplied together with an oxygen-containing gas, an oxidation zone ZO. As the oxygen-containing gas in the embodiment, air L is used. The amount of supplied air L is adjusted depending on the demand for a product gas to be generated. In addition, via the amount of air L, a temperature TO in the oxidation zone ZO can be set.

In this first process stage 12, the biomass B oxidizes substoichiometrically in the oxidation zone ZO. This produces a raw gas R and a carbonaceous residue RK. The temperature TO in the oxidation zone is set below, but as close as possible to the ash melting point or ash softening point of the ashes of the carbonaceous residue RK. This avoids that the ash of the carbonaceous residue melts or softens in the oxidation zone ZO and is for bonding and in the region of the oxidation zone ZO comes. On the other hand, a reduction of the tar content in the raw gas R is already achieved by a very high temperature TO in the oxidation zone ZO. The raw gas R and the carbonaceous residue RK are then partially gasified in a second process stage 13 in a gasification zone ZV. Gasification zone ZV can be heated indirectly by means of a heating device 15. Otherwise, the temperature TV in the gasification zone ZV can be adjusted, for example, by introducing heat from the oxidation zone ZO, in particular by introducing hot carbonaceous residue RK and hot raw gas R. The heater 15 may include at least one burner 16 in the preferred embodiment.

The temperature TV in the gasification zone ZV can be adjusted via the heating device 15 independently of the temperature in the oxidation zone ZO. The temperature TV in the gasification zone ZV is in the embodiment at least 800 ° C and at most 1000 ° C. The carbonaceous residue RK is partly gasified in the gasification zone ZV with gas components of the raw gas, wherein in the embodiment, up to about 75% of the carbonaceous residue RK are gasified. The gas components used for the gasification of the carbonaceous residue RK are mainly water vapor and carbon dioxide.

Under these conditions, a hot product gas PH, which still has an undesirably high proportion of tar, and activated carbon AK is formed in the gasification zone ZV. The hot product gas PH and a certain amount of activated carbon MAK2 are then supplied to the cooling zone ZK to co-cool the product gas PH and the determined amount of activated carbon MAK2, so that the tar from the hot product gas PH on the amount of activated carbon MAK2 during co-cooling on the certain amount of activated carbon MAK2 is transferred. In this way, precipitation of the tar on the wall of the chamber providing the cooling zone ZK can be prevented because the certain amount of activated carbon MAK2 absorbs the tar. On the other hand, we used the activated carbon AK efficiently.

The amount of activated carbon MAK2, which is cooled together with the product glass PH, is determined by the amount of supplied biomass MB, which led to the activated carbon AK and the product glass PH. The supplied amount of biomass MB usually contains water and ash and has a Mass mBroh on. This corresponds to a mass mBwaf in a reference state water-and ash-free (waf). The amount of activated carbon MAK2, which is supplied to the cooling zone, has a mass mAK2 that corresponds to a minimum of 2% to a maximum of 10% of the mass mWAF of the supplied biomass B based on a water and ash-free reference state of the supplied biomass B.

In a third process stage 14, the hot product gas PH and the specific amount of activated carbon MAK2 and the ashes produced in the gasifier are cooled indirectly with the aid of a cooling device 17. In this case, takes place in the cooling zone ZK an adsorption process in which the tar from the product gas PH binds during the co-cooling with the specific amount of activated carbon MAK2. The amount of activated carbon MAK2 is enriched by the tar from the product gas PH during cooling in a common chamber.

The hot product gas PH can be cooled within the cooling zone ZK, for example to a temperature of below 50 ° C. The product gas PH and the determined amount of activated carbon MAK2 are preferably not cooled together in the third stage of the adsorption process below a lower limit temperature which is greater than the dew point temperature of the product gas PH. In this way, a high benefit can be drawn from the loading capacity of the activated carbon. By enriching the activated carbon MAK2 by the tar from the product gas PH, a cooled product gas PA, which can also be referred to as pure gas PR, is formed at the end of the cooling zone ZK. The clean gas PR is completely tar-free or contains only a negligible tar content. The clean gas PR can be used to generate energy and, in particular, requires no further expensive aftertreatment for tar removal. In particular, the clean gas PR can be used directly in heating plants.

In addition to the specific amount of activated carbon MAK2 for co-cooling may remain an excess amount of activated carbon MAK1 from the Vergaserzone ZV. This can, as indicated by the arrow P in FIG. 1 indicated, branched off or removed before the cooling zone ZK. The excess subset MAK1 with a mass flow mAK1 can be supplied for further fine cleaning of the clean gas PR a cleaning tank assembly to further reduce the residual tar content of the clean gas PR after co-cooling. Such cleaning container arrangement for gas purification are known per se, so that can be dispensed with a detailed description.

As in FIG. 1 illustrated by dashed lines, the cooled product gas PA and the clean gas PR can be freed of dust in a suitable Staubabscheideeinheit 18, for example by filters, electrostatic devices, cyclones or the like.

The amount of activated carbon MAK2 can be removed from the cooling zone ZK and ground or finely ground with the aid of a grinder 19. The ground activated carbon, hereinafter referred to as coal dust SK, can be used as an energy source for combustion. For example, the coal dust SK or at least a part thereof can be supplied to the burner of the heating device 15 for indirect heating of the gasification zone ZV.

In FIG. 1 In addition, two possibilities for using an exhaust gas G of the at least one burner 16 of the heating device are illustrated. The exhaust gas G can on the one hand in a drying device 20 for drying the Biomass B be used before feeding into the oxidation zone ZO. Alternatively or additionally, the exhaust gas G can be used in a preheating device 21 for preheating the air L or the oxygen-containing gas prior to feeding to the oxidation zone ZO.

The process may be carried out as a mixed form of autothermal and allothermal gasification. For the optional indirect heating of the gasification zone ZV in the second process stage 13, in one example at most 10% of the energy content of the biomass is needed. The clean gas PR has a calorific value between 1.5 and 2 kWh / m ³ . Cold efficiencies of over 80% can be achieved. The removal of the tar from the product gas PH by the adsorption during co-cooling of the product gas PH and the specific amount of activated carbon MAK2 in the third process stage 14 is extremely economical and requires neither high investment costs, nor a high maintenance.

In FIG. 2 a further embodiment of the method according to the invention or the device according to the invention is illustrated. The following are the differences from the embodiment in FIG. 1 described. Otherwise, the description applies to the embodiment according to FIG. 1 ,

The first process stage 12 is in the embodiment according to FIG. 2 divided into a heating stage 12i and an oxidation stage 12ii. In the heating stage 12i, the biomass B is fed to a heating zone ZE. In the heating zone ZE, the biomass B is dried and heated so that the volatiles escape from the biomass B. This creates a gas from the volatile components PY (pyrolysis gas) and a carbonaceous residue RK. As illustrated, the Heating zone ZE are heated with the exhaust gas G of the burner 16 of the heater 15. Alternatively or additionally, but not shown, the heating zone ZE can be heated with exhaust gas of a gas engine, which is fed with the clean gas PR from the process. The temperature TE in the heating zone is about 500 ° C, for example. The pyrolysis gas PY is supplied to the oxidation zone ZO. The oxidation zone ZO is also supplied with an oxygen-containing gas, for example air L, in an amount such that the pyrolysis gas PY is substoichiometrically oxidized in the oxidation zone ZO. The air L can be preheated in a preheating device 21 which is supplied with heat to the exhaust gas of the burner 16.

The carbonaceous residue RK can be conducted together with the pyrolysis PY of the oxidation zone ZO and / or be fed directly to the gasification zone ZV bypassing the oxidation zone ZO. A portion of the carbonaceous residue RK can substoichiometrically oxidize in the oxidation zone ZO.

The exhaust gas of the burner 16 of the heater 15 may optionally be used to heat the gasification zone ZV.

By a spatial separation of heating for drying and pyrolysis on the one hand and oxidation on the other hand, the process is carried out stepped. The desired temperature TO in the oxidation zone ZO can thus be achieved and adjusted largely independently of the piece size of the biomass B and the moisture of the biomass.

In FIG. 3 is schematically illustrated in a partially sectioned side view of an embodiment of an apparatus 11 for the gasification of biomass B. The device 11 has a substantially vertically arranged, for example, cylindrical reaction vessel 22 which defines a common reaction chamber 23. In an upper portion of the reaction chamber 23 and the reaction vessel 22, the oxidation zone ZO and in a subsequent section, the gasification zone ZV is formed. The vertical arrangement allows a simplified transport within the reaction chamber 23 without consuming conveyors reach. Alternatively, the at least one reaction chamber 23 may be oriented horizontally or inclined to the vertical and horizontal.

The oxidation zone ZO and the gasification zone ZV can alternatively also be formed in reaction chambers which are separate from one another (in FIG FIG. 3 not shown). The separate reaction chambers may be arranged in separate reaction containers.

At the vertically upper end of the reaction vessel 22 of the reaction chamber 23 carbonaceous residue RK and pyrolysis PY can be supplied. The carbonaceous residue RK and the pyrolysis gas PY can be generated in a separate from the reaction chamber 23 heating chamber 24 of the device 11, which provides a heating zone ZE in the heating chamber 24 for drying and pyrolysis of the biomass B. The heating chamber is connected to the reaction chamber 23 via a pipe 25 for pyrolysis gas PY and carbonaceous residue RK.

The heating chamber 24 is fed from a silo 26 or intermediate tank with biomass B. In addition, the silo 26 or the intermediate container is connected to the inlet 27 of the heating chamber 24. Between the silo 26 and the heating chamber 24 for drying and pyrolysis is a first lock 28 is arranged. For example, with this first lock 28, the mass flow mBroh can be adjusted to biomass B, which is supplied to the heating chamber 24. In the heating chamber 24, which is inclined relative to the vertical or horizontal, a conveyor 29, such as a screw conveyor is arranged to promote the biomass B from the entrance 27 of the heating chamber 24 through the heating chamber 24. At the outlet 30 of the heating chamber 24, this is connected via the line 25 to the reaction chamber 23, which provides the oxidation zone ZO and the gasification zone ZV. The heating chamber ZE and the reaction chamber 23 are separate from each other chambers, so that the temperature in the reaction chamber 23 and the heating chamber 24 can be adjusted largely independently. In the upper portion of the reaction vessel 22, there is also provided a gas supply means 31 for supplying the oxygen-containing gas and the air L into the oxidation zone ZO, respectively. The air is conducted, for example, by means of a line 32 of the gas supply device 31 directly into the oxidation zone ZO. In the reaction chamber 23, a temperature sensor 33 for detecting the temperature TO in the oxidation zone ZO is present. The detected temperature is transmitted to control the temperature to a process control device not shown. Likewise, in the heating zone ZE and in the gasification zone ZV not shown temperature sensors may be arranged, which detect the temperature in the heating zone ZE or in the gasification zone ZV and can forward it to the process control device.

At the lying in the conveying direction end 34 of the reaction chamber 23 may be indicated by the arrow in FIG FIG. 3 indicated branching device 35, which is adapted to excess activated carbon AK, not for the common cooling of activated carbon AK and product gas PH in the cooling zone ZK is to be used to branch off in front of the cooling zone ZK. At the end 34 of the reaction chamber 23, this is connected to a cooling chamber 36, which is contained in a cooling chamber container 37. The cooling chamber 36 provides a cooling zone ZK. The cooling chamber 36 is also inclined relative to the vertical and horizontal. Alternatively, this can be aligned, for example, vertically or horizontally. In the cooling chamber 36, a conveyor 38, such as a screw conveyor, arranged, which is adapted to a certain amount, for example, a certain mass flow, the activated carbon AK produced in the reaction chamber 23 to lead through the cooling chamber 36. In addition, the conveyor 38 can contribute to the promotion of the hot product gas PH in the cooling chamber 36 and the cooling zone ZK. At the lying in the conveying direction of the activated carbon AK and the product gas PH end 39 of the cooling chamber 36, this is connected to a separation chamber 40 having a filter 18 and an outlet 41 for the clean gas PR. The filter 18 can be fed, for example, with activated carbon AK branched off before the cooling zone ZK. At the outlet 41, a temperature sensor 42 is arranged, which detects the gas outlet temperature of the purified product gas PR and transmitted to the process control device. The Abscheidekammer 40 also has at its lower end an outlet 43 for the loaded with tar activated carbon AK. At the outlet 43, the separation chamber 40 is connected to a reactor 44 for combustion of the tar laden activated carbon AK. Between the separation chamber 40 and the reactor 44, a second lock 45 is arranged, through which the tar-charged activated carbon AK is conveyed into the reactor 44 for combustion of the tar-charged activated carbon. The reactor 44 may also be fed in one embodiment with branched off before the cooling zone ZK excess activated carbon AK, with a corresponding Supply line in FIG. 3 not shown. The second lock 45, like the first lock 28, is arranged at the inlet 27 of the heating chamber 24 in such a way that the device 11 in the heating chamber 24, the reaction chamber 23 of the cooling chamber 36 and the separation chamber 40 is at an elevated ambient pressure, for example 5 bar. can be operated.

The reactor 44 for the combustion of the loaded activated carbon AK has an outlet 46 for the ash, wherein the ash can be conveyed for example by means of a turntable 47 to the exit. At the outlet 46, the reactor 44 has a third lock 48, which, like the other locks 28, 45, is set up such that the device 11 can be operated at elevated pressure relative to ambient pressure.

The heating chamber 24, which provides the heating zone ZE, is enclosed by an insulating jacket 49. Between the insulation jacket 49 and the outer wall of the container 50 for the heating chamber 24, a heating chamber 51 is formed. In the exemplary embodiment, the heating chamber 51 is connected to the reactor 44 for combustion of the tar-charged activated carbon via a corresponding line 52, via which the heating chamber 51 can be supplied with exhaust gas G of the reactor 44. Alternatively or additionally, the heating chamber 51, as indicated by the arrow 52, with exhaust gases of a gas engine (not shown) are heated to generate electricity, which is fed for example with the purified product gas PA, PR as fuel. The exhaust gas G can be discharged from the heating chamber 51 via an outlet 53 in the insulating jacket 49.

The reaction chamber 23 is likewise surrounded by an insulation jacket 54, which contains both the oxidation zone ZO, as well as the gasification zone ZV encloses. Between the insulating jacket 54 and the reaction chamber 23, a heating chamber for indirect heating of the gasification zone ZV and / or the oxidation zone ZO may be arranged (not shown), which can also be fed with exhaust gas G of the reactor 44.

The cooling chamber container 37 is enclosed by a jacket 56, wherein between the jacket 56 and the cooling chamber container 37, a cooling space 57 is formed, which can be fed via an input 58 with a coolant C, in the embodiment air. The cooling space 57 has an outlet 59 for discharging the air C from the cooling space 57. The heated by indirect cooling of the cooling chamber 36 air C can be supplied via a arranged between the outlet 59 and the reactor 44 line 60 to the reactor 44 for the combustion of activated carbon AK.

The outlet 41 for discharging the clean gas PR may, for example, be connected to a gas engine (not shown) which is to be operated with the clean gas PR. For generating the clean gas PR, the device 11 operates, for example, as follows:

In the steady state, when the gas engine is to provide a constant mechanical power, the continuous production of clean gas PR by the device 11 or by the method 10 is usually in demand. To generate the clean gas PR is usually a constant mass flow of biomass mBroh (reference state raw) from the silo 26 for the biomass B using the first lock 28 and, for example, gravity and the conveyor 29 of the heating chamber 24 for drying and pyrolysis of the biomass B. fed. The biomass flow mBrohr corresponds to a biomass flow mBwaf (state of reference water- and ash-free). In the heating chamber 24 or the heating zone ZE, the biomass B is dried by indirect heating of the heating zone ZE by the exhaust gas G of the reactor 44 and / or the gas engine at, for example, about 500 ° C and heated so that the volatile components from the biomass B escape (pyrolysis). This results in carbonaceous residue RK and pyrolysis PY, which may have a tar content of several grams per cubic meter.

The carbonaceous residue RK and the pyrolysis PY be promoted by means of the conveyor 29 in the oxidation zone ZO. There, the pyrolysis PY under the supply of an oxygen-containing gas, such as air L, substoichiometrically oxidized at about 1000 to 1200 ° C, wherein a crude gas R is formed. The tar constituents in the pyrolysis gas PY are for the most part cracked. The air of the oxygen-containing gas L is regulated to adjust the temperature TO in the oxidation zone ZO. For example, 1 cubic meter of air per kilogram of biomass (waf) is needed. By preheating the air flow can still be reduced and the heating value of the clean gas PR can be increased. In the oxidation zone ZO or the oxidation stage 12ii, the tar content in the raw gas R is lowered to well below 500 mg per cubic meter.

The gas transport of the raw gas R into the gasification zone ZV arranged below the oxidation zone ZO is achieved, for example, by feeding the oxygen-containing gas L at the vertically upper end 61 to the reaction chamber 23 and thus pushing the gas L vertically downwards in the reaction chamber 23. Alternatively or additionally, at the end 34 of the reaction chamber 23 or the device 11, a suction device, not shown, for the product gas PH may be connected to bring about the gas transport within the reaction chamber 23 or support.

In the gasification zone ZV, which can also be referred to as a reduction zone, the majority of the carbonaceous residue RK is gasified endothermically, the gas temperature correspondingly falls to, for example, 700 ° C. The proportion of carbonaceous residue RK from originally 20% after pyrolysis to, for example, 5% based on the supplied biomass flow mBwaf (reference water and ash-free) decline. The result is coal AK with a strong porous structure (activated carbon).

The process control device of the device 11 is set up by controlling the process parameters, such as temperature and possibly also pressure, and / or by means of the branching device 35 and / or the conveyor 38 of the cooling chamber 36 a certain mass flow of activated carbon MAK2 from a range of minimum 0th , 02 kilograms to a maximum of 0.1 kilograms per kilogram of supplied biomass B (based on the reference state water and ash-free) from which the activated carbon AK were generated to promote from the gasification zone ZV in the cooling zone ZK of the cooling chamber 36 and there together with the at the gasification from the supplied biomass B teerbehafteten product gas PH to cool indirectly cooled to near ambient temperature. During the co-cooling, the product gas PH is purified from the tar by the adsorption process and then supplied to the gas engine as pure gas PR.

When the demand for clean gas PR changes or when the calorific value of the currently provided biomass B changes greatly, the mass flow mBroh of supplied biomass B is correspondingly changed. With time delay, this will result in a modified mass flow of activated carbon mAK in the gasification zone generated. The process control device is configured to take into account that the change of the mass flow mAK of activated carbon AK delayed occurs to the change of the mass flow of supplied biomass mBroh. Therefore, the quantity MAK2 or the mass flow mAK2 which is to be supplied to the cooling zone ZK from the mass flow activated carbon currently provided in the gasification zone ZV is also determined when there is a changing demand for clean gas PR, based on the amount or the supplied mass flow biomass (quantity or mass) Mass flow relative to reference state waf) from which the activated carbon mass flow mAK currently produced in the gasification zone ZV was generated.

The tar constituents and other pollutants from the product gas PH are adsorbed during the co-cooling of the activated carbon MAK2. The loading capacity (adsorption capacity) of the activated carbon AK is so high that at a loading of only 2 percent by weight per kilogram of biomass B (waf), for example, 1 gram of tar constituents can be removed from the product gas PH. The product gas PH and the specific amount of activated carbon MAK2 are preferably not cooled below a lower limit temperature above the dew point of the product gas PH in the co-cooling, since the loading capacity of the activated carbon AK drops sharply toward a relative humidity of the product gas PH of 100%. In the exemplary embodiment, air C is used for the indirect cooling of the cooling zone ZK, the heated cooling air C being fed to the reactor for combustion of the activated carbon MAK2 on the tar.

The product gas PA, PR is separated in the embodiment after the cooling zone ZK with a dust filter 18 of the laden with pollutant activated carbon MAK2. The loaded with pollutant activated carbon MAK2 is the reactor 22 via the second lock 45 and supplied with the consumed Cooling air C burned. The ash is deposited, for example, via the turntable 47 and the third lock 48.

At high humidity of the biomass B, it may be appropriate to heat the heating zone ZE by indirect heating both with the exhaust gases of the gas engine and with the exhaust gases of the reactor 44 for the combustion of the tar-coated activated carbon MAK2.

The gasification at elevated pressure with corresponding locks 28, 45, 48 at the inlet and outlet of the carburetor 11 has the advantage that the purified product gas PR can be supplied to the pressure-charged gas engine without a compressor. In addition, this can increase the loading capacity of the activated carbon AK.

With the method 10 according to the invention and the fine cleaning device 11 according to the invention, engine-friendly product gas PR can be produced without requiring downstream cleaning (for example by means of a wet scrubber, electrostatic precipitator or the like). The cold gas efficiency of the carburettor is over 80% even with very moist biomass.

The invention relates to a method 10 for gasification of biomass B and a device 11 set up for this purpose. The method takes place in at least three process stages 12, 12i, 12ii, 13, 14. In a first process stage 12, biogenic residue biomass of a heating zone ZE are fed to dry the biomass B and let the volatiles escape to produce a pyrolysis PY therefrom. The pyrolysis PY is fed to an oxidation zone ZO and there oxidized substoichiometric, wherein a raw gas R is produced. The coke-like, carbonaceous residue RK, which is produced in the heating zone ZE, is partly gasified together with the raw gas R in a second process stage 13 in a gasification zone ZV. The heating zone ZE can be heated indirectly. The gasification zone ZV can also be heated indirectly. The heating zone ZE and the oxidation zone ZO are preferably separate zones from each other in separate chambers 23, 24. The gasification produces activated carbon AK and a hot process gas PH. The inventive method 10 includes or the device 11 is adapted to a certain amount of activated carbon from a minimum of 0.02 kilograms to a maximum of 0.1 kilograms per kilogram of supplied biomass (water and ash free, waf), from which the activated carbon in the Gasification zone ZV has arisen, and the hot product gas PH in a third process stage 14 in a cooling zone ZK, for example, at most 50 ° C to cool. The apparatus is preferably set up or includes the method in which the activated carbon AK and the hot process gas PH are cooled together in such a way that the temperature of the process gas PH in the cooling zone ZK remains above a lower limit temperature during co-cooling with the activated carbon AK is greater than the dew point temperature of the product gas PH. The adsorption process taking place during the co-cooling of activated carbon AK and product gas PH causes tar to accumulate on the activated carbon AK in the cooling zone during cooling from the hot process gas PH. As a result, after the third process stage 14, a clean gas PR, PA is obtained, which is essentially free of tar. The tar-enriched activated carbon AK can be at least partially combusted to heat the heating zone ZE and / or the gasification zone ZV. LIST OF REFERENCE NUMBERS 10 method 11 contraption 12 first stage of the process 12i heating step 12ii oxidation state 13 second process stage 14 third stage of the process 15 heater 16 burner 17 cooling device 18 Staubabscheideeinheit 19 grinder 20 drying device 21 preheater 22 reaction vessel 23 reaction chamber 24 heating chamber 25 management 26 silo 27 entrance 28 first lock 29 Conveyor 30 output 31 Gas supply means 32 management 33 temperature sensor 34 The End 35 branch facility 36 cooling chamber 37 Cooling chamber container 38 Conveyor 39 The End 40 deposition 41 outlet 42 temperature sensor 43 outlet 44 reactor 45 second lock 46 outlet 47 turntable 48 Third lock 49 insulation jacket 50 Container for the heating chamber 51 boiler room 52 arrow 53 outlet 54 insulation jacket 56 coat 57 refrigerator 58 entrance 59 outlet 60 management 61 top end B biomass L air R raw gas RK Carbonaceous residue PH product gas AK activated carbon PA, PR Cooled product gas, clean gas SK coal dust G exhaust PY pyrolysis MB Amount of supplied biomass MAK2 certain amount of activated carbon MAK1 excess amount of activated carbon mBroh Mass, mass flow biomass (reference state raw) mBwaf Mass, mass flow biomass (state of reference water- and ash-free) mAK Mass, mass flow in the gasification zone resulting activated carbon MAK2 Mass, mass flow of activated carbon for the common cooling MAK1 Mass, mass flow of excess activated carbon ZO oxidation zone TO Temperature oxidation zone ZV gasification zone TV Temperature in gasification zone ZK cooling zone ZE heating zone TE Temperature heating zone P arrow

Claims (15)

Method (10) for gasifying biomass (B),
wherein a device (11) biomass (B) is supplied for gasification,
wherein from the supplied biomass (B) in a first process stage (12, 12i, 12ii) a raw gas (R) and a carbonaceous residue (RK) is generated,
wherein the carbonaceous residue (RK) is partially gasified with gas constituents of the raw gas (R) in a second process stage (13) in a gasification zone (ZV), whereby activated carbon (AK) and a hot product gas (PH) are formed,
wherein per unit mass supplied biomass (B) based on the reference state water and ash-free (waf) between a minimum of 0.02 mass unit and a maximum 0.1 mass unit of activated carbon (AK) and the hot product gas (PH), to which the supplied biomass (B ), taken from the gasification zone (ZV), fed to a cooling zone (ZK) and cooled together in the cooling zone (ZK) in a third process stage (14), so that an adsorption takes place, in which the activated carbon (MAK2) during of the cooling is enriched by tar from the hot product gas (PH). Process according to claim 1, wherein the product gas (PH) and the activated carbon (MAK2) in the third process stage (14) for the adsorption process in the cooling zone (ZK) together do not fall below a lower limit temperature be cooled, which is greater than the dew point temperature of the product gas (PA, PR). The method of claim 2, wherein the lower limit temperature between a minimum of 10 K and a maximum of 20 K is greater than the dew point temperature of the product gas (PA, PR). Method according to one of the preceding claims, wherein in the first process stage (12, 12i, 12ii) the supplied biomass (B) is dried in a first sub-stage (12i) in a heating zone (ZE) and heated so that the volatiles of the biomass (B) escape, wherein a pyrolysis (PY) and the carbonaceous residue (RK) arise, and wherein at least the pyrolysis (PY) in a subsequent second stage (12ii) of the first process stage (12) in an oxidation zone (ZO) by supplying is substoichiometrically oxidized by an oxygen-containing gas (L), whereby the raw gas (R) is formed. A method according to claim 4, wherein the heating zone (ZE) on the one hand and the oxidation zone (ZO) on the other hand are separate zones. A method according to claim 4 or 5, wherein the substoichiometric oxidation of the pyrolysis gases (PY) and the gasification of the carbonaceous residue (RK) are carried out in separate zones. Method according to one of claims 4 to 6, wherein the substoichiometric oxidation at a temperature (TO) of at least 1000 ° C to a maximum of 1200 ° C in the oxidation zone (ZO) is performed. Method according to one of claims 4 to 7, wherein the temperature (TO) in the oxidation zone (ZO) by the amount of the supplied oxygen-containing gas (L) is adjusted. Method according to one of the preceding claims, wherein the method is carried out at elevated pressure relative to ambient pressure. A process according to any one of the preceding claims, wherein the product gas (PA, PR) purified by the adsorption process is a device, e.g. a gas engine is supplied as fuel, wherein the amount of biomass supplied (MB) and from the gasification zone (MAK2) removed amount of activated carbon (AK) are adjusted proportionally to the power requirement of the device. Method according to one of the preceding claims, wherein the raw gas (R) and the carbonaceous residue (RK) in the gasification zone (ZV) are heated by indirect heating and / or wherein the activated carbon (AK) and the hot product gas (PH) in the cooling zone (ZK) are cooled by indirect cooling. Method according to one of the preceding claims, wherein the activated carbon (AK) is burned with the tar adsorbed thereon from the third process stage (14) in a reactor (44) with the air, which in the third process stage (14) for cooling the product gas ( PH) and the activated carbon (AK) was used, wherein the exhaust gas (G) of the combustion is preferably used for heating the heating zone (ZE). Device (11) for gasification of biomass (B) with at least one chamber (24) with a heating zone (ZE),
a feed device (28, 29) which is adapted to feed the biomass (B) to the heating zone (ZE) in order to produce pyrolysis gas (PY) and carbonaceous residue (RK),
at least one chamber (23) having an oxidation zone (ZO) for the oxidation of the pyrolysis gas (PY) and a gasification zone (ZV) for the gasification of the carbonaceous residue (RK),
a conveying means (29) which is adapted to the pyrolysis gas (PY) from the heating zone (ZE) in the oxidation zone (ZO) and a raw gas (R) from the oxidation zone (ZO) in the gasification zone (ZV) to promote and is set up to convey the carbonaceous residue (RK) from the heating zone (ZE) into the gasification zone (ZV),
a gas supply device (31) which is set up to supply to the oxidation zone (ZO) an oxygen-containing gas (L) in an amount such that the pyrolysis gas (PY) present in the oxidation zone (ZO) substoichiometrically oxidizes, whereby the crude gas (R) arises
with a heating device for heating the gasification zone, which is set up to adjust the temperature (TV) in the gasification zone (ZV) such that the carbonaceous residue (RK) is partially gasified with gas constituents of the raw gas (R), whereby activated carbon (AK) and a hot product gas (PH) arise,
wherein the device (11) is adapted to provide a certain amount (MAK2) of the activated carbon (AK) and the product gas (PH) from the gasification zone (ZV) in a cooling zone (ZK),
wherein the determined amount (MAK2) of activated carbon has a mass of at least 2 percent to a maximum of 10 percent of the mass of the supplied biomass (B) in relation to the water and ash free reference state from which the activated carbon (AK) and the hot product gas (PH ),
with a cooling device (ZK) which is set up to jointly cool the determined amount (MAK2) of activated carbon and the hot product gas (PH) in the cooling zone (ZK) in such a way that an adsorption process takes place in which the activated carbon (MAK2) during the Cooling is enriched by tar from the hot product gas (PH). Apparatus according to claim 13, wherein the heating zone (ZE) on the one hand and the oxidation zone (ZO) on the other hand in separate chambers (23, 24) are arranged and / or wherein the gasification zone (ZV) on the one hand and the cooling zone (ZK) on the other hand in separate chambers ( 23, 36) are arranged. Apparatus according to claim 13 or 14, wherein the device (11) is adapted to perform the gasification at elevated pressure relative to ambient pressure.

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