Method and apparatus for the production of activated carbon

Abstract

A process (100) for the production of activated carbon within a gasification process, comprising: a first process stage (P1) comprising the thermal decomposition (S1) of a carbonaceous feedstock in a first reaction zone (2) to produce pyrolysis coke (21) and pyrolysis gas; transferring (S4) at least a portion of the produced pyrolysis gas from the first reaction zone (2) to a second reaction zone (3) and transferring at least a portion of the pyrolysis coke (21) from the first reaction zone (2) to a third reaction zone (4); a second process stage (P2) comprising the production (S5) of a product gas from the pyrolysis gas in the second reaction zone (3) that can be used to activate the pyrolysis coke (21); transferring (S6) the product gas to the third reaction zone (4); and a third process stage (P3), comprising an activation (S7) of at least part of the pyrolysis coke (21) to activated carbon using the product gas in the third reaction zone (4).

Description

The invention relates to a method and an apparatus for producing activated carbon in a gasification process.Due to limited resource availability and ever increasing energy requirement, waste materials are increasingly being recycled. There are various approaches to recycle these waste materials, for example biomass, plastic waste, residual waste and / or the like, in a lasting manner. For example, pyrolysis methods are known which allow the generation of clean, renewable energy from waste materials. In the thermal decomposition of organic substances, isolated gaseous constituents can be processed, for example, and burnt or used materially as a product gas for energy generation. The energy content of further byproducts which are dropped during the decomposition of the waste materials or during the processing of the gaseous constituents can be used in this case to maintain the decomposition or the processing, for example by the further byproducts being burned and the thermal energy obtained in this case being used for the thermal decomposition of the organic materials. Alternatively, however, such byproducts can also be further processed externally and used in other material terms.DE 199 36 524 A1 discloses a process and a device for thermolytic workup of polymer- and cellulose-containing substances, in particular shredder light material. The polymeric and cellulosic materials are fed, together with a nitrogen-containing aggregate catalyst mixture, to a heated main reactor and decomposed into char and char by heating to a temperature of 350-600°C. The char is treated with the char gas in an after-treatment reactor at temperatures of 360 to 600° C., degassed further and activated by the water vapor contained in the char gas.DE 10 2008 027 858 A1 discloses a thermal carburetor and a method for operating the same. The gasifier consists of a pyrolysis reactor, a gasification reactor and a converter. In the pyrolysis reactor, in a first process step, fuel serving as starting material is decomposed by pyrolysis into, on the one hand, volatile (gaseous) products and, on the other hand, a pyrolysate or activate. While in a respective second process step the volatile constituents are freed of tar in the converter in order to obtain a tar-poor product gas, the pyrolysate is separately gasified in the gasification reactor in order to obtain a gasification gas with the formation of residual material and feed it to the converter, which generates a product gas therefrom and from the de-tared pyrolysis gas as the end product of the gasifier or method.DE 10 2007 047 931 A1 discloses a method for thermally degassing organic waste for producing gas, oil and activated coke. In a main reactor, the organic wastes are broken down into coke and oil-containing gas by pyrolysis at temperatures of 500 to 650 °C. The coke is activated again in a downstream activated coke reactor by means of steam, which is obtained from wash water used for wet cleaning of the pyrolysis gas.DE 697 03 945 T2 discloses a process and an apparatus for converting sludges. The apparatus includes a first reactor for thermally evaporating oil-producing organic materials in the slurry as feedstock in the absence of oxygen. The apparatus further comprises a downstream second reactor in which the sludge residue from the first reactor is contacted in the absence of oxygen with oils of reduced water content condensed from the gaseous pyrolysis products in order to produce solid products or coal in addition to high-quality oil products.It is an object of the invention to further improve the utilization of waste materials and in particular to make them more efficient.The solution of this object is achieved according to the teaching of the independent claims. Various embodiments and developments of the invention are the subject matter of the dependent claims.A first aspect of the invention relates to a method for activating activated carbon within a gasification process, comprising: (i) a first process stage, comprising thermally decomposing a carbonaceous starting material, in particular biomass, in a first reaction zone to produce pyrolysis coke and pyrolysis gas; (ii) transferring at least a part of the generated pyrolysis gas from the first reaction zone into a second reaction zone and transferring at least a part of the pyrolysis coke from the first reaction zone into a third reaction zone; (iii) a second process stage, comprising generating a product gas from the pyrolysis gas that can be used to activate the pyrolysis coke in the second reaction zone; (iv) transferring the product gas into the third reaction zone; (v) a third process stage, comprising activating at least a portion of the pyrolysis coke to activated carbon with the aid of the product gas in the third reaction zone.In contrast to conventional methods in which the pyrolysis coke remaining in the first process stage in the thermal decomposition process of the starting material is co-burned or discharged and fired to provide the heat requirement of the decomposition process, for example in a multicomponent burner, the pyrolysis coke can be processed according to the invention and used as activated carbon with a broad range of applications. The processing takes place in this case preferably immediately after the production of the product gas in the second process stage, i.e. after processing of the pyrolysis gas, in a third process stage. One can therefore also speak of an integrated activation process.The invention thereby advantageously allows the coupled, in particular the at least substantially simultaneous, generation of an energy-rich product gas, which can be fired for example for electricity and / or heat generation, and of activated carbon, which can be used elsewhere, for example as adsorbent for filtering or as support material of catalysts. The production of the activated carbon according to the invention is particularly efficient because, in contrast to conventional approaches, the product gas preferably produced immediately beforehand is used for this purpose. As a result, it is not necessary to perform a separate activation of the pyrolysis coke obtained during the production of the product gas from the starting material in complicated and energy-intensive external processes.According to the invention, the physical activation of the activated carbon can be carried out particularly reliably and efficiently, since the product gas after the second process stage, i.e. after the separate treatment of the pyrolysis gas in the second reaction zone, is rich in gas components which have a high activation potential, for example water vapor and / or carbon dioxide. For this purpose, the processing includes, for example, steam reforming. This eliminates the need for the, generally energy-intensive, separate or external provision of an activation gas specifically designed for activation.In addition, the thermal energy contained in the product gas, which remains unused in conventional methods, can be utilized in the course of activation and in this way enable or at least support activation. The provision of further energy necessary for activation can thus be rendered superfluous or at least reduced. The invention therefore enables a particularly efficient, in particular multistage, utilization of the product gas.Overall, the invention allows improved, in particular more efficient, utilization of carbon-containing starting material, in particular biomass.Preferred embodiments of the invention and their developments are described below, which can be combined with one another as desired and with the aspects of the invention described below, unless this is explicitly excluded.In some embodiments, the thermal energy required for activating the pyrolysis coke is provided at least partially, preferably exclusively, by the product gas. In this case, the pyrolysis coke does not have to be heated, or only slightly separately, to an activation temperature, but can be heated at least partially, preferably exclusively, by the product gas. For this purpose, the pyrolysis coke can be activated in thermal insulation, for example in a thermally insulated third reaction zone, so that the thermal energy provided by the product gas does not dissipate, or dissipates only slightly, in the third reaction zone. This enables a particularly efficient production of activated carbon from the pyrolysis coke produced in the first process stage.By the separate generation of the product gas in the second reaction zone, preferably in the context of a homogeneous gas phase reaction, in particular a steam reforming, the product gas can have a temperature level which is particularly suitable for the physical activation of the pyrolysis coke. For example, the reforming of the pyrolysis gas can take place at about 950 DEG C., so that the thermal energy contained in the product gas, in particular supplied in the context of the second process stage, is sufficient to bring about the activation. Therefore, it is usually not necessary to provide additional heat in the third reaction zone.Alternatively or additionally, however, at least some of the thermal energy required for activation can also be introduced into the third reaction zone in another way, for example via an external heating system. For example, it is conceivable to fire a portion of the pyrolysis coke and to supply the heat generated in this process to the third reaction zone. Although this reduces the amount of activated carbon that can be produced, it allows a particularly stable activation temperature in the third reaction zone and therefore a particularly reliable activation of the pyrolysis coke fed to the third reaction zone, i.e. a particularly high activation efficiency.In some embodiments, the pyrolysis coke is activated at an activation temperature that depends on a generation temperature in the generation of the product gas, in particular, is defined at least substantially by the generation temperature. In particular, the activation temperature can correspond, at least substantially, to the generation temperature. For this purpose, the third reaction zone can be arranged in the vicinity, in particular directly next to, the second reaction zone, such that a short gas-conducting compound for transferring the product gas between the second and third reaction zones can be produced or exists. Preferably, the gas-conducting compound is thermally insulated in order to avoid or at least reduce dissipation of heat during the transfer. Thereby, it is possible to control the activation conditions in the third reaction zone by adjusting the generation temperature, i.e., the conditions in generating the product gas from the pyrolysis gas. This simplifies the realization of the overall process.The activation temperature in the third reaction zone is preferably coupled to the production temperature in the second reaction zone in such a way that the activation temperature is 100° C. or less, preferably 50° C. or less, in particular 25° C. or less, below the production temperature. This allows a particularly efficient use of the energy used in the production of the product gas from the pyrolysis coke.In some embodiments, the product gas is generated at a generation temperature that is between 700 and 1200° C., preferably between 800 and 1000° C., in particular between 925 and 975° C. In addition to a reliable, in particular at least substantially complete, conversion of the pyrolysis gas into product gas, this production temperature also enables a particularly rapid and / or reliable, in particular at least substantially complete, conversion of the pyrolysis coke in the third reaction zone. A complete conversion of the pyrolysis coke is to be understood here and below in particular as a uniform activation of the pyrolysis coke to form activated carbon.The pyrolysis gas can be subjected to a heat exchange process in the second reaction zone in order to reach the generation temperature, in which heat energy is preferably transferred from a solid, for example a heat transfer medium, to the pyrolysis gas. In particular, additional thermal energy can be introduced in this case until the desired generation temperature is reached.For example, the production temperature can be reached by introducing a heat transfer medium preheated to a defined temperature, in particular made of dimensionally stable particles such as steel balls, into the second reaction zone. The heat transfer medium can pass through the second reaction zone in the form of a moving bed, it being possible for the pyrolysis gas transferred from the first reaction zone into the second reaction zone to flow through it, preferably in the countercurrent direction. The pyrolysis gas is converted into the product gas. In this case, the temperature of the product gas generated can be reliably adjusted.In some embodiments, steam is added to the pyrolysis gas, with the aid of which steam the product gas is generated in the second reaction zone. In this way, steam reforming of the pyrolysis gas can be achieved. The amount of added steam can be selected in particular such that the product gas produced thereby has a high steam content, for example of more than 15 vol. %, in particular of more than 25 vol. %, as a result of which long-chain hydrocarbon molecules in the product gas can preferably be thermally decomposed completely into short-chain molecules. The product gas produced in this way can not only be advantageously burnt for energy generation, but the pyrolysis coke in the third process stage can also be converted into activated carbon in a particularly reliable manner, in particular at least substantially completely.Preferably, the water vapor is introduced into the first reaction zone for this purpose. This enables an improvement in convective heat transfer and / or good mixing of pyrolysis gas and water vapor.Alternatively, however, the water vapor can also be introduced into the second reaction zone. This enables a particularly targeted mixing of pyrolysis gas and steam, in particular at a generation temperature which is particularly favorable for steam reforming and is elevated compared to a pyrolysis temperature prevailing in the first reaction zone.For this purpose, the water vapor is preferably provided outside the first and / or second reaction zone, e.g. produced in a steam generator, and introduced into the first reaction zone. This makes it possible to facilitate the temperature management in the first reaction zone or to keep the temperature stable. Alternatively, however, water can also be introduced into the first or second reaction zone, which is converted into water vapor on account of the pyrolysis temperature prevailing in the first or second reaction zone. In particular, the water vapor can be at least partially contained in the carbon-containing starting material, in particular in the biomass, and can be released during the thermal decomposition. As a result, the energy used for thermal decomposition of the starting material or for generating the product gas can be utilized particularly efficiently.In some embodiments, the water vapor is added and / or the production temperature is selected in such a way that the product gas has at least one of the following: (i) a water vapor content of between 15 and 45 vol. %, preferably between 20 and 40 vol. %, in particular about 30 vol. %; (ii) a carbon dioxide content of between 5 and 30 vol. %, preferably between 10 and 20 vol. %, in particular about 15 vol. %; and / or (iii) a carbon monoxide content of between 10 and 30 vol. %, preferably between 15 and 25 vol. %, in particular about 20 vol. %. This makes it possible to ensure that the product gas produced can be combustible efficiently for generating energy, on the one hand, and can be used for particularly reliable, in particular at least substantially complete, conversion of the pyrolysis coke, on the other hand. This is because the steam preferably present in the product gas and the carbon dioxide preferably present in the product gas both have, individually or in combination with one another, an activation potential with respect to the activation of pyrolysis coke, the ranges below (i) and (ii) corresponding to particularly advantageous gas properties for the activation. The carbon monoxide preferably likewise present in the product gas makes it possible, in particular in the range indicated under (iii), to produce particularly pure activated carbon from the pyrolysis coke.The addition of the water vapor and / or the generation temperature are preferably controlled in such a way that at least one of the aforementioned properties of the product gas mentioned under (i) to (iii) is established. In other words, the composition of the product gas can be adjusted by controlled addition of the steam and / or by controlled the production temperature, for example by metered supply of the preheated heat transfer medium.In this case, the amount of water vapor added is preferably regulated and / or the time of addition is matched to the desired properties of the product gas. The regulation of the generation temperature may include maintaining the temperature for a predetermined amount of time and alternatively or additionally, driving temperature ramps. The generation of the product gas in the second reaction zone can thereby be precisely coordinated with the activation of the pyrolysis coke in the third reaction zone.By adding steam and / or selecting the production temperature, production conditions can be set in the second reaction zone which permit the production of a particularly low-tar product gas, as a result of which activated carbon of high quality can subsequently be produced.In some embodiments, at least some of the water vapor is already added in the first reaction zone during the thermal decomposition, so that partially activated pyrolysis coke is produced, which is activated in the third reaction zone with the aid of the product gas at least predominantly, preferably at least substantially completely. The activation process in the third reaction zone by the product gas is thus facilitated and can accordingly be carried out particularly reliably.The water vapor can be fed into the first reaction zone, for example, together, in particular simultaneously, with the carbon-containing starting material. If desired, water may also be introduced with the starting material into the first reaction zone, which then vaporizes. This makes it possible to ensure that the water vapor comes into direct contact with the decomposition products of the starting material.In some embodiments, the pyrolysis coke is partially activated in the first reaction zone with the aid of the added steam at a temperature which is defined by a pyrolysis temperature at which the starting material is thermally decomposed, in particular corresponds to the pyrolysis temperature, or at least depends on the pyrolysis temperature. Preferably, the water vapor is supplied in the first reaction zone below the starting material for this purpose, so that it circulates or flows through the starting material during its thermal decomposition before it mixes with the pyrolysis gas formed in the process and is transferred into the second reaction zone. As a result, the pyrolysis coke does not cool down until partial activation, and a particularly comprehensive partial activation of the pyrolysis coke is made possible.In some embodiments, the starting material is decomposed in the first reaction zone at a pyrolysis temperature that is between 300 and 900° C., preferably between 600 and 800° C., in particular between 650 and 750° C. In addition to a reliable, in particular at least substantially complete, decomposition of the starting material into pyrolysis coke and pyrolysis gas, this pyrolysis temperature also enables a particularly reliable, in particular comprehensive, partial activation of the pyrolysis coke in the first reaction zone.Advantageously, it is possible, by selecting the pyrolysis temperature at which the pyrolysis coke is partially activated and, if appropriate, also by regulating the addition of the steam, to determine at least partially the properties of the activated carbon produced later in the third reaction zone. It is conceivable, for example, to adapt the partial activation to the quantity of pyrolysis coke to be activated later, so that it can be ensured that the product gas stream generated in the second reaction zone, i.e. the quantity of product gas generated per unit time, is sufficient to completely convert the partially activated pyrolysis coke into activated carbon in the third reaction zone.In some embodiments, at least a portion of the pyrolysis coke is preconditioned upon transfer to the third reaction zone. In particular, a portion of the pyrolysis coke produced in the first reaction zone can be discharged from the first reaction zone and a binder can be added before it is introduced into the third reaction zone for activation. Alternatively or additionally, the pyrolysis coke discharged and optionally admixed with a binder can also be converted in a shaping step into a predetermined shape, for example pressed into pellets, before it is introduced into the third reaction zone for activation. The pyrolysis coke preconditioned in this way can be activated particularly effectively, in particular completely, in the third reaction zone.In some embodiments, the pyrolysis coke in the third reaction zone is continuously mixed, at least substantially, with the product gas during activation. For this purpose, a fluidized bed of product gas can be provided in the third reaction zone, which fluidized bed mixes the pyrolysis coke or at least contributes to its mixing. In particular, for this purpose, the product gas can be introduced, in particular blown, into the third reaction zone in a manner such that the fluidized bed is formed. Alternatively, the pyrolysis coke can be accommodated in a drum through which the product gas can flow, and the drum can be rotated to mix the pyrolysis coke, in particular the pyrolysis coke, with the product gas. As a result, pyrolysis gas can flow around the pyrolysis coke, at least substantially, completely, so that at least a major part of the pyrolysis coke to be activated, in particular a major part of its surface, comes into contact with the pyrolysis gas.Alternatively or additionally, the mixing of the pyrolysis coke can also be achieved, at least substantially, when the pyrolysis coke is fed into the third reaction zone. It is conceivable, for example, to pour the pyrolysis coke onto a conveying means of the third reaction zone, in particular onto a moving bed, in such a way that the pyrolysis coke can mix in the free fall, in particular with the product gas.In some embodiments, the product gas is passed through the third reaction zone countercurrent to the pyrolysis coke. For example, the product gas can flow through the third reaction zone counter to a conveying direction in which the pyrolysis coke is transported through the third reaction zone. It is conceivable, for example, to sweep the product gas counter to the conveying direction over a conveying means of the third reaction zone, in particular a moving bed of a moving bed reactor. Passing the product gas in countercurrent through the third reaction zone enables particularly good heat transfer from product gas to pyrolysis coke within the third reaction zone.Preferably, the pyrolysis coke is fed to the third reaction zone in an inlet region. In an outlet region, the activated carbon produced from the pyrolysis coke can be discharged from the third reaction zone. The product gas is preferably fed to the third reaction zone via an inlet opening in the outlet region and removed again via an outlet opening in the inlet region after activation of the pyrolysis coke. The product gas can be transferred via a connection between the inlet opening and the second reaction zone into the outlet region. The activated carbon removed from the third reaction zone in the outlet region thus comes into contact once again with hot product gas, which can have, in particular, a high water vapor, carbon dioxide and / or carbon monoxide content, as a result of which an at least nearly complete reaction, in particular a substantially uniform activation, of the pyrolysis coke can be ensured.The pyrolysis coke entering the third reaction zone in the inlet region, on the other hand, can first come into contact with product gas which may be slightly cooled in comparison with it, and which may optionally also have a steam, carbon dioxide and / or carbon monoxide content which is reduced in comparison with it.Alternatively to the countercurrent, the product gas can, however, also be passed through the third reaction zone in cocurrent or in cross-flow, i.e. at least substantially along or perpendicular to a transport direction of the pyrolysis coke through the third reaction zone.In some embodiments, after the activation of the pyrolysis coke, the product gas is passed through a separating device and is there cleaned, in particular physically, of pyrolysis coke residues and / or activated carbon residues. Particles contained in the product gas can be separated, for example, by utilizing the centrifugal force, for example, in a separating device configured as a cyclone. The purified product gas can be burnt or used materially, optionally after further, in particular chemical, purification steps for energy generation.The pyrolysis coke residues and / or activated carbon residues filtered from the product gas stream are preferably transferred back into the third reaction zone. This makes it possible to convert the pyrolysis coke produced preferably completely into activated carbon.In some embodiments, a portion of the pyrolysis coke is fired in a heating device in order to heat a heat transfer medium which is fed to the second reaction zone for generating the product gas and / or to the first reaction zone for thermal decomposition of the starting material. Preferably, the part of the pyrolysis coke to be fired is determined in dependence on an amount of pyrolysis coke that can be activated by the product gas produced. The pyrolysis coke produced during the thermal decomposition can thus be utilized particularly efficiently, in particular completely.Alternatively or additionally, it is also conceivable to discharge a portion of the, optionally partially activated, pyrolysis coke and to feed it to another material utilization, for example as biocarbon. Preferably, the part of the pyrolysis coke to be discharged is determined in dependence on an amount of pyrolysis coke that can be activated by the product gas produced. The pyrolysis coke produced during the thermal decomposition can thus be utilized particularly efficiently, in particular completely.A second aspect of the invention relates to an apparatus for producing activated carbon, which is configured to carry out a method according to the first aspect of the invention. Such an apparatus permits an alternative or additional material utilization of the pyrolysis coke produced during the thermal decomposition of the starting material, in contrast to conventional installations in which the pyrolysis coke is exclusively fired or even remains unused.The device has a first reaction zone in which pyrolysis coke and pyrolysis gas can be generated by thermal decomposition of carbon-containing starting material, in particular biomass. A second reaction zone is connected to the first reaction zone in a gas-conducting manner and is configured to generate a product gas that can be used for activating the pyrolysis coke from at least a portion of the pyrolysis gas. In a third reaction zone, which is connected to the second reaction zone in a gas-conducting manner, at least some of the pyrolysis coke can be processed to activated carbon with the aid of the product gas. In addition, a first conveying device is configured to transfer at least a portion of the pyrolysis coke from the first reaction zone into the third reaction zone.The first and the second reaction zone can preferably be filled with a heat transfer medium, via which the pyrolysis temperature required for thermal decomposition or the generation temperature required for generating product gas from the pyrolysis gas is reached. For this purpose, the device preferably has a heating zone which is configured to heat the heat transfer medium and which can be heated, in particular by means of a heating device. The first reaction zone is preferably arranged below the second reaction zone, which is in turn arranged below the warming zone. The heat transfer medium, which is heated in particular to the production temperature, can then be transferred simply by utilizing gravity into the second reaction zone, where the pyrolysis gas flows around it. The heat transfer medium cools down further to the pyrolysis temperature and can then be transferred easily, likewise using gravity, into the first reaction zone.The first reaction zone is preferably configured to mix the heat transfer medium with the carbonaceous feedstock to ensure complete thermal decomposition of the feedstock. After the starting material has been decomposed into pyrolysis coke and pyrolysis gas, which preferably draws off into the second reaction zone, the pyrolysis coke can be separated from the heat transfer material in a separation zone and transferred by means of the first conveying device, for example a conveying screw, into the third reaction zone. The separated heat transfer material is preferably transported back into the heating zone by means of a further, second conveying device.The third reaction zone can be configured in a preferred manner as a rotary tube reactor which has a rotatably mounted drum and is configured to rotate the drum for mixing the pyrolysis coke received by it. Alternatively, however, the third reaction zone can also be configured in another way, for example as a moving bed reactor with a conveying means in which the pyrolysis coke transported by means of the conveying means can be swept over by the product gas.The features and advantages described with respect to the first aspect of the invention and its advantageous embodiment also apply, at least where technically expedient, to the second aspect of the invention and its advantageous embodiment and vice versa.Further features, advantages and possible applications of the invention will become apparent from the following description in conjunction with the figures, in which the same reference numerals are used throughout for the same or corresponding elements of the invention. They show, at least partially schematically: FIG. 1 shows a first exemplary embodiment of a device for producing activated carbon; FIG. 2 shows a second exemplary embodiment of a device for producing activated carbon; FIG. 3 shows an exemplary embodiment of a second reaction zone; FIG. 4 shows an exemplary embodiment of a third reaction zone; and FIG. 5 shows an exemplary embodiment of a method for producing activated carbon.FIG. 1 shows a first exemplary embodiment of a device 1 for producing activated carbon, having a first reaction zone 2 in which a carbon-containing starting material can be thermally decomposed, a second reaction zone 3 in which a product gas can be produced from a pyrolysis gas produced during thermal decomposition, and a third reaction zone 4 in which pyrolysis coke produced during thermal decomposition can be activated by means of the product gas. The transport paths of solids, in particular solid reactants or products, between the individual components of the apparatus 1 are indicated by arrows.The carbon-containing starting material, for example biomass or carbon-containing residues, is preferably actively or passively transferred from a reservoir into the first reaction zone 2 by means of a conveying system 5, for example by means of a transport belt or a conveying screw or a downwardly inclined shaft. The reservoir can be formed by a container, a warehouse and / or a landfill from which the starting material is actively removed or flows out or slips passively.The conveying installation 5 is advantageously configured to preheat the conveyed starting material before introduction into the first reaction zone 2 in order to facilitate the thermal decomposition in the first reaction zone 2. Alternatively or additionally, the first conveyor system 5 can also be configured to connect a drying device for drying the starting material to the first reaction zone 2. Furthermore, it is conceivable to configure the conveying system 5 as a drying device, so that the starting material is dried during the feeding to the first reaction zone 2.The first reaction zone 2 is preferably designed as an internally heatable, in particular cylindrical, shaft into which a heat transfer medium can be introduced in addition to the starting material. As described further below, the heat transfer medium is preheated and brings about a pyrolysis temperature of between 500 and 900° C., preferably between 600 and 800° C., in particular between 650 and 750° C., within the first reaction zone 2.The second reaction zone 3 is advantageously arranged above the first reaction zone 2, so that the heat transfer medium can be introduced into the first reaction zone 2 by utilizing gravity, i.e. without an active conveying means.When the starting material and the heat transfer medium are introduced, for example via a respective lock arranged in the upper region of the shaft, the starting material and the heat transfer medium mix in a preferred manner. This can be effected, for example, by simultaneous introduction through two locks arranged in the immediate vicinity and / or by mutually coordinated, in particular sequential, introduction. Alternatively or additionally, however, the first reaction zone 2 can also have a mixing device, in particular a mechanical mixing device, for mixing the starting material with the heat transfer medium.The starting material, which may be preheated, is thereby heated to the pyrolysis temperature and decomposes thermally to form pyrolysis coke and a pyrolysis gas, the latter being passed into the second reaction zone 3 and there being converted into a product gas which is in turn passed into the third reaction zone 4. Details in this regard are described further below in connection with FIGS. 2 and 3.The pyrolysis coke is preferably discharged together with the heat transfer medium into a separation zone 6 in order to separate the pyrolysis coke from the heat transfer medium. The separation zone 6 can be arranged below the first reaction zone 2, so that the mixture of pyrolysis coke and heat transfer medium can be transferred from the first reaction zone 2 into the separation zone 6 by utilizing the force of gravity.The separation zone 6 can have, for example, a mechanical screening arrangement which is configured for screening. The heat transfer medium, preferably a bulk material with dimensionally stable particles, for example steel balls or ceramic balls, with a defined, narrow particle size distribution, can be drawn off as coarse material, while the pyrolysis coke is preferably drawn off as fine material. It is likewise conceivable to configure the separation zone 6 in such a way that a wind classification of the heat transfer medium can be carried out.The pyrolysis coke separated from the heat transfer medium is transported by means of a first conveying device 10, for example a conveying screw or another conveying device suitable for operation at high temperatures, to the third reaction zone 4, where it is converted into activated carbon by means of the product gas likewise transferred into the third reaction zone 4. The thermal energy required in the activation of the pyrolysis coke is preferably provided by the product gas which is passed as a preferably continuous product gas stream from the second reaction zone 3 through the third reaction zone 4. Therefore, the third reaction zone 4 is advantageously arranged in the vicinity of, in particular directly next to, the second reaction zone 3, so that the product gas only has to travel a short distance and in the process cools down only insignificantly, if at all. The first conveying device 10 can therefore be configured in particular to transfer the pyrolysis coke from the first reaction zone 2, in particular from the separation zone 6, counter to the force of gravity into the third reaction zone 4.Further details for activating the pyrolysis coke in the third reaction zone 4 are explained in conjunction with FIG. 4.During the conversion of the pyrolysis coke into activated carbon, pyrolysis coke particles and / or activated carbon particles can pass into the product gas stream and be discharged together with the product gas after activation. In order to remove this impurity from the product gas stream again before the product gas is used further, the pyrolysis coke and / or activated carbon particles can be filtered out in a separating device 12. The separating device 12 is designed, for example, as a cyclone in which the particles contained in the product gas are separated by the centrifugal force. Compared to a purely chemical purification of the product gas, this has the advantage, among other things, that the filtered-out particles can be transferred back into the third reaction zone 4.The activated carbon produced is then transferred to an after-treatment device 7, where the activated carbon is prepared for its further use, for example by means of an HCl wash.The heat transfer medium separated from the pyrolysis coke in the separation zone 6 is transferred via a further, second conveying device 9, for example a bucket elevator or a container elevator, into a heating zone 8, in which the heat transfer medium is brought to a production temperature which is necessary or at least advantageous for producing the product gas from the pyrolysis gas. In this case, the second conveying device 9 can be configured to preheat conveyed heat transfer medium already, so that the generation temperature can be reached more easily.Since the heat transfer medium is preferably to be transferred from the heating zone 8 into the second reaction zone 3 by utilizing the force of gravity, the heating zone 8 is preferably arranged above the second reaction zone 3. The further conveying device can therefore also be configured to transfer the heat transfer medium against the force of gravity from the first reaction zone 2, in particular from the separation zone 6, into the warming zone 8.The heat transfer medium passes through the heating zone 8, preferably by gravity, as a moving bed, and hot flue gas flows around it, in particular in countercurrent. As a result, the heat transfer medium can be heated up to the production temperature. The hot flue gas can be generated, for example, by means of a heating device 11 and conducted from the heating device 11 through a connection indicated as a dashed line into the heating zone 8.The heating device 11 can be designed, for example, as a multi-component burner in which one or more different fuels can be burned. These fuels are preferably provided outside the device 1. In one embodiment, however, the fuel can be formed, at least partially, by a part of the pyrolysis coke produced in the first reaction zone 2, which is drawn off, in particular after separation from the heat transfer medium in the separation zone 6, and fed to the heating device 11, optionally with one or more further external fuels. Alternatively or additionally, a part of the product gas can also be burnt in the heating device. These possibilities are indicated by dashed arrows.FIG. 2 shows a second exemplary embodiment of a device 1 for producing activated carbon. The device 1 shown corresponds substantially to the device described in connection with FIG. 1. However, transport paths of gases, in particular volatile reactants or products, between the individual components of the device 1 are indicated by arrows.The carbonaceous starting material fed to the first reaction zone 2 is thermally decomposed to produce pyrolysis coke and pyrolysis gas, and the pyrolysis gas formed thereby rises in a preferred manner into the second reaction zone 3 connected to the first reaction zone 2 in a gas-conducting manner. The gas-conducting connection between the first and second reaction zones 2, 3 is preferably provided in addition to the lock described in connection with FIG. 1, through which the heat transfer medium from the second reaction zone 3 is introduced into the first reaction zone 2, in order to allow unhindered outflow of the gas from the first reaction zone. The heat transfer medium can, on the other hand, be introduced through the lock sequentially or in metered fashion from the second into the first reaction zone 3, 2.The pyrolysis gas preferably flows in the second reaction zone 3 through a bed of heat transfer medium which is heated to a production temperature for producing product gas from pyrolysis gas, in particular for cracking tars present in the pyrolysis gas. When the heat carrier medium flows through, the pyrolysis gas is converted into the product gas. Further details for generating the product gas are described further below in connection with FIG. 3.In order to ensure complete conversion of the pyrolysis gas into a product gas which can be used for activating the pyrolysis coke in the third reaction zone 4, steam is preferably added to the pyrolysis gas. The addition of the steam can take place in particular in the first reaction zone 2, so that the thermal decomposition, i.e. the conversion of the carbon-containing starting material into pyrolysis coke and pyrolysis gas, can take place in the presence of steam, in particular in a steam-containing atmosphere. This has the advantage that the pyrolysis coke is already partially activated, so that it can be more easily completely converted into activated carbon in the third reaction zone 4 and / or activated carbon of even higher quality can be produced.The product gas, in particular low-tar and / or high-hydrogen product gas, which is produced in this way in the second reaction zone 3 and is preferably present at the production temperature between 700 and 1200° C., preferably between 800 and 1000° C., in particular between 925 and 975° C., is fed into the third reaction zone 4 connected to the second reaction zone 3 in a gas-conducting manner. In order to ensure that the temperature of the product gas does not drop, or at least does not drop significantly, during the transfer, the transport path for the product gas between the second and third reaction zones 3, 4 is kept as short as possible, for example by the third reaction zone 4 being arranged directly next to the second reaction zone 3. Alternatively or additionally, the gas-conducting compound between the second and third reaction zones 3, 4 can be thermally insulated.In order to make possible a simple transfer of the product gas, the third reaction zone 4 can additionally be arranged at least slightly above the second reaction zone 3, so that product gas can rise passively into the third reaction zone 4. Alternatively or additionally, however, it is also conceivable to provide a suitable active conveying means, for example a fan, in order to ensure the product gas flow from the second into the third reaction zone 3, 4 and optionally also the flow of the pyrolysis gas from the first into the second reaction zone 2, 3. Due to the high temperatures in this region of the apparatus 1, the conveying means can also be arranged further downstream, in particular downstream of the third reaction zone 4, where the product gas has already cooled.In the third reaction zone 4, the product gas comes into contact with the pyrolysis coke, which is likewise transferred into the third reaction zone 4 and is thereby processed to give activated carbon. The product gas can subsequently be used further, for example, be fired in a combined heat and power plant for generating energy. However, the product gas should still be purified beforehand, in particular physically by means of a separating device 12 which has already been explained in detail in connection with FIG. 1. In addition, a cleaning device 13 can be provided, which is configured for the further, in particular chemical, cleaning of the product gas, optionally depending on the intended further use of the product gas.In order to heat the heat transfer medium to the production temperature, a heating device 11 can be provided, as already explained in connection with FIG. 1, which is connected to the heating zone 8 in a heat-conducting manner. The thermal energy generated by the heating device 11 can be provided in particular, optionally additionally and / or at least partially, in the form of hot combustion exhaust gases in the heating zone 8. The combustion exhaust gases are preferably conducted in countercurrent to the heat transfer medium, in particular through a bed of the heat transfer medium at the base of the heating zone 8, and escape in an upper region of the heating zone 8.Since the heat transfer medium is already transferred from the first reaction zone 2, optionally from a separation zone (see FIG. 1 ), into the warming-up zone 8 at a base temperature of more than 500° C., the combustion exhaust gases generally have a residual temperature in the range of the base temperature, which can be used in a heat recovery device 14, for example a heat exchanger. The exhaust gases are, if required, further supplied to an exhaust gas purification device 15 where they can be purified, physically and / or chemically, for example in view of legally prescribed limit values, and subsequently pushed.FIG. 3 shows an exemplary embodiment of a second reaction zone 3, through which a pyrolysis gas generated in a first reaction zone 2 arranged below the second reaction zone 3 flows, which pyrolysis gas is converted into a product gas for activating pyrolysis coke.The product gas is generated from the pyrolysis gas at a generation temperature that is above the pyrolysis temperature necessary for generating the pyrolysis gas from a carbonaceous starting material. The production temperature is reached by filling the second reaction zone 3 with a preheated heat transfer medium 16, which is preferably embodied as bulk material, for example steel balls or ceramic balls, and collects on the bottom of the second reaction zone 3 in the form of a bed 17.The pyrolysis gas enters the second reaction zone 3 via a gas-conducting compound 18 between the first and second reaction zones 2, 3, wherein the gas-conducting compound 18 opens into the second reaction zone 3 in an upper region of the first reaction zone 2 and in a lower region, in particular in the region of the base of the second reaction zone 3. The hot pyrolysis gas heated to the pyrolysis temperature can easily rise in this way, be transferred to the second reaction zone 3, flow through the bed 17 there and be heated to the higher production temperature and be discharged from the second reaction zone 3, in particular transferred to a third reaction zone (see FIG. 1 ), as product gas through a product gas discharge line 19 which is advantageously arranged in the upper region of the second reaction zone 3.Preheated to the production temperature, the heat transfer medium 16 enters the second reaction zone 3 in the upper region of the second reaction zone 3, for example through a first bulk material lock 20 a, wherein the heat transfer medium 16 can preferably be metered by the first bulk material lock 20 a, in particular introduced cyclically into the second reaction zone 3. The second heat transfer medium falls into the second reaction zone 3 due to the force of gravity. By means of the second bulk material lock 20 b, the heat transfer medium 16 cooled to the pyrolysis temperature in the meantime, in particular due to the preferably continuous flow of the cooler pyrolysis gas through the bed 17, can be transferred into the first reaction zone 2 while utilizing the force of gravity once again, wherein here too a metering of the heat transfer medium 16 can take place.The gas-conducting compound 18 preferably leads around the second bulk material lock 20 bto allow unhindered passage of the pyrolysis gas from the first into the second reaction zone 2, 3 even when the second bulk material lock 20 bis closed. The opening of the gas-conducting compound 18 into the second reaction zone 3 is arranged in the second reaction device 3 in such a way that the pyrolysis gas emerging from it must flow through the bed 17 on the bottom of the second reaction zone 3. This makes it possible to ensure that the pyrolysis gas is completely heated to the production temperature and, for example, tars contained in the pyrolysis gas are cracked, so that a tar-poor product gas is formed.FIG. 4 shows an exemplary embodiment of a third reaction zone 4 for producing activated carbon from pyrolysis coke 21 with the aid of a product gas. The third reaction zone 4 is designed as a rotary tube reactor with a drum 22, into which the pyrolysis coke 21 can be introduced via an inlet region 22 aand can be designed as activated carbon via an outlet region 22 b. The drum 22 is rotatably mounted so that a mixing of the pyrolysis coke 21 within the drum 22 is made possible.The conveying of the pyrolysis coke 21 from the inlet region 22 ato the outlet region 22 balong a conveying direction 23 can be at least assisted by the rotation of the drum 22, in particular if the third reaction zone 4 is tilted with respect to a horizontal, such that the outlet region 22 bis below the inlet region 22 a.The third reaction zone 4 is in this case flowed through by the product gas as product gas stream 24 in the opposite direction to the conveying direction 23. In this manner, particularly in conjunction with the rotation of the drum 22, the product gas comes completely into contact with the pyrolysis coke 21, so that a complete and uniform conversion to activated carbon can take place.The product gas preferably enters the third reaction zone 4 through an inlet opening 25 ain the outlet region 22 band exits the third reaction zone 4 through an outlet opening 25 bin the inlet region 22 a. The inlet opening 25 ais connected in a gas-conducting manner to a second reaction zone (see FIG. 2 ), so that product gas can be provided in the third reaction zone 4, at least substantially continuously. The outlet opening 25 bis preferably connected in a gas-conducting manner to a separating device (see FIG. 1 ), in which the product gas stream 24 can be cleaned of pyrolysis coke and / or activated carbon particles received in the drum 22 when the pyrolysis coke 21 flows around it. The pyrolysis coke and / or activated carbon particles separated from the product gas stream 24 can be fed back to the third reaction zone 4 via the inlet region 22 a.Preferably, the temperature in the third reaction zone 4 for activating the pyrolysis coke 21 is regulated exclusively by the product gas entering the drum 22 via the inlet opening 25 a. In other words, the activation temperature at which the pyrolysis coke 21 is activated corresponds at least substantially, preferably to a production temperature at which pyrolysis gas produced during thermal decomposition is converted into the product gas.Alternatively or additionally, a zone heater (not shown) can be provided, which is configured to provide heat and to introduce the generated heat into the third reaction zone 4. In the zone heater, one or more different fuels may be burned. These fuels are preferably provided outside the device. In one embodiment, however, the fuel can be formed, at least partially, by a part of the pyrolysis coke generated in the first reaction zone. Alternatively or additionally, a part of the product gas can also be burnt in the zone heater.FIG. 5 shows a preferred exemplary embodiment of a method 100 for producing activated carbon. In a process step S 1, a carbon-containing starting material, for example biomass or similar biogenic waste, which is produced in households and / or industrial processes, is thermally decomposed in a first reaction zone into pyrolysis coke and pyrolysis gas.To drive the decomposition process, a preheated heat transfer medium can be supplied to the first reaction zone, which ensures a defined pyrolysis temperature in the first reaction zone. In order to enable the most complete, homogeneous decomposition of the starting material possible, the heat transfer medium is preferably embodied as bulk material, i.e. as dimensionally stable particles, for example steel balls or ceramic balls, having a diameter of between 0.1 and 200 mm, preferably between 1 and 100 mm, in particular between 10 and 50 mm. The heat transfer medium can therefore advantageously mix with the starting material.To control the temperature in the first reaction zone, the first reaction zone can introduce the heat transfer medium into the first reaction zone in metered fashion, in particular by means of a bulk material lock. If the temperature in the first reaction zone falls over time, for example as a result of the progressive decomposition of the starting material, further hot heat transfer medium can be supplied accordingly.In order to facilitate a later activation of the pyrolysis coke, steam can be supplied to the generated pyrolysis gas in a further method step S 2. The water vapor is preferably added in the first reaction zone. As a result, partial activation of the pyrolysis coke is achieved directly during the formation.After the production of the pyrolysis coke, the heat transfer medium should be separated from the pyrolysis coke again. Preferably, the mixture is therefore separated in a separation zone in a further process step S 3, for example by mechanical screening or wind classification.The thermal decomposition of the starting material, the metered feeding of the carrier material into the first reaction zone, the addition of water vapor and the separation of the heat carrier medium are preferably part of a first process stage P 1, which preferably includes all process steps which are carried out within or at least corresponding to the first reaction zone.In a further process step S 4, the pyrolysis gas produced is transferred to a second reaction zone and the pyrolysis coke produced is transferred to a third reaction zone. While the transfer of the pyrolysis gas is preferably achieved via a gas line which opens into the first and second reaction zones and through which the pyrolysis gas can escape from the first reaction zone into the second reaction zone, a first conveying device, for example a conveyor belt or a conveying screw, can be provided for the transfer of the pyrolysis coke.In a further process step S 5, the pyrolysis gas is converted in the second reaction zone into a product gas which can be used for activating the pyrolysis coke. For this purpose, the pyrolysis gas is preferably heated to a production temperature which is above the pyrolysis temperature in the first reaction zone, so that tars contained in the pyrolysis gas are cracked. For example, the pyrolysis gas can be passed through a bed of the heat transfer medium at the base of the second reaction zone. In particular, the pyrolysis gas can be passed through the second reaction zone in countercurrent to the heat transfer medium before it exits in an upper region of the second reaction zone.It is also conceivable to provide a catalyst in the upper part of the second reaction zone, which catalyst at least promotes the production of the product gas from the pyrolysis gas.In order to regulate the temperature in the second reaction zone, the heat transfer medium preheated in a heating zone is preferably metered, for example via a bulk material lock in the upper region of the second reaction zone, into the second reaction zone, where it forms the bed. If, for example, the temperature in the second reaction zone falls, additional, hot heat transfer medium can be supplied from above, while already cooled heat transfer medium can be transferred to the first reaction zone on the bottom of the second reaction zone.The production temperature is preferably selected in such a way that not only a complete conversion of the pyrolysis gas into hydrogen-rich, tar-poor product gas is ensured, but also a particularly reliable activation of the pyrolysis coke is possible at this temperature.If the water vapor fraction in the product gas is not sufficiently high, for example because only as much water vapor was added in the first reaction zone as is necessary for partial activation of the pyrolysis coke, additional water vapor can optionally be added in the second reaction zone. This additional steam is preferably added in the region of the gas line between the first reaction zone and the second reaction zone before the pyrolysis gas comes into contact with the hot heat transfer medium in the second reaction zone.The production of the product gas, the metered feeding of the support material into the second reaction zone and the addition of further steam are preferably part of a second process stage P 2, which preferably comprises all process steps which are carried out within or at least corresponding to the second reaction zone.In a further process step S 6, the product gas produced is transferred to the third reaction zone. The temperature of the product gas is preferably kept stable. For example, the temperature falls off at less than 100° C., preferably less than 50° C., in particular less than 25° C., compared to the production temperature during the transfer to the third reaction zone.In a further process step S 7, the pyrolysis coke is charged with the hot product gas fed into the third reaction zone in order to achieve activation of the pyrolysis coke. For this purpose, the pyrolysis coke can be transported, for example, through the third reaction zone, for example by means of a transport belt or by slipping due to gravity, while the hot product gas sweeps over or flows around the pyrolysis coke. In order to enable the best possible heat transfer, the product gas is preferably passed through the third reaction zone in countercurrent to the pyrolysis coke.The pyrolysis coke is preferably mixed, particularly preferably with the pyrolysis gas. For this purpose, the third reaction zone can be designed, for example, as a rotary reactor, wherein the pyrolysis coke runs through a rotatable drum of the reactor. In addition to the thorough mixing, the rotational movement, in particular when the axis of rotation of the drum inclines toward a horizontal, can bring about or at least support the transport of the pyrolysis coke through the third reaction zone.In a further process step S 8, the product gas is purified in a preferred manner, in particular physically, after the activation of the pyrolysis coke. For this purpose, the pyrolysis gas can pass through a separation device in which particles absorbed by the product gas during activation are separated off again. Subsequently, the product gas physically purified in this way can be subjected to further chemical purification steps before it is utilized in terms of energy or material.The activated carbon is also preferably purified, in particular chemically, before further use. For this purpose, the activated carbon can be transferred in a further process step S 9 from the third reaction zone into an aftertreatment device and processed there, in particular according to the intended use.The activation of the pyrolysis coke, the cleaning of the product gas and the processing of the activated carbon are preferably part of a third process stage P 3, which preferably includes all process steps which are carried out within or at least corresponding to the third reaction zone.List of reference characters1 Apparatus 2 First reaction zone 3 Second reaction zone 4 Third reaction zone 5 Conveying system 6 Separation zone 7 Aftertreatment device 8 Warming zone 9 Second conveying device 10 First conveying device 11 Heating device 12 Separation device 13 Cleaning device 14 Heat recovery device 15 Exhaust gas cleaning device 16 Heat transfer medium 17 Bed 18 Gas line 19 Product gas outlet 20 a, bFirst, second bulk material lock 21 Pyrolysis coke 22 Drum 22 a, b Eintritts region, outlet region 23 Conveying direction 24 Product gas stream 25 a, b Opening, outlet opening 100 Methods S 1-S 9 Method steps P 1-P 3 Process steps

Claims

Method (100) for producing activated carbon within a gasification process, comprising: a first process stage (P1), comprising thermally decomposing (S1) a carbonaceous starting material in a first reaction zone (2) to produce pyrolysis coke (21) and pyrolysis gas; transferring (S4) at least a part of the generated pyrolysis gas from the first reaction zone (2) into a second reaction zone (3) and transferring at least a part of the pyrolysis coke (21) from the first reaction zone (2) into a third reaction zone (4); a second process stage (P2) comprising generating (S5) from the pyrolysis gas in the second reaction zone (3) a product gas usable for activating the pyrolysis coke (21); transferring (S6) the product gas into the third reaction zone (4); and a third process stage (P3), comprising activating (S7) at least a part of the pyrolysis coke (21) to activated carbon with the aid of the product gas in the third reaction zone (4).Method (100) according to claim 1, wherein the thermal energy required for activating the pyrolysis coke (21) is provided at least partially, preferably exclusively, by the product gas.Method (100) according to claim 1 or 2, wherein the pyrolysis coke (21) is activated at an activation temperature that depends on a generation temperature in the generation (S5) of the product gas.Method (100) according to one of the preceding claims, wherein the product gas is produced (S5) at a production temperature which is between 700 and 1200°C, preferably between 800 and 1000°C, in particular between 925 and 975°C.Method (100) according to one of the preceding claims, wherein water vapor is added (S2) to the pyrolysis gas, with the aid of which the product gas is generated in the second reaction zone (3).Method (100) according to either of Claims 4 and 5, wherein the steam is added and / or the generation temperature is selected in such a way that the product gas has at least one of the following: - a steam content of between 15 and 45% by volume, preferably between 20 and 40% by volume, in particular about 30% by volume; - a carbon dioxide content of between 5 and 30% by volume, preferably between 10 and 20%, in particular about 15% by volume; and / or - a carbon monoxide content of between 10 and 30% by volume, preferably between 15 and 25% by volume, in particular about 20% by volume.Method (100) according to either of Claims 5 and 6, wherein at least some of the water vapor is already added in the first reaction zone (2) during the thermal decomposition (S1), such that partially activated pyrolysis coke (21) is produced, which is activated in the third reaction zone (4) with the aid of the product gas at least predominantly, preferably at least substantially completely.The method (100) according to claim 7, wherein the pyrolysis coke (21) is partially activated by means of the added water vapor in the first reaction zone (2) at a temperature defined by a pyrolysis temperature at which the starting material is thermally decomposed.The method (100) according to claim 8, wherein the starting material is thermally decomposed in the first reaction zone (2) at a pyrolysis temperature that is between 500 and 900°C, preferably between 600 and 800°C, in particular between 650 and 750°C.Method (100) according to one of the preceding claims, wherein at least a part of the pyrolysis coke (21) is preconditioned during transfer into the third reaction zone (4).Method (100) according to one of the preceding claims, wherein the pyrolysis coke (21) is at least substantially continuously mixed with the product gas in the third reaction zone (4) during the activation.Method (100) according to one of the preceding claims, wherein the product gas is passed through the third reaction zone (4) in countercurrent (24) to the pyrolysis coke (21).Method (100) according to one of the preceding claims, wherein the product gas, after activation of the pyrolysis coke (21), is passed through a separating device (12) and is there cleaned, in particular physically, of pyrolysis coke residues and / or activated carbon residues.Method (100) according to one of the preceding claims, wherein a part of the pyrolysis coke (21) is fired in a heating device (11) in order to heat a heat transfer medium (16), which is fed to the second reaction zone (3) for generating the product gas and / or to the first reaction zone (2) for thermal decomposition of the starting material.Device (1) for producing activated carbon, configured to carry out a method according to one of the preceding claims, wherein the device (1) has: a first reaction zone (2) in which pyrolysis coke (21) and pyrolysis gas can be produced by thermal decomposition of carbon-containing starting material; a second reaction zone (3) which is connected to the first reaction zone (2) in a gas-conducting manner and in which a product gas which can be used for activating the pyrolysis coke (21) is produced from at least a part of the pyrolysis gas; a third reaction zone (4) which is connected to the second reaction zone (3) in a gas-conducting manner and in which at least a part of the pyrolysis coke (21) can be activated to give activated carbon; and a first conveying device (10) which is configured to transfer at least a part of the pyrolysis coke (21) from the first reaction zone (2) into the third reaction zone (4).

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