EP0031351A1

EP0031351A1 - Process and plant for the gazeification of solid fuels

Info

Publication number: EP0031351A1
Application number: EP80901251A
Authority: EP
Inventors: Karl Kiener
Original assignee: Individual
Current assignee: Individual
Priority date: 1979-07-05
Filing date: 1980-07-04
Publication date: 1981-07-08
Also published as: DE2927240A1; WO1981000112A1; DE2927240C2

Abstract

Le combustible tel que le charbon bitumineux, le lignite, le bois, la paille et analogue, est carbonise a la pression approximativement atmospherique dans une premiere etape par chauffage indirect entre 300 et 600 C et en agitant constamment (1). Les gaz degages chauds sont melanges avec de l'air prechauffe et partiellement brules (27) dans une deuxieme etape. Simultanement, ils sont craques thermiquement a des temperatures comprises entre 850 et 1200 C et ensuite ils passent a travers une zone de reaction (35) composee de coke de basse carbonisation obtenu pendant la premiere etape. Dans une troisieme etape le coke subit une combustion partielle, par exemple au moyen d'air et de vapeur d'eau. Le melange gazeux se trouvant initialement a une temperature comprise entre 900 et 1200 C est aspire a travers une zone de reaction formee du coke de basse carbonisation ou la temperature des gaz est diminuee grace a une reaction endothermique et ou la valeur calorifique des gaz est simultanement augmentee. Ces gaz et les gaz provenant de la deuxieme etape seront conduits vers des echangeurs de chaleur (44 a 46) et des laveurs a gaz (61).Fuel such as bituminous coal, lignite, wood, straw and the like is carbonized at approximately atmospheric pressure in a first step by indirect heating between 300 and 600 C and stirring constantly (1). The hot off gases are mixed with preheated air and partially burned (27) in a second step. Simultaneously, they are thermally cracked at temperatures between 850 and 1200 C and then they pass through a reaction zone (35) composed of low carbonization coke obtained during the first stage. In a third step, the coke undergoes partial combustion, for example by means of air and steam. The gas mixture initially found at a temperature between 900 and 1200 C is sucked through a reaction zone formed of low carbonization coke where the temperature of the gases is reduced by an endothermic reaction and where the calorific value of the gases is simultaneously increased. These gases and the gases from the second stage will be conducted to heat exchangers (44 to 46) and gas washers (61).

Description

Process and plant for gasifying lumpy pieces

Fuels

The invention relates to a method for gasifying lump fuels such as bituminous hard coal, lignite, wood, straw and the like. Like., At least approximately atmospheric pressure, in which the fuels carbonized in a first process stage by indirect heating at temperatures between 300 and 600 ° C with constant circulation and in a second process stage, the hot smoldering gases partially burned by mixing with preheated air, at the same time at temperatures of Thermally cracked at 850 to 1200 ° C. and then passed through a reaction zone formed from the coke in the first stage.

The invention further relates to a plant for carrying out such a method. In the past decades, a large number of processes and plants for gasification, pyrolysis and / or high-temperature distillation of fuels of the most varied types have been developed, which have at least partially been implemented in practice. This consisted of an initial smoldering and / or coking of the given fuels in the absence of air through direct or indirect heating, by means of which the volatile constituents are expelled and separated from the solid fuels, possibly with thermal cracking. Depending on the type and composition of the fuels used, the coke formed in this process could either be withdrawn as a salable end product or else be decomposed by a further thermal treatment by adding steam to preferably CH ₄ , CO and H ₂ -containing fuel gases . So z. B. in DE-PS 972 468 describes a method for producing a fuel gas from bituminous fuels, in which the fuels are degassed in a first chamber of a conventional coke oven block and the distillation gases obtained are transferred via pipes and a template into a second, identically designed chamber , in which the glowing, already fully cooked distillation residues from a previous degassing process are located. This chamber is supplied with heat from the outside through the chamber walls. In order to control the composition of the fuel gases produced, finely atomized fuel, e.g. B. oil or tar, together with the hot raw gas introduced into the second chamber. The fuel, which is finely atomized in the connecting line, forms a warm aerosol together with the hot raw gases, which is split into the gap volume of the glowing coke. In addition to spraying liquid fuel, water or steam can also be added to the raw gases to carry out the water gas reaction in the glowing coke of the second chamber. According to this method, a fuel gas enriched in terms of its calorific value can be generated, but the coke in the second chamber only takes part in the reactions in extremely small amounts, so that gasification of this coke does not occur or only to an insignificant extent.

This method is therefore primarily based on fuels with only minor impurities, i. H. low ash and sulfur content, limited as feed materials. A complete conversion of e.g. B. hard coal or brown coal with a high sulfur and ash content is not easily possible, since the coke obtained can be processed only with difficulty.

DE-OS 24 08 461 describes a method and a plant for the production of synthesis gas using a rack generator charged with coke, in which the fully cooked batch of coke from the generator is introduced in the heated state from the upstream coking furnace into the rack generator via a pressure lock .

In this way, the heat content of the coke is retained for the subsequent gasification process. Part of the distillation gases obtained are used for indirect heating of the coke chambers, while another part is fed into the rack generator.

The gasifying agent consists of a mixture of oxygen saturated with hot water, to which air can optionally be added, and of water vapor. This gasification medium passes through a heat exchanger with temperatures between 200 and 300 ° C in the lower part of the tapping generator previously charged with hot coke. The hot fuel gases are dedusted and give off their heat content to waste heat boilers before they are fed to a washer cooler as synthesis gas. The coking gases mixed with the gasification agent formed from oxygen and water vapor can be introduced into the coke filling of the tapping generator.

Disadvantages of this known procedure are, on the one hand, the extraordinarily high outlay on technical equipment and, on the other hand, the relatively high temperatures of the synthesis gas generated.

In a process described in DE-PS 424 724 for the extraction of low-boiling hydrocarbons from carbonization gases, carbonization is carbonized in a jacket-heated rotating drum, the carbonization gases are removed separately from the carbonization coke from the drum and thermally in an externally heated pipe system at temperatures of approximately 700 ° C cracked, so that the low-boiling hydrocarbons split off from these carbonization gases. Gasification of the smoldering coke is not intended.

Furthermore, a process for the production of fuel gases from lumpy waste and other waste materials is described in DE-PS 24 32 504, in which the waste is untreated in a carbonization drum at temperatures between 300 and 600 ° C, the carbonization gases separately from the fe Most of the smoldering residues are removed and, in a further process stage, heated to approximately 1000 ° C. by admixing predetermined amounts of combustion air and thereby thermally cracked, flowing through a reaction zone formed from red-hot coke and possibly other carbon carriers. The highly endothermic water gas reaction takes place, through which the proportions of elemental carbon (soot) generated during substoichiometric combustion and cracking are converted into appropriate amounts of carbon monoxide and hydrogen together with water vapor and carbon dioxide. Due to the heat consumption in these reactions, there is an intensive cooling of the crack gases, which are approx. 1000 ° C, to an extraction temperature of approx. 500 ° C within a flow path of approx. 500 mm.

In this process, the glowing foreign coke in the reaction zone remains largely uninvolved in the reactions taking place, i. H. it serves on the one hand as a heat store and on the other hand as a carrier for the soot particles with an extraordinarily large surface area. The solid charring residues discharged from the rotating drum are sorted into smoldering coke, other usable and worthless residues. Gasification of the smoked coke is not provided for in this known method.

The object of the invention is to provide a method and a system for gasifying ash and sulfur-rich bituminous fuels, in which the continuously produced fuel gases are largely free of environmentally harmful contaminants, e.g. B. hydrogen sulfide, and at the same time have a relatively high calorific value. This object is achieved according to the invention in that in a third process stage the smoldering coke is partially burned in a substoichiometric ratio by introducing a gaseous oxygen carrier, in that the gas mixture obtained, which is initially between 900 and 1200 ° C., is sucked through an immediately adjacent reaction zone formed from the smoldering coke, in which the gas temperatures are reduced by endothermic reactions and at the same time the calorific value of the gases is increased, and that these gases are then mixed with the fuel gases from the second process stage and the mixture obtained is fed to heat exchangers and scrubbers in a known manner.

This method according to the invention has a number of advantages over known fuel gasification methods, which include lie in the extraordinarily simple process control and control and on the other hand in the quality of the fuel gas, which has a high calorific value and is practically free of sulfur, chlorine and heavy metal compounds as well as harmful hydrocarbons even with ash or sulfur-rich feed materials. Furthermore, the above-mentioned method offers the possibility of effectively and completely gasifying fuels with ash contents of up to 30% by weight. In addition, other different fuels, such as ash-rich coking coal, lignite, peat, and also wood, wood chips, straw and the like. Like., serve as feed materials.

According to the invention, the smoked coke fulfills several functions in the fuel gas reactor. On the one hand, it serves to support the cracking processes of the smoldering gases during their substoichiometric partial combustion, on the other hand the soot particles formed during the partial combustion and cracking process are deposited on the smoldering coke grains, with extraordinarily large overs surfaces are formed. The carbonization gases react with the deposited soot, whereby carbon monoxide and hydrogen are produced from the carbonization gases using sensible heat in accordance with the known water gas equations. Corresponding processes also play out for the conversion of the gas mixtures generated in the low-level zone during the partial combustion of the coke. The continuous burning of the smoked coke in the lowest reaction zone results in a gradual lowering movement of the entire coke filling across the different reaction zones. The speed of this gradual lowering movement and thus also the intensity of the gasification of the Schwelkoks can be controlled in the simplest way by simply adjusting the amount of combustion air and steam.

The admixture of steam produced by the sensible heat of the fuel gases produced into the combustion air has the advantage of intensifying the water gas reactions in the third process stage.

For a continuous and uniform course of the process, it is expedient if, on the one hand, the carbonization gases and, on the other hand, the combustion air for the carbonization coke are introduced into the reaction zones formed in each case over the entire reactor cross-section, evenly distributed. For this purpose, the partial combustion takes place with simultaneous thermal cracking of the carbonization gases with intensive turbulence in a reaction space separate from the water gas reaction zone containing the lumpy carbonization coke. To evenly distribute the combustion air for the smoked coke, it can be expediently passed through it from a pressure chamber under the ash conveyor be introduced into the combustion zone.

The system for carrying out the process comprises a carbonization drum heated indirectly via its hollow jacket, preferably by exhaust gases, and a shaft-shaped fuel gas reactor charged with the carbonization gases and the coke from the carbonization drum, and as auxiliary units, air preheaters and scrubbers for the fuel gases produced, an upper partial combustion according to the invention in the fuel gas reactor - And cracking zone for the smoldering gases, an adjoining water gas reaction zone filled with smoldering coke for the cracked smoldering products, then a withdrawal zone for the fuel gases generated, and then a water gas reaction zone filled with smoldering coke for the reaction products from the partial smelting coke and thereon a hot combustion zone for the smoked coke with feed lines for the preheated combustion air and steam is then formed at the bottom.

A gas-permeable partition is expediently provided between the upper partial combustion and cracking zone for the carbonization gases and the water gas reaction zone adjoining it, which partition is advantageously designed as a uniformly perforated ceramic plate.

Further advantages are the subject of subclaims.

Exemplary embodiments of a gas generation plant according to the invention are described in detail below with reference to the drawing. Show it:

1 shows the block diagram of a first embodiment, 2 shows the fuel gas reactor of the plant according to FIG. 1 in an enlarged schematic illustration,

Fig. 3 shows the block diagram of another embodiment with common charging of the fuel gas reactor with carbonization gas and carbonization coke.

The gas generation plant shown in FIG. 1 contains a smoldering drum 1, a fuel gas reactor 2 and a gas engine 3 as main units.

The lumpy bituminous fuels are introduced into the entry end of the rotary drum 1 via a funnel 4 with locks 5, 6 arranged in an entry shaft 7 and a horizontal conveyor 8. The rotary drum 1 consists of the actual smoldering drum 10, in which hollow, essentially longitudinally oriented internals 11 in the form of longitudinal ribs or blades are arranged. This smoldering drum 10 is surrounded by a jacket 12, which is connected via a line 13 to the exhaust system 14 of the gas engine 3. In this way, the rotary drum is heated indirectly by the exhaust gases of the gas engine 3 which are at approximately 600 ° C. For start-up and / or emergency operation, an additional burner 15 is provided on the drum discharge side, the exhaust gases of which flow into the jacket space 12 and the carbonization of the Start fuels inside the drum. In normal operation, however, the heat supply in the exhaust gases of the gas engine 3 is sufficient for a complete carbonization of fuels, even with a high ash and water content. To intensify the heat transfer between the hot exhaust gases and the char the hollow internals 11 are flowed through by the hot exhaust gases, which on the one hand increases the heat transfer surfaces and on the other hand the heat transfer to the feed or smoldering material is improved by the conveying effect of these internals. With appropriate design of these internals 11, the interior of them can be enlarged so that they themselves form the jacket 12. After flowing through the internals 11 or the drum casing 12, the exhaust gases are discharged into the atmosphere via a line 16 with a metering valve 17. The line 16 is connected by a branch line 18, a blower 19 and a metering valve 20 to the burner 15 or the entry-side distribution chamber 21 in the drum jacket 1-2 in order to control the temperature of the heating gases by admixing predetermined, already cooled gas quantities.

The rotary drum 1 is adjustable in the usual way in its inclination on - not shown - supporting and drive rollers.

The carbonization gas generated in the rotary drum 1 is fed at temperatures of 400 to 500 ° C. at the discharge end of the drum via pipes 22 to a burner 23 which opens into the upper part of the fuel gas reactor 2. Immediately upstream of an ejector part 24, a feed line 25 for the combustion air ends, which is intensively mixed in the ejector part 24 and the adjoining diffuser 26 of the burner 23 with the carbonization gases to obtain a partial combustion of the carbonization gases.

The fuel gas reactor 2 has in its upper part a chamber 27 free of internals, in which one in aggressive swirling of the partially burned smoldering gases flowing in through the burner 23 takes place. The thermal cracking of the carbonization gases heated to approx. 1000 to 1200 ° C by the substoichiometric partial combustion takes place in this chamber.

This chamber 27 is delimited at the bottom by a partition wall 28, which consists of a ceramic plate of approximately 100 to 200 mm in thickness, in which a plurality of holes 29 are provided in a suitable size. The flow resistance of this plate 28 or the holes 29 is selected so that there is a slight overpressure in the chamber 27, which ensures a uniform flow through the plate 28 over the entire cross section of the shaft-shaped fuel gas reactor.

At a predetermined distance below the gas-permeable partition 28, at least one feed conveyor 30 is provided, which has a hydraulically or pneumatically operated piston slide 31 as the feed member. The smoldering coke is fed to this feed conveyor 30 from the discharge end of the rotary drum 1 via a chute 32 and a pressure-tight metering wheel device 33. The feed conveyor 30 feeds the fuel gas reactor 2 via a side, sealed entry opening 34 with the smoked coke produced in the rotary drum 1. The fuel gas reactor is charged in such a way that a sufficient height of the coke bed 35 is present in the fuel gas reactor.

At a predetermined distance below the infeed conveyor there is a discharge for the fuel gases which is designed as an annular channel 36 and which consists of a plurality of radial There are openings in the reactor wall.

The reactor floor is formed by a discharge conveyor 37 for the ash and slag of the smoked coke, which is driven by a motor 38 via a gear 39. Below this discharge conveyor 37, which is designed as a rotating grate, there is provided a discharge chute 41 sealed by piston slide 40, through which the ash or slag loosened and crushed by means of the discharge conveyor 37 is discharged. Air and steam lines 42 open into the interior of this discharge chute 41.

A hot gas line 43 leads from the fuel gas outlet designed as an annular duct 36 to an air preheater 44 and to evaporators 45, 46. The air preheater is connected via a warm air line 47 with an air line 48 leading to the pipe 25 via a metering valve 49 and via an air line 50 and further metering valve 51 connected to the air connections 42. In the evaporators 45 and 46, quantities of water supplied are evaporated by means of metering pumps 53, 54, which are fed via a steam line 55 into the warm air line 48 downstream of the valve 49 and on the other hand via a further steam line 56 into the warm air line 50 downstream of the metering valve 51 .

The fuel gases flow from the heat exchangers 44 to 46 via a gas line 60 into a scrubber 61, which is only shown schematically and in which pollutants and other by-products are separated in several stages, if necessary. The cleaned fuel gas is fed to the gas engine 3 via a line 62, the output shaft of which is coupled to a generator 63. The operation of the system described above and in particular of the fuel gas reactor (using FIG. 2) is described in detail below.

The bituminous fuels supplied via an endless conveyor, not shown, such as sulfur and ash-rich hard coal, lignite, peat, wood and wood waste, as well as straw and other organic constituents, pass through the funnel 4 by alternately actuating the piston slides 5, 6 into the entry shaft 7 which they are entered into the interior of the smoldering drum 10 by means of the screw conveyor 8. After drying in the left part of the smoldering drum in FIG. 1, the degassing of the fuels commences at approx. 200 ° C., which continues continuously up to temperatures of approx. 500 ° C. at the right discharge end of the drum. The carbonization gases are extracted by the ejector action of the burner 23 via the lines 22 at temperatures of approximately 400 to 500 ° C. At the same time, the smoked coke is introduced via the discharge chute 32, the metering wheel 33 and the feed conveyor 30 into the fuel gas reactor 2 below the intermediate wall 28.

The reactions taking place in the carbonization gas are described in detail below with reference to FIG. 2. The smoldering gases are partially burned by admixing metered amounts of air in the burner 23 and flow with a comparatively high kinetic energy into the empty chamber 27, in which intensive swirling of the gases 1 takes place. These eddy currents cause a temperature of approximately 1000 ° C. in the entire chamber, at which the thermal cracking of the carbonization gases takes place with high efficiency. Maintaining the temperature is achieved by introducing appropriate amounts of air and thus by the intensity of the carbonization gas combustion. The partially burned and Cracked carbonization gases flow through the holes 29 in the intermediate wall 28 into the coke bed 35, the surface of which is heated to a temperature of about 900 to 1000 ° C. The proportions of elemental carbon (soot) formed during the cracking process and during the substoichiometric combustion of the carbonization gases accumulate on the surfaces of the carbonization coke and react with the combustion products and with the water vapor under carbon monoxide, hydrogen and possibly methane formation. These processes are highly endothermic, so that the gases flowing from the partial combustion and cracking zone I through the partition wall 28 into the water gas reaction zone II in the coke layer 35 from initially 900 to 1000 ° C to a discharge temperature of about 500 ° C through the endothermic reaction processes are cooled off through the openings 36a in the refractory brick walls of the reactor 2 and the annular channel 36 (discharge zone III).

The combustion air introduced into the space 41 below the conveyor via the line 50, the ring channel 42 and the openings 42a in the reactor wall flows through the spaces between the conveyor grate bars 37 and partial combustion of the smoked coke occurs in a temperature range of immediately above the conveyor grate 37 1000 to 1200 ° C. The intensity of this partial combustion is achieved by adjusting the air supply by means of the metering valve 51. The gases formed by the partial combustion of the smoked coke flow through zone IV of the coke bed and are withdrawn from the fuel gas reactor through the exhaust openings 36a, the annular channel 36 and the fuel gas line 43. Because of the steam added to the combustion air, strongly endothermic reactions also occur when this flows through the coke filling in reaction zone IV Increase in calorific value and simultaneous temperature reduction - according to the reactions in Zone II -.

The system shown in FIG. 3 corresponds in its essential components and functional features to that of FIG. 1. The corresponding components are identified by reference numerals expanded by 100. This system is particularly suitable for feed materials in which the carbonization produced in the carbonization drum is on the one hand sufficiently granular to be introduced into the fuel gas reactor together with the carbonization gases via the burner 123 and forms a coke bed of sufficient gas permeability on the other However, the coke should also be swirled by the combustion gases in space 127 in order to enable deposition that is largely uniform over the entire cross section of the fuel gas reactor.

In terms of investment, this version has the advantage that the separate feed conveyor 30 for the coke and the gas-tight metering wheel lock 33 can be omitted. In order to ensure a continuous addition of the coke bed 135 in the reactor 2, the perforated partition 28 according to FIG. 1 is missing in this embodiment. It follows that the variant according to FIG. 3 is technically simpler, but that the control of the process sequence has fewer possibilities for intervention offers, since the entire Schwelkoks discharged from the smoldering drum 110 goes directly into the fuel gas reactor. The other units (such as heat exchangers, scrubbers, gas engines, etc.) of this system correspond to those in FIG. 1, so that it was not necessary to show them in the drawing. The invention is not limited to the embodiments shown and described. For example, the preheating of the combustion air and / or the steam generation for the water gas reaction can be carried out in the third process stage by further utilizing the waste heat from the exhaust gases of the gas engine.

Furthermore, there is also the possibility to separate the fuel gases obtained by the thermal cracking of the carbonization gases on the one hand and on the other hand the fuel gases obtained by the gasification of the carbonization coke separately from the fuel gas reactor and to further treat them according to their possibly different chemical composition. Although the utilization of the fuel gases in a gas engine is one of the most energy-efficient options, since the engine's exhaust gases can be used to heat the smoldering drum, the fuel gases generated can also be used for other heating purposes or as a chemical raw material. In this case, the smoldering drum could be indirectly heated by the generated, approximately 600 ºC hot fuel gases themselves, which are then passed through the hollow jacket or the hollow internals in the drum.

A further process and system variant is suitable for special applications, in particular for the use of fuels with a high ash content, in which the incombustible components tend to cake and sinter, in which the smoldering coke in the reactor shaft is wholly or partly in the state of a calmed fluidized bed (Fluid bed) is added. For this purpose, a sufficiently high overpressure is generated in the air chamber on the bottom, which leads to gas flows evenly distributed over the bottom cross-section into the filling coke. Should the Generation of the fluidized bed necessary gas amount exceed the amount of air required for partial combustion of the Schwelkoks, this combustion air can either be mixed with a corresponding part of the fuel gas generated and / or a corresponding part of the exhaust gases. At least some of these exhaust gases from the internal combustion engine (gas engine) operated with the fuel gas produced are thermally cracked in the hot partial combustion zone. The admixed fuel gases, on the other hand, preferably have a fluidic carrier function for producing the fluidized bed.

Claims

Expectations - - - - - - - - - - - - - - - - -

1. Process for the gasification of lumpy fuels, such as bituminous coal, lignite, wood, straw and the like. Like., At least approximately atmospheric pressure, in which the fuels carbonized in a first process stage by indirect heating at temperatures between 300 and 600 ° C with constant circulation and in a second process stage, the hot smoldering gases partially burned by mixing with preheated air, at the same time at temperatures of 850 to 1200 ° C thermally cracked and then passed through a reaction zone formed from the coke in the first stage, characterized in that in a third process stage the coke is partially burned in a substoichiometric ratio by introducing a gaseous oxygen carrier (air), so that the between initially 900 and 1200 ° C hot gas mixture is sucked through an immediately subsequent reaction zone formed from the Schwelkoks, in which the gas temperature is reduced by endothermic reactions and at the same time de r calorific value of the gases is increased, and that these fuel gases and the fuel gases from the second process stage are then supplied in a known manner to heat exchangers and washers.

2. The method according to claim 1, characterized in that that metered amounts of water vapor are added to the combustion and gasification air for the smoked coke to achieve the water gas reaction.

3. The method according to claim 1 or 2, characterized in that the fuel gases from the second process stage are mixed with the fuel gases from the third process stage and are fed together to the air preheaters and washers.

4. The method according to claim 1, characterized in that the partial combustion with simultaneous thermal cracking of the carbonization gases with intensive swirling of the reacting gases is carried out in a separate from the lumpy coke-containing water gas reaction zone reaction space and that the reaction products obtained over the water gas reaction zone flow through their entire cross-section evenly.

5. The method according to any one of the preceding claims, characterized in that the fuel gases generated are discharged in a region between the second and the third process stage.

6. The method according to any one of the preceding claims, characterized in that the slag and ash formed in the third process stage is removed mechanically comminuted.

7. The method according to any one of the preceding claims, characterized in that the smoldering coke in the third process stage is flowed through by the combustion and gasification air evenly distributed over the entire cross-section, and that the amount of smoldering coke in this third process stage is adjusted so that the fuel gases generated are sufficiently cooled with temperatures by the endothermic water gas reactions taking place are supplied to the heat exchangers in the range of 400 to 700 ° C.

8. The method according to any one of the preceding claims, characterized in that the fuel gas generated is used in an internal combustion engine, the exhaust gases and the heating medium for the carbonization in the first process stage.

9. The method according to any one of the preceding claims, characterized in that the intensity of the gasification of the Schwelkokses and thus the height of the reaction zone in the third process stage is controlled by adjusting the amounts of combustion air introduced into the Schwelkoks.

10. The method according to any one of the preceding claims, characterized in that the combustion air for the carbonization gases and for the carbonization coke is preheated by the approximately 500 ° C hot fuel gases.

11. The method according to claim 2, characterized in that the steam fed into the smoked coke in metered amounts by utilizing the sensible heat of approximately 500 ° C hot fuel gases is generated.

12. The method according to any one of the preceding claims, characterized in that the carbonization gases and the carbonization coke from the first process stage are fed together to the second process stage.

13. The method according to any one of claims 1 to 11, characterized in that the carbonization gases and the carbonization coke from the first process stage are each withdrawn separately and fed to the second process stage.

14. Plant for carrying out the method according to one of the preceding claims, with a carbonization drum heated indirectly via its hollow jacket and a shaft-shaped fuel gas reactor charged with the carbonization gases and the carbonization coke from the carbonization drum, and with air preheaters and a scrubber for the combustion gases produced, characterized in that the combustion gas reactor an upper partial combustion and cracking zone I for the carbonization gases, an adjoining water gas reaction zone II filled with carbonization coke for the cracked carbonization gases, then a common extraction zone III for the fuel gas produced, and then a water gas reaction zone IV filled with carbonization coke for the Reaction products of the partial smoked coke and then a hot combustion zone V for the smoked coke with feed lines (42, 142) for the preheated combustion air and possibly the steam.

15. Plant according to claim 14, characterized in that in the upper, as a free swirl chamber (37) formed partial combustion and cracking zone I a with the carbonization gases and the preheated air ejector burner (23, 123) is arranged.

16. Plant according to claim 14 or 15, characterized in that a gas-permeable partition (28, 29) is provided between the upper partial combustion and cracking zone I and the subsequent water gas reaction zone II.

17. Plant according to claim 16, characterized in that the partition (28) is a uniformly perforated ceramic plate.

18. Plant according to one of claims 14 to 17, characterized in that an entry device (30) for the smoked coke is arranged on the fuel gas reactor (2) below the partition (28).

19. Plant according to one of claims 14 to 18, characterized in that the exhaust (36) for the fuel gases produced is designed as an annular channel on the outer circumference of the fuel gas reactor (2), which with a plurality of evenly distributed in the circumferential direction radial openings (36 a) sloping underside is connected to the coke filling (35) in the fuel gas reactor (2).

20. Plant according to one of claims 14 to 19, characterized in that that a discharge conveyor (37 to 39) for the ash and slag as well as connections (42, 42a) for the preheated combustion air and possibly the steam are arranged at the bottom of the fuel gas reactor (2).

21. Plant according to claim 20, characterized in that a sealed distributor chamber (41) is provided for the combustion air under the discharge grate (37) designed, which distributes the combustion air through the rotation grate (37) evenly over the entire reactor cross section into the Introduces smoldering gas filling.

22. Plant according to one of claims 14 to 21, characterized in that the entry conveyor (30) for the Schwelkoks has a piston valve as a conveying and sealing member.

23. Plant according to claim 14, characterized by a common rotary drum discharge (132) for the carbonization gases and the carbonization coke.

24. Plant according to one of the preceding claims, characterized in that a sufficiently high gas pressure is set to form a so-called settled fluidized bed in the distributor chamber (41).

25. Plant according to claim 24, characterized in that the fluid generating medium in the distribution chamber (41) is a mixture of partial combustion air, water vapor, generated in the reactor, recycled fuel or carbonization gas and / or exhaust gas from the gas engine operated with the fuel gas .