EP3548587A1

EP3548587A1 - Method and system for carbon reduction in the bottom product of a fluidized-bed gasifier

Info

Publication number: EP3548587A1
Application number: EP17811206.6A
Authority: EP
Inventors: Ralf Abraham; Domenico Pavone; Dobrin Toporov
Original assignee: ThyssenKrupp AG; ThyssenKrupp Industrial Solutions AG
Current assignee: Gidara Energy BV
Priority date: 2016-11-24
Filing date: 2017-11-15
Publication date: 2019-10-09
Anticipated expiration: 2037-11-15
Also published as: ES2877770T3; DK3548587T3; WO2018095781A1; PT3548587T; EP3548587B1; PL3548587T3; DE102016223318A1

Abstract

The invention relates to a system for converting carbon-containing fuels into synthesis gas, comprising a gasification reactor (10), which has at least one fluidized-bed zone (11), in which the fuels are gasified by means of suitable gasification agents, wherein a carbon-containing ash flow is produced as a bottom product in a bottom region arranged below the fluidized-bed zone (11) and wherein a device is arranged below the gasification reactor (10), in which device the bottom product is oxidized by the feeding of an oxidant, wherein an additional fluidized-bed combustion chamber (12) is arranged below the fluidized-bed zone (11) of the gasification reactor (10) as a device for oxidizing the bottom product.

Description

Process and plant for carbon reduction in the bottom product of a fluidized bed gasifier

The present invention relates to a plant for the conversion of carbonaceous fuels in synthesis gas comprising a gasification reactor having at least one fluidized bed zone, in which the gasification of the fuels by suitable gasification, wherein in a below the fluidized bed zone arranged bottom area as a bottom product, a carbon-containing ash stream is obtained and wherein below the gasification reactor a device is arranged in which an oxidation of the bottom product takes place by supplying an oxidizing agent.

Processes for converting carbonaceous fuels in the fluidized bed have long been known. In particular, here is the high-temperature Winkler method (HTW method) to call, which is considered a proven technology with which both lumpy and liquid or pasty fuels are converted into synthesis gas. As a fuel also difficult fuels with a very high proportion of ash and biologically based fuels are used. These are introduced into a fluidized bed, which is operated as a bubbling fluidized bed, and gasified with oxygen. The HTW process works in comparison to other gasification processes at comparatively moderate temperatures, at which the resulting ash does not leave the gasification reactor in a molten state. This has operational advantages, especially with corrosive ashes.

In the known HTW process gasification is usually done via separate nozzles with the gasification agents, such as water vapor, carbon dioxide, oxygen or air. These nozzles are arranged, for example, in different planes, for example both in the fluidized bed zone and in the so-called freeboard zone (FB). In this freeboard zone (FB) a high material and energy transfer rate is achieved and the return of the unreacted solids over the cyclone and return line in the fluidized bed, a uniform temperature distribution over the fluidized bed can be secured. To avoid the formation of particle agglomerations, the temperature of the fluidized bed should be kept below the temperature of the ash softening point.

In addition, in the conventional HTW process gasification agent, usually oxygen, in the FB zone, which is located above the fluidized bed, registered. By injecting this "secondary" oxygen, various effects are achieved, namely on the one hand, the implementation of a portion of the finely divided fuel, which is discharged from the fluidized bed and on the other hand, the temperature of the gases is increased, so that further oxidation and / or cracking of the volatiles (tars and hydrocarbons) expelled from the feed can take place simultaneously with reaction of the fine, dispersed fuel particles with steam and C0 ₂ according to the Boudouard reaction.

The proportion of the total oxygen above the fluidized bed is, for example, between about 60% and about 10% in an HTW process. To the slag in the Preferably, the temperatures should preferably not exceed certain limits while the operating temperature should preferably be at least about 100 ° C lower than the ash softening point. For this one can mix steam with oxygen and bring it into the reactor. However, the addition of oxygen into the post-gasification zone also leads, in side reactions, to partial combustion of the synthesis gas reservoir (CO + H ₂ ) and consequently to a reduction in the synthesis gas yield. Therefore, one must increase the gas and particle temperature in order to accelerate the gasification reaction.

In the gasification of ash-containing fossil fuels in the high-temperature Winkler gasifier (HTW carburetor) under stationary fluidized bed conditions, a carbon-containing ash stream (so-called bottoms product BP) is withdrawn at the bottom of the carburetor. To exploit the energy and to achieve landfill capacity, the bottom product is previously fed to an external furnace. For economic reasons, this time-consuming post-treatment should be avoided.

The need for suitable processes for the gasification of carbonaceous fuels such as straw, waste wood, coal or the like is generally increasing. As a result, there is an increasing need to develop low cost gasification processes which do not require additional equipment to dispose of the carbonaceous bottoms product.

WO 2015/003778 A1 describes a method and a device for the aftertreatment of the carbon-containing bottom product obtained in the gasification of carbonaceous fossil fuels in a high-temperature Winkler method (HTW method) in the direction of gravity below the fluidized bed. It is proposed not to supply the bottom product to an external firing device to utilize the energy of the bottom product and to achieve the landfill capability, but to apply open-cell ceramic elements such as gas purging bricks, foamed ceramics or the like in a bottom product oxidizer below the fluidized bed with an added oxidant. In this way, a further oxidation is to be achieved and the carbon material turnover in the HTW carburetor can be increased.

From EP 1 201 731 Al a process for the gasification of carbonaceous solids in the fluidized bed is known in which below the fluidized bed, a first post-gasification zone and a second post-gasification zone are arranged, so as to achieve a substantial implementation of C-containing solids. In the first post-gasification zone, a gasification agent is injected via nozzles in order to achieve a certain loosening of the solid in this zone. However, it is expressly pointed out here that the flow conditions typical for a stationary fluidized bed should be avoided. Rather, one wants to achieve that the heavier ash agglomerates that have formed in the fluidized bed zone, sink faster down than the smaller residual coke particles, which still contain carbon, so that the latter dwell longer in the post-gasification zone. The known device is designed so that they are in the Downstream of the fluidized bed zone continuously tapers conically in cross section and then tapered conically further in the first post-gasification zone arranged thereunder, while the container in the lowest second post-gasification zone has the smallest cross-section and is cylindrical.

The object of the present invention is to provide an improved apparatus and a method for the economic gasification of different feedstocks in a pressure-charged fluidized bed gasification, which is suitable for comparatively high operating pressures of preferably above 10 bar and is economical with high safety and availability.

The solution to this problem provides a plant for the conversion of carbonaceous fuels in synthesis gas comprising a gasification reactor with at least one fluidized bed zone of the type mentioned with the features of claim 1.

According to the invention, an additional fluidized bed combustion chamber is arranged as a device for the oxidation of the bottom product below the fluidized bed zone of the gasification reactor. In this additional fluidized bed combustor, by supplying a suitable oxidizer, effective combustion of the bottoms product from the gasification reactor can be achieved. Preferably, the reactor forming the additional fluidized-bed combustion chamber is somewhat smaller than the gasification reactor.

This additional fluidized-bed combustion chamber is positioned below the gasification reactor and connected, for example via a cross-sectional constriction with the fluidized bed zone of the gasification reactor. In the context of the present invention, a cross-sectional constriction is understood to mean such a shape of the gasification reactor that the cross-section in the area of the cross-sectional constriction, which is below the fluidized bed zone, is less than in the area of the fluidized bed zone, whereas the cross section of the additional fluidized bed combustion chamber, in turn is arranged below the cross-sectional constriction, at least in sections again larger than in the region of the cross-sectional constriction. In other words, when looking at the gasification reactor from top to bottom, the cross-section below the fluidized bed zone decreases, where the cross-sectional constriction is and then below the cross-sectional constriction, the cross section in the additional fluidized bed combustion chamber increases again.

The fluidized-bed zone itself preferably has a conical cross-section tapering from top to bottom so that the cross-section in the region of the cross-sectional constriction which subsequently adjoins downward is preferably at most as large as the smallest cross section at the lower end of the fluidized bed zone. Further downwards, in the area of the additional fluidized bed combustion chamber, the cross section of the reactor increases again. Preferably, the fluidized bed combustion chamber is formed as a separate chamber of the gasification reactor, which is connected only via the cross-sectional constriction with the fluidized bed zone, but preferably nevertheless part of the entire gasification reactor and is not a separate reactor (with separate container). Preferably, at least in its lower region, the additional fluidized-bed combustion chamber is in turn formed with a conically tapering cross-section downwards.

The oxidizing agent, which is fed into the additional fluidized bed combustion chamber via the at least one feed device, is preferably injected or injected, preferably comprises oxygen and / or air and may additionally contain, for example, steam and / or CO ₂ . If several feed devices are used, these can be used to supply the additional fluidized bed combustion chamber via these oxidizing fluid streams having a different composition from one or more of the abovementioned gases / fluids.

Preferably, the oxygen content of the oxidant, when supplied in admixture with steam, is less than about 21% by volume. The oxygen content and the amount of oxygen should be selected depending on the amount of carbon in the bottoms product to be combusted in the additional fluidized bed combustor and the combustion temperature below the ash softening.

A preferred embodiment of the invention provides that the system has at least one temperature measuring device for measuring the temperature in the additional fluidized bed combustion chamber. By means of this temperature measuring device, it is possible to measure the temperature in the additional fluidized-bed combustion chamber and, depending on the measured temperature, one can conclude the carbon content of the fuel and adjust the oxygen content of the supplied oxidizing agent accordingly, preferably in such a way that excess stoichiometric ratios result.

Preferably, a control device is furthermore provided in order to regulate the amount and / or the oxygen content of an oxygen and / or air and / or vapor and / or CO ₂ -containing fluid flow injected via the at least one feed device into the additional fluidized bed combustion chamber ,

The control device is preferably in operative connection with the temperature measuring device in order to determine the quantity and / or the oxygen content of the oxygen and / or air and / or vapor and / or CO ₂ -containing fluid stream injected into the additional fluidized bed combustion chamber via the at least one feed device To regulate dependence on the measured temperature in the additional combustion chamber. Preferably, according to an embodiment of the invention, the feed device is designed such that by the injected into the additional fluidized bed combustion oxygen and / or air and / or steam and / or C0 ₂ -containing fluid stream in the additional combustion chamber to be burned bottom product is fluidized. This has the procedural advantage that one for the fluidization, ie. For the production of the fluidized bed in the additional combustion chamber no additional fluid needed, but this can use the already supplied oxidant.

Preferably, the feed device comprises at least one nozzle, preferably a multi-fluid nozzle, for injecting a fluid mixture of at least two different oxidizing fluids into the additional combustion chamber. Here, for example, a multi-component nozzle can be used, as described in WO 2014/026748 AI. The content of this document is hereby incorporated by reference.

Furthermore, the supply device is preferably associated with at least one valve for shutting off and / or regulating the supplied oxidizing fluid flow, so that the supply of the oxidizing agent can be regulated and / or optionally shut off.

According to a preferred development, the system according to the invention comprises at least two feed devices for supplying differently composed oxidizing fluid streams, wherein each feed device is assigned in each case at least one valve for shutting off and / or regulating the respectively supplied oxidizing fluid flow. In this way, the fluidized bed combustion chamber differently differentiated fluid streams may optionally be differentiated in different places in the particular desired amount.

Preferably, the system according to the invention comprises at least one pressure difference measuring device and display device in order to indicate a pressure difference between the pressure in the fluidized bed of the gasification reactor and the pressure in the additional fluidized bed combustion chamber. The measured pressure difference can be used, for example, in order to optimize the conditions for the fluidization of the fluidized bed in the gasification reactor by the flue gases exiting from the additional fluidized bed combustion chamber on the one hand and by the supplied oxidant on the other hand.

A preferred development of the system according to the invention provides that it has at least one connecting line for the return of raw gas from the gasification reactor, which leads out of the gasification reactor and into the additional fluidized-bed combustion chamber. In this way, you can at least a partial flow of the raw gases generated in the gasification reactor in the additional fluidized bed combustion chamber and use there, for example, for the fluidization (generation of the fluidized bed) and / or optionally also for the oxidation and promotion of combustion, as far as the raw gas contains oxidizing gas components. A preferred development of the system according to the invention comprises at least one compressor for the compression of recirculated raw gas from the gasification reactor into the additional fluidized-bed combustion chamber so that the crude gas can be compressed for the recirculation.

The present invention furthermore relates to a process for the conversion of carbonaceous fuels into synthesis gas in which a gasification of the fuels takes place in a gasification reactor having at least one fluidized bed zone by means of suitable gasification means, wherein a carbonaceous ash stream is obtained as bottom product in a bottom region arranged below the fluidized bed zone, and below Gasification reactor is arranged a device in which an oxidation of the bottoms product takes place by supplying an oxidizing agent, wherein the oxidation of the bottoms product takes place in an arranged below the fluidized bed zone of the gasification reactor additional fluidized bed combustion chamber.

Preferably, according to the invention, the resulting in the oxidation of the bottom product in the additional fluidized bed combustion flue gas is passed from the bottom into the gasification reactor and serves to generate there fluidization of the particles to be gasified or at least to support this fluidization.

According to a preferred embodiment of the method according to the invention, a portion of the raw gas generated in the gasification in the gasification reactor is recycled from the gasification reactor via at least one connecting line in the additional fluidized bed combustion chamber.

Preferably, the recirculated portion of the raw gas produced in the gasification in the gasification reactor is compressed prior to introduction into the additional fluidized bed combustion chamber by means of at least one compressor.

A preferred development of the method provides that the exit velocity of the bottom product from the gasification reactor into the underlying additional fluidized bed combustion chamber is preferably adjusted by means of the flow of the recirculated gas such that only particles of coarser particle size due to gravity from the gasification reactor in the underneath get lying additional fluidized bed combustion chamber. The finer particle class thus remains in the gasification reactor, which also reduces the carbon content.

The inventive method provides that preferably the gasification of the fuels in the gasification reactor at an operating pressure of at least about 10 bar.

According to a preferred development of the method, an oxidizing fluid flow which contains oxygen and / or air and / or vapor and at least one second is injected via at least one first feed device into the additional fluidized-bed combustion chamber Feeder is injected into the additional fluidized bed combustion chamber, a fluid stream containing C0 ₂ and / or recycled gas from the gasification reactor.

It is advantageous if the temperature in the additional fluidized-bed combustion chamber is measured, since the temperature permits conclusions about the course of the combustion process and the carbon content of the local soil product after the gasification process. Thus, depending on the measured temperature, it is possible to adjust the oxygen content of the oxidizing agent supplied to the fluidized-bed combustion chamber in accordance with the carbon content of the fuel, it being preferable to adjust over-stoichiometric conditions.

The gasification reactor used for the gasification in the fluidized bed zone according to the present invention is particularly preferably a high-temperature Winkler gasifier and the gasification process is carried out under appropriate conditions with respect to pressure, temperature and other parameters, reference being made to the cited document and the relevant literature becomes .

Hereinafter, the present invention will be explained in more detail by means of embodiments with reference to the accompanying drawings. Showing:

Figure 1 is a simplified schematic representation of an exemplary system according to the invention;

FIG. 2 shows an enlarged detailed representation of a detail from the plant shown in FIG. 1, wherein the lower region of the gasification reactor and the additional fluidized-bed combustion chamber are shown.

Hereinafter, with reference to Figure 1, a possible embodiment of the present invention will be explained in more detail. The illustration shows a schematically simplified representation of an exemplary system according to the invention which has a delivery system 20 by means of which the starting material, for example coal, biomass, waste or the like, is fed to the gasification reactor 10. This conveying and feeding system 20 comprises, for example, a number of conically ending containers 21 and possibly locks and is suitable for bringing the starting material to a pressure level which also prevails in the gasification reactor 10. For example, via a screw conveyor 22, the material can then be spent in the gasification reactor.

The gasification reactor 10 comprises a fluidized bed zone 11 and above a so-called "free board zone", that is, a mixing region 16 (also called freeboard zone), wherein in these two zones 11, 16, the gasification of the starting material at elevated temperatures of, for example, about 800 Furthermore, a cyclone separator 18 connected to the gasification reactor 10 is provided, in which the entrained partially gasified particles (ash particles) are separated from the synthesis gas produced in the gasification reactor, such as that the dust-free synthesis gas via an output line 19 can be dissipated. A return line 23 is provided, which starts from the lower region of the cyclone separator 18 and serves to recirculate ash particles entrained with the synthesis gas, which were separated in the cyclone separator 18, into the fluidized bed zone 11.

Solid by-products (ash particles) from the bottom product of the gasification reactor 10 arrive in the inventive process in an additional fluidized bed combustion chamber 12, which is arranged below the fluidized bed zone 11 of the gasification reactor 10 and connected thereto via a cross-sectional constriction, so that in particular by gravity particles of the bottom product from the gasification reactor 10 down into the additional fluidized bed combustor 12 may fall, while lighter smaller particles remain due to the fluidization in the gasification reactor 10. As seen in Figure 1, the additional fluidized bed combustor 12 is substantially smaller than the gasification reactor 10 and is only a fraction of the size of the gasification reactor.

As can further be seen from FIG. 1, the addition of the oxidizing agent, which consists in particular of oxygen / steam, air or CO ₂ , can take place in different areas of the installation in different height positions. 1, for example, a first upper nozzle 24 is provided for the addition of the oxidizing agent into the gasification reactor in the lower region of the "free board zone." Addition of, for example, a mixture of oxygen and steam below it into the fluidized bed zone 11 takes place Finally, an addition of this or another oxidizing agent of any of the above-described compositions via a fourth lower nozzle 27 is provided, which takes place directly into the additional fluidized bed combustion chamber 12 into the gasification reactor via a second middle nozzle 25. These various nozzles for the supply of the oxidant can be connected in the simplest case using oxidants of the same composition via lines and fed via common supply lines, but as well is a supply from different sources about each separate line systems possible.

The combustion residue emerging from the additional fluidized-bed combustion chamber 12 arranged below the gasification reactor 10, preferably downwards, is removed from the installation, for example via a water-cooled system of screw conveyors 38 and pressure vessels 39, in which it is cooled and brought to ambient pressure.

Below is an example of the area of the system in which the additional fluidized bed combustion chamber 12 is explained in more detail with reference to the enlarged detail of Figure 2. In principle, only the additional fluidized-bed combustion chamber 12 and in some cases the fluidized-bed zone 11 of the gasification reactor lying above can be seen here. It can be seen a first upper feeder 24 in the form of a nozzle or the like for example, a mixture of oxygen and steam, which is injected into the fluidized bed zone 11 of the gasification reactor. In the region of the cross-sectional constriction 13 provided between the two plant parts 11 and 12, a further central feed device 26 is arranged, via which in this case a mixture of recirculated raw gas and C0 ₂ from the gasification reactor is preferably supplied, which in this case supports the fluidization of the material to be gasified is used in the fluidized bed zone 11. A further lower nozzle 27 is provided, which is arranged on the outside of the additional fluidized-bed combustion chamber 12 and via which a supply of oxidant such as a mixture of oxygen and steam in the additional fluidized bed combustion chamber 12 can take place.

In the exemplary embodiment according to FIG. 2, a further lower nozzle 28 is arranged in the lower region of the additional fluidized-bed combustion chamber 12, via which in turn, for example, a mixture of recirculated raw gas from the gasification reactor and C0 ₂ can be injected into the additional fluidized-bed combustion chamber. In this way, one can fluidize the combustion residues / ash particles in the additional fluidized bed combustion chamber 12 and form a fluidized bed. To this nozzle 28, a line 29, in which a valve 30 is arranged, so that one can regulate the supply to the nozzle 28 and shut off or restrict, for example. This line 29 is connected to a line from which a branch line 31 leads, which leads to the nozzle 26, so that one can use a gas mixture from the gasification reactor, which is supplied by the latter via a common line for the fluidization in both parts of the plant, which then branches and leads to the nozzles 26 and 28, respectively. Also in the branch line 31, a valve 32 is arranged, so that one can shut off this branch line 27 separately, for example, if only one supply to the nozzle 28 is desired. Likewise, it is possible via another valve 35 to shut off the line before the branch of the branch line 31 or the supply of raw gas and C0 ₂ already there for both lines 29, 31 to regulate.

Furthermore, a temperature measuring device 33 is provided, by means of which one can measure the temperature in the additional fluidized bed combustion chamber 12. The measured temperature can be used to draw conclusions about the carbon content of the fuel in the combustion chamber 12, from which one then again calculates how much oxidizing agent has to be supplied to the combustion chamber 12 via the nozzle 27 to an optimum ratio of oxygen / carbon (preferably this is superstoichiometric).

Furthermore, a pressure difference measuring device 34 is provided in FIG. 2 which measures the respective pressure on the one hand in the fluidized bed zone 11 and on the other in the additional fluidized bed combustion chamber 12, wherein the pressure difference between the two values is determined and displayed. From this pressure difference one can conclude conclusions about the flow conditions in the cross-sectional constriction 13 between the two parts of the system. Depending on this, the supply of the fluid via the line 27 and the nozzle 26 can again be regulated in the region of the cross-sectional constriction 13, which takes place, for example, via the valve 32. In this way One can influence the degree of fluidization of the fluidized bed zone 11 by the recycled raw gas.

LIST OF REFERENCES

10 gasification reactor

11 fluidized bed zone

12 fluidized bed combustion chamber

13 cross-sectional constriction

14 feeder

15 valve

16 free board zone

17 connection line

18 cyclone separators

19 output line for synthesis gas

20 conveyor system / feed system

21 conical ending container

22 screw conveyor

23 return line

24 first top nozzle for oxidant feed

25 second middle nozzle

26 third middle nozzle

27 fourth lower nozzle

28 nozzle

29 line

30 valve

31 branch line

32 valve

33 temperature measuring device

34 pressure difference measuring device

35 valve

38 screw conveyors

39 pressure vessels

Claims

claims

1. Plant for the conversion of carbonaceous fuels in synthesis gas comprising a gasification reactor (10) having at least one fluidized bed zone (11), in which the gasification of the fuels by suitable gasification agent, wherein in a below the fluidized bed zone (11) arranged bottom region as a bottom product, a carbon-containing ash stream and wherein below the gasification reactor (10) is arranged a device in which takes place by supplying an oxidizing agent, an oxidation of the bottoms product, characterized in that as means for the oxidation of the bottoms product below the fluidized bed zone (11) of the gasification reactor (10) an additional fluidized bed -Brennkammer (12) is arranged.

2. plant for the conversion of carbonaceous fuels in synthesis gas according to claim 1, characterized in that the additional fluidized bed combustion chamber (12) via a cross-sectional constriction (13) with the fluidized bed zone (11) of the gasification reactor (10) is connected.

3. Plant for the conversion of carbonaceous fuels into synthesis gas according to claim 1 or 2, characterized in that at least one feed device (27) for the supply of oxygen and / or air and / or steam and / or C0 ₂ in the additional fluidized bed combustion chamber ( 12) is provided.

4. plant for the conversion of carbonaceous fuels in synthesis gas according to claim 3, characterized in that a temperature measuring device (33) for measuring the temperature in the additional fluidized bed combustion chamber (12) is provided.

5. Plant for the conversion of carbonaceous fuels in synthesis gas according to claim 3 or 4, characterized in that at least one control device (30, 35) is provided to the amount and / or the oxygen content of the at least one feed device (27, 28) in to control the additional fluidized bed combustor (12) injected oxygen and / or air and / or steam and / or C0 ₂ -containing fluid stream.

6. plant for the conversion of carbonaceous fuels in synthesis gas according to claim 5, characterized in that the control device with the temperature measuring device (33) is operatively connected to the amount and / or the oxygen content of the at least one feed device (27, 28) in the additional fluidized bed combustion chamber (12) injected oxygen and / or air and / or steam and / or C0 ₂ -containing fluid flow in dependence on the measured temperature in the additional combustion chamber (12) to regulate.

7. plant for the conversion of carbonaceous fuels in synthesis gas according to one of claims 3 to 6, characterized in that the feed device (28) is designed such that by the in the additional fluidized bed combustion chamber (12) injected oxygen and / or air and / or steam and / or C0 ₂ -containing fluid stream which is fluidized in the additional fluidized bed combustion chamber (12) to be burned bottom product.

8. Plant for converting carbonaceous fuels into synthesis gas according to one of claims 3 to 7, characterized in that the feed device (27, 28) at least one nozzle, preferably a multi-fluid nozzle for injecting a fluid mixture of at least two different oxidizing fluids in the additional combustion chamber ( 12).

9. Plant for converting carbonaceous fuels into synthesis gas according to one of claims 3 to 8, characterized in that the feed device (27, 28) at least one valve (30, 35) for shutting off and / or regulating the supplied oxidizing and / or fluidizing fluid flow assigned.

A plant for the conversion of carbonaceous fuels into synthesis gas according to one of claims 3 to 9, characterized in that it comprises at least two supply means (27, 28) for supplying differently composed oxidizing fluid streams, each supply means each comprising at least one valve (30, 35 ) is assigned to shut off and / or control of the respectively supplied oxidizing fluid flow.

A carbonaceous fuel conversion plant in synthesis gas according to any one of claims 1 to 10, characterized in that it comprises at least one pressure difference measuring device (34) and display device for detecting a pressure difference between the pressure in the fluidized bed zone (11) of the gasification reactor (10) and the pressure in the additional fluidized bed combustion chamber (12) to measure and display.

12. Plant for the conversion of carbonaceous fuels in synthesis gas according to one of claims 1 to 11, characterized in that at least one connecting line (29) for the return of raw gas from the gasification reactor (10) is provided, the at least portions of the generated raw gas stream back into the additional fluidized bed combustion chamber (12) leads into it.

13. plant for the conversion of carbonaceous fuels in synthesis gas according to one of claims 1 to 12, characterized in that at least one compressor for the Compression of recirculated raw gas from the gasification reactor (10) is provided in the additional fluidized bed combustion chamber (12).

14. A process for the conversion of carbonaceous fuels into synthesis gas in which in a gasification reactor (10) with at least one fluidized bed zone (11) gasification of the fuels is carried out by suitable gasification, wherein in a below the fluidized bed zone (11) arranged bottom region as a carbonaceous ash stream is obtained and wherein a device is arranged below the gasification reactor (10) in which oxidation of the bottoms product takes place by supplying an oxidizing agent, characterized in that the oxidation of the bottoms product is effected in an additional fluidized bed below the fluidized bed zone (11) of the gasification reactor (10). Combustion chamber (12) takes place.

15. The method according to claim 14, characterized in that in the oxidation of the bottom product in the additional fluidized bed combustion chamber (12) resulting flue gas is passed from the bottom into the gasification reactor (10) and serves there to fluidize the gasified Generate particles.

16. The method according to any one of claims 14 or 15, characterized in that a part of the gasification in the gasification reactor (10) generated raw gas from the gasification reactor via at least one connecting line (29) is fed back into the additional fluidized bed combustion chamber (12).

17. The method according to claim 16, characterized in that the recycled part of the gasification in the gasification reactor (10) generated raw gas before being introduced into the additional fluidized bed combustion chamber (12) is compressed by means of at least one compressor.

18. The method according to any one of claims 16 or 17, characterized in that the

The exit velocity of the bottoms product from the gasification reactor (10) into the underlying additional fluidized bed combustor (12) is preferably adjusted by means of the recycle gas flow such that only coarser particle size particles from the gasification reactor (10) into the underlying gas due to gravity get additional fluidized bed combustion chamber (12).

19. The method according to any one of claims 14 to 18, characterized in that the

Gasification of the fuels in the gasification reactor (10) at an operating pressure of at least about 10 bar.

20. The method according to any one of claims 14 to 19, characterized in that via at least one first feed device (27) in the additional fluidized bed combustion chamber (12) an oxidizing fluid flow is injected, which contains oxygen and / or air and / or vapor and A fluid stream containing C0 ₂ and / or recycled gas from the gasification reactor (10) is injected into the additional fluidized bed combustor (12) via at least one second feeder (28).

21. The method according to any one of claims 14 to 20, characterized in that one measures the temperature in the additional fluidized bed combustion chamber (12) and depending on the measured temperature, the oxygen content of the fluidized bed combustion chamber (12) supplied oxidizing agent sets accordingly.