DE102010028816A1 - Fluidized bed reactor useful for producing product gas from carbon-containing input materials via allothermal gasification comprises combustion chamber with first fluidized bed, reformer reactor with second fluidized bed and feeding device - Google Patents

Abstract

Fluidized bed reactor (10) for producing product gas from carbon-containing input materials via allothermal gasification comprises: a combustion chamber (100) with a first fluidized bed (104) for producing heat required for the allothermal gasification; a reformer reactor (200) for carrying out the allothermal gasification with a second fluidized bed (208); and a feeding device for the input materials to be gasified. The reformer reactor is at least partially immersed in the combustion chamber, and defines a flow channel passing through the first fluidized bed. Fluidized bed reactor (10) for producing product gas from carbon-containing input materials via allothermal gasification comprises: a combustion chamber (100) with a first fluidized bed (104) for producing heat required for the allothermal gasification; a reformer reactor (200) for carrying out the allothermal gasification with a second fluidized bed (208); and a feeding device for the input materials to be gasified, where the reformer reactor is at least partially immersed in the combustion chamber, and defines a flow channel passing through the first fluidized bed, and the second fluidized bed is circulated in the flow channel in a predetermined flow direction. An independent claim is also included for producing product gas from carbon-containing input materials via allothermal gasification using the fluidized bed reactor, comprising: (a) producing the pyrolysis gas through pyrolytic conversion of the carbon-containing input materials in the pyrolysis section of the flow path; (b) producing a circulating flow of the second fluidized bed along the flow path, where the circulating flow comprises the pyrolysis gas and the solids formed during the pyrolytic conversion; (c) producing the product gas in the reforming section by absorbing heat from the first fluidized bed; (d) separating the product gas and the solids in the cyclone; and (e) recycling the solids in the pyrolysis section, and discharging the product gas from the fluidized bed reactor.

Description

The present invention relates to a fluidized bed reactor for producing product gas from carbonaceous feedstocks by allothermic gasification and a corresponding method which is carried out with the aid of said fluidized bed reactor.

Due to the non-uniform use in the literature, definitions of some central terms are used. There are basically three options for the thermal utilization of biomass: combustion, pyrolysis and gasification. Against the background of the present invention, only the gasification will be discussed in more detail below. Gasification is a physico-chemical process in which a carbon support, referred to herein as a "carbonaceous feed", is converted to heat and a combustible gas by means of an oxygen-containing gasifier, referred to herein as a product gas and elsewhere as a syngas becomes. The main components of the product gas, the composition of which is highly dependent on the raw materials and the process, are carbon monoxide (CO), carbon dioxide (CO ₂ ), hydrogen (H ₂ ), methane (CH ₄ ), and water vapor (H ₂ O). Undesirable by-products are various tars and condensates, which are disadvantageous because they can lead to clogging and sticking of the technical equipment operated with the product gas. The conversion is done by heating, so that one speaks in the occurring reactions also of "heat-induced gasification reactions". The air ratio λ - which is defined as the ratio of the actually available air quantity (exact amount of oxygen) to the air quantity necessary for a stoichiometric, ie complete conversion - is 0 <λ <1 (combustion: λ ≥ 1, pyrolysis: λ = 0) ). The individual gasification reactions are partly exothermic, partly endothermic. A gasification is referred to as a total "allothermic" when the necessary heat is not provided as in an "autothermal" gasification taking place in a carburetor (partial) oxidation - ie by the exothermic gasification reactions - but the gasifier, here as a fluidized bed reactor is designated and formed, is supplied from the outside, as it is z. B. in the so-called heat pipe reformer, as he for example from the WO 00/77128 A1 is known, the case is. In the case of allothermal gasification, the next-to-last step is omitted in the sequence of drying → pyrolysis → oxidation → reduction (the "actual" gasification step) which is valid for almost all gasification processes. Depending on the (main) gasification agent, the gaseous reactant (oxidizing agent) of the substance to be gasified, which introduces free or bound oxygen into the process, a distinction is made between hydrogenating gasification and steam gasification (water vapor as gasification agent). The allothermal steam gasification is also referred to here as reforming, which takes place here in a reformer reactor.

In the reduction - which, as already mentioned above, "actual" gasification step - the combustion products resulting from the oxidation of carbon dioxide (CO ₂ ) and water (H ₂ O) are reduced. Mainly in this case the so-called Boudouard reaction (1) and the heterogeneous water gas reaction (2) take place, which are coupled together: C + CO ₂ ↔ 2CO (1) C + H ₂ O ↔ CO + H ₂ (2)

The process of fluidized bed gasification carried out with the aid of the above-mentioned fluidized bed reactor is particularly suitable for reforming, since due to the high heat transfer rates, large amounts of heat can be transferred from heat sources through heating surfaces into the heat sink of the fluidized bed gasification chamber. The method of the above-mentioned heat pipe reformer, which comprises a combustion chamber and a gasification chamber (part of the reformer reactor) connected thereto via a heat pipe, uses the principle of heat transfer to heating surfaces in the respective fluidized beds Heat transport from the combustion fluidized bed to the gasification fluidized bed optimally.

The present invention is based on a "fluidized bed reactor for the production of product gas from carbonaceous feedstocks" (reference 10 2009 030 543.2-41) described in a previously unpublished application of the same applicant, which has a combustion chamber with a first fluidized bed for generating allothermal gasification necessary heat and a reformer reactor for carrying out the allothermal gasification with a second fluidized bed and a feed device for the task of the feedstock to be gasified, wherein the reformer reactor at least partially extends into the combustion chamber. The disadvantage here is that drying, heating, pyrolysis and reforming of the starting materials takes place simultaneously and therefore incomplete, since the fluidized bed by the effect of the stirred tank homogenizing effect on the temperatures and the gas quality, with the result that the product gas processed at the outlet with incomplete Substances is mixed.

It is therefore an object of the present invention to provide a fluidized bed reactor and a process for producing a product gas to provide carbonaceous feedstocks, wherein the quality of the product gas is increased by a comparison with the prior art improved design or process control.

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

According to the present invention, a fluidized bed reactor for producing product gas from carbonaceous feedstocks by allothermic gasification comprises a combustor having a first fluidized bed for generating the heat necessary for allothermal gasification, a reformer reactor for carrying out the allothermal gasification with a second fluidized bed and a feeder Task of the starting materials to be gasified, wherein the reformer reactor defines a flow channel passing through the first fluidized bed, in which circulates the second fluidized bed in a predetermined flow direction. The spatial relationship between the combustion chamber and the reformer reactor reflected in these features proves to be advantageous because it allows the overall height of the fluidized bed reactor to be reduced. It has the further advantage that an optimum heat transfer between the combustion chamber and the reformer reactor is possible almost loss-free, where the combustion chamber and the reformer reactor penetrate, that is, the flow channel of the second fluidized bed passes through the first fluidized bed. Because the construction of the invention requires in contrast z. B. to constructions whose heat transfer in the gasification chamber based solely on heat pipes, no heat transfer medium; the heat transfer takes place directly over the boundary surfaces of the flow channel. In other words: at the same height as z. For example, a heat pipe reformer allows direct heat transfer between both fluidized beds to increase the power of the fluidized bed reactor by a factor of 2.5 to 3. As defined in claim 1, the second fluidized bed "circulates" along the flow channel, forming one the so-called "circulating fluidized bed" (CFB), which has the advantage that the substance to be gasified in the reformer reactor (hereinafter referred to as "gasification substance" in analogy to the "fuel" converted in the combustion chamber), is in addition to the bed material part of the second fluidized bed, a non-gassed at a first circulation share the flow channel again, so that the efficiency of the gasification is increased. According to claim 1, the reformer reactor further comprises a supply device for the gasification substances. Since the task of the gasification substances takes place on hot bed material, the gasification material dries quickly and pyrolysis begins a short time after the task.

According to an advantageous embodiment according to claim 2, the flow channel comprises a reforming section, which is arranged within the combustion chamber, and a pyrolysis section. This means, first, that according to the invention, the above-mentioned process steps of pyrolysis and reforming (i.e., the "actual" gasification in the sense of a chemical reduction) are advantageously arranged spatially separated along the flow channel. This spatial separation is particularly effective and the reactions taking place in each case can be controlled particularly well independently of each other, if - as it is defined in an advantageous embodiment according to claim 12 - the pyrolysis section is arranged outside the combustion chamber. Spatial separation has a positive effect on gas quality (less tars), performance, excess vapor (which is lower) and carbon turnover.

According to an advantageous embodiment of claim 3, the pyrolysis section comprises a gasification chamber into which the feed device opens. This has the advantage that one can use fuel, taking advantage of gravity, dropped on the surface of the pyrolysis fluidized bed, so you do not need a mechanical feeder. The risk of burnback that may be caused by this can be eliminated by a simple purge gas device.

According to an advantageous embodiment of claim 4, the flow channel comprises a main flow channel in which the second fluidized bed is conveyed in the flow direction through a downcomer from a cyclone to the gasification chamber, the cyclone being located above the gasification chamber. Since the "cycle of transformation" begins in the gasification chamber, the following arrangement of components of the fluidized bed reactor is thereby defined along the (closed) flow channel: gasification chamber → cyclone → downpipe → gasification chamber. For a closed flow channel to be present, it follows from this arrangement that the second fluidized bed moves upwards in the reforming section to the cyclone. During the upward movement, the second fluidized bed absorbs heat from the surrounding fluidized bed, which is required for reforming the already partially reacted substances contained therein. The cyclone, a centrifugal separator, serves to separate solid particles of the second fluidized bed, which are conveyed down through the downcomer, and the product gas, which is discharged from the fluidized bed reactor for further use. That is, the product gas will come in contact with solids (ash, coke, Bed material) into tangential inlets of the cyclone which directs the solids into the downcomer and the product gas via a suitable outlet to the outside for further use. The pyrolysis residues are kept in the cyclic process (see above) and gasified or ground until they are smaller than the marginal grain of the cyclone. Blocking of the processes by too large Vergasungsstoff pieces is thus largely excluded.

According to an advantageous embodiment of claim 5, the gasification chamber is formed as a flow distributor and the flow channel comprises n Nebenströmungskanale in which the second fluidized bed is transported by n risers from the gasification chamber to the cyclone, where n> 1. The section of the flow channel leading from the gasification chamber to the cyclone arranged above the second fluidized bed is thus an arrangement formed by the fluidic connection of n riser pipes, n flow channels being realized by the n riser pipes. Each of the n riser pipes passes through the first fluidized bed and receives from it the heat required to reform the part of the second fluidized bed flowing in it. In this way, the heat transfer available separation surface (pipe wall) between the first and second fluidized bed is increased and thus increases the efficiency.

According to an advantageous embodiment according to claim 6, at least one connected to the gasification chamber end portion of each of the riser pipes is disposed within the combustion chamber. This has the advantage that the part of the second fluidized bed, which flows from the gasification chamber into the n riser pipes, is preheated by utilizing the high temperatures prevailing in the combustion chamber before it enters the reforming section, so that the conversion efficiency is increased.

According to an advantageous embodiment according to claim 7 (a), the end sections of the risers each contain a siphon section, (b) the gasification chamber is connected to a first fluidization device and each riser is connected to a second fluidization device in the region of its siphon section, and (c ), the cyclone is connected to a product gas line for discharging the product gas. Advantageously, therefore, at least the respective end portion of each riser connected to the gasification chamber passes through the combustion chamber and then merges into the siphon portion, which in turn merges into the upwardly leading portion of the riser, referred to below as the "vertical pipe section". The siphon section can be arranged partially or completely outside the combustion chamber. The second fluidization device, whose purpose is to put the second fluidized bed in a circulating movement along the flow channel of the reformer reactor, works this purpose depending on the type of coupling of the second fluidizing in the riser and its constructive interpretation so far as the fluidizing agent also a force driving the second fluidized bed back into the gasification chamber is applied thereto. The design of the siphon section, whose function can be compared with a check valve, helps to minimize or even ideally prevent this counteracting effect. Advantageously, at least one lowermost end of the siphon section (in the mathematical sense the area around the minimum of the U-shaped siphon section) protrudes downwards out of the bottom of the combustion chamber so that the siphon section in this area projects easily with the second fluidization device can be connected.

According to an advantageous embodiment according to claim 8, the longitudinal axis of the drop tube is a vertically oriented n-fold symmetry axis about which the n risers are arranged symmetrically, and the mouth points of the risers are arranged at intervals of 360 ° / n on a circle whose center on the n-fold symmetry axis lies. It should be noted that the count of the axis of symmetry, of course, refers only to the arrangement of the riser pipes, not to any cross-sectional area of the downer itself, which may be basically arbitrary, preferably circular. Due to the n-fold symmetry of the riser arrangement, a uniform penetration of the combustion chamber through the reformer reactor is achieved, so that the heat transport from the combustion chamber into the individual riser pipes does not lead to excessive local cooling of the combustion chamber or of the first fluidized bed. In addition, a symmetrical arrangement of the riser tubes is also preferable for the further process control - in particular with regard to the flow of the second fluidized bed (conveying the second fluidized bed from the gasification chamber into the riser tubes, inflow of the second fluidized bed into the cyclone, etc.) ,

According to an advantageous embodiment of claim 9 (a), the gasification chamber is in the form of a right circular cylinder whose axis of symmetry coincides with the n-fold axis of symmetry, (b) the fluidized bed reactor comprises a blind tube whose axis of symmetry coincides with the n-fold symmetry axis and protrudes with its open end from below into the gasification chamber, so that in the gasification chamber, an annular space is formed around the sack tube, and (c) is located in the operation of the fluidized bed reactor, the open end below the Surface of the first fluidized bed. From (a) and (b) follows the symmetrical arrangement of main components of the fluidized bed reactor, namely the gasification chamber, the blind tube and the n riser tubes to each other or better "into each other". From (c) at least two advantageous alternatives of the relative spatial arrangement of the first and second fluidized bed result: The individual siphon sections are located completely within or at least partially outside the first fluidized bed. In the first case, the sack tube and the siphon sections are advantageously bypassed during operation of the fluidized bed reactor by the first fluidized bed, so that an optimal heat transfer is ensured by the first to the second fluidized bed. In this case, there is preferably a predetermined distance between a bottom of the combustion chamber and the respective lower ends of the sack tube and the siphon sections, and the bottom of the combustion chamber has - preferably uniformly distributed - inlet openings for the fluidizing means of the first fluidization device for fluidizing the first fluidized bed , Supply lines for the fluidizing means of the second fluidizing device for fluidizing the second fluidized bed in this case penetrate the first fluidized bed. The second case, however, when the individual siphon sections are at least partially outside the combustion chamber, offers the advantage of easier accessibility to the siphon sections and the sack tube, but this is due to a lower warming of the siphon sections than in the first case. Sections flowing through the second fluidized bed and larger sealing problems is purchased. The bottom of the combustion chamber is penetrated in the first case by the second fluidization device and in the second case by the flow channel (the siphon sections), so that the penetration points have to be correspondingly dense. It should be noted that the lower ends of the siphon sections need not be level with the lower end of the sack tube, which may result in structural and / or procedural advantages, and may result in hybridizing the first and second alternatives described above.

According to an advantageous embodiment according to claim 10, the fluidized bed reactor comprises a heat pipe arrangement with at least one heat pipe whose heat-emitting end portion extends into the second fluidized bed. The effective transfer of heat by means of heat pipes (heat pipes), here from a first fluidized bed of a combustion chamber into a second fluidized bed of a gasification chamber, is well known, in particular for example from US Pat DE 10 2006 016 005 A1 the applicant of the present invention, where the heat pipes are used in the above-mentioned heat pipe reformer. By exploiting the high temperatures in the combustion chamber to heat the second fluidized bed can be completely dispensed with a separate heating of the gasification chamber ideally, but it can at least be dimensioned smaller and the fluidized bed reactor thus made more compact.

According to an advantageous embodiment according to claim 11, the longitudinal axis of the at least one heat pipe is parallel to the n-fold axis of symmetry, and the at least one heat pipe penetrates the gasification chamber between the blind tube and the n siphons. Advantageously, the cross-sectional areas - ideally circular areas - the entry points of the siphon sections in the gasification chamber equidistant on a first circle with a radius r ₁ and the at least one heat pipe on a concentric to the first circle second circle with a radius r ₂ , wherein r ₂ <r ₁ , and the longitudinal axis of the blind tube passes through the centers of the two circles. However, it is any other - but, as already mentioned above, preferably symmetrical - arrangement of these components possible as long as the heat pipes from the first fluidized bed in the second fluidized bed is transported and the functions of the fluidized bed reactor according to the invention are ensured with sufficient efficiency.

It should be noted that in all cases where a dichotomous description is given above, e.g. B. if the gasification chamber is either inside or outside the combustion chamber, the cases defined thereby are to be understood as limiting cases that do not exclude intermediate solutions in principle - the latter may even be advantageous - as long as the overall function of the fluidized bed reactor according to the invention is ensured.

According to the present invention, a process for producing product gas from carbonaceous feedstocks by allothermic gasification by means of the fluidized bed reactor of any one of claims 1 to 12 comprises the steps of: generating pyrolysis gas by pyrolytic reaction of the carbonaceous feedstocks in the pyrolysis section of the flowpath; Generating a circulating flow of the second fluidized bed containing the pyrolysis gas and solids resulting from the pyrolytic reaction along the flow path; Generating the product gas in the reforming section by absorbing heat from the first fluidized bed; Separating the product gas and the solids in the cyclone; and returning the solids to the pyrolysis section and removing the product gas from the fluidized bed reactor. The advantages of the method according to the invention will become apparent from the above description of the fluidized bed reactor of this embodiment according to the invention.

The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description made with reference to the accompanying drawings. In the drawings are:

1 a schematic sectional view of a fluidized bed reactor according to a first embodiment of the present invention (variant 1);

2 a schematic sectional view of a fluidized bed reactor according to a second embodiment of the present invention (variant 1);

3 a schematic sectional view of a fluidized bed reactor according to a third embodiment of the present invention (variant 1);

4 a schematic sectional view of a fluidized bed reactor according to a fourth embodiment of the present invention (variant 1); and

5 a schematic sectional view of a fluidized bed reactor according to a fifth embodiment of the present invention (variant 1).

First Embodiment

1 shows a schematic sectional view of a fluidized bed reactor 10 according to a first embodiment of the present invention. The fluidized bed reactor 10 includes a combustion chamber 100 and a reformer reactor 200 Partially into the combustion chamber 100 extends.

The combustion chamber 100 includes a container 102 formed in the form of a right circular cylinder with a first axis of symmetry A, and in which - in 1 in the operating state of the fluidized bed reactor 10 shown - a first fluidized bed 104 has trained. The first fluidized bed 104 extends from a floor 106 up to a height h1 of 5 m, to give an example of an order of magnitude. In the ground 106 inlet openings (not shown) are arranged for a combustion chamber fluidizing means, which by means of a combustion chamber fluidizing device (not shown) for generating the first fluidized bed 104 through the inlet openings in the combustion chamber 100 is initiated.

The reformer reactor 200 can be functional in a pyrolysis section 202 according to the embodiment outside the container 102 is arranged, and a reforming section 204 that is inside the container 102 The chemical reactions to which this is notionally referenced are more spatially separated by a transition "region" and, strictly speaking, an exact boundary can not be specified. The reformer reactor 200 also has an n-fold symmetry with respect to a symmetry axis B which is in alignment with the axis of symmetry A, which is described in more detail below. Structurally includes the reformer reactor 200 a gasification chamber 206 with a - in 1 in the operating state of the fluidized bed reactor 10 shown - second fluidized bed 208 , n risers 210 (of which in 1 only two are shown), each containing the gasification chamber 206 with a cyclone 212 connect, and a downpipe 214 that is different from the cyclone 212 extends vertically downwards and with its lower end in the second fluidized bed 208 empties. The n risers 210 are at angular intervals of α = 360 ° / n between each two adjacent of the n risers 210 arranged so that a rotation of the reformer reactor 200 about its axis of symmetry B by a multiple of the angle α this again transferred to itself (n-fold symmetry). As it is in 1 shown includes each of the risers 210 a generally V- or U-shaped siphon section formed from one of the gasification chamber 206 down leading section 216 and a subsequent leading to this section 218 is formed. In the area of the transition from the section 216 to the section 218 each of the n risers 210 are inflow openings 220 for a riser fluidizing means, which by means of a second fluidizing means (not shown) of the reformer reactor 200 for the circulation of the second fluidized bed 208 in the n riser pipes 210 is initiated. The second fluidized bed 208 flows out of the gasification chamber 206 in that it was generated by means of a first fluidizing device (not shown) by introducing a gasification chamber fluidizing means and from where it penetrates downwardly into the sections 216 enters the sphere of action of the riser fluidizing agent. To generate and maintain the in the reformer reactor 200 circulating second fluidized bed thus serve n + 1 fluidizing means, one of them with the gasification chamber 206 and the others each with one of the n risers 210 connected is. According to the embodiment, the leading portions are 218 the n risers each with a parallel to the axes A, B extending vertical pipe section 222 of the reforming section 204 connected in one piece and seamlessly. The vertical pipe sections 222 in turn lead into respective horizontal pipe sections 224 that in the cyclone 212 lead. The cyclone 212 thus comprises n fluidized bed inlets for introducing the second fluidized bed 208 over the n horizontal pipe sections 224 the n risers, a solids outlet 226 , which comes with a top end of the downpipe 214 connected, and a product gas outlet 228 , about which through the cyclone 212 from the second fluidized bed 208 separate product gas for further use to the outside of the fluidized bed reactor 10 is dissipated. The product gas outlet 228 one penetrates the ground 106 opposite cover 230 of the container 102 ,

In operation of the fluidized bed reactor 10 according to the first embodiment is in the container 102 by introducing the combustor fluidizing means, the first fluidized bed 104 generated. The first fluidized bed 104 consists of a mixture of a bed material, for example quartz sand, and a suitable fuel, which is contained in the container 102 the combustion chamber 100 is exothermally converted by means of the oxygen contained in the combustion chamber fluidizing agent. Part of the heat generated in the conversion of the fuel is applied to the riser pipes 210 , more precisely their vertical pipe sections 222 , and the downpipe 214 transfer. By introducing the first fluidizing agent into the gasification chamber 206 becomes in this the second fluidized bed 208 generated. The second fluidized bed 208 consists of a mixture of a bedding material, for example quartz sand, and a suitable gasification material placed in the gasification chamber 206 and the sections adjacent in a flow direction v 216 . 218 . 222 and 224 of each of the n risers 210 So, on the way from the gasification chamber 206 to the cyclone 212 is converted as completely as possible allothermic into the product gas. The cyclone 212 , a centrifugal separator, thus separates the second fluidized bed 208 ideally in a gaseous fraction consisting of the product gas and via the product gas outlet 228 is derived to the outside, and a solid fraction from that in the second fluidized bed 208 Also included bedding material and the downpipe 214 in the gasification chamber 206 is returned. In the real case, however, not all the gasification material is completely converted; Residues of it that have not been converted, therefore, together with the bed material in the gasification chamber 206 returned and go through the cycle again.

Second Embodiment

2 shows a schematic sectional view of a fluidized bed reactor 10 according to a second embodiment of the present invention. The fluidized bed reactor 10 again comprises - for reasons of uniformity and better understandability with the same reference numerals as provided in the first embodiment - a combustion chamber 100 with a first fluidized bed 104 and a reformer reactor 200 with a second fluidized bed 208 passing along one in the reformer reactor 200 trained flow channel circulates.

The essential difference of the second embodiment from the first embodiment is the arrangement of the entire reformer reactor 200 including its gasification chamber 206 , inside the combustion chamber 100 and the replacement of the n risers 210 by a functionally equivalent tube arrangement of an inner tube 232 and an outer tube 234 , As it is in 2 is shown by the in the direction of the axes A, B overlapping and concentric to this arranged tubes 232 . 234 a closed flow channel for the circulating second fluidized bed 208 formed on which the second fluidized bed 208 from in the form of the inner tube 232 trained gasification chamber 206 via an inner annular gap 236 that between the inner tube 232 and the outer tube 234 is formed, an outer annular gap 238 that is between the outer tube 234 and a cylindrical outer wall 240 the reformer reactor 200 is formed, the cyclone 212 and the downpipe 214 into the inner tube 232 is returned. The inner annular gap 236 and the part of the outer annular gap 238 extending from a cylindrical outer wall 240 down in 2 final floor 242 the reformer reactor 200 up to an upper end of the inner tube 232 extends corresponds to the downward leading section 216 or the leading section 218 the first embodiment. Analogous to the first embodiment are inlet openings 220 for introducing the riser fluidizing means by means of the second fluidizing means (not shown) in the region of the transition from the inner annular gap 236 to the outer annular gap 238 and inflow ports for introducing the gasification chamber fluidizing means by means of the first fluidizing means (not shown) below the inner tube 232 in the ground 242 arranged. As it is in 2 is shown is the entire reformer reactor 200 , z. B. via a suitable flange, suspended in the combustion chamber 100 arranged so that between the cylindrical outer wall 240 and the container 102 the combustion chamber 100 an annular gap 244 is trained.

As it is in 2 is shown, the reformer reactor 200 a gasification feed port 246 on top of the horizontal pipe section 224 interspersed. The over the gasification material feed opening 246 supplied gasification substance preferably falls in the inner annular gap 236 , whose unreacted residues then only after passing through the flow channel in the gasification chamber 206 (the inner tube 232 ) reach.

As it is in 2 shown can be the temperature in the gasification chamber 206 on the one hand be increased by the fact that heat from the combustion of the fuel in the combustion chamber 100 (ie in the first fluidized bed 104 ) results, from there into the gasification chamber 206 is transferred, and on the other hand be increased by that heat over heat pipes 248 whose heat-dissipating end portion is in the second fluidized bed 208 extends, from an external heat source in the gasification chamber 206 or the second fluidized bed 208 is transmitted. This alternative is in 2 just sketched. The heat source may be considered "external" to the fluidized bed reactor 10 or as "external" to the reformer reactor 200 to be viewed as. In the latter case, the first fluidized bed 104 serve as the external heat source.

Third Embodiment

3 shows a schematic sectional view of a fluidized bed reactor 10 according to a third embodiment of the present invention. The third embodiment is different from that in FIG 2 shown second embodiment in that the inner tube 232 (including the bottom section bounding this down 250 of the soil 242 ) so far relative to bem other soil 242 shifted downwards, that it is in the first fluidized bed 104 extends, and secondly, that heat pipes 248 with its heat receiving end portion through the bottom portion 250 in the first fluidized bed 104 stand out from this heat in the gasification chamber 206 (the inner tube 232 ) to transport. In this way, compared with the second embodiment, a height difference ΔH between a height of the surface of the second fluidized bed 208 in the gasification chamber 206 (which is equal to the height of the inner tube 232 formed gasification chamber 206 itself) and a height of the second fluidized bed 208 in the downpipe 214 to and the height of the inner annular gap 236 from. However, the amount of the height difference ΔH has no particular effect on the function of the fluidized bed reactor 10 so that neither a particularly high nor a particularly low would be desirable and desirable; the various "fluid levels" or surfaces of the respective fluidized beds only reflect the pressure ratios that correspond to the principle of communicating tubes in the fluidized bed reactor 10 to rule.

Fourth Embodiment

4 shows a schematic sectional view of a fluidized bed reactor 10 according to a fourth embodiment of the present invention. The fourth embodiment includes structural elements of the first and third embodiments, and thus may be construed as a combination of these embodiments. The fluidized bed reactor 10 includes a reformer reactor 200 whose structure is very similar to that of the first embodiment. In particular, the reformer reactor comprises 200 the fourth embodiment n risers, each one with the gasification chamber 206 connected, down leading section 216 in an area where the inflow openings 220 are arranged in the upwardly leading section 218 which in turn merges seamlessly into the vertical pipe section 222 and finally the horizontal pipe section 224 that in the cyclone 212 flows, passes, embraces. As in the first embodiment, the sections leading from the respective down and up are 216 . 218 n formed siphon sections of the reformer reactor 200 at regular angular intervals of 360 ° / n around the gasification chamber 206 arranged. In contrast to the first embodiment, however, according to the fourth embodiment, the pyrolysis section is located 202 , and not the reforming section 204 within the first fluidized bed 104 , where the boundaries between the pyrolysis section 202 and the reforming section 204 although this is not exactly to be specified, rather by the surface of the first fluidized bed 104 as through the ground 106 the combustion chamber 100 (first embodiment), by which a temperature profile is generated.

Compared to the third embodiment extends in the in 4 shown fluidized bed reactor 10 the outer tube 234 the reformer reactor 200 up to its bottom 242 , and the gap 238 between the outer tube 234 and the cylindrical outer wall 240 in which according to the third embodiment, the second fluidized bed 208 up to the cyclone 212 is transported through the n risers 210 replaced. Further, according to the fourth embodiment, the reformer reactor emerges 200 so far in the first fluidized bed 104 one that the surface of the first fluidized bed 104 higher than that of the second fluidized bed 208 is. In this construction, the desired flow direction is the second fluidized bed 208 , in the 4 represented by arrows, linked to a geometric condition: the annular surface A _{2 of} the second fluidized bed 208 in the inner annular gap 236 must be much larger than the annular surface A _{1 of} the second fluidized bed 208 between the downpipe 214 and the gasification chamber 206 : A ₂ >> A ₁ .

Fifth Embodiment

5 shows a schematic sectional view of a fluidized bed reactor 10 according to a fifth embodiment of the present invention. The fifth embodiment differs from the fourth embodiment only in that the temperature in the gasification chamber 206 not only over the cylindrical outer wall 240 , but also via heat pipes 248 , whose heat-absorbing end portions in the first fluidized bed 104 the combustion chamber 100 protrude, is increased.

Although the present invention has been disclosed in terms of the preferred embodiments in order to facilitate a better understanding thereof, it should be understood that the invention can be embodied in various ways without departing from the scope of the invention. Therefore, the invention should be understood to include all possible embodiments and embodiments to the illustrated embodiments which can be practiced without departing from the scope of the invention as set forth in the appended claims. This means in particular that the position of the gasification chamber (inside or outside the first fluidized bed), the return of the second fluidized bed (in risers or otherwise), the arrangement of the riser pipes (uniform or irregular), the temperatures of the individual fluidized beds used Fluidizing agents, etc. can be adapted to the chemical reaction to be performed in the fluidized bed reactor and / or the technological boundary conditions and are not limited to those described above, as long as the scope defined in the claims is not exceeded.

LIST OF REFERENCE NUMBERS

10

Fluidized bed reactor

100

combustion chamber

102

Container of 100

104

first fluidized bed

106

Ground of 102

200

Reforming reactor

202

pyrolysis section

204

reforming section

206

gasification chamber

208

second fluidized bed

210

risers

212

cyclone

214

downspout

216

down leading section

218

leading section

220

inflow

222

vertical pipe section

224

horizontal pipe section

226

Solids outlet

228

Product gas outlet

230

Cover of 102

232

inner tube

234

outer tube

236

inner annular gap

238

outer annular gap

240

cylindrical outer wall

242

Ground of 200

244

annular gap

246

Gasification material feed opening

248

heat pipes

QUOTES INCLUDE IN THE DESCRIPTION

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Cited patent literature

• WO 00/77128 A1 [0002]
• DE 102006016005 A1 [0017]

Claims (14)

Fluidised bed reactor for producing product gas from carbonaceous feedstocks by allothermic gasification, with: A combustion chamber with a first fluidized bed for generating the heat necessary for the allothermal gasification, A reformer reactor for carrying out the allothermal gasification with a second fluidized bed and a feed device for discharging the feedstocks to be gasified, - wherein the reformer reactor is at least partially immersed in the combustion chamber, and - wherein the reformer reactor defines a first fluidized bed passing through the flow channel in which circulates the second fluidized bed in a predetermined flow direction. Fluidized bed reactor according to claim 1, characterized in that the flow channel comprises a reforming section, which is arranged within the combustion chamber, and a pyrolysis section. Fluidized bed reactor according to claim 2, characterized in that the pyrolysis section comprises a gasification chamber into which the feed device opens. Fluidised bed reactor according to claim 3, characterized in that: - The flow channel comprises a main flow channel in which the second fluidized bed is conveyed in the flow direction through a downpipe from a cyclone to the gasification chamber; in which - The cyclone is located above the gasification chamber. Fluidized bed reactor according to claim 4, characterized in that the gasification chamber is formed as a flow distributor and the flow channel comprises n Nebenströmungskanäle in which the second fluidized bed is conveyed by n risers from the gasification chamber to the cyclone, where n> 1. A fluidized bed reactor according to claim 5, characterized in that at least one end portion connected to the gasification chamber of each of the riser tubes is disposed within the combustion chamber. Fluidised bed reactor according to claim 6, characterized in that: The end sections of the riser pipes each contain a siphon section; - The gasification chamber is connected to a first fluidizing means and each riser in the region of its siphon portion with a second fluidizing means; and - The cyclone is connected to a product gas line for the discharge of the product gas. Fluidized bed reactor according to claim 6 or 7, characterized in that the longitudinal axis of the drop tube is a vertically oriented n-fold symmetry axis about which the n riser tubes are arranged symmetrically, and the mouth points of the riser tubes are arranged at intervals of 360 ° / n on a circle whose center lies on the n-fold symmetry axis. Fluidized bed reactor according to claim 8, characterized in that - The gasification chamber is designed in the form of a right circular cylinder whose axis of symmetry coincides with the n-fold axis of symmetry; - The fluidized bed reactor comprises a blind tube whose axis of symmetry coincides with the n-fold axis of symmetry and which projects with its open end from below into the gasification chamber, so that in the gasification chamber, an annular space is formed around the blind tube; and - During operation of the fluidized bed reactor, the open end is below the surface of the first fluidized bed. Fluidized bed reactor according to one of claims 1 to 9, characterized in that it comprises a heat pipe arrangement with at least one heat pipe whose heat-emitting end portion extends into the second fluidized bed. Fluidized bed reactor according to claim 10, characterized in that the longitudinal axis of the at least one heat pipe is parallel to the n-fold axis of symmetry and the at least one heat pipe penetrates the gasification chamber between the blind tube and the n siphons. Fluidized bed reactor according to one of claims 1 to 11, characterized in that the allothermal gasification is an allothermic hydrogen gasification. A method for producing product gas from carbonaceous feedstocks by allothermic gasification using the fluidized bed reactor of any of claims 1 to 12, the method comprising the steps of: - producing pyrolysis gas by pyrolytic reaction of the carbonaceous feedstocks in the pyrolysis section of the flowpath, - generating a circulating Flow of the second fluidized bed, containing the pyrolysis gas and solids produced in the pyrolytic reaction, along the flowpath, Producing the product gas in the reforming section by absorbing heat from the first fluidized bed, separating the product gas and the solids in the cyclone, and returning the solids to the pyrolysis section and discharging the product gas from the fluidized bed reactor. A method according to claim 13, characterized in that the allothermic gasification is an allothermic hydrogen gasification.

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