Aftertreatment arrangement and method for the aftertreatment of at least gases downstream of a fluid bed gasification system, and logic unit and use.

Abstract

The invention relates to an aftertreatment arrangement (10) for the aftertreatment of at least gases downstream of a fluid bed gasification system, in particular downstream of an HTW gasifier (1) of a pressure-loaded fluid bed gasification system, having a particle separation unit (2; 11) which can be arranged downstream of the fluid bed gasification system and upstream of a gas cooler (3) that can be used for the further aftertreatment of the gases, wherein the aftertreatment arrangement comprises an intermediate cooling unit (12) which can be arranged downstream of the fluid bed gasification system and upstream of the particle separation unit (11), having a return (B1) for gasification vapor (B) that can be coupled to the fluid bed gasification system . The invention further relates to a method for the aftertreatment of at least gases downstream of a fluid bed gasification system and to the use of an intermediate cooling unit.

Description

[0001] The invention relates to an arrangement and a method for post-treating at least gases downstream of a fluidized bed gasification process, in particular downstream of an HTW gasifier. This post-treatment must include, in particular, particle separation and cooling. Furthermore, the invention also relates to the use of components for treating the gas in this arrangement. In particular, the invention relates to an arrangement and a method according to the preamble of the respective claim.

[0002] High-temperature fluidized bed gasification (HTW) according to Winkler is carried out at elevated pressure and can be described as pressurized fluidized bed gasification, particularly at pressures above 20 bar, at which point dust is discharged from the system. The original Winkler fluidized bed gasification, in contrast, was carried out at ambient pressure. HTW gasification can be advantageously used for a wide range of applications. Examples include: the production of synthesis gas, especially for products of the petrochemical industry; applications in power plants for electricity generation; and the gasification of biomass, municipal solid waste, or hard coal with a high ash content.

[0003] A recirculation cyclone is typically used in high-temperature gasification (HTW) processes. The raw gas, laden with particulate matter, is routed from the gasifier through the recirculation cyclone to a raw gas cooler. In many cases, the efficiency or effectiveness of dust separation in the recirculation cyclone is insufficient, particularly at high pressures or high gas densities due to the increased difficulty of particle separation. Therefore, one or more hot gas filters are installed downstream of the recirculation cyclone or raw gas cooler. However, this is not a particularly satisfactory solution. Due to insufficient particle separation, a high proportion of contaminants, especially carbon, accumulate in the hot gas filters. These contaminants cannot be easily recovered and must be recycled back into the process or disposed of separately using a complex process.In particular, the foreign substances that accumulate in the hot gas filter must be returned to the gasifier by means of a piping system (especially screw conveyors), or burned in separate boilers at great expense, for which the supply of auxiliary fuels is also sometimes necessary.

[0004] EP 1 201 731 A1 describes a fluidized bed gasifier with a first and second post-gasification zone, which, unlike conventional high-temperature gasifiers, uses a recirculation zone to allow all the ash to remain in the system. In a splash zone located above the fluidized bed zone, the dust load of the raw gas is reduced before it enters a cooling zone. Cooling is achieved by removing superheated steam to a temperature range preferably of 550 to 650 °C.

[0005] DE 10 2006 017 353 A1 describes a virtually pressureless process for process-integrated gas cleaning, in which intermediate cooling to 150 to 700 °C and dust removal take place in a so-called multicyclone and in a downstream battery of sintered metal filters.

[0006] DE 43 39 973 C1 describes a process for the gasification of waste materials.

[0007] US 4,474,583 A describes a process for gasifying solid carbon-containing fuels.

[0008] WO 00 / 71644 A2 describes an electricity-generating system by gasification.

[0009] EP 1 201 731 A1 describes a process for handling carbonaceous solids in a fluidized bed and suitable gasifiers for this purpose.

[0010] US 4,483,692 A describes a method for the recirculation of coal dust from a fluidized bed coal gasification reactor.

[0011] FR 2 493 333 A1 discloses a method and a device for coal gasification using coal dust.

[0012] CN 201 684 496 U a cleaning unit for coal gas from a steel melting furnace.

[0013] EP 0 659 462 A1 discloses a system for dust removal from exhaust gas.

[0014] However, existing processes cannot be satisfactorily used in many respects in connection with fluidized bed gasification, especially not for or in HTW gasification. Increased demands on efficiency, purity, and process flexibility necessitate the further development of existing plants and processes.

[0015] The object of the invention is to provide an arrangement and a method in connection with fluidized bed gasification, in particular high-temperature gasification (HTW gasification), with which different feedstocks can be advantageously treated in or after fluidized bed gasification, especially pressurized fluidized bed gasification (HTW process). In particular, the invention aims to enable the widest possible range of operating pressures. High economic efficiency and high operational reliability are also desirable, not least to ensure good practical applicability.

[0016] This problem is solved according to the invention by a post-treatment arrangement as set out in the appended claims. This provides high efficiency in general for fluidized bed gasification, and especially in conjunction with an HTW gasifier. Steam can be used directly as the gasification agent. In particular, the separation of foreign matter or dust can be carried out more effectively. Last but not least, a particularly high gasification efficiency can also be achieved. Furthermore, plant costs can be reduced, especially with regard to the operation of the hot gas filters and the screw conveyors (discharge screws) that are no longer required.

[0017] An arrangement "downstream of a fluidized bed gasification", in particular "downstream of an HTW gasifier", is to be understood as an arrangement behind the respective component in the direction of gas flow towards a synthesis gas outlet.

[0018] In the following, fluidized bed gasification and HTW gasification are used synonymously, and vice versa. The intermediate cooling unit is located directly downstream of the HTW gasifier, i.e., without any intermediate components or process steps.

[0019] The particle separation unit is arranged directly downstream of the intermediate cooling unit, i.e. without the interposition of further components or process steps.

[0020] An "output-side" arrangement is understood to be an arrangement in the material flow direction of soil products, i.e., in the direction of a plant component by means of which soil product or dust is discharged.

[0021] The post-treatment arrangement can also include components already used in an HTW process, e.g. the HTW carburetor and / or the raw gas cooler.

[0022] The particle separation unit is designed as a cyclone candle filter unit. This offers process engineering advantages, in particular enabling effective fine separation in downstream ceramic filters. The cyclone candle filter unit can be combined with the intermediate cooling unit as a single plant / process component.

[0023] According to one embodiment, the cyclone candle filter unit has a dust return system that is coupled to, or can be coupled to, the fluidized bed gasification or the HTW gasifier. This enables an efficient process. In particular, the advantage is that the cyclone candle filter unit can be used repeatedly as a type of pre-separator.

[0024] According to one embodiment, the post-treatment arrangement comprises a soil product oxidation chamber located / arrangable on the discharge side of the fluidized bed gasification or the HTW gasifier, in particular coupled / coupled to the HTW gasifier, and in particular configured for carbon conversion. This allows carbon to be reduced to such an extent that the soil product becomes suitable for landfill disposal, in particular with less than 4% carbon by weight.

[0025] According to one embodiment, the post-treatment arrangement comprises a soil product cooling unit arranged / arrangable on the discharge side of the fluidized bed gasification or the HTW gasifier, in particular arranged / arrangable on the discharge side of a soil product oxidation chamber or coupled / coupled to it.

[0026] In one embodiment, the cyclone spark plug filter unit and the intercooler unit are combined into a single unit. This allows for a wide temperature range to be covered. The combined unit can be located directly downstream of the HTW carburetor.

[0027] The aforementioned problem is also solved according to the invention by a method for post-treating at least gases (and optionally also for post-treating soil product) downstream or on the discharge side of a fluidized bed gasification or an HTW gasifier of a pressurized fluidized bed gasification, comprising a particle separation unit arranged directly downstream of the fluidized bed gasification or the HTW gasifier and directly upstream of a (raw) gas cooling unit usable for further post-treatment of the gases, wherein gas from the fluidized bed gasification is subjected to intermediate cooling upstream of the particle separation unit or is passed over at least one intermediate cooling unit, in conjunction with a return of gasification vapor from the intermediate cooling unit or an intermediate cooling unit back to the fluidized bed gasification, wherein the particle separation (11) is carried out by means of a cyclone candle filter unit, wherein the intermediate cooling is carried out at 640-660 °C.This can provide an advantageous procedure, in particular an economical and flexibly applicable procedure.

[0028] In this process, gasification vapor from the intermediate cooling stage is recycled back into the fluidized bed gasification stage, resulting in a high degree of flexibility with regard to process parameters. This also leads to a particularly compact design. Finally, a lock system is not required.

[0029] Intercooling is carried out to 640-660 °C, specifically from approximately 950 °C to 640-660 °C, or exactly 650 °C. This allows for simple coupling with a cyclone candle filter unit.

[0030] According to one embodiment, particle separation is carried out using a cyclone cartridge filter unit. This minimizes the load or stress on other filter units. The cyclone cartridge filter unit offers particular advantages for the entire process, especially in the process chain described here.

[0031] According to one embodiment, dust from the particle separation process is recycled back into the fluidized bed gasification process. This results in process engineering advantages.

[0032] According to one embodiment, soil product, particularly carbon, is oxidized on the discharge side of the fluidized bed gasification process. Soil product from the fluidized bed gasification or from the HTW gasifier is oxidized, particularly in an oxidation chamber located downstream of the HTW gasifier. This enables or facilitates the removal of the soil product to the landfill.

[0033] According to one embodiment, soil product cooling takes place on the discharge side of the fluidized bed gasification or the HTW gasifier, in particular on the discharge side of a soil product oxidation or a corresponding oxidation chamber. This results in the aforementioned advantages.

[0034] According to one embodiment, the gas downstream of the fluidized bed gasification or the HTW gasifier undergoes a series of processes: first intermediate cooling, then particle separation, and then (raw) gas cooling. This combination of processes results in a particularly flexible overall process, even when combined with a compact plant design.

[0035] According to one embodiment, synthesis gas is produced by passing gas from the fluidized bed gasification downstream of the (raw) gas cooling unit through at least one water scrubbing unit, a shift unit, and a desulfurization unit. This allows the process to be easily coupled with further post-treatment steps. The shift unit can be provided by a fixed bed with a catalyst. The previously used warm gas filter is no longer required, particularly thanks to the cyclone candle filter.

[0036] The procedure described above can advantageously be carried out using a previously described post-treatment arrangement.

[0037] The aforementioned problem is also solved according to the invention by using an intermediate cooling unit downstream of a fluidized bed gasifier or an HTW gasifier and upstream of a particle separation unit for gases from the fluidized bed gasifier, in conjunction with dust recirculation from the intermediate cooling unit back to the fluidized bed gasifier, particularly in synthesis gas production in a previously described post-treatment arrangement or in a previously described process. This results in the aforementioned advantages.

[0038] Further features and advantages of the invention will become apparent from the description of at least one embodiment with reference to the drawings, as well as from the drawings themselves. Reference numerals that are not explicitly described in relation to a single figure refer to the other figures. These figures are shown schematically. Fig. 1 shows an arrangement with an HTW gasifier in which gas is discharged downstream into a recirculation cyclone and into a soil product cooling screw, and Fig. 2 shows a post-treatment arrangement according to an embodiment incorporation downstream or on the discharge side of an HTW gasifier.

[0039] The Fig. 1 Figure 1 shows a high-temperature Winkler (HTW) gasifier 1, a recirculation cyclone (particle separator) 2 arranged downstream of it on a first gas flow path, a raw gas cooler 3, a hot gas filter 4, a water scrubber or water scrubber unit 5, a shift unit 6, a desulfurization unit 7, and, each downstream of the HTW gasifier 1 on a second or third gas flow path, a conveying device, in particular a screw conveyor 8, arranged once in the configuration as a cooling screw conveyor 8a for dust, and once in the configuration as a cooling screw conveyor 8b for soil product, further downstream of each of these, a discharge screw conveyor 8c, and finally a fluidized bed chamber 9.

[0040] Dust A is recirculated from particle separator 2 back to HTW gasifier 1 via a dust return system A1. Gasification vapor B, air, oxygen, CO2 (supply C), and fuel D are fed to HTW gasifier 1. Carbon-containing soil product E and carbon-containing dust F are fed to fluidized bed chamber 9. Synthesis gas G is discharged downstream of the desulfurization unit 7.

[0041] The Fig. 2 Figure 1 shows a post-treatment arrangement 10 with a particle separation unit 11, in particular designed as a cyclone spark plug filter unit. An intermediate cooling unit 12 is provided downstream of the HTW carburetor 1 and upstream of the cyclone spark plug filter unit 11.

[0042] Dust from the particle separation unit 11 is recirculated A back to the HTW gasifier 1. Gasification vapor B is supplied to the HTW gasifier 1, which can be returned from the intermediate cooling unit 12 via a return line B1. Air, oxygen, CO2 (supply C), and fuel D are also supplied to the HTW gasifier 1.

[0043] Downstream of the cyclone candle filter unit 11, which is arranged on a first gas flow path, are a raw gas cooler 3, a water scrubber or water scrubber unit 5, a shift unit 6, and a desulfurization unit 7. Synthesis gas G is discharged downstream of the desulfurization unit 7. A hot gas filter (reference numeral 4 in Fig. 1 ) is no longer needed. Thanks to the cyclone spark plug filter 11, a hot gas filter is no longer required.

[0044] Conveying devices, in particular screw conveyors, are not provided. Instead, downstream of the HTW gasifier 1, a soil product oxidation unit, or at least one oxidation chamber 13 for soil product, and a soil product cooling unit, or at least one soil product cooling unit 14, are arranged on a second gas flow path. Ash H is discharged downstream of the soil product cooling unit 14.

[0045] A logic unit 20 is coupled to at least the HTW carburetor 1, the particle separation unit 11, the intermediate cooling unit 12, the oxidation chamber 13 and / or the soil product cooling unit 14. Reference symbol list:

[0046] 1 Fluidized bed gasification with high-temperature Winkler (HTW) gasifier 2 Recirculation cyclone (particle separator) 3 (Raw) gas cooler or (raw) gas cooling 4 Hot gas filter 5 Water scrubber or water scrubbing unit 6 Shift unit or shift unit 7 Desulfurization unit or desulfurization unit 8 Conveying device, in particular screw conveyor 8a Cooling screw conveyor for dust 8b Cooling screw conveyor for soil product 8c Discharge screw conveyor 9 Fluidized bed chamber A; A1 Dust or dust recirculation B; B1 Gasification vapor or gasification vapor recirculation C Air, oxygen, CO2 D Fuel Ec-containing soil product F Gc-containing dust Synthesis gas H Ash 10 Post-treatment arrangement 11 Particle separation or particle separation unit, in particular cyclone candle filter unit 12 Intercooling or intercooling unit 13 Soil product oxidation or oxidation chamber for soil product 14 Soil product cooling or soil product cooling unit 20 Logic unit

Claims

1. Post-treatment arrangement (10) for the post-treatment of at least gases downstream of a fluidised bed gasification, in particular downstream of an HTW gasifier (1) of a pressurised fluidised bed gasification, with a particle separation unit (11) that can be arranged downstream of the fluidised bed gasification and upstream of a gas cooler (3) usable for further post-treatment of the gases; characterised in that the post-treatment arrangement comprises an intermediate cooling unit (12) that can be arranged directly downstream of the fluidised bed gasification and directly upstream of the particle separation unit (11), with a recirculation (B1) for gasification steam (B) that can be coupled to the fluidised bed gasification, wherein the particle separation unit (11) is designed as a cyclone candle filter unit, and wherein the intermediate cooling unit is configured to perform intermediate cooling to 640-660 °C.

2. Post-treatment arrangement according to claim 1, wherein the cyclone candle filter unit (11) has a dust recirculation (A1) that can be coupled to the fluidised bed gasification.

3. Post-treatment arrangement according to one of the preceding claims, wherein the post-treatment arrangement (10) comprises a bottom product oxidation chamber (13) that can be arranged on the discharge side of the fluidised bed gasification, in particular couplable to an / the HTW gasifier.

4. Post-treatment arrangement according to one of the preceding claims, wherein the post-treatment arrangement (10) comprises a bottom product cooling unit (14) that can be arranged on the discharge side of the fluidised bed gasification, in particular of the HTW gasifier (1), in particular arrangable on the discharge side of a / the bottom product oxidation chamber (13).

5. Post-treatment arrangement according to one of the preceding claims, wherein the particle separation unit (11) is combined with the intermediate cooling unit (12) into one unit.

6. Method for post-treating at least gases downstream of a fluidised bed gasification, in particular downstream of an HTW gasifier (1) of a pressurised fluidised bed gasification, comprising a particle separation (11) that can be arranged directly downstream of the fluidised bed gasification and directly upstream of a gas cooling (3) usable for further post-treatment of the gases; characterised in that gas from the fluidised bed gasification is subjected to intermediate cooling (12) upstream of the particle separation (11), in connection with a recirculation of gasification steam (B) from the intermediate cooling back to the fluidised bed gasification, wherein the particle separation (11) is carried out by means of a cyclone candle filter unit, and wherein the intermediate cooling is carried out to 640-660 °C.

7. Method according to claim 6, wherein dust (A) from the particle separation (11) is recirculated into the fluidised bed gasification, in particular into the HTW gasifier (1).

8. Method according to one of the preceding method claims, wherein oxidation of bottom product occurs on the discharge side of the fluidised bed gasification; and / or wherein bottom product cooling (14) occurs on the discharge side of the fluidised bed gasification, in particular on the discharge side of a / the oxidation (13) of bottom product.

9. Method according to one of the preceding method claims, wherein the gas downstream of the fluidised bed gasification is subjected in series first to the intermediate cooling (12), then to the particle separation (11), and then to a / the gas cooling (3).

10. Method according to one of the preceding method claims, wherein synthesis gas (G) is produced by passing gas from the fluidised bed gasification downstream of the gas cooling (3) through at least one water scrubbing unit (5), a shift unit (6), and a desulphurisation unit (7).

11. Method according to one of the preceding method claims, carried out by means of a post-treatment arrangement (10) according to one of the preceding claims.

12. Use of an intermediate cooling unit (12) downstream of a fluidised bed gasification, in particular downstream of an HTW gasifier (1) and upstream of a particle separation unit (11) for gases of the fluidised bed gasification, in connection with a recirculation of gasification steam (B1) from the intermediate cooling unit (12) back to the fluidised bed gasification, in the production of synthesis gas in a post-treatment arrangement (10) according to one of claims 1-5 or in a method according to one of claims 6-11.

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