EP3060632A1

EP3060632A1 - Method and plant for gasifying input material

Info

Publication number: EP3060632A1
Application number: EP14781446.1A
Authority: EP
Inventors: Thomas Heidrich; Gerald GAUBE; Jens Buschmann
Original assignee: Linde GmbH
Current assignee: Linde GmbH
Priority date: 2013-10-22
Filing date: 2014-10-07
Publication date: 2016-08-31
Also published as: DE102013017546A1; WO2015058837A1; AU2014339350A1; CN105899647A; US20160244327A1

Abstract

The invention relates to a plant for at least partly gasifying solid organic input material, with a low-temperature gasifier (1) in which pyrolysis can yield a tar-containing pyrolysis gas (B) from a solid organic input material (A), and with a high-temperature gasifier (2) having an oxidation unit (21) and an endothermic gasifier (22), where the pyrolysis gas (E) can be converted to a synthesis gas (D) by partial oxidation in the oxidation unit (21) followed by partial reduction in the endothermic reactor (22), said endothermic reactor (22) having a form which widens conically in the vertical direction and which has at least one side offtake to take off unwanted particulate solids at not less than one height (H), more particularly at not less than two or more different heights (H).

Description

description

Process and plant for the gasification of feedstock

The present invention relates to a method and a plant for the at least partial gasification of solid, organic feedstock, in particular of biomass, with a low-temperature gasifier and a high-temperature gasifier.

State of the art

Processes for the production of synthesis gas from solid organic feedstock, also referred to for short as gasification processes, are known. Advantageously, coal or biomass are used as starting material for such processes. In biomass gasification processes, for example, used wood and forestry wood or so-called energy wood, but also agricultural residues such as straw or chaff are used.

By gasification of biomass to synthesis gas with downstream

Process steps (so-called Biomass-to-Liquids method, BTL) can

For example, synthetic biofuel can be obtained in its

physicochemical properties of known gas-to-liquids (GTL) and coal-to-liquid (CTL) fuels. An example of a plant for the production of BTL fuels is in Kiener, C. and Bilas, I .: Synthetic biofuel of the second generation. World's first commercial BTL production plant. Energy 2.0, July 2008, p. 42-44. Processes and plants for the at least partial gasification of solid, organic feedstock are also known, for example, from EP 0 745 114 B1, DE 41 39 512 A1 and DE 42 09 549 A1. The present application relates in this case to such processes or plants which have a low-temperature gasifier and a high-temperature gasifier, as explained below. Compared to other methods, these allow, inter alia, a lower consumption of feed and have a higher cold gas efficiency. In a low-temperature carburetor, the feedstock, for example

Biomass, by partial gasification with a gasification agent at temperatures between about 300 ° C and 600 ° C to coke (so-called in the case of biomass

Biokoks) and Schwelgas implemented. The implementation is under this

Registration referred to as "smoldering". Smoldering is known to be characterized by a stoichiometric oxygen supply and thus an incomplete

Combustion at a comparatively low temperature.

The carbonization gas is then transferred to a combustion chamber of the

High-temperature gasifier and transferred there with an oxygen-containing gas, for example with more or less pure oxygen, but also with air and / or oxygen-containing exhaust gases, e.g. from gas turbines or internal combustion engines, partially oxidized. By this oxidation released heat causes a temperature increase to 1200 ° C to 2000 ° C, for example 1400 ° C. Under such conditions, aromatics, tars and oxo compounds contained in the carbonization gas are completely decomposed. This forms a synthesis gas, which consists essentially only of carbon monoxide, hydrogen, carbon dioxide and water vapor. The synthesis gas can also be referred to as (synthesis) raw gas at this point. In a further stage, the synthesis gas thus produced is brought into contact with coke from the low-temperature gasifier, for example in a quench unit integrated in the high-temperature gasifier or in a quench unit connected downstream of it. The coke may be previously treated separately (e.g., by grinding and sifting) and then introduced into the quench unit. By endothermic reactions between coke and syngas, the latter is cooled to about 900 ° C. This causes partial conversion of the carbon dioxide to carbon monoxide.

The carbon monoxide-rich synthesis gas thus produced can then be further conditioned. The conditioning includes, for example, another

Cooling, dedusting, compaction and / or the separation of

Residual carbon dioxide.

Until now, care had to be taken in the selection of the feed materials that the proportion of solid and / or inert foreign substances, for example sand, does not exceed a certain maximum value in order to be able to ensure that none excessive accumulation of such foreign substances takes place in the gasifier. In the previous system, it was necessary to turn off the carburetor and to remove these solids manually to determine a large accumulation of such solids.

There is therefore a need for improvements in the operation of such facilities. In particular, a possibility should be created to be able to operate such systems with lower demands on the sand freedom of the starting materials. Disclosure of the invention

According to the invention, an installation and a method for the at least partial gasification of solid, organic feedstock, in particular of biomass, with the features of the independent patent claims are proposed. Preferred embodiments are subject of the subclaims and the following description.

Advantages of the invention The invention is based on a known method for at least partial

Gasification of solid, organic feedstock, such as biomass. From the feedstock a tar-containing carbonization gas is generated by smoldering in a low-temperature gasifier. The carbonization gas is then in a

High temperature carburetor by partial oxidation and then in an endothermic reactor or carburetor, which may be formed as part of the high-temperature gasifier, converted by partial oxidation and subsequent partial reduction to a synthesis gas. According to the invention can be ensured in a simple manner that in the synthesis gas predominantly on the pyrolysis coke

introduced solid (unwanted) foreign substances from the synthesis gas stream

can be deducted. This results in the possibility of less pure

To use starting materials. In particular, less stringent requirements for the freedom from sand (ie tolerance of starting materials with correspondingly higher quartz or silicon contents) can be tolerated while avoiding the accumulation of such foreign substances and in particular the melt phase formation of alkali metal silicates. The inventively provided side fins can be realized in a structurally simple manner in an endothermic carburetor at a desired height or desired different heights. Advantageously, the at least one height for a side draw below

Considering the cross section of the endothermic reactor at this level and a resulting flow rate of the upward flowing through the endothermic gasifier synthesis gas and a detected or expected size of the foreign particles to be subtracted selected.

In particular, the invention utilizes that, for example, unwanted (inert) sand particles have an average particle size (particle diameter). The flow velocity of the synthesis gas flowing upward in the endothermic gasifier decreases due to the conical expansion of the carburetor upwards. In a lower region of the endothermic carburetor, the (upward) force acting on the foreign particles by the flow is relatively large and exceeds the weight of the particles. At a certain level of the endothermic carburetor, these two forces balance out, so that there is an increased concentration of these undesirable particles at this altitude.

Conveniently, a side trigger is provided at this height.

It is preferred that the at least one side discharge is in operative connection with a vacuum pump, in particular a jet pump. By means of such

Vacuum pumps unwanted foreign substances can be easily removed from the endothermic carburetor.

Brief description of the drawings

FIG. 1 shows a plant which is suitable for carrying out a method according to the invention

Method is set up, in a schematic representation, and

Figure 2 shows a preferred embodiment of a part of an inventive

Investment.

Embodiment of the invention In Figure 1, a system is shown, which for carrying out a

set up according to the invention method and is generally designated 10. The plant 10 comprises a low temperature carburetor 1 and a

High temperature carburettor 2.

In the low temperature carburetor 1, a feedstock A, for example

Biomass such as wood or corresponding waste, as previously explained, fed. For example, oxygen can be fed via a line 11. The low temperature carburetor 1 is for fuming the solid organic

Feedstock A set up.

Via a line 12 can be discharged from the low temperature carburetor 1, a carbonization B and transferred to the high temperature carburetor 2. Of the

Hochtemperaturvergaser 2 is formed in two parts. It comprises an oxidation unit 21 and an endothermic reactor (quench unit) 22. In the oxidation unit 21, the carbonization gas B is partially oxidized with a supplied oxygen-containing gas, resulting in temperatures of, for example, 1400 ° C. to 2000 ° C., as explained. As a result, a synthesis gas is obtained, which is designated C.

Via a fluid connection between the oxidation unit 21 and the endothermic reactor / gasifier 22, the synthesis gas C is transferred into the endothermic reactor 22. There is ground coke, especially pyrolysis from the

Low temperature carburetor 1, initiated. A line via which pyrolysis coke is introduced into the endothermic reactor is designated by 23. As a result of the endothermic reactions taking place in this way, the gas temperature cools down to approximately 900 ° C. in a short time, at least partial reduction occurs.

The resulting gas mixture D, which is still referred to as (now carbon monoxide rich) synthesis gas is fed to a cooler 3 and cooled there, for example, to a temperature of 600 ° C. The synthesis gas D can then be dedusted in a cyclone 4. The dedusted synthesis gas E, in the context of this application also referred to as "gas mixture derived from the synthesis gas", now has a temperature of, for example, 500 ° C and can in another Cooler 6 are cooled. It can then be supplied, for example, to a carbon dioxide separation device 7.

Downstream of the Kohlendioxidabtrenneinrichtung 7 can receive a received in this

Gas mixture are compacted for example in a compressor 8.

Via a line 15, the gas stream is discharged from the system 10. to

Ensuring a sufficient pressure gradient and thus the avoidance of backflow, the system 10 expediently a pressure regulator 19 with not shown on.

The endothermic reactor (quench unit) 22 has an upwardly conically widening shape, as indicated in FIG. 1 and shown in detail in FIG. This endothermic reactor will now be explained in more detail with reference to FIG. It should be noted that the details discussed here can also be implemented in the system according to FIG.

The syngas stream denoted by C in FIG. 1 is moved upwards by 90 degrees, for example in a deflection chamber, not shown. redirected to the vertical. The synthesis gas thus flows substantially vertically upwards through the conical endothermic carburetor 22 which widens conically upwards. The ground coke used for the reduction from the low-temperature gasifier 1 is, for example, in the lower region 22a of the endothermic reactor 22 in operative connection with the conduit 23, for example Screw conveyor (symbolically represented by arrow 23a) introduced. This pyrolysis coke reacts in the manner described with the synthesis gas C, wherein the particle size of the pyrolysis coke particles with

increasing reaction, ie with increasing residence time within the endothermic gasifier 22 decreases (symbolized by two schematically represented particles p,

P ') -

However, undesirable foreign particles, such as grains of sand, which are predominantly introduced into the endothermic reactor via the pyrolysis coke, are inert and do not substantially react within the endothermic reactor 22, thus maintaining their particle size. In the lower region 22a of the endothermic reactor 22, these foreign particles are carried upwards due to the relatively high flow rate of the crude synthesis gas. Due to the conical extension of the endothermic reactor, however, there is a slowing down of the flow velocity of the

Synthesis gas, so that within the reactor 22, a height H can be calculated and / or determined, at which the weight of the foreign particles (grains of sand) compensates the upward, mediated by the flow of the synthesis gas force. At this altitude, there is an accumulation or concentration of foreign particles.

On or in the area of this height H is the endothermic carburetor with a

Side trigger 25 is formed. The side trigger 25 is connected via a line (symbolized as arrow 26) to a jet pump 28. For example, water is used as the pump medium, which is introduced via a line 29 into the jet pump and leaves it via a line 30. By means of the

Jet pump generated negative pressure are concentrated at the level H particles or foreign particles are withdrawn from the endothermic reactor and removed with the water via the line 30 from the system. It can not be completely avoided that the foreign particles also carry a small proportion of synthesis gas as well as pyrolysis coke particles. However, the proportion thereof is very low compared to the proportion of synthesis gas leaving the endothermic reactor via line 24. The over the line 30

discharged substances can be suitably separated from each other, and optionally fed back to the system.

The jet pump 28 expediently performs a full quench for the withdrawn mass flow. By adjusting the negative pressure generated by the jet pump 28, the amount of laterally drawn mass flow can be variably adjusted.

The system according to the invention can continue to be operated by accumulation of inert solid particles, such as sand, without interruption of operation by corresponding actuation of the jet pump 28. In particular, such a side trigger prevents melt phase formation, such as Alkali silicates. Overall, according to the invention, the purity requirements for the starting material of the gasification are significantly reduced.

Instead of a jet pump (water jet pump) with the driving medium water, a jet compressor (gas jet pump) with a driving medium such as steam or CO 2 can be used as a vacuum pump.

In addition, to prevent melt gases, additives such as kaolin, limestone or dolomite may be added to the endothermic gasifier. The total mixture can then be withdrawn laterally without sticky particles forming.

A side take-off can also be provided on comparable run-of-river reactors which serve for endothermic quenching.

Claims

claims

Plant for the at least partial gasification of solid, organic

Feedstock with a low-temperature gasifier (1), in which a tar-containing carbonization gas (B) can be obtained by smoldering from a solid organic feedstock (A), and a high-temperature gasifier (2) with an oxidation unit (21) and an endothermic gasifier (22), the

Smoldering gas (E) can be converted by partial oxidation in the oxidation unit (21) and subsequent partial reduction in the endothermic reactor (22) to a synthesis gas (D), wherein the endothermic reactor (22) has a conically widening in the vertical direction form which has at least one height (H), in particular at least two or more different heights (H), at least one side draw for the withdrawal of undesired solid particles.

Plant according to claim 1, wherein the at least one height (H) below

Considering the cross-section of the endothermic reactor (22) at this level and from this at this height resulting

Flow rate of the upward flowing synthesis gas and a detected or expected size of the unwanted solid particles is selected.

Installation according to one of the preceding claims, characterized in that the at least one side draw (25) with a vacuum pump (28) in

Active compound is.

Plant according to claim 3, characterized in that the vacuum pump (28) is designed as a jet pump or jet compressor.

Process for the at least partial gasification of solid, organic

Feedstock, being from the feedstock in one

Low temperature carburetor (1) by smoldering a tar-containing carbonization is recovered and the carbonization subsequently in an oxidation unit (21) of a Hochtemperaturvergasers (2) partially oxidized and then in an endothermic reactor (22) of the Hochtemperaturvergasers (2) by partially Reduction to a synthesis gas (D) is reacted, wherein the endothermic reactor (22) has a conically widening in the vertical direction form, wherein synthesis gas flows through the endothermic reactor (22) in a substantially vertical direction from bottom to top, and predominantly via the

Pyrolysis coke are registered in the synthesis gas undesirable solid particles over at least one at a height (H) provided side deduction deducted.

A method according to claim 5, characterized in that the unwanted solid particles by means of one on the side trigger (25) provided

Vacuum are withdrawn from the endothermic reactor (22).