CN201205497Y - Gasification Reactor - Google Patents

Abstract

The utility model relates to a gasification reactor, which comprises a pressure shell and a reaction zone, wherein the reaction zone is bounded by a vertically oriented tubular membrane wall, and the wall has one or more openings, wherein a fixed a slag deflector on the wall above the opening. By arranging the slag deflector above the opening of the membrane wall, less or no slag ingress results, thus causing less damage.

Description

Gasification Reactor

technical field

The utility model relates to a gasification reactor comprising a pressure shell and a reaction zone, wherein the reaction zone is partially bounded by vertically oriented tubular membrane walls. The membrane wall has one or more openings.

Background technique

Such a gasification reactor is described in US-A-4202672. This publication describes a coal gasification reactor having a pressure shell, a reaction zone and membrane walls which partially define the reaction zone. The tubular shaped membrane wall comprises interconnected conduits in which evaporative cooling water is present.

In US-A-4959080 a coal gasification process is described which can be carried out in the above gasification reactor. The publication describes that during the gasification of coal a layer of slag is formed on the membrane wall. This layer of slag will flow down the inside of the membrane wall.

According to "Gasification" by Christofer Higman and Maarten van der Burgt, 2003, Elsevier Science, Burlington MA, pp. 118-120, the Shell Coal Gasification Process also utilizes a gasification reactor, which includes pressure Shell and reaction zone enclosed by membrane forming walls. According to this publication, the Shell coal gasification process is generally carried out at 1500°C and a pressure of 30 to 40 bar. Horizontal burners are placed at the openings of the membrane walls.

The applicant has successfully implemented the Shell coal gasification process using different types of feedstock. However, when processing a feedstock with a relatively high ash content, and more particularly when processing the feedstock at higher pressures, we have found that the operation of the process becomes more difficult due to the ingress of slag into the openings in the membrane wall . The ingress of slag may cause damage to the area forming the opening of the burner.

Utility model content

The object of the present invention is to provide a gasification reactor which is more suitable for processing raw materials with high ash content.

This object is accomplished by the gasification reactor described below. A gasification reactor comprising a pressure shell and a reaction zone partially bounded by a vertically oriented tubular membrane wall provided with one or more openings, wherein a slag deflector ( slag defleclor), the slag deflector is attached to the wall and is located above the opening.

The applicants have found that by providing a slag deflector over the opening of the membrane wall, less or no slag ingress results, thus causing less damage.

Preferably, the upper end of the slag deflector is set at 0.1-3 times the opening width above the upper end of the opening. The slag deflector can be a flange fixed on the membrane wall, and the flange (rim) preferably has a refractory coating. Preferably, the deflector is a conduit fixed on the membrane wall, with an inlet port and a Outlet ports, respectively for cooling medium and used cooling medium. More preferably, the conduit has a portion situated higher above the opening and a lower portion of the conduit extending laterally whereby in use at least a portion of downwardly flowing slag is deflected away from the opening . The conduit preferably has a refractory coating.

The slag deflector is preferably made of low alloy steel with up to 5 wt% Cr content or high alloy steel with higher than 15 wt% Cr content.

Preferably, 2 or more deflectors are arranged above the opening, and each deflector is vertically spaced from adjacent deflectors. Most preferably, two deflectors are placed over the opening. The second deflector is preferably placed 0.5-3 times the width of the opening above the upper end of the first deflector. Such an embodiment with more than one deflector above the opening in the membrane wall provided with the burner is particularly suitable. The deflector above such a burner opening is preferably designed such that a portion of the slag is directed away from the lower opening and a portion of the slag maintains a vertical downward flow path. This results in less slag being close to the opening while at the same time causing sufficient slag flow to remain close to the opening to provide the necessary isolation function.

If the opening in the membrane wall relates to the opening of the equipment, which will only be used at start-up, a stronger slag deflector is preferred. This is because slag may accumulate and solidify in such openings during normal operation. Examples of equipment placed in such openings during start-up are start-up burners, igniters and flame detection tools such as: flame monitors. For whatever reason, if the gasification reactor needs to be shut down and restarted, the hardened slag needs to be mechanically removed from these openings, for which purpose the start-up burner and igniter need to be disassembled. This is a time consuming operation which is preferably avoided. The Applicant has now found that by placing a slag deflector over these openings - which deflects all slag during normal operation - it is thus possible to avoid the entry of slag into said openings and solidify.

The remaining advantages and preferred embodiments are described below, with reference to Figures 1-4.

Description of drawings

Fig. 1 is a preferred gasification reactor according to the present invention.

Figure 2 is a detail view of a burner opening in the membrane wall of the reactor shown in Figure 1 and illustrates a CC' sectional view of the same detail shown in Figure 3 .

Figure 3 is a detail view of the burner opening in the membrane wall of the reactor shown in Figure 1 .

Figure 3a and Figure 3b are cross-sectional views of BB' and AA' in Figure 3, respectively.

Figure 4 is a detail view of the start-up burner opening in the membrane wall of the reactor shown in Figure 1 .

Fig. 4a is a cross-sectional view of DD' in Fig. 4 .

Detailed ways

FIG. 1 shows a gasification reactor with a vertically oriented tubular pressure shell 1 , a membrane wall 3 and a reaction zone 2 . The part 3a of the membrane wall 3 is tubular in shape, the membrane wall 3 is formed by a number of vertical ducts through which water flows, the water is supplied to the membrane wall through the supply line 4 connected to a common distributor 5, the used cooling water - generally in the form of a water/steam mixture - is withdrawn from the reactor through common header 6 and discharge line 7 . The reactor is further provided with a quench gas supply 8, to which the invention is particularly suitable, in which the reaction zone 2 has a product gas outlet 9 at its upper end and a slag discharge outlet 10 at its lower end. The product gas consists of a mixture of hydrogen and carbon monoxide produced in the gasification reactor. Two diametrically arranged openings 13 are shown on the membrane wall 3 . In these openings 13, two diametrically arranged burners 14 are placed. The reactor may comprise, for example, two or more pairs of such burners at the same level or at different levels. The burner 14 is adapted to carry out the gasification of a solid or liquid carbonaceous feedstock comprising ash. For solid carbonaceous feedstock - suitably coal - suitable burners are described, for example, in US-A-4523529 and US-A-4510874. These burners are supplied through a coal supply line 11 and an oxygen supply line 12 . Remaining openings not shown in Fig. 1 for reasons of clarity may also be provided on the membrane wall 3 for mounting start-up burners, igniters and flame eyes. The slag deflector 15 positioned above the opening 13 is shown.

FIG. 2 is a detail view of the reactor opening 13 shown in FIG. 1 , which is located in the tubular portion 3 a in the membrane wall 3 . In this figure, two deflectors 15a and 15b are shown, which are spaced above the opening 13 from each other. In the opening 13 there is a burner 14, in which burner and its flame the gasification reaction takes place. The opening 13 is further provided with a muffle 16 . The muffle 16 comprises several vertically oriented, concentric and connected rings 17 . Preferably, at least one or more and more preferably all rings 17 are conduits having an inlet for cooling medium through line 20 and an outlet for cooling medium through line 22 . Said ring 17 is preferably made of a low-alloy steel with a Cr content of up to 5% by weight or a high-alloy steel with a Cr content of more than 15% by weight. The flameproof refractory shield 16 extends a certain distance into the reaction zone 2 as shown, creating a slag trough 18, thereby allowing the residual slag 19a to flow around the opening 13 as it flows towards the opening 13, preventing the slag 19a from entering the opening. 13.

Figure 2 also shows a refractory coating 21 on the membrane wall 3a. In order to keep the coating 21 fastened to said wall 3a, studs 23 are provided in connection with the wall 3a.

Lines 20 are respectively fluidly connected to a cooling medium, typically water, a distributor 24 and a common header 25, typically a water/steam mixture. These rings 17 are preferably welded together.

Figures 3, 3a and 3b illustrate views of the reactor part of the membrane wall 3a as shown in Figure 2, looking from the center of the reaction zone 2, reference numbers refer to the same parts. As shown, the deflector 15a has an inlet 27 for cooling medium and an outlet 26 for used cooling medium. The deflector 15b is also provided with an inlet 29 and an outlet 28 for cooling medium and used cooling medium, respectively. The deflectors 15a and 15b are provided with downwardly extending lower portions having an angle α of 90°-140° when viewed from the side in the horizontal direction, as shown in FIG. 3 .

Figure 4 illustrates a slag deflector 30 that is preferably used over the opening of the apparatus, which is only used during start-up as discussed above. In Figures 4 and 4a, a starting burner 37 and igniter 36 are shown. The slag deflector 30 consists of two parallel conduits 31 and 32 which extend farther into the reaction zone 2 than the deflectors 15a and 15b in FIG. 38 is deflected away from opening 33 during normal operation. The deflector 30 is provided with an inlet 34 and an outlet 35 for cooling medium and used cooling medium, respectively.

The cooling medium—preferably cooling water—supplied to the muffle refractory shroud 16 or the above-illustrated deflector embodiments may come from the same source as the cooling water supplied to the membrane walls through 4 . It can also be from a different source, possibly with lower water temperature and/or different pressure.

The applicant has found that the gas reactor manufactured according to the invention is particularly suitable for the preparation of a mixture of carbon monoxide and hydrogen from a feedstock having an ash content of 6-50 wt%. It has been found that the reactor according to the invention is particularly suitable for feedstocks with a high ash content, more preferably above 15 wt%, more preferably above 20 wt%. For economical reasons, the ash content is preferably below 40 wt%. Feedstocks with an even higher ash content are preferably mixed with lower ash content feedstocks so that the total ash content of the combined feedstock is a value within the above range. Suitable ash-containing solid carbonaceous feedstocks are coal and biomass such as wood and agricultural waste. Suitable ash-laden liquid carbonaceous feedstocks are tar sands fractions and other bituminous oils. A particularly suitable feedstock is coal with the abovementioned ash content.

The gasification of the feedstock, or also known as partial oxidation, is carried out in the presence of an oxygen-containing gas and preferably a moderator gas. One suitable retarder gas is steam. The solid carbonaceous feedstock is preferably provided to the combustor as a mixture of solid particles in a carrier gas. Suitable carrier gases are carbon dioxide and nitrogen. The gasification in reaction zone 2 is carried out at a temperature in the range of 1200-1800°C and a pressure of 1-200 bar, preferably in the range of 30-100 bar, more preferably at a pressure range above 35 bar and below 70 bar Inside.

Claims (10)

1, a kind of gasification reactor, it comprises pressure vessel and reaction zone, and described reaction zone is by the tubulose membranous wall limited boundary of vertical orientation, and described wall is provided with one or more opening, wherein, has the slag air deflector that invests on the wall admittedly and be positioned at described opening top.

2, gasification reactor according to claim 1, wherein, described slag air deflector is for investing the conduit on the membranous wall admittedly, this conduit is provided with arrival end that is used for cooling medium and the port of export that is used for used cooling medium, and wherein, described conduit have the part that is positioned at the more high position on the opening and along this conduit that extends laterally than lower part, at least a portion of the slag that so in use flows downward is deflected and leaves opening.

3, according to each described gasification reactor of claim 1-2, wherein two or more air deflectors are arranged at opening top, and wherein each air deflector and adjacent air deflector separate in vertical direction.

4, according to each described gasification reactor of claim 2-3, wherein air deflector part is extended downwards, so that direction is seen and formed 90-140 ° angle from the side.

5,, the burner of startup and/or igniter are arranged in opening wherein according to each described gasification reactor of claim 1-4.

6, according to each described gasification reactor of claim 1-5, flame monitor is arranged in opening wherein.

7, according to each described gasification reactor of claim 1-6, burner is arranged in opening wherein, this burner is used to carry out a kind of the contain solid of ash or the gasification of liquid carbon-containing raw material.

8, gasification reactor according to claim 7, wherein burner is placed in the opening by the fire-resistant cover of burner muffle.

9, according to each described gasification reactor of claim 1-8, wherein air deflector is made by having up to the low-alloy steel of 5wt%Cr content or having the high-alloy steel that is higher than 15wt%Cr content.

10, according to each described gasification reactor of claim 1-9, wherein reaction zone has the outlet that is used for product gas in the top and has the outlet that is used for slag in its lower end.

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