Gasification reactor and process for entrained-flow gasification
A process and device for the gasification of liquid or fine-grain solid fuel materials with the aid of oxygenous, gaseous gasification agents in a reactor is described. Liquid slag is separated on the walls of the reactor. The synthesis gas is generated in a first reaction chamber arranged in the upper part of the reactor and the feedstock is fed to the upper part. Liquid slag precipitates on its lateral walls, with free downflow and no solidification of the slag surface. The lower side has a hole with a slag drop-off edge, from which the generated synthesis gas can be withdrawn in downward direction and the liquid slag can drop off the edge. A second chamber which is delimited by a water film is located under the opening and used to keep the synthesis gas dry and cool. A third chamber is adjacent to the bottom of the second and fed with water to cool the synthesis gas. A water bath is adjacent the bottom of the third chamber and collects the slag particles already solidified and dropped off or those particles still in the liquid phase. The synthesis gas is withdrawn from the pressure vessel in an area below or on the side of the third chamber but in any case located above the water bath.
1. A process for the generation of synthesis gas by gasification of liquid or fine-grain, solid fuel materials at a pressure of 0.3 to 8 MPa and a temperature ranging from 1200 to 2000° C., with the aid of oxygenous, gaseous gasification agents in a cooled reactor, liquid slag being separated on the walls of the said reactor which is housed in a pressure vessel, comprising:
generating synthesis gas in a first reaction chamber arranged in the upper part of the reactor;
feeding the feedstock to the upper part;
precipitating liquid slag on its lateral walls, with free downflow and no solidification on the slag surface;
providing a hole with a drop off edge on the reactor's lower side, from which the generated synthesis gas can be withdrawn in downward direction and the liquid slag can drop off the said edge;
providing a second chamber located under the opening and used to keep the synthesis gas dry and cool;
delimiting the second chamber by a water film produced by adequate devices and with free downflow;
providing a third chamber located adjacent to the bottom of the second one and fed with water to ensure cooling of the synthesis gas, wherein the water film separates the second chamber and the third chamber;
arranging a water bath adjacent to the bottom of the third chamber and collecting the slag particles already solidified and dropped off or those particles still in the liquid phase; and
withdrawing the generated and cooled gas from the pressure vessel in an area below or on the side of the third chamber but in any case located above the water bath; wherein
the water film separating the second chamber from the third one is speeded up with the aid of a tapered water chute which is protected from heat or dust by means of a protective shield, which shield is designed as a cooled device partitioning the second chamber from an outer space with the aid of a gaseous coolant or water sprinkling originating from the outer space.
2. The process in accordance with claim 1 , wherein solid fuel materials, such as coal, petroleum coke, biological waste or fuel materials or fine-grain plastic materials can be used as feedstock.
3. The process in accordance with claim 1 , wherein the grain size of the solid fuel materials does not exceed 0.5 mm.
4. The process in accordance with claim 1 , wherein oil, tar, refinery residues or aqueous suspensions are used as liquid fuel.
5. The process in accordance with claim 1 , wherein the gasification reaction takes place in a cloud of dust or droplets.
6. The process in accordance with claim 1 , wherein the feeding of the fuel materials and gasification agents to the gasifier can be performed by at least two burners fixed by means of separate fixtures to the lateral wall of the first reaction chamber, the burners being optionally arranged at one or several levels.
7. The process in accordance with claim 1 , wherein the feed of the fuel materials and gasification agents to the gasifier can take place by at least one burner arranged in the ceiling of the gasification reactor.
8. The process in accordance with claim 1 , wherein prior to entering the reactor, the stream of gasification agents can be provided with a swirl motion by means of baffle plates or a special design of the burner.
9. The process in accordance with claim 1 , wherein the third chamber is equipped with a vertical partition wall so as to ensure that the generated synthesis gas first flows downwards in the inner space formed by the said partition wall, the said gas then being reversed to ascend in the outer space formed by the partition wall prior to leaving the pressure vessel.
10. The process in accordance with claim 9 , wherein the partition wall is wetted with water on the inner and outer sides.
11. The process in accordance with claim 1 , wherein a circulating stream is generated in the water bath arranged in the lower section.
12. The process in accordance with claim 1 , wherein the water originating from the water bath is returned to the third chamber by means of an appropriate pumping facility and used for the formation of a water film.
13. Process in accordance with claim 1 , wherein the water used is slightly acidified.