Dry powder solid fuel gasifying technology and system with waste heat recovery

Abstract

The invention relates to a dry powder solid fuel gasifying technology and a system with waste heat recovery and aims at solving the problems of the existing equipment such as complicated structure, high equipment investment and operation cost, easy dust deposition of system, low stability and environmental pollution. The technical scheme is as follows: pulverized coal is fed into a reaction chamber of a gasifier and conducts a gasifying reaction under the effect of a gasifying agent at 1200-1650 DEG C to generate a crude synthesis gas; the crude synthesis gas is cooled by water mist sprayed out by an atomizing nozzle when rising above the reaction chamber; then, the crude synthesis gas rises, is fed into a fire tube boiler through a gas pipe with a membrane water wall and further cooled through heat exchange with water between a tube pass and a shell pass, and then is fed into a multi-tube cyclone dust collector and a fly-ash filter for further dust removal until the dust content is less than 1mg / m<3>; and after the dust removal, the crude synthesis gas enters an economizer again and is further cooled to 220-260 DEG C before entering the next process. The technology and system provided by the invention have the advantages of simple technology, wide coal adaptability, low equipment investment cost and operation cost and environmental friendliness.

Description

technical field [0001] The invention relates to a coal gasification process and its system, in particular to a dry powder solid fuel gasification process with waste heat recovery and its system. Background technique [0002] Pulverized coal pressurized gasification technology and coal water slurry pressurized gasification technology are the second generation entrained bed pulverized coal pressurized gasification technology. Compared with fixed bed coal gasification technology, it has very prominent advantages in terms of energy saving, environmental protection and coal type adaptability. Among the relatively advanced second-generation gasification technology, the most representative ones are the coal-water slurry pressurized gasification technology of GE and ConocoPhillips in the United States, SCGP and Siemens GSP dry pulverized coal pressurized gasification technology of Dutch Shell . [0003] The main features of SHELL dry pulverized coal gasification process are dry pu...

AI Technical Summary

Problems solved by technology

This process has the following disadvantages: 1. The structure of the equipment is complex, the manufacturing is difficult, the construction period is long, and the cost is high

The solid content of the syngas after deashing by the deashing system is generally 5-10 mg / Nm3, which cannot be directly used in downstream processes, and needs to be further deashed through the wet cleaning section and clarification section. The washed ash is wet ash and cannot be recycled.

[0004] GSP pulverized coal gasification technology generally adopts a water quenching process, which has high water consumption, high carbon content in ash, low carbon conversion rate, high energy consumption, short burner life, and cannot meet the requirements of long-term use of large-scale equipment. The carbon content is large The wet ash can not be effectively used, which has adverse effects on the environment

[0005] Synthetic gas produced by coal gasification technology needs to be washed and separated from gas and liquid. Venturi scrubbers, water washing towers, multi-stage gas-liquid separators, saturated hot water towers, large clarification tanks, etc. are required. The process is long, the equipment investment is large, and the occupation Water resources and sewage discharge will cause serious harm to the environment

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