Method and system for preparing synthesized gas and pyrolyzed gas through pyrolysis and gasification of solid fuel

Abstract

The invention relates to a method and system for preparing synthesized gas and pyrolyzed gas through pyrolysis and gasification of a solid fuel. Oxygen carrier particles are subjected to an oxygen release reaction in an oxygen release reactor in the presence of water vapor to produce a gas mixture of oxygen and water vapor, the gas mixture is subjected to a gasification reaction with semicoke in a gasification reactor, the oxygen carrier particles serve as a solid heat carrier after oxygen loss, the oxygen carrier particles and a catalyst participate in a pyrolysis reaction of the solid fuel in a pyrolysis reactor, then, the oxygen-released oxygen carrier particles react with oxygen-containing gas in an oxidation reactor to achieve oxydizing regeneration, thus, the oxygen carrier particles are circulated among the oxygen release reactor, the pyrolysis reactor and the oxidation reactor, a continuous oxygen producing process is achieved, solid fuel pyrolysis and semicoke gasification processes are coupled together, and the cost and energy consumption are low. The synthesized gas is high in combustible gas concentration and high in synthesized gas calorific value; and the oxygen carrier particles play a role in catalyzing tar cracking, so that the content of tar in crude pyrolyzed gas is lowered, and the yield of the pyrolyzed gas is increased.

Description

technical field [0001] The invention relates to a method and system for preparing synthesis gas and pyrolysis gas by pyrolysis and gasification of solid fuel. Background technique [0002] Solid fuel gasification is the process of converting solid fuel into gaseous fuel through thermochemical reaction. The gas products obtained from gasification are mainly hydrogen, methane, carbon monoxide, carbon dioxide and other hydrocarbons. At present, the gasification agents used in the gasification of solid fuels mainly include air, oxygen, water vapor, carbon dioxide, and mixtures of water vapor-oxygen or water vapor-air. When air is used as the gasification agent, due to the N in the gas 2 The existence of synthetic gas greatly reduces the calorific value of the synthesis gas; using water vapor or carbon dioxide as the gasification agent, the gasification of solid fuel coke and methane with the gasification agent is a strong endothermic reaction, and the amount of gasification age...

AI Technical Summary

Problems solved by technology

When air is used as the gasification agent, due to the N in the gas 2 The existence of synthetic gas greatly reduces the calorific value of the synthesis gas; using water vapor or carbon dioxide as the gasification agent, the gasification of solid fuel coke and methane with the gasification agent is a strong endothermic reaction, and the amount of gasification agent is large, which is economical. poor

Compared with air and water vapor, pure oxygen is the most suitable gasification agent for solid fuel gasification. Technology (low temperature rectification, pressure swing adsorption, membrane separation) has the disadvantages of high energy consumption and high cost of oxygen production, which will increase the cost of pure oxygen oxidation of solid fuel and reduce its economy

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