High-low temperature cycling four-layer separation decoking method during biomass gasification process

Abstract

The invention relates to a high-low temperature cycling four-layer separation decoking method during the biomass gasification process. The method comprises the following steps: (1) materials are ignited and air is introduced; (2) the air enters an oxidation zone in a gasification furnace after being heated; (3) the air is subjected to combustion reaction with carbon generated after fuel combustion in the oxidation zone; (4) the gas obtained in step (3) enters a reduction zone in the gasification furnace to carry out reduction reaction with the carbon and water vapor; (5) the gas generated in the oxidation zone and the reduction zone enters a cracking layer for cracking reaction to generate a split product; (6) the gas in the split product enters a drying zone in the gasification furnace for exchanging heat with the materials to obtain dried materials, water vapor and flammable gas; (7) the flammable gas is subjected to cracking through a dolomite catalytic cracking layer and a charcoal catalytic cracking layer to obtain gas containing remaining tar; and (8) the gas containing the remaining tar is heated at a furnace end for fully cracking and burning the remaining tar. By adoptingthe high-low temperature cycling four-layer separation decoking method, the tar content during the biomass gasification process is effectively lowered.

Description

technical field [0001] The invention relates to the field of tar treatment in the biomass gasification process, in particular to a high-low temperature cycle four-layer separation decoking method in the biomass gasification process. Background technique [0002] The goal of biomass gasification is to obtain as many combustible gas products as possible, but coke and tar are unavoidable by-products in the gasification process. Among them, since tar is gaseous at high temperature and completely mixed with combustible gas, and condenses into liquid at low temperature (generally lower than 200°C), its separation and treatment are more difficult, especially for the situation where the gas needs to be cooled and used (such as gas When used in family life), the problem is more prominent. [0003] The presence of tar has many adverse effects on gasification. First of all, it reduces the gasification efficiency. The energy of tar products in gasification generally accounts for 5-15%...

AI Technical Summary

Problems solved by technology

Judging from the current decoking technology, there is energy waste and secondary pollution in the water washing decoking method, and the purification effect can only barely meet the requirements of the internal combustion engine; the thermal cracking method can obtain higher conversion efficiency above 1100 ° C, but in practical applications It is difficult to realize; the catalytic cracking method can convert tar into combustible gas, which not only improves the energy utilization rate of the system, but also completely reduces secondary pollution. It is a promising technology at present

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