Method for improving yield of coal microwave pyrolysis tar by using methane and carbon dioxide as reactant gases

Abstract

The invention discloses a method for improving the yield of coal microwave pyrolysis tar by using methane and carbon dioxide as reactant gases. The method is characterized in that: methane of which the volume ratio is 50-90% and carbon dioxide of which the volume ratio is 10-50% are used as reactant gases, methane and carbon dioxide are mixed together, then the mixed gas is introduced into a pyrolysis reactor and is subjected to co-pyrolysis with a mixture containing coal of which the mass percent is 30-90% and semi-coke of which the mass percent is 10-70% under the condition that the microwave heating temperature is 400-700 DEG C for a constant temperature time of 10-40min, volatile products after pyrolysis leave the reactor and then enter a condensing system for gas-liquid separation, and then a tar product is collected. The method disclosed by the invention has the advantages that the semi-coke is used as a catalyst, and methane and carbon dioxide replace hydrogen and serve as hydro-pyrolysis reactant gases, so that the yield of the pyrolysis tar can be obviously improved, and the hydro-pyrolysis cost is reduced; and the semi-coke is used as a catalyst for activating methane and carbon dioxide, the catalyst does not need to be recovered and separated from the product, the semi-coke is generated continuously during pyrolysis, and the problem of catalyst deactivation is avoided.

Description

technical field [0001] The invention belongs to the field of energy technology, and relates to a method for increasing the yield of coal microwave pyrolysis tar by using methane and carbon dioxide as reaction gases. The method can be applied to coal microwave pyrolysis to produce semi-coke, tar and pyrolysis gas, especially Increase tar yield during pyrolysis. Background technique [0002] Coal pyrolysis refers to a series of physical changes and chemical reactions that occur when coal is heated to a higher temperature in an inert atmosphere or in the absence of air. Compared with the gasification or liquefaction process, the coal pyrolysis process is simple, the processing conditions are mild, the investment is small, and the production cost is low. Coal pyrolysis can obtain liquid fuel and chemical raw materials with tar as the target product. Pyrolysis in an inert atmosphere and isolated from air, the tar yield is low; the hydropyrolysis process to improve the coal pyro...

AI Technical Summary

Problems solved by technology

The disadvantage of this invention is that the structure of the reactor is relatively complicated, and a supported metal catalyst is required, and the catalyst is prone to carbon deposition and deactivation; after the pyrolysis reaction, the catalyst needs to be recovered and regenerated, which is not conducive to continuous industrial production