Method for secondarily reforming tar by utilizing in-situ composite semicoke made from high alkaline coal and biomass

Abstract

The invention discloses a method for carrying out secondary catalytic reforming on tar by using in-situ thermal-state composite semicoke made after high alkaline coal difficult to utilize industrially and biomass are pyrolyzed as a catalyst. According to the method, after being subjected to pretreatment, the biomass and the coal are uniformly mixed, the high alkaline coal is used as a provider of alkali metal ions of K, Na and the like, which play a main catalytic role, and has a mass ratio of approximately being 20 to 30 percent in a mixed sample. The well prepared mixed sample is added into a lower layer of a two-stage fixed bed pyrolysis reactor to carry out pyrolysis, so as to prepare a subsequently needed catalyst; after the pyrolysis on the lower layer is completed, the charging on an upper layer is started to carry out the pyrolysis; the in-situ thermal-state composite semicoke on the lower layer is used as a carbon bed; a tar-containing pyrolysis gas obtained through the pyrolysis on the upper layer is subjected to the secondary catalytic reforming through the carbon bed on the lower layer by utilizing a carrier gas. According to the method, the characteristics that the high alkaline coal is rich in alkaline-earth metals and the biomass is loose and porous are effectively utilized; by utilizing the preparation of composite semicoke, the shortage that the semicoke is separately pyrolyzed as the catalyst is made up; the catalytic efficiency is improved; the catalytic cost is decreased.

Description

technical field [0001] The invention belongs to the field of high-efficiency conversion and utilization of biomass energy, and specifically relates to a catalytic reaction method for producing in-situ thermal compound semi-coke catalytic reforming tar by pyrolyzing high-alkali coal and biomass to increase gas production. Background technique [0002] With the continuous development of human society and the depletion of conventional fossil fuels, it is imperative to seek alternative energy sources. Due to its renewable, wide source, large output, easy storage and other characteristics, people are gradually realizing its broad application prospects as an alternative energy source. my country is rich in biomass resources. At present, the output of crop straw alone is more than 800 million tons per year, accounting for about 30% of the world's total straw, equivalent to about 400 million tons of standard coal. [0003] However, in general, the utilization efficiency of biomass ...

AI Technical Summary

Problems solved by technology

[0005] Tar is an unavoidable by-product in the pyrolysis process. Tar will condense in the pipeline and adhere to the wall of the pipeline, which will seriously affect the operation safety of the equipment

After tar sticks to fly ash, water and other substances, it will also cause a series of problems such as blockage of pipelines and corrosion of equipment. Therefore, how to reduce the production of tar in the pyrolysis process has become a major problem in the development of pyrolysis technology.

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