Biomass graded temperature-control slow pyrolysis process and its system

Abstract

The invention relates to biomass grading temperature controlling slow speed pyrolysis technology and its system. The technology includes the following steps: dividing the pyrolysis into many independent stages with temperature increasing; processing countercurrent flow for external heat source and biomass; heating the biomass grade by grade to make it pyrolyse; pre-drying and deep drying the material to make sure its water content is 5-10%; pre-charring and charring to gain charcoal, pyrolysis gas, little gas state biological crude oil; processing the secondary decompose for the crude oil at roasting stage to gain the pyrolysis product. The system is made up of external hot gas source and its bypass route, main heat exchanger, multiple-stage pyrolyzer, and multiple-stage heat exchanger. The invention has the advantages of wide material accommodation limit, easy adjustable pyrolysis process, easy controllable pyrolysis product, utilizing waste heat to increase gasification efficiency.

Description

technical field [0001] The invention belongs to the technical field of biomass energy and relates to the preparation of biomass pyrolysis products, in particular to a biomass graded temperature-controlled slow pyrolysis process and a system thereof. Background technique [0002] The development and utilization of biomass energy is a hot spot in the research and application of countries all over the world, and the biomass gasification technology aimed at producing various syngas has also been widely used. According to the characteristics of the biomass gasification process, it can be seen that the characteristics of the gasification raw materials and the particle size of the gasification raw materials will directly affect the operating load of the gasifier, the yield of syngas and tar, and the efficiency of raw material gasification. Various indicators. Usually, when different raw materials are reacted in different gasifiers, the requirements for their particle size are also...

AI Technical Summary

Problems solved by technology

[0006] However, in the existing biomass pyrolysis pretreatment process, whether it is the autothermal method or the external heating method, the pyrolysis process of the above-mentioned stages is completed in only one pyrolysis reactor, and it is difficult to ensure that the entire pyrolyzer Uniformity of internal heating rate

Therefore, biomass raw materials in different locations may be in different stages of pyrolysis, which makes it difficult to meet proper pyrolysis conditions and cannot guarantee the quality of pyrolysis products

Especially for the pyrolysis process of self-heating mode, the following problems are more likely to occur: First, the local temperature in the combustion area is too high and the heating rate is too fast, which makes the temperature distribution in the entire pyrolysis reactor extremely uneven, and the heating rate cannot be strictly controlled. control, it is bound to make it difficult to meet the requirements of the operating temperature in the pyrolysis process, and then the pyrolysis products do not meet the requirements, which affects the subsequent gasification process; secondly, the self-heating method of partially burning biomass will make the CO in the pyrolysis gas 2 content significantly increased, thereby significantly reducing the gasification efficiency of the gasification system

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