A method and device for preparing synthesis gas by pyrolysis and gasification of biomass

Abstract

The invention provides a method and a device for preparing synthesis gas by biomass pyrolysis and gasification. The method comprises three stages of roasting at low temperature, catalytically gasifying at high temperature, and reforming through microwave; the three stages are respectively continuously performed in three relatively-independent spaces in a gasifying device, so as to obtain high-quality synthesis gas. The device comprises a double-shaft spiral pyrolysis reactor which is equipped with a roasting section at the front section, a gasifying section at the medium section, and a microwave assisting reforming section at the tail section; raw materials are fed into the double-shaft spiral pyrolysis reactor through a feeding device; the way of combining internal heat and external heat which are produced by smoke heat exchange, heat carried by a catalyst and microwave assisting heating is adopted to provide proper temperature of the three reaction stages to achieve staged pyrolysis and gasification; the produced gas is processed by a gas solid separator to obtain the synthesis gas; meanwhile, the deactivated catalyst and carbon coke and the like discharged by the reactor are fed into a combustion furnace to generate high-temperature smoke and regenerate the catalyst. With the adoption of the method and the device, the process system for preparing the synthesis gas can be simplified, the semi-coke and tar contents in pyrolysis and gasification can be decreased, and the gasifying efficiency of the system and the quality of the synthesis gas can be improved.

Description

technical field [0001] The invention belongs to the technical field of preparing synthesis gas by pyrolysis and gasification of biomass, and in particular relates to a method and a device for preparing synthesis gas by pyrolysis and gasification of biomass. Background technique [0002] Biomass is mainly carbohydrates formed by photosynthesis of plants to fix solar energy. It has the advantages of wide distribution, huge reserves, environmental friendliness, especially zero emission of greenhouse gases, and is the only one that can be converted into gas, liquid and solid fuel at the same time. Renewable Energy. With the decrease of traditional fossil energy and the aggravation of environmental pollution caused by the use of fossil energy, it has become the consensus of governments to attach importance to and develop green and renewable energy. Through thermochemical conversion, biochemical conversion and other methods, biomass energy can be converted into clean gas or liqui...

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Problems solved by technology

[0008] However, as mentioned above, there are obvious problems in this method. First, the fluidized bed gasification process is adopted, which has strict requirements on the particle size and water content of biomass raw materials, and requires more complicated pretreatment equipment; Secondly, the use of steam or steam / air gasification requires additional steam generators and superheating equipment, and operates at high pressure, which makes the overall complexity of the device and reduces safety and reliability; in particular, there is no response to catalyst deactivation measures, the overall gasification efficiency is difficult to guarantee, and it is difficult for the device to operate stably for a long time

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