Fluidized-bed pyrolysis device for preparing biomass gas with high calorific value

Abstract

The invention discloses a fluidized-bed pyrolysis device for preparing biomass gas with high calorific value. The fluidized-bed pyrolysis device comprises a fluidized bed, a cyclone separator, a heatexchanger and a feeder, wherein the feeder is used for conveying crushed and dried biomass materials into the fluidized bed; an inlet of the cyclone separator is communicated with the top part of thefluidized bed; the heat exchanger is arranged at a dense-phase section in the fluidized bed, and provides heat needed by pyrolysis for the biomass materials by heat exchange. The fluidized-bed pyrolysis device also comprises a booster fan and a biomass-gas burner; an exhausting port of the cyclone separator is connected with a gas inlet of the booster fan; a gas outlet of the booster fan is connected with a gas inlet of the burner; a hot-smoke outlet of the burner is connected with a hot-medium inlet of the heat exchanger. Compared with the prior art, the fluidized-bed pyrolysis device disclosed by the invention has the advantages that the heat needed by thermal cracking in a furnace is met by self-produced gas; compared with the pyrolysis mode utilizing external fuel and electric energy,the fluidized-bed pyrolysis device has the advantage that the operation cost is reduced.

Description

technical field [0001] The invention relates to a fluidized bed pyrolysis device for preparing high calorific value biomass gas. Background technique [0002] Biomass solid waste is rich in resources, vigorously developing the resource utilization of biomass solid waste will help to improve my country's energy structure dominated by fossil fuels, which can not only reduce the emission of sulfide and nitrogen oxides, but also relieve the effect. Biomass pyrolysis gasification technology realizes the transformation of low-grade biomass into high-quality gas, which can replace fossil energy such as coal and petroleum in many fields. Biomass gasification is a more efficient biomass energy utilization technology. The basic principle is that biomass is insufficiently oxidized with gasification agents (such as air, oxygen or water vapor) at relatively high temperatures (700-900°C). The reaction produces a flammable gas mainly composed of carbon monoxide, hydrogen and methane. Bio...

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Problems solved by technology

When oxygen-enriched or pure oxygen is used as the gasification agent, the reaction temperature is high, the reaction speed is fast, the tar content is low, and the calorific value is high (up to 2500kCal / Nm3), but the cost of oxygen production is high and the economy is poor

When water vapor is used as the gasification agent, the gas quality is good, the hydrogen content is high, and the gas with a medium calorific value (4200kCal / Nm3) is produced, or when air and water vapor are used together as the gasification agent, the calorific value can also reach 2500kCal / Nm3 or more, but the system needs to be equipped with steam generators and superheating equipment, as well as external heat supply sources, poor system independence, complicated technology, and high operating costs

Hydrogen gasification is a process in which hydrogen reacts with carbon and water to generate a large amount of methane. The reaction conditions are harsh, and it needs to be carried out under the conditions of high temperature and high pressure and a hydrogen source. It can produce high calorific value gas with a calorific value of about 5800kCal / Nm3. There are basically no actual cases

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