Low-rank fuel low-temperature gasification device based on screw pyrolyzers and fluidized bed gasifier

Abstract

A low-rank fuel low-temperature gasification device based on screw pyrolyzers and a fluidized bed gasifier belongs to the field of gasification of low-rank fuels. The power output shaft of a motor 1 is connected with the power input shaft of a transmission gearbox in a transmission mode, a first-order screw pyrolyzer is mutually coupled with a gas lock device through a transmission gearbox, the screw shaft of the first-order screw pyrolyzer is connected with the screw shaft of a second-order screw pyrolyzer through a shaft coupling, and the second-order screw pyrolyzer communicates with the fluidized bed gasifier; the upper part of the second-order screw pyrolyzer is provided with a water vapor inlet; the fluidized bed gasifier communicates with a cyclone separator, the fluidized bed gasifier communicates with a gas inlet system, and a residue discharging tube communicates with the bottom of the fluidized bed gasifier; and the cyclone separator communicates with a first-stage return tube, the first-order return tube communicates with a screw return device, the screw return device communicates with a second-order return tube, and the second-order return tube communicates with the second-order screw pyrolyzer. The in-situ catalytic cracking of parts of tar by pyrolytic coke and the re-adsorbed alkali metal and alkali earth metal catalyzed low-temperature gasification of coal coke are used to realize the high-efficiency low-temperature gasification of the low-rank fuel.

Description

technical field [0001] The invention relates to a low-grade fuel low-temperature gasification device based on a spiral pyrolyzer and a fluidized bed gasifier, belonging to the field of low-grade fuel gasification. Background technique [0002] Gasification refers to the use of carbon-containing fuels (coal, coal char or biomass, etc.) as raw materials, oxygen (air, oxygen-enriched or industrial pure oxygen), water vapor, carbon dioxide, etc. A series of chemical reactions occur at a certain temperature and pressure to convert solid fuel into CO, H 2 、CH 4 Process such as combustible gas. [0003] Low-rank fuels (low-rank coal, biomass, and kitchen waste) are rich in reserves and sources, with low metamorphism, high volatile content, and high gasification activity. In addition, the alkali metals and alkaline earth metals rich in low-rank fuels (low-rank coal is rich in sodium, calcium and magnesium, biomass is rich in potassium, calcium and magnesium, and kitchen waste mai...

AI Technical Summary

Problems solved by technology

[0006] However, in terms of tar removal, the existing patents only remove tar through catalytic cracking of high-temperature coke tar or high-temperature cracking of tar itself in the gasification stage. The gasification temperature is relatively high, while tar removal in the pyrolysis stage Except not considered; higher gasification temperature will inevitably lead to lower cold gasification efficiency (for coal, cold gasification efficiency), when the gasification temperature increases from 900 °C to 1600 °C, the cold gasification efficiency drops by 20 %about

In terms of coke gasification, the existing patents increase the gasification rate by increasing the temperature or pressure, which makes insufficient use of alkali metal and alkaline earth metal catalysts in low-order fuels; higher gasification temperature and pressure will also lead to higher investment and operating costs

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