Compound circulating fluidized bed gasification reaction device

Abstract

The invention provides a compound circulating fluidized bed gasification reaction device. The compound circulating fluidized bed gasification reaction device comprises a reactor body, a multistage cyclone separator, a particle fuel feeding system, a powder fuel feeding system, a central jet flow gasification burner nozzle and a material returning system, wherein the outlet of the reactor is connected with a primary cyclone separator; the primary cyclone separator is connected with a secondary cyclone separator; crude particles separated by the primary cyclone separator are returned to a gasification furnace body by virtue of the material returning system; fine particles separated by the secondary cyclone separator enter the central jet flow gasification burner nozzle by virtue of the powder fuel feeding system and are finally sprayed to the gasification furnace body. A circulating fluidized bed reactor is used as a gas reaction body; the slag is continuously discharged by gasifying at a medium-high temperature; by virtue of application of high-temperature jet flow two-stage grading gasification, the carbon conversion rate and the cold gas efficiency are increased; a simplified slag discharging device is combined with the design of an air distributing plate; the operation stability and the running stability are improved; the compound circulating fluidized bed gasification reaction device is suitable for gasifying and converting various carbon-containing solid fuels and has large-scale popularization and application prospects.

Description

technical field [0001] The invention relates to a composite circulating fluidized bed gasification reaction device, which belongs to the technical field of coal gasification polygeneration. Background technique [0002] Gasification technology for the production of clean energy and products has a long history, dating back to England in the late 18th century. The early form of gasification was to use local coal resources to produce "town gas". Modern gasification technology began in the early days of World War II and was developed during World War II. Germany's oil supply was cut off and it was urgent to find alternative ways to produce its own transport fuels. As a result, more and more advanced gasification technologies were developed during this period. Since then, Sasol in South Africa has taken the lead in using gasification technology to produce commercialized gasification derivatives on a large scale with price competitiveness, thus laying the foundation for the mode...

AI Technical Summary

Problems solved by technology

[0004] my country's lignite and other low-rank coal resources are abundant, accounting for about 50% of the country's proven coal reserves. Low-rank coal such as lignite has the characteristics of high ash, high water and high sulfur ("three highs"), and some high ash melting points. The existing coal gasification technologies mainly include entrained bed coal water slurry gasification, entrained bed dry coal gasification and fixed bed pulverized coal gasification. From the perspective of gasification technology, the impact of entrained bed coal water slurry gasification on coal slurry characteristics The requirements are high, and the high moisture content of lignite cannot meet the pulping conditions. The entrained bed dry pulverized coal gasification technology needs to make coal into pulverized coal, and the total moisture content of pulverized coal should be less than 2%. The dehydration cost and energy consumption of high-moisture lignite Huge, and the overall requirement of entrained bed gasification is that the ash melting point should not be too high, otherwise the operating costs such as liquid slag discharge and oxygen consumption will increase greatly

The fixed bed gasification technology adopts crushed coal or briquette gasification technology. Modern large-scale mechanical coal mining greatly reduces the particle coal yield of the original low-strength brittle lignite, and a large amount of pulverized coal produced is not suitable for fixed bed gasification and needs to be processed. The energy consumption is huge, the proportion of raw coal that can be directly used for gasification is about 10%, and the post-treatment system of fixed bed gasification technology is responsible, the extraction and separation of coal tar is difficult, and environmental protection issues are prominent

According to the current status of gasification technology, circulating fluidized bed gasification technology currently has no reliable technology for long-term stable operation to choose from, and some technical bottlenecks need further research and development breakthroughs

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