Combined method and combined system based on low-rank coal pyrolysis, water vapor coke quenching and water gas producing hydrogen

Abstract

The invention relates to a combined method and a combined system based on low-rank coal pyrolysis, water vapor coke quenching and water gas producing hydrogen. The method includes the steps of: 1) increasing temperature of semicoke generated in a low temperature dry distillation furnace and enabling the semicoke to move down slowly; 2) continuously spraying water vapor upwardly so that heat exchange is carried out between the water vapor and the high-temperature semicoke; 3) after temperature increase through the heat exchange, performing a gasification reaction to the water vapor and a part of the high-temperature semicoke to generate water gas; 4) collecting, purifying and separating the water gas to produce H2 and CO, and performing a reaction to the CO to obtain H2, and mixing and purifying all of the H2 to obtain pure H2; and 5) in a moving down process, carrying out heat exchange to the other part of the high-temperature semicoke, which is not subjected to the gasification reaction, with the water vapor to reduce the temperature, and cooling the semicoke further and outputting the semicoke. In the invention, a hydrogen production method, which has lowest cost, is found for coal tar hydrogenation, wherein the raw material, semicoke, which is low in cost and high in quality, is completely utilized, and a coke quenching system and a hydrogen production system are optimized and integrated. The combined method has simplified process route, is convenient and safe to carry out, and is beneficial to industrial development of clean and high-effective utilization of coal.

Description

technical field [0001] The invention relates to the technical field of clean and efficient utilization of coal, in particular to a combined method and system based on low-rank coal pyrolysis, steam coke quenching, and water gas hydrogen production. Background technique [0002] With the adjustment of the national energy strategy, the clean and efficient utilization of coal is listed as the eighth among the 100 major projects in my country's 13th Five-Year Plan. At present, the clean and efficient utilization of coal resources mainly includes: high-volatility and low-rank coal low-temperature pyrolysis pyrolysis upgrading, coal tar hydrogenation to fuel oil, raw gas power generation, synthetic fuels and production of high value-added chemical product raw materials. Among them, coal tar hydrogenation to produce diesel, gasoline and other fuel products requires a large amount of pure hydrogen raw materials. The existing hydrogen production methods mainly include: hydrogen prod...

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Problems solved by technology

The existing hydrogen production methods mainly include: hydrogen production by electrolysis of water, oxygen production by hydrocarbons, oxygen production by natural gas, hydrogen production by methanol, hydrogen production by coal gasification, etc. These methods are due to expensive raw materials, high energy consumption, large investment in process equipment, and difficult operation process. High cost, high cost of pure hydrogen products

In addition, the hot semi-coke after low-temperature carbonization of coal is mainly quenched with water to cool down, and then dried again, which seriously wastes water and heat sources, and the quality of semi-coke products is poor due to secondary pollution.

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