Gas transformation deep purifying technique for separating and purifying CO and H2 of calcium carbide furnace

Abstract

The invention relates to a gas transformation deep purifying technique for separating and purifying CO and H2 of a calcium carbide furnace. The gas transformation deep purifying technique comprises a pressurizing and deep dedusting system, a transforming system, a decarbonization and desulfurizing system, a deep purifying system, a pressure swing adsorption system, a dehydrogenation and dehydration system, and a deoxidizing, decarbonization and dehydration system. The assorted gas transformation deep purifying technique which is capable of realizing industrial scale and high purity is firstly provided for separating and purifying CO and H2, the problems about dust extraction of tail gas of the calcium carbide furnace, high-concentration CO transformation, various complicated-component impurities in the tail gas of the calcium carbide furnace, removal of low-concentration sulfur and the like are solved, the gas transformation deep purifying technique has the advantages of high CO and H2 yield, stability of operating of devices, high heat utilization rate, and industrial exhaust gas can be effectively recycled, energy is saved, and emission is reduced. The gas transformation deep purifying technique is applicable to the technical field of gas separation.

Description

technical field [0001] The invention relates to the technical field of coal gas separation, and is particularly suitable for the deep purification of calcium carbide furnace gas shift for separating and purifying CO and H2. Background technique [0002] Calcium carbide is an industry with high energy consumption and high emissions. In calcium carbide production, calcium carbide furnace gas is the biggest source of pollution. Data show that there are currently nearly 400 calcium carbide production enterprises in the country, with a total annual output of more than 15 million tons. Calcium carbide furnaces emit about 8 million tons of waste gas (carbon dioxide) and 600,000 tons of dust every year, causing great pollution to the environment; especially the main component of calcium carbide furnace gas is carbon monoxide (75%~90%), all of which are white "sky lanterns" , which is equivalent to wasting 2.4 million tons of standard coal each year and emitting about 12 million to...

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Problems solved by technology

The problems that need to be solved to realize the comprehensive utilization of calcium carbide furnace gas: First, the dust removal of the furnace gas: first, the dust and a small amount of tar in the furnace gas must be removed. Due to the high temperature of the furnace gas, the particle size of the dust contained is equivalent to the soot level, and contains tar , which brings difficulties to furnace gas purification; secondly, the conversion of high-concentration CO is difficult, and domestic coal gasification technologies such as Lurgi, Shell, Tsinghua Furnace, and four-nozzle pressurized gasifier have the highest CO concentration in furnace gas. 60%, while the CO concentration in the tail gas of calcium carbide furnace can reach 75%~80%. In the prior art, adiabatic furnaces are often used to control the temperature, which will cause overheating phenomenon. In order to avoid overheating phenomenon, a large number of furnaces must be invested, but It will cause high consumption of furnace gas and huge investment; third, there are many types of impurities in the tail gas of calcium carbide furnace, the content of impurities is low and the composition is complex. The furnace gas contains acetylene, ethylene, propylene, butene, chlorine, phosphorus, arsenic, sulfur, HCN and other impurities, the removal requirement is less than 0.1ppm, and the deep purification requirements for low-content impurities are strict and difficult; fourth, there are many types of sulfur in the tail gas of calcium carbide furnace and the content is low, and it is difficult to remove low-concentration sulfur. The form of sulfur in the exhaust gas is as H 2 S, COS, CS 2 , mercaptan, sulfide, thiophene, etc., are low in content and difficult to remove below 0.1ppm, and the sulfur content in the syngas of coal gasification is relatively simple, so coal gasification does not need to consider various impurities

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