Ultra-deep removal device for organic sulfur in coke oven coal gas, and removal process thereof

Abstract

The invention discloses an ultra-deep removal device for organic sulfur in coke oven coal gas, and a removal process thereof. The device comprises an oil removal tower, a first heat exchanger, a pre-hydrogenation and first-stage hydrogenation reactor, a condenser, a normal-temperature desulfurization tower, a second heat exchanger, a second-stage hydrogenation reactor, a cobalt-molybdenum hydrogenation reactor, a fine desulfurization tower and an ultra-fine desulfurization tower. According to the scheme, the cobalt-molybdenum hydrogenation reactor and the ultra-fine desulfurization tower are simultaneously arranged at the front end and the rear end of the fine desulfurization tower, and the cobalt-molybdenum hydrogenation reactor is arranged between the second-stage hydrogenation reactor and the fine desulfurization tower, so that the content of the residual organic sulfur in the fine desulfurization tower is less than 0.03 ppm; and the ultra-fine desulfurization tower is arranged behind the fine desulfurization tower, so that the content of the organic sulfur in coke oven coal gas is continuously and stably controlled at less than 0.01 ppm so as to improve the service life of a catalyst in a methanation process, reduce the use cost of the catalyst by more than 30%, improve the stability of the methanation process, improve the yield of natural gas by more than 5% and substantially reduce the production and operation cost.

Description

technical field [0001] The invention relates to the technical field of desulfurization, in particular to an ultra-deep removal device for organic sulfur in coke oven gas and a removal process thereof. Background technique [0002] After the coke oven gas is pretreated, the coke oven gas still contains organic sulfur mainly carbon sulfide and thiophene, and the organic sulfur is toxic to the catalyst (zinc oxide) in the subsequent methanation of coke oven gas to natural gas. The two-stage hydrogenation and fine desulfurization process removes organic sulfur in coke oven gas. Since the ability of zinc oxide to remove organic sulfur is weaker than hydrogen sulfide, it is difficult to effectively reduce the sulfur content of organic sulfur in coke oven gas. Coke oven gas There are still traces of organic sulfur such as carbon sulfide and thiophene remaining in the gas, and the total organic sulfur content is often greater than 0.1ppm, which can easily cause catalyst poisoning, g...

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Problems solved by technology

[0002] After the coke oven gas is pretreated, the coke oven gas still contains organic sulfur mainly carbon sulfide and thiophene, and the organic sulfur is toxic to the catalyst (zinc oxide) in the subsequent methanation of coke oven gas to natural gas. The two-stage hydrogenation and fine desulfurization process removes organic sulfur in coke oven gas. Since the ability of zinc oxide to remove organic sulfur is weaker than that of hydrogen sulfide, it is difficult to effectively reduce the sulfur content of organic sulfur in coke oven gas. There are still traces of organic sulfur such as carbon sulfide and thiophene remaining in the gas, and the total organic sulfur content is often greater than 0.1ppm, which can easily cause catalyst poisoning, greatly reduce its service life, and cause the production cost of natural gas to be too high

[0003] Installing a cobalt-molybdenum hydrogenation reactor between the secondary hydrogenation reactor and the fine desulfurization tower can reduce the organic sulfur content in the coke oven gas from the usual 0.1ppm to below 0.03ppm, but the value of the organic sulfur content is easy to fluctuate , sometimes between 0.01ppm ~ 0.03ppm, sometimes less than 0.01ppm, the content of organic sulfur is relatively unstable, and the catalyst in the subsequent methanation process is very sensitive to the content of organic sulfur, even if coke oven gas contains 0.01 ~ 0.03 A very small amount of organic sulfur in ppm will still shorten the service life of the catalyst and cause an increase in the production cost of the methanation process

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