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 Coke Oven Gas |
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| DDS desulfurization project for coke oven gas in Tonglin Taifu Special Material Co., Ltd. |
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Our company successfully operated the coke oven gas desulfurization project in Tongling Taifu Special Material Co., Ltd.
The amount of coke oven gas in Tongling Taifu is 120000Nm³/h, and the hydrogen sulfide content in coke oven gas is 3000~12000 mg/Nm³. The process is that the coke oven gas from the pressurized fan enters the first-level desulfurization and the second-level desulfurization in series. The coke oven gas after the secondary desulfurization is sent to the boiler of the power plant to be burned to generate electricity. The first-stage desulfurization is used in parallel by two sets of high-tower regeneration desulfurization systems, each with a coke oven gas input of 60,000Nm³/h. The situation of a single high-tower regeneration desulfurization system: the diameter of the desulfurization tower is φ7000mm, and the height of the packing is 18 meters. The solution circulation volume is 2000m³/h, and the regeneration air volume is 1500Nm³/h. The second-level desulfurization is a single-tower one-tower desulfurization device. The desulfurization tower has a diameter of 9000mm, the height of the packing is 18 meters, a solution circulation volume of 3000m³/h, and a regeneration air volume of 2000Nm³/h. The total desulfurization solution holdings for the primary desulfurization and secondary desulfurization are about 3000m³.
The company used to use PDS catalyst for desulfurization. The first-level desulfurization outlet has a hydrogen sulfide content of 800~1000mg/Nm³; the second-level desulfurization outlet has a hydrogen sulfide content of 15~150mg/Nm³. Under this desulfurization efficiency, PDS is consumed every day with the cost of about 10,000~15,000 yuan. At this time, we did a research on the amount of PDS and found that when we continue to increase the amount of PDS input, the desulfurization efficiency cannot be significantly improved. The content of SO₂ in the flue gas after the combustion of coke oven gas in power plants is greater than 100mg/Nm³.
Since the enterprise has used PDS, serious tower blockage has often occurred, the system resistance is very large, and production cannot be continued. In this case, the owner decided to use DDS biological desulfurization technology to replace PDS desulfurization technology.
Under the same process parameters and operating conditions, after changing to DDS biological desulfurization technology, the hydrogen sulfide content at the first-level desulfurization outlet is reduced to 300~500mg/Nm³; the hydrogen sulfide content at the second-level desulfurization outlet is reduced to 0~10mg/Nm³, it cannot be detected In most cases. While maintaining this desulfurization efficiency, the daily cost of DDS catalyst series products is about 15,000~18,000 yuan (due to the factory’s habit: desulfurization solution is used to extract salt every day, and tens of cubic meters of desulfurization solution are lost every day. We told them that it is unnecessary to carry out salt extraction now. Even if the salt is to be extracted, do not use activated carbon for decolorization. The mother liquor after the salt extraction can be returned to the system. If there is no loss of the desulfurization solution, the consumption will be lower). In the early stage (about 30 days), the cost of the DDS catalyst series chemicals used to replace the desulfurization solution is about 3.6 million yuan. After adopting the DDS biological desulfurization technology, the system resistance does not increase, the process can continue to operate, and the desulfurization efficiency is significantly improved. At the same time, the content of SO₂ in the flue gas after the combustion of coke oven gas in power plants is reduced to 8~50mg/Nm³. |
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