The transformation of blast furnace gas fine desulfurization in steel industry has become a general trend

Currently, the desulfurization technology route of the iron and steel industry is mainly controlled from the source and governance at the end. The end treatment needs to set up desulfurization facilities at multiple points, the scale of equipment and facilities becomes larger, and the amount of waste gas after gas combustion is large; the source control is to implement fine desulfurization of blast furnace gas to reduce the sulfur content in the gas, which can greatly reduce the pressure of the end treatment, and even save Drop end treatment facilities. Environmental governance is a systematic project. It is necessary to adhere to the combination of source control and end treatment. If the source is well controlled, the end treatment will be more effective and economical. Fine desulfurization of blast furnace gas has become a technical practice with low resistance, high efficiency and stable operation.

Desulfurization (especially hydrogen sulfide H2S, carbonyl sulfide COS) is in full swing in iron and steel enterprises throughout the country. The removal of carbonyl sulfide is not only the focus of the refined desulfurization process, but also the difficulty to overcome. After a number of measures including laboratory tests, on-site pilot tests, and performance evaluations, and combined with the excellent index effects of the cases that have been put into production, Mingsheng Environmental Protection proposed a "blast furnace gas hydrolysis adsorption multi-stage desulfurization process."

1. Organic sulfur desulfurization mechanism

Since there are few methods for directly removing organic sulfur, organic sulfur is generally treated as inorganic sulfur before removal.

There are two main methods for converting carbonyl sulfide and carbon disulfide into hydrogen sulfide: hydrolysis and hydroconversion. The removal of organic sulfur by hydrolysis method can avoid the occurrence of strong exothermic methanation side reaction because the operating temperature is medium and low temperature. It is a very active research field in the removal of organic sulfur from coal gas at home and abroad. The principle of hydrolysis to remove organic sulfur is mainly to convert organic sulfur into easily removed hydrogen sulfide through a hydrolysis reaction.

2. Dry hydrogen sulfide removal-activated carbon adsorption method

Activated carbon is arranged inside the adsorption tower, the reactor adopts radial flow, advanced design, top loading, and bottom discharge of adsorbent. It can well reduce the pressure drop of coal gas passing through the reactor bed, and the activated carbon utilization rate is high.

The activated carbon adsorption process is mature, and it is widely used as an adsorption medium in the desulfurization and denitration industry. The activated carbon adsorbent has a high sulfur capacity, so that a small amount of activated carbon can meet the adsorption effect and reduce investment and operating costs. The process is simple, the area is small, the investment is low, and no solid waste is generated (saturated activated carbon is sent to sintering as a fuel, and on-site operability needs to be confirmed).

The iron and steel industry should choose mature and applicable environmental protection transformation technologies based on plant conditions, choose reasonable transformation technology routes, and choose as much as possible to cooperate with units with experience in implementing key emission reduction technology projects such as high-efficiency dust removal, hierarchical desulfurization, activated carbon desulfurization and denitrification, and SCR denitrification. , I also hope that the state will give the enterprises in the transformation process sufficient time to continuously improve.