Coke Gas Low Temperature Desulfurizer Development And Industrial Desulfurization Process Design

Activated carbon is usually used as sorbents because of its abundant and developed pore structures, especially for bleaching and odor removal. Since 1930s, activated carbon has been used in the petroleum and fertilizer industries for H2S removal. The modified activated has many advantages such as high efficiency、high sulfur capacity and high-accuracy for sulfur removal. In this thesis a modified activated carbon desulfurizing agent has been developed for the hydrogen sulfide removal from coal gas at low temperature. The design of the desulfurizing equipment and the technology has also been made for a practical industrial application.Firstly, the effects of the content of impregnated agent and additive have been investigated. The best content of Na2CO3 and additive are 6% and 0.5%, respectively. The sulfur capacity could reach up to 60% by weight. It showed that the Na2CO3 could change the chemical property of surface but the additive couldn’t. The best operation conditions of sulfur removal are:the content of Ot is four times of the concentration of H2S, the RH of coke gas is rang from 80% to100%、the temperature is 40℃and as low space velocity as possible.Secondly, according to experimental observations the mechanism of sulfur removal has been presented:the sulfur removal process took place in the pore of the activated carbon. The water in coke gas was absorbed on the activated carbon surface to form a water film. The H2S and O2 dissolved into the water film followed by diffusing into activated carbon pore. H2S is hydrolysed into H+and HS’. The O2 was absorbed and activated after diffusing into activated carbon pores. Then it reacts with HS" to sulfur accumulated on the activate carbon pores. At the same time, the O-O is broken and more reacted with the HS- in the water film. This mechanism can be used to interpret most experimental observations well.Finally, the industrial equipment and technology for H2S removal from 5500m3/h coke gas have been designed. The cost and economic benefits of the technology have been analyzed. It is concluded that this H2S removal technology can be used in the production of top-grade ceramics.