Influence of Impurities on Sulfur Removal from Coke-Oven Gas

摘要

The extraction of hydrogen sulfide from coke-oven gas by means of alkaline aqueous solutions occurs in the presence of several acidic components, which dissolve to form acids with different degrees of dissociation. The relation between the acidic components of the gas depends on the batch composition and the corresponding coking conditions. The ratio H2S/CO2 decreases on coking coal with low sulfur content and elevated calcium content and with an elevated content of gas coal. There is little scope for slowing the CO2 absorption. The selectivity of H2S capture increases somewhat with increase in content of ballast salts. A general analysis of ballast-salt formation is proposed for circulatory and oxidative methods of sulfur removal. The influence of ballast salts on the activity of the absorbent solution in arsenic-soda sulfur removal is not critical. That may be explained in terms of As5+/As3+ conversion. The oxidation of hydrogen cyanide by strong acids produces compounds that cannot be regenerated; recommendations are made for slowing that process. The influence of organic contaminants on the removal of sulfur from coke-oven gas is considered.