Is Hydrogen Cyanide a Detriment to Coke Gas Purification Technology?

摘要

The Ukraine annually produces 18 million mt of coke, which is accompanied by formation at coke and chemicals plants of something on the order of 12 thousand mt of hydrogen cyanide per year. Most of the HCN is concentrated in the coke gas. Coke chemists are not perturbed by the presence of 0.5-1.5 g/m~3 HCN in coke gas, but this component is of much concern in the coke gas treatment process, i.e., its purification. That portion of the HCN which remains in the coke gas after it goes through a standard purification system is burned off in coke ovens and metallurgical furnaces. A total of 350-400 ppm of nitrogen-containing components (NH_3, HCN, C_5H_5N) per m~3 of combustion product volume is formed in burning this gas; these components also pollute the atmosphere of industrial areas. The presence of HCN creates definite difficulties in the coke gas purification process. The main requirement imposed coke gas purification, other than limitation of nitrogen-containing components, is that of holding the contents of hydrogen sulfide and organosulfur compounds within the limits set by the European Convention on Long-Range Transboundary Air Pollution (1979), which was ratified at the time by both the USSR and Ukraine.