| 摘要 |
<p>In a process for manufacturing sulphuric acid using nitric oxide by burning gases containing hydrogen sulphide and nitrogen-hydrogen compounds with air to gases containing sulphur dioxide and water vapour, the combustion is carried out with a limited excess of air, e.g. up to 100 per cent excess of the theoretical amount for complete combustion of all the combustible constituents of the gases at temperatures above 1150 DEG C. with formation of nitric oxide and the combustion gases are cooled immediately after formation of the nitric oxide to a point where nitric oxide is not decomposed to any appreciable extent, say 320 DEG C., and the cooled gases, without any or any substantial addition of nitric oxide or nitric acid, are afterwards treated in a lead chamber, tower, or other NO-system to form sulphuric acid. The nitric oxide in the gases is sufficient to maintain the nitrosyl content of the circulating chamber or tower acid constant for some time. The hydrogen sulphide gases may be any commercial gases, such as those from wet desulphurization of coke-oven gas, working up crude oils, or hydrogenation of coal or oil, which contain hydrogen cyanide and ammonia. Cooling may be effected by passage through a waste heat boiler. The air passed to the burner may be preheated.</p> |
