PROCESS FOR TREATING A GAS STREAM

摘要

A process for treating a gas comprising hydrogen sulfide and carbon dioxide by contacting the gas with a scrub solution comprising ammonium sulfite and ammonium bisulfite in a first contact zone to produce ammonium thiosulfate. The scrub solution can be formed in a second contact zone by contacting ammonia and hydrogen sulfide with an aqueous solution. The oxidation potential of the first contact zone effluent liquid can be controlled by modulating the amount of sulfur dioxide supplied to the second contact zone. Alternatively, the sulfite concentration of the first contact zone effluent can be measured with an infrared analyzer and the amount of sulfur dioxide supplied to the second contact zone modulated in response. Additionaily, the amount of ammonia supplied to the second contact zone can be modulated in response to the pH in the second contact zone. The process can further comprise a solvent scrubber to remove carbon dioxide from the first contact zone overhead gas. A third contact zone can be included in the process to separate the hydrogen sulfite from the carbon dioxide in the solvent regenerator overhead gas.