Recent Developments in Sulfur Production from Hydrogen Sulfide-Containing Gases

Since the 1950's there has been a remarkable growth in sulfur production from the hydrogen sulfide of natural and refinery gases. Once a minor source of world brimstone, sour gas now makes a very significant contribution to world sulfur production. The early pioneering work on sour gas production and conversion to sulfur has been followed in the last ten years by some remarkable developments in both recovery and processing. Deep, hot, high pressure sour gas deposits, previously avoided as technologically unworkable, can now be produced using modern metallurgy and anticorrosion techniques. Improved methods for separating the acid gases (H 2 S, CO 2 ) from the hydrocarbon component using kinetic rather than equilibrium control of sweetening solution loading have been developed. The efficiency of the Claus Process, long the means of conversion of H 2 S to sulfur, has been increased through improvements in reaction furnace, catalyst bed and computerized feed composition control leading to recovery efficiencies in excess of 98%. Recent development of a Claus Process under pressure may yield further important improvements. Add on tail gas clean-up processes have further reduced plant effluent in response to environmental protection requirements. The sulfur product itself has also been the subject of recent research and development with improvements in handling, storage and transportation of both liquid and new types of formed, solid sulfur.