Sulfur Recovery from Sour Natural Gas: A Review of Gas Treating/Claus Plant Design and Operations

Abstract

American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc. Abstract The decision to build a sour natural gas treating facility for the purpose of sweetening the gas and recovery of elemental sulfur involves many considerations, and usually represents a significant investment. Selection of the optimum gas treating process and sulfur recovery scheme may to a process and sulfur recovery scheme may to a complex problem. Many well established criteria are important to consider during the design phase of such a project. Subsequent operation of these facilities requires a good knowledge of potential problem areas. This paper is a general review of the main factors that should be considered in the selection, design, and operation of a gas treating/sulfur recovery facility. Introduction Today we are facing a serious energy crisis in this country. All available natural gas reserves will be needed in the future. Some operating companies are reluctant to produce sour gas wells today, because of the high cost of treating the gas to remove H2S and other contaminants to meet sales gas specifications. This picture is changing rapidly as the price for gas increases and the supply of available energy dwindles. In the past (1965–1970), an added incentive for treating sour gas was recovery of the elemental sulfur. At present, the market situation for sulfur is not very favorable. The supply is plentiful and the price is somewhat depressed. However, the price is somewhat depressed. However, the future looks brighter. About 50% of all sulfur produced in the U.S. and Canada is consumed in the manufacture of fertilizers. Since the world population growth and need for fertilizers is on the incline, it is probably safe to assume that the price for probably safe to assume that the price for sulfur will follow an upward trend in the future. Once a sour gas well is drilled or a "sour gas field" drilling activity is completed, the producer must consider such questions as:Is it more economical to lay a sour gasline to the nearest gas treating plant, which may have excess capacity, and pay a treating cost to have the gas sweetened?Or, is it more economical to lease equipment for on-site sweetening?