DEVELOPMENT OF MATHEMATICAL MODELLING FOR THE EXTRACTION OF HaS FROM LPG USING DEA AS A SOLVENT

Abstract

Liquefied petroleum gas (LPG) is a subcategory of a versatile class of petroleum products known as natural gas liquids (NGLs) that are produced along with natural gas. LPG is also produced from the refining of crude oil. LPG is commercially defined as mixture of propane and butane. When LPG is produced from the refining of crude oil, various common contaminants like 002, H2S, mercaptans, COS, CS2 and elemental sulfur are present in LPGs. Each of these contaminants can cause problems in the finished products. H2S is corrosive and its presence can lead to deposition of free sulfur. Sulfur may also corrode the fuel system and engine parts. Burning of these contaminants with LPG causes air pollution. So acid gas contaminants must be removed before selling and using LPG. Several methods have been used to remove these contaminants. If the quantities of the contaminants are small, a simple caustic wash can be used. For larger quantities molecular sieves and amine treating system can be • used. While molecular sieves has large capital and operating cost. So the use of amine has become popular. In recent years, there has been increasing interest in removing H2S from LPG with amines. Although limited data and design considerations are available in the literature, an operating experience was broadened during the last decade for diethanolamine (DEA). The removing of H2S from LPG using amine solution is basically an absorption process. Hence an effort has bee made to develop a mathematical model for the above absorption process for the removal of H2S from LPG using DEA as a solvent.