Pressure Swing Adsorption Technology

Abstract

Separation and purification of gas mixtures by pressure swing adsorption (PSA) technology has become an important unit operation in the chemical industry in the last twenty-five years. A large variety of binary and multi-component gas mixtures are commercially being separated using this technology. Table 1 provides a comprehensive list of the major applications of the technology [1-3] and Figure 1 shows the year-by-year tally of the number of worldwide patents issued between 1970-1987 [4] with PSA as the key words in the titles. It is apparent that the growth in research and development and commercialization of PSA processes has been rather spectacular in the last two decades and the future of this technology is very promising. The key reason for this outstanding progress is that the PSA technology can provide a very flexible and efficient means of gas separation and it can reduce the energy and cost of separation compared to conventional separation processes like absorption and distillation for many applications. This is particularly important today when international competition is formidable and energy costs are high. Table 1 Major Applications of Pressure Swing Adsorption Technology • Gas Drying • Air Separation Production of 80-95% 02 enriched gas from air. Production of 25-50% 02 enriched gas from air. Production of 95-99.9+% N2 from air. Argon purification from crude argon produced by liquid air distillation. Removal of water and carbon dioxide from air feed to distillation columns. • Carbon Dioxide-Methane Separation Purification of landfill gas Upgrading crude natural gas • Carbon Monoxide Production Carbon monoxide recovery from blast furnace and other waste gases from steel industry. 285