Economic assessment of Temperature Swing Adsorption systems as Claus Tail Gas Clean Up Units

Current regulations of SO_x emissions require Sulfur Recovery Units (SRUs) to achieve recoveries in excess of 99.9%. Capital cost of existing commercial Claus Tail gas clean up technologies capable of achieving that benchmark can amount to 45% of the total capital cost of the SRU. Adsorption based processes hold significant potential for achieving the targeted recovery at lower costs considering their high selectivity towards removal of ppm level contaminants. This work assesses the economics of a Tail Gas Treatment Unit relying on a Temperature Swing Adsorption module for treating a typical industrial feed. An optimization problem is formulated and solved to determine the designs that minimize Net Present Worth (NPWC) of total capital investment,operating and bed replacement costs ensued during a 30 years project life. The total capital investment contribution of the optimized TGTU is around $20M comprising ~65% of the NPWC value. Operating costs ranged between $3.0 and $3.6 per tonne of sulfur. Both figures compare favorably with commercial technologies.