Sour gas sulfur recovery using high density circulating fluidized bed reactor technology

The use of high density circulating fluidized bed (HDCFB) reactor technology for sour gas sulfur recovery was discussed. Some of the benefits of circulating fluidized bed (CFB) reactors include the excellent gas-solid contacting , near isothermal operation, and continuous catalyst regeneration. The modified Claus process includes those characteristics plus fast, reversible, exothermic reactions. The use of pneumatic transport and low density fast fluidized CFB riser reactors in a Claus plant being fed 200 t/d of sulfur was simulated. The relatively low solids hold-up prevented the achievement of the overall sulfur recovery. It was suggested that if the hold-up were increased, the H2S conversion would be attainable. HDCFB risers are a subset of the fast fluidization regime in which the lower dense zone extends throughout the entire length of the riser. Solids hold-ups in excess of 20 per cent, are achievable in HDCFB risers and deserve examination in a Claus application. A model for an HDCFB Claus converter was developed to determine whether it could achieve the necessary H2S conversion required to eliminate the need for tail-gas clean-up units