The Claus process is the most significant gas desulfurizing process that recovers elemental sulfur from gaseous hydrogen sulfide found in raw natural gas and from the by-product gases containing hydrogen sulfide derived from refining crude oil, gasification, and other industrial processes. Fluor's proprietary Claus process can accommodate a wide range of applications. It can be configured to process acid gas streams relatively rich in H2S with a maximum recovery of 98% from a three stage design. For acid gases that are diluted in H2S and/or containing certain levels of contaminates such as BTX, ammonia, and cyanide. Fluor's proprietary process configurations can be customized to provide the highest safety, reliability, and cost-effective scheme for any applications in the industry. For applications where recovery loss via formation of COS and CS2 is a concern, our proprietary design utilizes TiO2 catalyst in the Claus catalytic stages to achieve the highest desirable sulfur recovery efficiency.