Sorbents for Desulfurization of Gasoline Blends

Conventionally, deep desulfurization in a refinery is accomplished by a multistep process including hydrodesulfurization (HDS) over CoMo/Al2O3 and NiMo/Al2O3 catalysts and subsequent removal of the H2S. The HDS process, however, is not suited well to produce ultraclean (essentially sulfur free) transportation fuels. At the severe reaction conditions required for deep desulfurization, the olefins and aromatics in the gasoline become saturated, decreasing the octane number and value of the fuel. TDA Research, Inc. (TDA) proposed to develop a low-cost, high-capacity sorbent that removes the organic sulfur from gasoline blend stocks, producing a fuel the meets the new 30 ppm sulfur specification for gasoline. In Phase I, TDA will prepare various sorbent formulations and screen them to determine their capacity to remove sulfur under representative conditions. Based on the performance results, TDA will carry out a preliminary design of the desulfurization system and estimate its size and cost. An engineering assessment to evaluate its merits also will be conducted. To reduce the emissions of environmental pollutants, the U.S. Environmental Protection Agency (EPA) has announced new regulations that require refineries to reduce sulfur levels in the transportation fuels; the allowable sulfur in gasoline is being reduced from 330 to 20 ppmw in diesel by 2006. TDA’s technology will supply U.S. refineries with a cost-effective sulfur removal technology that helps them to meet the EPA target and the even lower target that likely will be implemented in the future.