(159c) Development of catalysts for removal of sulfur compounds from natural gas

Removal of sulfur compounds, such as H2S and mercaptans from natural gas, has become important due to their negative impact on the environment if released, as well as corrosion in equipment and pipelines. Previous studies have been conducted on the removal of mercaptans at relatively high temperatures using different materials . However, there is a need of developing new catalysts to remove mercaptans at low temperatures and pressures. These operating conditions could result in significant cost savings. The main goal of this research is to develop catalysts that perform better than the state of the art removing sulfur compounds from natural gas. These new catalysts could be applied as a pre-treatment to C1 upgrading into specialty chemicals, especially as part of a distributed network to produce specialty chemicals at well sites. The development on new catalysts requires detailed investigation of the adsorption/reaction mechanisms for ethyl/methyl mercaptans on different catalysts. Breakthrough experiments were performed for ethyl mercaptan removal from natural gas to determine optimum operating conditions. Results were correlated with catalysts’ composition. An online bench scale flow system where the outlet of a packed bed reactor is connected to a Gas Chromatograph/Mass Spectrometer was used to study the catalysts efficiencies, reaction by-products, and adsorption/reaction mechanisms. Several techniques were used to characterize the raw and spent catalysts, such as BET, FTIR, PIXE, and SEM analyses. Integration of data from these analytical tools also assisted on the development of reaction mechanisms and the correlation with surface composition, which will yield new synthesis strategies for catalysts.