Experimental Study on the Influence of Metal Oxide Catalyst Performance in Sulfur Compounds Removal from Natural Gas

Sulfur compounds are extremely toxic and highly corrosive (e.g. mercaptans and hy-drogen sulfide) and are commonly found in natural gas streams and can be damaging even if only minute amounts are present in natural gas streams because it can affect the quality of fuels and cause failure of downstream equipment. Many metal oxides have been used as adsorbent/catalyst for the removal of sulfur compounds from natural gas; however, they vary greatly in how well they can remove sulfur compounds, and the underlying mechanisms of these processes are still not fully understood. Therefore, the purpose of this study was to examine the adsorption/removal performance of many metal oxides on halloysite support at the same conditions to identify the relationship between the electronic properties (specifically bandgap energy) and breakthrough time (a measure of removal/adsorption efficiency). The experimental results indicate large differences in the adsorption performance of the studied oxides and some commercial metal oxides had lower than expected adsorption performance. Conversely, all the studied oxides with the lowest bandgap energies showed higher sulfur compound (e.g. ethyl mercaptan) uptake and longer breakthrough times indicating that the electronic properties of the oxides are important in determining the strength of interaction be-tween the sulfur compounds and the metal oxide. The experimental results from this study will provide understanding of why certain metal oxides may not perform as good as others during natural gas desulfurization and assist in developing a systematic method for selecting adsorbents/catalysts that will improve the overall natural gas desulfurization process. Furthermore, incorporating palladium oxides into the base catalyst formulation achieved a maximum breakthrough time of 630 minutes at 25°C 200 psi, and 36 mL/min. These findings provide critical insights for developing catalysts that integrate metal oxides to enhance adsorption efficiency while reducing hazardous byproducts during sulfur compounds (e.g. mercaptans and hydrogen sulfide) removal from natural gas.