Enabling Cleaner Fuels: Desulfurization by Adsorption to Microporous Coordination Polymers

Microporous coordination polymers (MCPs) are demonstrated to be efficient adsorbents for the removal of the organosulfur compounds dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (DMDBT) from model diesel fuel and diesel fuel. For example, packed bed breakthrough experiments utilizing UMCM-150 find capacities of 25.1 g S/kg MCP for DBT and 24.3 g S/kg MCP for DMDBT from authentic diesel indicating that large amounts of fuel are desulfurized before the breakthrough point. Unlike activated carbons, where selectivity, has been a problem, MCPs selectively adsorb the organosulfur compounds over other, similar components of diesel. Complete regeneration using toluene at modest temperatures is achieved. The attainment of high selectivities and capacities, particularly for the adsorption of the refractory compounds that are difficult to remove using current desulfurization techniques, in a reversible sorbent indicates that fuel desulfurization may be an important application for MCPs.