Desulfurization of diesel fuels by adsorption via pi-complexation with vapor-phase exchanged Cu(I)-Y zeolites.

Desulfurization of a commercial diesel fuel by vapor-phase ion exchange (VPIE) copper(I) faujasite zeolites was studied in a fixed-bed adsorber operated at ambient temperature and pressure. The zeolite adsorbed approximately five thiophenic molecules per unit cell. After treating 18 cm3 of fuel, the cumulative average sulfur concentration detected was 0.032 ppmw-S. GC-FPD results showed that the pi-complexation sorbents selectively adsorbed highly substituted thiophenes, benzothiophenes, and dibenzothiophenes from diesel, which is not possible by using conventional hydrodesulfurization (HDS) reactors. The high sulfur selectivity and high sulfur capacity of the VPIE Cu(II)-zeolites were due to pi-complexation.