Selective sorbents for purification of hydrocarbons

摘要

CuY and AgY zeolites as selective sorbents for desulfurization of liquid fuels. Thiophene and benzene were used as the model system, and vapor phase isotherms were measured. Compared with NaY, CuY and AgY adsorbed significantly larger amounts of both thiophene and benzene at low pressures. It is hypothesized that this is due to pi-complexation with Cu+ and Ag+. On a per-cation basis, more thiophene was adsorbed by Cu+ than by Ag+, eg. 0.92 molecule/Cu+ versus 0.42 molecule/Ag+ at 2x10-5 atm and 120° C. Molecular orbital calculations confirmed the relative strengths of pi-complexation: thiophene>benzene and Cu+>Ag+. The experimental heats of adsorption for pi-complexation are in qualitative agreement with theoretical predictions. The invention further comprises a process and sorbents for removal of aromatics from hydrocarbons.