Development of novel copper-based sorbents for hot gas cleanup

The objective of this investigation is to evaluate two novel copper-based sorbents (i.e. copper-chromium and copper-cerium) for their effectiveness in removing hydrogen sulfide from fuel gas in the temperature range of 650[degree] to 850[degree]C. New sorbent compositions from the selected Cu-Cr-O and Cu-Ce-O binary oxides were prepared and characterized by BET N[sub 2]-desorption surface area measurement following various calcination/time-temperature exposures. The general trends reported last quarter (on 11 different compositions) were validated this quarter in that both binary oxides lose surface area as the amount of CuO is increased. Time-resolved sulfidation tests were conducted at 850[degree]C using the equimolar CuO.Cr[sub 2]O[sub 3] composition. The two selected binary oxides prepared in larger qauntities (for testing in a two-inch reactor) have physical properties typical of the sorbents prepared in past programs. Two multicycle desulfurization tests, conducted this quarter on the Cu-Ce-O sorbent at 850[degree]C, using a feed gas containing 5000 ppm H[sub 2]S, 10 vol % H[sub 2] and 10 vol % H[sub 2]O at a space velocity (STP) of 2000 h[sup [minus]1], demonstrated high sulfur removal efficiency for the first one or two cycles, and a significant reduction in efficiency in the following cycles.