Regenerable MgO promoted metal oxide oxygen carriers for chemical looping combustion

摘要

The disclosure provides an oxygen carrier comprised of a plurality of metal oxide particles in contact with a plurality of MgO promoter particles. The MgO promoter particles increase the reaction rate and oxygen utilization of the metal oxide when contacting with a gaseous hydrocarbon at a temperature greater than about 725° C. The promoted oxide solid is generally comprised of less than about 25 wt. % MgO, and may be prepared by physical mixing, incipient wetness impregnation, or other methods known in the art. The oxygen carrier exhibits a crystalline structure of the metal oxide and a crystalline structure of MgO under XRD crystallography, and retains these crystalline structures over subsequent redox cycles. In an embodiment, the metal oxide is Fe2O3, and the gaseous hydrocarbon is comprised of methane.

主权项

1. A method of combusting a gaseous hydrocarbon comprising:
establishing the gaseous hydrocarbon at a temperature greater than 725° C., thereby generating a heated gaseous hydrocarbon; and contacting the heated gaseous hydrocarbon and an oxygen carrier, where the oxygen carrier is comprised of a promoted oxide solid, where the promoted oxide solid is comprised of a plurality of metal oxide particles and a plurality of MgO promoter particles, where the plurality of metal oxide particles comprise at least 50 weight percent of the promoted oxide solid, and where at least some portion of the plurality of metal oxide particles is in physical contact with at least some portion of the MgO promoter particles, thereby producing combustion gases and a reduced carrier, where the combustion gases are comprised of CO2 and H2O and where the combustion gases have a substantial absence of CO and H2, and where the reduced carrier is comprised of a plurality of reduced metal oxide particles and the plurality of MgO promoter particles, where the plurality of reduced metal oxide particles are a reduction product of the plurality of metal oxide particles, thereby combusting the gaseous hydrocarbon.