NO_x removal membrane reactors using oxygen- permeable dense film of perovskite-type oxide

摘要

Two types of NO_x removal membrane reactorsusing an oxygen-permeable dense film ofLa_0.2Sr_0.8Co_0.8Fe_0.2O_3(LSCF 2882) were constructedand their working performance was investigated. One reactor wasthe NO decomposition type, NO?LSCF 2882?He, to catalyze thedirect decomposition of NO(2 NO -> N_2+O_2) and the otherwas the NO reduction type, NO?LSCF 2882?CH_4, to catalyzethe reduction of NO with CH_4(4NO+CH_4->2 N_2 +CO_2+2H_2O). Both types of membrane reactors worked steadily, andthe rate of N_2 formation at the NO side, R[N_2], in thereduction-type reactor was higher than that in the decomposition-type reactor. When La_0.8Sr_0.2CoO_3 powder catalyst wascoated on the NO side, R[N_2] increased but the rated of O_2 andCO_2 formation at the other side of the membrane were lowerthan the values expected from the R[N_2], indicating that thereactor performance is limited by the rate of oxygen permeationthrough the membrane.