ADVANCED CATALYST FOR NOX REDUCTION USING HYDROCARBONS FROM LEAN-BURNING GAS-ENGINE

For a catalytic NOx reduction process for natural gas-fueled lean-burn ing engines; selective catalytic reduction of NOx by propane was studi ed on metal ion-exchanged zeolite catalysts. A comparative study on Cu -and Co-ZSM-5 showed the superiority of Go-bared catalysts for C3H8-SC R in the presence of water vapor. Investigation into various Go-zeolit e catalysts showed that Go-Beta has superior activity and selectivity for NOx reduction. Durability tests of the catalyst in a model gas sim ulating gas engine exhaust showed that the activity of Go-Beta is suff icient even in the presence of SOx after 5000 h of operation, whereas Co-Mordenite and Co-ZSM-5 lost their activity in several hundred hours of operation, (C) 1997 Elsevier Science B.V.