METHOD FOR TREATING NOX IN EXHAUST GAS AND SYSTEM THEREFORE
    10.
    发明公开
    METHOD FOR TREATING NOX IN EXHAUST GAS AND SYSTEM THEREFORE 有权
    方法第尾气和系统处理NOX THEREOF

    公开(公告)号:EP2238320A1

    公开(公告)日:2010-10-13

    申请号:EP08864597.3

    申请日:2008-11-10

    Abstract: The present invention relates to a method for the treatment of an exhaust gas comprising NOx, wherein the method comprises the step of subjecting the exhaust gas to an exhaust gas treatment system comprising, in order of the exhaust stream: (a) a first NOx storage catalytic converter (2, 2' ); (b) a catalytic converter (3) for selective catalytic reduction (SCR) downstream of the first NOx storage catalytic converter; and (C) a catalytic converter (4) having oxygen storage capacity downstream of the SCR catalytic converter; wherein the exhaust gas treatment system is operated in alternating rich and lean phases, wherein the rich phase is terminated when the amount of reducing components leaving the first NOx storage catalytic converter is at least 0.05 times the amount of reducing components consumed by the first NOx storage catalytic converter during the time interval beginning when the air/fuel ratio upstream of the first NOx storage catalytic converter turns from lean to rich conditions and ending when the air/ fuel ratio downstream of the first NOx storage catalytic converter turns from lean to rich conditions. Optionally there can be provided a close coupled three-way or diesel oxidation or NOx storage catalytic converter (1, 1').

Patent Agency Ranking