Abstract:
内燃機関において、機関排気通路内に炭化水素供給弁(15)と、排気浄化触媒(13)とが配置される。排気浄化触媒(13)に流入する炭化水素の濃度が200ppm以上の予め定められた範囲内の振幅および5秒以下の予め定められた範囲内の周期でもって振動せしめられる。このとき予め定められた量以上のNO x が排気浄化触媒(13)に吸蔵されたとき又は吸蔵される可能性があるときには排気浄化触媒(13)に吸蔵されたNO x を脱離させるために排気浄化触媒(13)に流入する炭化水素の濃度が一時的に増大される。
Abstract:
内燃機関において、機関排気通路内に炭化水素供給弁(15)と、排気浄化触媒(13)とが配置される。排気浄化触媒(13)に流入する炭化水素の濃度が200ppm以上の予め定められた範囲内の振幅および5秒以下の予め定められた範囲内の周期でもって振動せしめられ、それによって排気ガス中に含まれるNO x が排気浄化触媒(13)において還元せしめられる。このときNO x の還元過程で生成される窒素含有中間体が排気浄化触媒(13)から排出され、排出された窒素含有中間体を浄化するための中間体浄化触媒(14)が排気浄化触媒(13)の下流に配置される。
Abstract:
Provided are emissions treatment systems for an exhaust stream having an ammonia- generating component, such as a NOx storage reduction (NSR) catalyst or a lean NOx trap (LNT) catalyst, and an SCR catalyst disposed downstream of the ammonia-generating catalyst. The SCR catalyst can be a molecular sieve having the CHA crystal structure, for example SSZ- 13 or SAPO-34, which can be ion-exchanged with copper. The LNT can be layered, having an undercoat washcoat layer comprising a support material, at least one precious metal, and at least one NOx sorbent selected from the group consisting of alkaline earth elements, rare earth elements, and combinations thereof and a top washcoat layer comprising a support material at least one precious metal, and ceria in particulate form, the top washcoat layer being substantially free of alkaline earth components, The emissions treatment system is advantageously used for the treatment of exhaust streams from diesel engines and lean burn gasoline engines.
Abstract:
The present invention relates to a harmful emissions reduction apparatus for an engine using a reformer, a reformer for the same, and a harmful emissions reduction method for an engine using the same. The harmful emissions reduction apparatus for an engine comprises: a reformer (20) which reforms oxygen (O) and hydrocarbons (HC) included in the exhaust gas from an engine into hydrogen (H2) and carbon monoxide (CO), and increases the temperature of the exhaust gas by exothermic reaction; an exhaust gas recirculation unit (EGR) (30) which supplies the engine (10) with the exhaust gas which was reformed by the reformer (20) to increase the hydrogen (H2) content, and stabilizes the homogeneous charge compression ignition (HCCI) combustion of the engine (10); a hydrocarbon-added selective catalytic reduction unit (HC-SCR) (40) which receives the exhaust gas which was reformed by the reformer (20) to increase the hydrogen (H2) content, and transforms the nitrogen oxide (NOx) into nitrogen (N2) and water vapor (H2O) using hydrocarbons as a reducing agent in a state that enhances the reduction reaction of the nitrogen oxide (NOx); and a diesel particulate filter (DPF) (50) which receives the exhaust gas which was reformed by the reformer (20) to increase the hydrogen (H2) content, and removes particulate matter (PM) deposited thereinside through oxidation. The harmful emissions reduction apparatus for an engine of the present invention treats the exhaust gas more efficiently as post-processing apparatuses such as the selective catalytic reduction (HC-SCR) and the diesel particulate filter (DPF) are interacting in addition to the application of the HCCI combustion and the reformer.
Abstract:
An exhaust system(10) for a lean-burn internal combustion engine (12) comprises a first substrate monolith (16) comprising a catalyst for oxidising nitric oxide (NO) comprising a catalytic oxidation component followed downstream by a second substrate monolith (18) which is a wall-flow filter having inlet channels and outlet channels, wherein the inlet channels comprise a NO x absorber catalyst (20) and the outlet channels comprise a catalyst for selective catalytic reduction (22) of nitrogen oxides with nitrogenous reductant.
Abstract:
The disclosure sets forth operating a spark-ignition, direct-fuel injection internal combustion engine equipped with an exhaust aftertreatment system including a lean-NOx reduction catalyst upstream of a second converter element. The engine preferentially operates in one of a homogeneous charge combustion mode and a stratified charge combustion mode based upon temperature of the lean-NOx reduction catalyst. Exhaust gas flow is selectively diverted to the second converter element.
Abstract:
Die Erfindung betrifft eine Vorrichtung und ein Verfahren zur Reinigung von Abgasen für eine Brennkraftmaschine mit einem wenigstens bereichsweise mehrere Teilabgasstränge aufweisenden, mehrflutigen Abgassystem, in dem eine NO x -Speicherkatalysatoreinrichtung und eine SCR-Katalysatoreinrichtung angeordnet sind. Erfindungsgemäß sind die NO x -Speicherkatalysatoreinrichtung (7) und die SCR-Katalysatoreinrichtung (9) so auf unterschiedliche Teilabgasstränge (6, 8) verteilt angeordnet, dass bei einem mit Stickoxiden befüllten Stickoxidspeicher der NO x -Speicherkatalysatoreinrichtung (7) für eine vorgegebene Zeitdauer eine vorgegebene Menge eines durch einen unterstöchiometrischen Fettbetrieb der Brennkraftmaschine (2) erzeugten Abgasstroms (16) zur Reduktionsmittelerzeugung, insbesondere Ammoniakerzeugung, über die NO x -Speicherkatalysatoreinrichtung (7) zur SCR-Katalysatoreinrichtung (9) strömt, in der das erzeugte Reduktionsmittel, insbesondere Ammoniak, einspeicherbar ist.
Abstract:
内燃機関において、機関排気通路内にNO x 選択還元触媒(14)が配置され、NO x 選択還元触媒(14)の上流に排気ガス中に含まれるNO x を吸蔵しうるNO x 吸蔵触媒(12)が配置される。NO x 吸蔵触媒(12)にミスト状の燃料が供給され、NO x 吸蔵触媒(12)に吸蔵されているNO x と供給された燃料とはNO x 吸蔵触媒(12)上において反応せしめられてNO x 一分子に対して当量比以上の炭化水素分子とNH 2 との結合分子からなる中間生成物が生成される。これら中間生成物はNO x 選択還元触媒(14)に吸着され、吸着された中間生成物により排気ガス中のNO x が還元される。
Abstract:
A method of operating a syngas generator within a desired temperature range, despite a need for intermittent syngas output, involves switching between operating the syngas generator in a rich mode and a lean mode. Operation of the syngas generator in both the rich mode and the lean mode sustains the operating temperature of the syngas generator within that desired temperature range, particularly for non-catalytic reactors. The method of switching from the lean mode to the rich mode of operation can include decreasing the oxygen-to-carbon ratio of reactants supplied to the syngas generator. The flow rate of one or more of the reactant streams supplied to the syngas generator can be actively controlled in order to switch operation of the syngas generator between the rich and lean modes.