Exhaust gas catalyst
    51.
    发明授权
    Exhaust gas catalyst 失效
    废气催化剂

    公开(公告)号:US06180075B2

    公开(公告)日:2001-01-30

    申请号:US09056641

    申请日:1998-04-08

    IPC分类号: B01J802

    摘要: A single-layered three-way catalytic converter containing palladium as the only catalytically active noble metal, with high activity and heat resistance. The catalyst contains, in addition to finely divided, stabilized aluminum oxide, at least one finely divided cerium/zirconium mixed oxide and optionally finely divided nickel oxide as well as highly dispersed amounts of cerium oxide, zirconium oxide and barium oxide. The palladium is distributed largely uniformly throughout the entire catalyst.

    摘要翻译: 包含钯作为唯一催化活性贵金属的单层三元催化转化器,具有高活性和耐热性。 除了细分散的稳定化的氧化铝之外,催化剂还含有至少一种细碎的铈/锆混合氧化物和任选的细碎的氧化镍以及高分散量的氧化铈,氧化锆和氧化钡。 钯在整个催化剂中大部分均匀分布。

    Process for the operation of a nitrogen oxides storage catalyst
    52.
    发明授权
    Process for the operation of a nitrogen oxides storage catalyst 有权
    氮氧化物储存催化剂的操作方法

    公开(公告)号:US06171565B2

    公开(公告)日:2001-01-09

    申请号:US09227589

    申请日:1999-01-08

    IPC分类号: B01D5356

    摘要: A process of operating a nitrogen oxides storage catalyst of an exhaust gas treatment system is described. The process relates to the cycling of the normalized air/fuel ratio &lgr;-value of the exhaust gas exiting the engine, in which a lambda value greater than 1 represents oxygen-rich, lean burn conditions in which a sorption phase for the sorption of nitrogen oxides takes place; and in which a lambda value less than 1 represents oxygen-poor, rich burn conditions in which a desorption and conversion phase for the desorption and conversion of nitrogen oxides takes place. The &lgr;-value of the exhaust gas downstream from the storage catalyst is monitored during the desorption and conversion phase to determine the end of the desorption and conversion phase based on the &lgr;-value falling below a predetermined threshold value. Advantages of the process described include the ability to distinguish permanent from temporary damage to the nitrogen oxides storage catalyst, the ability to compensate for the slow deterioration in storage capacity, and the ability to determine when the storage capacity of the catalyst falls below a certain minimum capacity after which the storage catalyst must be either replaced or thermally treated while still installed in the exhaust gas treatment system.

    摘要翻译: 描述了操作废气处理系统的氮氧化物存储催化剂的方法。 该过程涉及离开发动机的废气的归一化空气/燃料比率lambd值的循环,其中大于1的λ值表示富氧的稀燃条件,其中用于吸附氮的吸附相 氧化物发生; 并且其中小于1的λ值表示氧贫,富氧燃烧条件,其中发生用于解吸和转化氮氧化物的解吸和转化相。 在解吸和转化阶段期间监测从储存催化剂下游排出的废气的羔羊值,以基于羔羊值低于预定阈值确定解吸和转化阶段的结束。 所述方法的优点包括将永久物与临时损伤区分为氮氧化物储存催化剂的能力,补偿储存容量缓慢劣化的能力以及确定催化剂的储存容量何时低于某一最低值的能力 容量之后,储存催化剂必须被替换或热处理,同时仍然安装在废气处理系统中。

    Process for regenerating a nitrogen oxides storage catalyst
    54.
    发明授权
    Process for regenerating a nitrogen oxides storage catalyst 有权
    再生氮氧化物储存催化剂的方法

    公开(公告)号:US07351677B2

    公开(公告)日:2008-04-01

    申请号:US10630303

    申请日:2003-07-29

    IPC分类号: B01J20/34

    摘要: The present invention provides a process and a device for regeneration of a nitrogen oxide storage catalyst in the exhaust system of a diesel engine. The process comprises a first and a second regeneration strategy. The first regeneration strategy is applied when the exhaust gas temperature is above a threshold value and comprises changing the air/fuel-ratio from a lean to a rich value during a first regeneration period. The second regeneration strategy is applied when the exhaust gas temperature is below a threshold value and comprises switching the air/fuel-ratio back and forth between lean and rich air/fuel-ratios, forming a sequence of between 2 and 10 rich pulses and between 2 and 10 lean pulses during a second regeneration period.

    摘要翻译: 本发明提供一种用于在柴油发动机的排气系统中再生氮氧化物存储催化剂的方法和装置。 该方法包括第一和第二再生策略。 当废气温度高于阈值时,应用第一再生策略,并且包括在第一再生期间将空气/燃料比从贫值改变为浓值。 当废气温度低于阈值时,应用第二再生策略,并且包括在稀空燃比之间来回切换空燃比,形成富二脉冲之间的序列,介于 在第二再生期间的2和10个贫脉冲。

    Process for reducing the nitrogen oxides content of exhaust gas from an internal combustion engine
    60.
    发明授权
    Process for reducing the nitrogen oxides content of exhaust gas from an internal combustion engine 失效
    降低来自内燃机的废气的氮氧化物含量的方法

    公开(公告)号:US06238525B1

    公开(公告)日:2001-05-29

    申请号:US09299630

    申请日:1999-04-27

    IPC分类号: C01B2100

    摘要: A process for reducing the nitrogen oxides content of the exhaust gas from an internal combustion engine includes treating the exhaust gas in an electric gas discharge such that at least one of nitrogen dioxide or nitric acid are formed from nitrogen oxides in the exhaust gas; storing the nitrogen dioxides and/or the nitric acid in the form of nitrates on a nitrogen oxides storage material during phases when the engine operates with a greater than a stoichiometric air/fuel ratio (i.e., the storage phase); decomposing the nitrates to give nitrogen oxides during brief phases when the engine operates with a less than the stoichiometric air/fuel ratio (i.e., the desorption phase); and reducing the nitrogen oxides which are released from the storage material to nitrogen. The nitrogen oxides storage material may be located in an electric gas discharge zone, and the exhaust gas may be passed through the discharge and then over the storage material.

    摘要翻译: 用于降低来自内燃机的废气的氮氧化物含量的方法包括以排气中的氮氧化物形成至少一种二氧化氮或硝酸的电气放电来处理排气, 当发动机以大于化学计量的空气/燃料比(即储存阶段)运转时,在氮氧化物储存材料中将氮氧化物和/或硝酸以硝酸盐的形式储存在相中。 当发动机以小于化学计量的空气/燃料比(即,解吸阶段)运行时,在短时间内分解硝酸盐以产生氮氧化物; 并将从储存材料释放的氮氧化物还原成氮气。 氮氧化物存储材料可以位于电气放电区域中,并且排气可以通过排出物,然后通过存储材料。