摘要:
A system for exhaust gas purification disposed in the exhaust pipe of an internal combustion engine, includes (1) an adsorbent comprising a monolithic carrier and (2) an adsorbent component having a hydrocarbon adsorptivity, loaded on the carrier, and a catalyst comprising a monolithic carrier and a catalyst component loaded on the carrier, having a purifiability for the harmful substances present in the exhaust gas emitted from the engine. The catalyst is provided downstream of the adsorbent in the flow direction of the exhaust and it can remove the hydrocarbons generated during engine cold gas. The adsorbent has a sectional shape satisfying the following relation: 1.2≦(major axis)/(minor axis)≦6.5 This system enables the desorption of hydrocarbons from the adsorbent in a longer time and can remove the hydrocarbon generated during engine cold start at a higher purification ratio.
摘要:
A catalyst for exhaust gas purification is capable of purifying the hydrocarbons, nitrogen oxides and carbon monoxide present in the exhaust gas discharged from an internal combustion engine. The catalyst has a carrier and a catalyst layer containing at least one kind of noble metal, Ba and Cs, formed on the carrier. This catalyst for exhaust gas purification is improved in hydrocarbon purification ability for a low-temperature fuel-rich exhaust gas (such as exhaust gas emitted during cold start) of automobile.
摘要:
A catalyst for exhaust gas purification is capable of purifying the hydrocarbons, nitrogen oxides and carbon monoxide present in the exhaust gas discharged from an internal combustion engine. The catalyst has a monolithic carrier and a catalyst layer containing Pd, Ba and a heat-resistant inorganic oxide, formed on the carrier. The amount of Pd supported on monolithic carrier is 100-300 g per ft3 of monolithic carrier (3.53×10−3 to 1.06×10−2 g per cc of monolithic carrier), the amount of Ba supported on monolithic carrier is 0.010-0.060 g per cc of monolithic carrier in terms of BaO, and the weight ratio of Pd and Ba as expressed as BaO is 1:2 to 1:10. This catalyst for exhaust gas purification is superior particularly in hydrocarbon purification for a low-temperature fuel-rich exhaust gas (such as exhaust gas emitted during cold start) of automobile.
摘要翻译:用于排气净化的催化剂能够净化从内燃机排出的废气中存在的烃,氮氧化物和一氧化碳。 催化剂具有整体式载体和在载体上形成的含有Pd,Ba和耐热无机氧化物的催化剂层。 在整体式载体上负载的Pd的量为100-300g / ft 3的整体式载体(3.53×10 -3至1.06×10 -2 g / cc的整体式载体),负载在单片载体上的Ba的量为0.010-0.060g / cc的整体载体,BaO表示的Pd和Ba的重量比为1:2〜1:10。 用于排气净化的催化剂在汽车的低温富油废气(例如冷启动时排出的废气)的碳氢化合物净化中尤其优异。
摘要:
A system for exhaust gas purification disposed in the exhaust pipe of an internal combustion engine, includes an adsorbent formed by loading, on a monolithic carrier, (1) a zeolite containing at least one kind of ion of an element having an electronegativity of 1.40 or more and (2) a catalyst material formed by loading at least one kind of noble metal selected from Pt, Pd and Rh on a heat-resistant inorganic oxide, and at least one loaded carrier formed by loading, on a monolithic carrier, a catalyst component having a purifiability for the harmful substances present in the exhaust gas emitted from the engine and/or an adsorbent component having an adsorptivity for the hydrocarbons also present in the exhaust gas, the loaded carrier being provided upstream of the adsorbent in the flow direction of the exhaust gas and having a total volume of 0.6 l or more. In this system for exhaust gas purification, the thermal deterioration of the adsorbent is reduced because there is used an adsorbent of higher HC desorption start temperature and because the thermal load applied to the adsorbent is decreased by the use of a particular means.
摘要:
A method for exhaust gas purification using an exhaust gas purification system including (a) an adsorbent for adsorbing hydrocarbons in internal combustion engine exhaust gas provided in the engine exhaust pipe, (b) at least one catalyst for reducing harmful substances present in the exhaust gas, provided in the exhaust pipe upstream of the adsorbent in the flow direction of the exhaust gas, (c) at least one catalyst for reducing harmful substances present in the exhaust gas, provided in the exhaust pipe down-stream of the adsorbent in the flow direction of the exhaust gas, (d) a first inlet for introduction of secondary air into exhaust gas, formed in the exhaust pipe upstream of the most downstream catalyst of the catalyst (b), and (e) a second inlet for introduction of secondary air into exhaust gas, formed in the exhaust pipe between the catalyst (b) and the most downstream catalyst of the catalyst (c). Secondary air is introduced from the first inlet at a time from engine start to activation of catalyst (b); when catalyst (b) has been activated, stopping secondary air introduction from the first inlet; meanwhile, introducing secondary air from the second inlet while the hydrocarbons of exhaust gas adsorbed by adsorbent (a) are desorbed therefrom as its temperature rises by the heat of the exhaust gas. This method effectively purifies the hydrocarbons discharged from an internal combustion engine in a large amount during cold start, without adversely affecting the purification of also-discharged NOx.
摘要:
A system for exhaust gas purification disposed in the exhaust pipe of an internal combustion engine, includes followings (i) a catalyst giving an excellent light-off performance at low temperatures, including a carrier and a catalyst layer supported thereon, the catalyst layer including a precious metal and a substance having an electron donatability and/or a nitrogen dioxide absorbability and releasability, and (ii) an adsorbent comprising a carrier and an adsorbent layer having a hydrocarbon adsorbability, supported on the carrier. This system for exhaust gas purification can effectively purify the harmful substances contained in the exhaust gases discharged from internal combustion engines of automobiles, etc., particularly the hydrocarbons discharged in a large amount from a gasoline engine during cold start.
摘要:
A system for exhaust gas purification disposed in the exhaust pipe of an internal combustion engine, which includes a zeolite as adsorbent component capable of adsorbing the hydrocarbons present in the exhaust gas emitted from the engine and a catalyst capable of reducing the harmful substances present in the exhaust gas; the system satisfies the following conditions: a/c=3 to 50 cc/g, wherein a is the total volume of the pores of diameters of 10 Å or smaller possessed by the zeolite as measured using N2, and c is the total amount of the hydrocarbons emitted from the engine during the period of 140 seconds from the start of the engine when the engine is operated in accordance with the LA-4 mode of FTP, thereby the adsorption capacity of the zeolite used as a HC adsorbent is optimized against the amount of the HC discharged from an engine during a certain period of the cold start so as to adsorb and purify the HC effectively.
摘要:
A catalyst for exhaust gas purification includes (1) a monolithic carrier having passages and (2) palladium-loaded alumina obtained by immersing alumina in a palladium solution and then firing the resulting alumina and loaded on the monolithic carrier as a catalyst layer. In the catalyst, the catalyst layer loaded on the partition walls of the passages of the monolithic carrier has a thickness of 5 to 100 &mgr;m and the palladium/alumina (Pd/Al2O3) weight ratio in the catalyst layer is 0.03 to 0.30. This catalyst is a Pd-only catalyst improved in hydrocarbon purifiability during the cold start of engine.
摘要翻译:用于废气净化的催化剂包括(1)具有通道的整体式载体和(2)通过将氧化铝浸入钯溶液中而获得的负载钯的氧化铝,然后焙烧所得氧化铝并作为催化剂层负载在整体式载体上。 在催化剂中,负载在整体式载体的通道的分隔壁上的催化剂层的厚度为5〜100μm,催化剂层中的钯/氧化铝(Pd / Al 2 O 3)重量比为0.03〜0.30。 该催化剂是在发动机冷起动期间提高烃纯化性能的仅Pd催化剂。
摘要:
This invention provides a honeycomb catalyst having an excellent purification efficiency and a small pressure loss and can be mounted even in a limited space, the honeycomb catalyst comprising: porous partition walls 4 having plural pores 25, which are arranged to form plural cells 3 allowing communication between two end faces; plugging portions being arranged to plug the cells 3 in one of the end faces; and catalytically active components 5, 15 loaded on surfaces of partition walls 4 and inner surfaces of pores 25, wherein many catalytically active component-loading pores 35 through which a gas can pass are formed in partition walls 4, and a ratio of a mass (MW) of the catalytically active component loaded on the surfaces of partition walls 4 to a mass (MP) of the catalytically active component 5 loaded on the inner surfaces of the pores 25 is (MW):(MP)=1:3 to 3:1.
摘要:
A system for exhaust gas purification includes at least one adsorbent capable of adsorbing harmful substances such as hydrocarbons and the like in exhaust gas and at least one catalyst containing a catalyst component, capable of reducing said harmful substances, both provided at an in-line position of exhaust pipe of internal combustion engine. In the system, the hydrocarbons, etc. in the exhaust gas emitted during cold engine start up of internal combustion engine are adsorbed by the adsorbent and the adsorbed hydrocarbons, etc. are desorbed from the adsorbent with the temperature rise of the adsorbent caused by the heat of the exhaust gas and are burnt on the catalyst. The adsorbent contains a H type β-zeolite having a SiO2/Al2O3 ratio of 100 or more and can maintain good adsorption capability even when exposed to an exhaust gas of 750° C. or more form an internal combustion engine. This system for exhaust gas purification can effectively purify harmful substances in exhaust gas, particularly the hydrocarbons, etc. emitted in large amounts during cold engine start up.
摘要翻译:废气净化系统包括至少一种能够吸附排气中的烃等有害物质的吸附剂,以及至少含有催化剂成分的能够还原所述有害物质的催化剂,两者均设置在排列位置 的内燃机排气管。 在该系统中,在内燃机的冷启动发动机期间排出的废气中的碳氢化合物等被吸附剂吸附,吸附的烃等从吸附剂中脱附,伴随着吸附剂的升温 废气的热量并在催化剂上燃烧。 该吸附剂含有具有100或更大的SiO 2 / Al 2 O 3比率的H型β-沸石,并且可以保持良好的吸附能力 即使暴露于750℃以上的废气也形成内燃机。 该排气净化系统能够有效地净化排气中的有害物质,特别是发动机冷启动时大量排放的烃类等。