公开(公告)号：JPH11347356A

公开(公告)日：1999-12-21

申请号：JP12487599

申请日：1999-04-30

Applicant: DEGUSSA

Inventor： LOX EGBERT DR ,  GIESHOFF JUERGEN DR ,  STREHLAU WOLFGANG DR ,  KREUZER THOMAS DR

IPC: B01D53/56 ,  B01D53/32 ,  B01D53/74 ,  B01D53/92 ,  B01D53/94 ,  F01N3/08 ,  F01N3/28 ,  F02B1/04

Abstract: PROBLEM TO BE SOLVED: To reduce the content of nitrogen oxide in the exhaust gas of an internal combustion engine while using a nitrogen oxide accumulating catalyst showing improved low temp. activity even at 150 deg.C or lower, making the use of platinum sufficiently unnecessary or enabling the substitution of platinum with a separate active component and having enhanced ageing stability. SOLUTION: In a method for reducing the content of nitrogen oxide in the exhaust gas of an internal combustion engine by accumulating nitrogen oxide on a nitrogen oxide accumulating material in a nitrate form in a stoichiometrically excessive amt. of an air/fuel ratio during the drive stage of a motor (accumulation stage) and decomposing nitrate to nitrogen oxide in a stoichiometrially insufficient amt. of an air/fuel ratio during a short time drive stage (desorption stage) and reducing dissociated nitrogen oxide, the exhaust gas is treated at least in a gas discharge area during the accumulation stage and formed nitric acid is accumulated on the nitrogen oxide accumulating material.

公开(公告)号：JP2000084405A

公开(公告)日：2000-03-28

申请号：JP23604899

申请日：1999-08-23

Applicant: DEGUSSA

Inventor： STREHLAU WOLFGANG DR ,  GOEBEL ULRICH ,  MUSSMANN LOTHAR DR ,  DOMESLE RAINER DR

IPC: B01D53/86 ,  B01D53/94 ,  B01J20/04 ,  B01J20/30 ,  B01J23/02 ,  B01J23/10 ,  B01J23/58 ,  B01J23/63 ,  B01J35/02 ,  B01J37/03 ,  F01N3/08 ,  F02B1/04

Abstract: PROBLEM TO BE SOLVED: To provide nitrogen oxides-accumulating material having high accumulation efficiency and aging stability. SOLUTION: In the nitrogen oxides-accumulating material containing at least one kind of accumulating constituents of nitrogen oxides in a form of particles of oxides of an alkaline earth metal and alkali metal, a mixed oxide, a carbonate or a hydroxide, on a support material of a high surface area, the support material is selected from doped cerium oxide, cerium/zirconium-mixed oxide, calcium titanate, strontium titanate, barium titanate, barium stannate, barium zirconate, magnesium oxide, lanthanum oxide, praseodymium oxide, samarium oxide, neodymium oxide, yttrium oxide, zirconium silicate, barium yttrium cuprite, lead titanate, tin titanate, bismuth titanate, lanthanum cobaltate, lanthanum manganate, barium cuprate, and their mixtures, and particles of the nitrogen oxides accumulating constituent have an average particle diameter less than 1.5 μm.

公开(公告)号：JPH11324654A

公开(公告)日：1999-11-26

申请号：JP10572999

申请日：1999-04-13

Applicant: DEGUSSA

Inventor： STREHLAU WOLFGANG DR ,  MUSSMANN LOTHAR DR ,  GOEBEL ULRICH

IPC: B01D53/94 ,  F01N3/08 ,  F01N3/20 ,  F01N3/24 ,  F01N3/28 ,  F01N9/00 ,  F01N11/00 ,  F02D41/04 ,  F02D41/14

Abstract: PROBLEM TO BE SOLVED: To make it possible to evaluate the deterioration of performance of a double functional occlusion catalyst by measuring a time difference during a change in air ratios on the upstream and downstream of the occlusion catalyst to evaluate its occlusion functions. SOLUTION: Oxygen sensors 1, 2 are severally arranged in exhaust gas pipes on the upstream and downstream sides of an occlusion catalyst. A signal from the sensor 1 follows the change of an air-fuel ratio through an engine electronic system, but a signal from the sensor 2 is influenced by the occlusion characteristics of the catalyst. An elapsed term Δt1 until the recording of reduction component by the sensor 2 depends upon the rate of the quantity of a nitrogen oxide occluded in the occlusion catalyst and oxygen occlusion component contained in a test piece. After the end of a thick mixture stage, the air- fuel ratio increases in value more than 1. But the sensor 2 indicates a value smaller than a stoichiometrical air-fuel ratio on the downstream side of the catalyst for a specified time Δt2. Since a time interval Δt2 depends only upon the oxygen occlusion capacity of the catalyst, the oxygen occlusion function of the catalyst can be evaluated by measuring the above time.

公开(公告)号：JP2000117110A

公开(公告)日：2000-04-25

申请号：JP29014699

申请日：1999-10-12

Applicant: DEGUSSA

Inventor： STREHLAU WOLFGANG DR ,  GOEBEL ULRICH ,  DOMESLE RAINER DR

IPC: B01D53/94 ,  B01J23/58 ,  B01J23/63 ,  B01J27/053 ,  B01J27/055

Abstract: PROBLEM TO BE SOLVED: To increase a load of a stored compound by a method wherein in a nitrogen oxide storage catalyst containing a fine catalytic material and a nitrogen oxide storage constituent, the nitrogen oxide storage constituent is so provided as to exist as fine barium sulfate and strontium sulfate after end of manufacturing the catalyst. SOLUTION: In a nitrogen oxide storage catalyst wherein a catalyst so structured as to provide a cover 2 on an inactive support 1 to be used for purifying an exhaust gas of a lean engine or the like, contains fine catalytic materials 3, 4 and a nitrogen oxide storing constituent 5, the nitrogen oxide storing constituent 5 is so formed as to exist as fine barium sulfate, and strontium sulfate, after end of manufacturing the catalyst, further a mixture or a mixed crystal of both sulfates, or as a decomposition product having at most 1 μm in average particle size. As the material 3, an activated aluminum oxide activated by use of platinum is used, and as the material 4, a constituent for storing oxygen or cerium/zirconium mixed oxide activated by use of rhodium is used.

公开(公告)号：JPH10323542A

公开(公告)日：1998-12-08

申请号：JP13534898

申请日：1998-05-18

Applicant: DEGUSSA

Inventor： STREHLAU WOLFGANG DR ,  LOX EGBERT DR ,  KREUZER THOMAS DR ,  HOEHNE JUERGEN

IPC: F01N3/08 ,  B01D53/86 ,  B01D53/94 ,  F01N3/10 ,  F01N3/28

Abstract: PROBLEM TO BE SOLVED: To avoid consumption of a fuel caused by the concn. increasing period which periodically occurs, by successively introducing the exhaust gas of a lean engine into a permanent reduction catalyst and a nitrogen oxide storage catalyst to purify the gas. SOLUTION: The exhaust gas system 2 of a lean engine 1 is equipped with two converters 3, 4. The converter 3 in the first stage contains a permanent reduction catalyst, while the converter 4 in the second stage contains a nitrogen oxide storage catalyst. Both of the catalysts in the converters 3, 4 can be theoretically assembled in one converter casing, however, it is preferable to assemble these catalysts separately in two converter casings separated from each other so as to keep the exhaust gas temp. in the storage catalyst in the main duration time of operation to the optimum temp. range for the storage catalyst. As for the permanent reduction catalyst used, an iridium-contg. catalyst or copper- contg. zeolite catalyst can be used.

公开(公告)号：JP2000033267A

公开(公告)日：2000-02-02

申请号：JP19066999

申请日：1999-07-05

Applicant: DEGUSSA

Inventor： VAN DEN TILLAART HANS DR ,  LEYRER JUERGEN DR ,  STREHLAU WOLFGANG DR ,  LOX EGBERT DR ,  KREUZER THOMAS DR ,  PLOG CARSTEN DR ,  ANDORF RENATO DR ,  MARKERT NORBERT ,  STENGEL THOMAS

IPC: B01D53/94 ,  B01J23/46 ,  B01J29/068 ,  B01J29/44

Abstract: PROBLEM TO BE SOLVED: To reduce nitrogen oxides by making iridium be contained on a carrier material comprising silicon dioxide or zeolite and the iridium exist on the outer surface of the carrier material in an average particle size within a specified range. SOLUTION: A catalyst is constituted by incorporating iridium on a carrier material comprising zeolite of the formula M2/nO.Al2O3.xSiO2.yH2O (wherein M is an n-valent cation; (x) is a modulus), which is silicon dioxide 10-30 nm in a particle size or an oxidized silicon/aluminum compound having a special crystal structure, and making iridium 5-30 nm in an average particle size exist on the outer surface face of the carrier material. The catalyst is used in the shape of a coating applied on the wall surface of the passage of a ceramic or metal honeycomb structure. In this way, nitrogen oxides can be reduced in an oxidative and reductive atmosphere.

公开(公告)号：JPH11350945A

公开(公告)日：1999-12-21

申请号：JP8438999

申请日：1999-03-26

Applicant: DEGUSSA

Inventor： STREHLAU WOLFGANG DR ,  GOEBEL ULRICH ,  LOX EGBERT DR ,  MUELLER WILFRIED ,  DOMESLE RAINER DR

IPC: B01D53/86 ,  B01D53/94 ,  B01J21/16 ,  F01N3/08 ,  F01N3/10 ,  F01N3/20 ,  F01N3/24 ,  F01N3/28 ,  F01N9/00 ,  F01N13/02 ,  F02D41/02 ,  F02D41/14

Abstract: PROBLEM TO BE SOLVED: To achieve the operation method of the exhaust emission control device for the internal combustion engine which is operated at lean air/fuel ratio for the main course of its operation. SOLUTION: An exhaust emission control device incorporating a nitrogen oxides storage catalytic converter and a sulfur trap, wherein: a) at the excess air factor higher than 1 and an exhaust gas temperature TK within an activity window ΔTNOX, the nitrogen oxides and the sulfur oxides contained in the exhaust gas are respectively stored on the nitrogen oxides storage catalyst and the sulfur oxides storage catalyst while simultaneously maintaining the exhaust gas temperature TS lower than the desulfurization temperature TS. De SOx and periodically reducing the excess air factor of the exhaust gas below 1 to discharge the stored nitrogen oxides (completion of 1 adsorption cycle); b) after each completion of a predetermined number N1 of cycles of nitrogen oxides adsorption cycle, the exhaust gas temperature TS is raised to a level at or higher than the desulfurization temperature TS. De SOx of the sulfur trap to desulfurize the sulfur trap and to reduce the excess air factor of the exhaust gas to below 1. The process a) and the process b) are periodically repeated.

公开(公告)号：JPH11257065A

公开(公告)日：1999-09-21

申请号：JP432099

申请日：1999-01-11

Applicant: DEGUSSA

Inventor： HOEHNE JUERGEN ,  STREHLAU WOLFGANG DR ,  LOX EGBERT DR ,  KREUZER THOMAS DR

IPC: F01N3/08 ,  B01D53/94 ,  F01N3/20 ,  F01N3/24 ,  F01N3/28 ,  F01N9/00 ,  F01N11/00 ,  F02D41/02 ,  F02D41/04

Abstract: PROBLEM TO BE SOLVED: To obtain a method for effectively actuating an NOx storage catalyst of an internal combustion engine. SOLUTION: A NOx storage catalyst is actuated by a circulatory change from the excess air ratio (absorption stage) of exhaust gas exceeding 1 to an excess air ratio (desorption and response stage) of less than 1. For this, the NOx stored in the catalyst in the absorption stage and separated in the desorption stage is reduced by the storage catalyst under the use of the reduced exhaust gas elements discharged from the internal combustion engine in the desorption stage. As a result, the decrease of NOx in the exhaust gas can be adjusted in a short period of time, making up for the loss of the long time period of the storage capacity of the catalyst.

公开(公告)号：JP2001003728A

公开(公告)日：2001-01-09

申请号：JP2000148696

申请日：2000-05-19

Applicant: DEGUSSA

Inventor： SCHAEFER-SINDLINGER ADOLF ,  STREHLAU WOLFGANG DR ,  LOX EGBERT DR ,  KREUZER THOMAS DR ,  GOEBEL ULRICH

IPC: F01N3/02 ,  B01D46/42 ,  B01D53/94 ,  B01J35/04 ,  F01N3/023 ,  F01N3/035 ,  F01N3/18 ,  F01N3/24 ,  F01N3/28 ,  F01N13/02

Abstract: PROBLEM TO BE SOLVED: To remove carbon black from exhaust gas of a diesel engine by a method wherein nitrogen monoxide contained in exhaust gas is oxidized to produce nitrogen dioxide, carbon black is separated from an exhaust gas flow and by using the produced nitrogen dioxide, carbon black is oxidized. SOLUTION: This method is executed at least at two continuous treatment stages and carbon black is separated from an exhaust gas flow with efficiency W of 0.05-0.95. In this case, each treatment stage is attached for a modulus of discharge for carbon black based on T-1-W and a modulus of total discharge at a treatment stage for carbon black is provided as a product of the moduli of discharge of all treatment stages.

公开(公告)号：JP2000157870A

公开(公告)日：2000-06-13

申请号：JP33814299

申请日：1999-11-29

Applicant: DEGUSSA

Inventor： KLEIN HARALD DR ,  STREHLAU WOLFGANG DR ,  LOX EGBERT ,  KREUZER THOMAS DR ,  MUELLER WILFRIED

IPC: B01D53/94 ,  B01J23/58 ,  B01J23/63 ,  B01J29/068 ,  B01J29/12 ,  B01J29/44 ,  B01J37/02 ,  F01N3/10 ,  F02B3/06

Abstract: PROBLEM TO BE SOLVED: To obtain the superior nitrogen oxide conversion rate on a continuous lean fuel-air mixture operation zone by additionally providing a second functional layer with hydrocarbon storage function for a catalyst having two functional layers consisting of a first layer of nitrogen oxide storage function and the second layer of catalyst function. SOLUTION: A catalyst for converting a nitrogen oxide in an oxygen rich exhaust gas from a diesel engine under the optimum utilization of a reducing component contained in exhaust gas is provided with a second functional layer absorbing the catalyst activities and also hydrocarbon contained in a lean exhaust gas and formed on a first functional layer of function of storing the nitrogen oxide. As an acidic carrier material for the catalyst activity component in the second functional layer, for example, aluminum silicate, silicon dioxide, titanium oxide or zirconium oxide can be used. The second functional layer contains aluminum-removed Y-zeolite, zeolite ZMS5, aluminumremoved mordenite or a mixture of them.