Showing papers on "Selective catalytic reduction published in 1978"
Patent•
29 Sep 1978TL;DR: In this article, the authors described derivatives of C-076 and are produced by catalytic reduction of the 22,23position of the C-76 molecule. The compounds thus produced are used for their profound anthelmintic, insecticidal, ectoparasiticidal and acaracidal activity.
Abstract: The invention provide compounds having the formula:
in which R, is iso-propyl orsec-butyl; R 2 is methoxy, hydroxy or loweralkanoyloxy; and R 3 is hydrogen; lower alkanoyl; α-L-oleandrosyl; 4'-(lower alkanoyl)-a-L- oleandrosyl; 4'-(α-L- oleandrosyl)-α-L-oleandrosyl or 4"-(lower alkanoyl)-4'- (α-L- oleandrosyl)-α-L- oleandrosyl. These compounds are derivatives of C-076 and are produced by catalytic reduction of the 22,23-position of the C-076 molecule. Further reaction of the reduced C-076 compouds is also possible. The compounds thus produced are used for their profound anthelmintic, insecticidal, ectoparasiticidal and acaracidal activity. Compositions containing the described C-076 derivatives as active ingredient are also disclosed.
44 citations
TL;DR: In this paper, it was found that preadsorbed NO promotes the adsorption of CO and showed that adding 1% Cr 2 O 3 to SnO 2 can significantly increase the amount of NO adsorbed in the gas phase.
41 citations
TL;DR: In this article, the rate of the NO-NH 3 reaction showed dependence on the partial pressures of both No and NH 3, in accordance with the Langmuir-Hinshelwood type of rate equation.
41 citations
TL;DR: In this paper, the reduction of nitric oxide by ammonia has been studied over a stepped platinum single crystal surface in a vacuum system equipped with Auger electron spectroscopy, low-energy electron diffraction, and mass spectrometry.
29 citations
Patent•
12 Jan 1978
TL;DR: In this paper, a non-noble transition metal compound supported on a shaped carrier comprising a titanium oxide and a clay mineral having an average particle size of 1 to 100 microns was used for the vapor phase reduction of nitrogen oxides with ammonia.
Abstract: A catalyst composition for the vapor phase reduction of nitrogen oxides with ammonia, which consists essentially of a non-noble transition metal compound supported on a shaped carrier comprising a titanium oxide and a clay mineral having an average particle size of 01 to 100 microns The shaped carrier preferably contains an additional component which is an inorganic fibrous material, silica hydrogel, silica sol, or a mixture of at least two of these An exhaust gas containing nitrogen oxides is treated, with a high percent NO removal, by contacting it with the catalyst composition in the presence of ammonia gas at 200° to 600° C
19 citations
Patent•
24 Mar 1978TL;DR: In this paper, a reducing agent that has a redox potential in the redox system of the reducing agent and its oxidation product that is more negative than the potential of the substance to be reduced and its reduction product is used as an anode material at which hydrogen can be oxidized in a fuel cell.
Abstract: Reducible pollutants can be detoxified by reduction and metals can be recred by reduction of the corresponding metal ions by bringing into contact a catalyst with the solution which is suitable for the electrochemical reduction of the ions in question, and mixing into the solution (or bubbling therethrough in the case of a gas) a reducing agent that has a redox potential in the redox system of the reducing agent and its oxidation product that is more negative than the redox potential of the substance to be reduced and its reduction product The catalyst is a material that is suitable for use as an anode material at which hydrogen can be oxidized in a fuel cell Such catalysts include finely divided platinum, activated carbon coated with platinum, tungsten carbide and activated carbon coated with tungsten carbide, particularly Hydrogen is a good reducing agent for the purpose
17 citations
TL;DR: In this paper, the selective catalytic reduction of nitric oxide with ammonia on an alumina-supported platinum catalyst has been studied by the method of differential reactor analysis and the results were fitted to several Langmuir-Hinshelwood models using a nonlinear least squares fitting computer program.
13 citations
TL;DR: In this article, the formation of hydrogen cyanide during the catalytic reduction of nitric oxide (NO) with carbon monoxide and hydrogen was studied with a bench-scale flow reactor.
Abstract: The formation of hydrogen cyanide during the catalytic reduction of nitric oxide (NO) with carbon monoxide and hydrogen was studied with a bench-scale flow reactor. The previously reported inhibition by sulfur dioxide of the formation of hydrogen cyanide was found to be counteracted by transient admission of oxygen to the catalyst. These results are discussed in the context of the control of automotive emissions of NO and the prevention of hydrogen cyanide production during such control.
12 citations
TL;DR: In this article, the catalytic activities of metal phthalocyanines for the reduction of nitric oxide with hydrogen were found to be in the order Mn Ni Cu > Zn.
11 citations
Patent•
09 Jun 1978
TL;DR: In this article, the termal decomposition of uranyl nitrate into uranium oxide and oxides of nitrogen is performed and the resulting heat is utilised for the thermal decomposition.
Abstract: In the termal decomposition of uranyl nitrate into uranium oxide and oxides of nitrogen, the oxides of nitrogen produced are catalytically reduced to N2 and the resulting heat is utilised for the thermal decomposition of further uranyl nitrate. The process is autothermic and gives UO3 with sufficiently high reactivity for subsequent processing into UF6 in known manner. The process proceeds without the prodn. of contaminated effluents or of nitric acid which cannot be used in the process.
10 citations
Patent•
05 Dec 1978TL;DR: In this paper, the authors describe a method to reduce nitrogen oxides in exhaust gases using catalytic reduction in the presence of oxygen and ammonia at 200° to 600° C. over a catalyst of at least one catalyst component selected from the group consisting of compounds of metals of groups 1B, 5A, 6A, 7A and 8 of the periodic table, and lanthanides and tin supported on a specific carrier comprising a main component of calcium silicate.
Abstract: Nitrogen oxides in exhaust gases are catalytically reduced in the presence of oxygen and ammonia at 200° to 600° C. over a catalyst of at least one catalyst component selected from the group consisting of compounds of metals of Groups 1B, 5A, 6A, 7A and 8 of the periodic table, and lanthanides and tin which is supported on a specific carrier comprising a main component of calcium silicate.
Patent•
08 Aug 1978
TL;DR: In this paper, an ilmenite-based catalyst which is hardly posioned with SO2 and dust at a temp. where NOx is reduced in the presence of NH3 and thus can maintain its activity over a long time.
Abstract: PURPOSE:To provide an ilmenite-based catalyst which is hardly posioned with SO2 and dust at a temp. where NOx is reduced in the presence of NH3 and thus can maintain its activity over a long time.
Patent•
28 Jul 1978
TL;DR: In this paper, a denitration catalyst for selective catalytic reduction using NH3, low temp activity has been improved without deteriorating strength and wear resistance, by supporting one or more out of oxides of Fe, V, Mn and Cu as active substances on a carrier and limiting the distribution of micropores of specified diameter.
Abstract: PURPOSE:To provide a denitration catalyst for selective catalytic reduction using NH3, low temp activity of which has been improved without deteriorating strength and wear resistance, by supporting one or more out of oxides of Fe, V, Mn and Cu as active substances on a carrier and limiting the distribution of micropores of specified diameter
Patent•
27 Dec 1978
TL;DR: The catalytic compositions used contain iron and chromium associated with alumina and optionally at least a promoter selected from rare earth oxides with a content between 0.1 and 1% in relation to the active material, the specific surface of the compositions being between 50 and 300 m 2 /g and the dimensions of the pores between 40 and 50,000 A as mentioned in this paper.
Abstract: Gaseous effluents polluted by nitrogen oxides are purified by catalytic reduction. The catalytic compositions used contain iron and chromium associated with alumina and optionally at least a promoter selected from rare earth oxides with a content between 0.1 and 1% in relation to the active material and crude platinum metals with a content between 1 and 5 ppm in relation to the active material, the specific surface of the compositions being between 50 and 300 m 2 /g and the dimensions of the pores between 40 and 50,000 A. These compositions are applicable for processes of purification of nitrogen oxides with any content.
Patent•
23 Mar 1978
TL;DR: In this article, the authors proposed a selective catalytic reduction of exhaust gas contg. NOx, obtd. by supporting oxide or sulfate of Fe, Cr, or Mn on a calcium silicate carrier.
Abstract: PURPOSE:Catalyst for selective catalytic reduction of exhaust gas contg. NOx, obtd. by supporting oxide or sulfate of Fe, Cr, or Mn etc. on calcium silicate carrier.
Patent•
13 Apr 1978
TL;DR: In this article, the authors proposed to eliminate NH3 exhaustion to the outside of the system and to throughly prevent the closure of machinery etc. by adding excess NH3 to the exhausted gas containing NOx and SOx to denitrate it due to the catalytic reduction.
Abstract: PURPOSE:To eliminate NH3 exhaustion to the outside of the system and to throughly prevent the closure of machinery etc. due to the product of ammonium sulfate etc. by adding excess NH3 to the exhausted gas containing NOx and SOx to denitrate it due to the catalytic reduction, and by decomposing the excess NH3 with the spacified NH3 decomposing catalyzer prior to the desulfurization.
Patent•
14 Nov 1978
TL;DR: In this paper, a denitrification catalyst having high capacity at high temperature range as a catalyst for catalytic reduction by supporting a catalyst component on a carrier of which the heat resistance porous surface is covered by titania and the like.
Abstract: PURPOSE:To obtain a denitrification catalyst having high capacity at high temperature range as a catalyst for catalytic reduction by supporting a catalyst component on a carrier of which the heat resistance porous surface is covered by titania and the like. CONSTITUTION:As a catalyst used in denitrification of nitrogen oxides in exhaust gas by catalytic reduction, a heat resistant porous substrate such as alumina, cordierite and the like is immersed in an aqueous solution of titania alcoholate, zirconium nitrate and the like to coat titania and zirconia. Thereafter a catalyst componenet such as oxide of cerium, tungsten, iron and the like is independently or in combined form supported on said substrate. The obrained catalyst removes nitrogen oxides in exhaust gas effectively and economically in a high temperature atmosphere of 400 deg.C or higher.
TL;DR: In this article, the catalytic reduction of NOx with NH3 on alumina supported Fe-Cr-V (18/1/1 atomic ratios) oxides and Fe-V 1/1-atom ratio oxides in simulated flue gas has been investigated.
Patent•
05 Jun 1978
TL;DR: In this article, the authors proposed to increase the contact effect of the catalyst with the gas, to improve the denitration capacity and, furthermore, to absorb and damp the noise energy of the exhaust gas, by forming the catalyst to plural elements.
Abstract: PURPOSE:To increase the contact effect of the catalyst with the gas, to improve the denitration capacity and, furthermore, to absorb and damp the noise energy of the exhaust gas, by forming the catalyst to plural elements and installing these catalyst elements in the exhausting duct of the gas turbine while arranging the elements in stratified formation.
Patent•
04 Feb 1978
TL;DR: In this paper, the authors used the catalyst obtained by supporting the oxides, etc. of metals consisting of transition metals of base metal group, Sn and Mo on the porous substance obtained by hardening hemihydrate gypsum by adding aluminium sulfate and water and then calcining, for the catalytic reduction of NOx.
Abstract: PURPOSE:To improve the SOx resistance and the denitrating capacity of the catalyst, by using the catalyst obtained by supporting the oxides, etc. of metals consisting of transition metals of base metal group, Sn and Mo on the porous substance obtained by hardening hemihydrate gypsum by adding aluminium sulfate and water and then calcining, for the catalytic reduction of NOx.
Patent•
02 Feb 1978
TL;DR: In this article, the authors proposed a method to prevent ammonium sulfate and ammonium hydrogensulfate from depositing on the catalyst in catalytic reduction of NOx contained in heavy oil combustion exhaust gas with ammonia as a catalyst by use of moving beds by the introduction of a seal gas under specific conditions to the side of the moving bed reactor, through the side the catalyst is charged or discharged.
Abstract: PURPOSE:To prevent ammonium sulfate and ammonium hydrogensulfate from depositing on the catalyst in catalytic reduction of NOx contained in heavy oil combustion exhaust gas with ammonia as a catalyst by use of moving beds by the introduction of a seal gas under specific conditions to the side of the moving bed reactor, through the side the catalyst is charged or discharged.
01 Jun 1978
TL;DR: In this paper, the reduction of 500 ppM nitric oxide/nitrogen dioxide mixtures with 667 ppM ammonia in the presence of 0 to 5% oxygen and 10% water in nitrogen at 200 to 450/sup 0/C was tested on unsupported and titanium dioxide-and alumina-supported vanadium pentoxide, ferric sulfate/ferric oxide and copper-II exchanged zeolite Y. The results were similar on all catalysts and showed that the conversion of nitrogen oxides to nitrogen has a maximum of 1:1 mole ratio of nit
Abstract: The reduction of 500 ppM nitric oxide/nitrogen dioxide mixtures (0 to 100% nitric oxide) with 667 ppM ammonia in the presence of 0 to 5% oxygen and 10% water in nitrogen at 200 to 450/sup 0/C was tested on unsupported and titanium dioxide- and alumina-supported vanadium pentoxide, ferric sulfate/ferric oxide, ferric sulfate on titanium dioxide, copper(II) exchanged zeolite Y, and cupric sulfate on titanium dioxide or alumina. The results were similar on all catalysts and showed that the conversion of nitrogen oxides to nitrogen has a maximum of 1:1 mole ratio of nitric oxide to nitrogen dioxide; that in the presence of oxygen, the oxidation of nitric oxide to nitrogen dioxide was large compared with the reduction by ammonia; and that nitrogen dioxide is reduced via nitric oxide to nitrogen by ammonia. The stoichiometry of the reactions was derived. 13 references.
Patent•
01 Mar 1978
TL;DR: In this paper, the authors proposed to increase the utilization efficiency of NH3 and the removal efficiency of NOx by reducing catalytically the exhaust gas containing O2 and NOx with NH3 gas using the catalyst of the specified composition.
Abstract: PURPOSE:To heighten the utilization efficiency of NH3 and the removal efficiency of NOx, by reducing catalytically the exhaust gas containing O2 and NOx with NH3 gas using the catalyst of the specified composition.
Patent•
27 Dec 1978
TL;DR: In this paper, the title catalyst supported on carrier of superior workability was obtained by fixing a catalytic substance to uneven faces such as acicularly protruded faces formed on a metal substrate.
Abstract: PURPOSE:To obtain the title catalyst supported on carrier of superior workability, which is effectively used in catalytic reduction of NOx in combustion exhaust gas to make the NOx harmless, by fixing a catalytic substance to uneven faces such as acicularly protruded faces formed on a metal substrate.
Patent•
22 Mar 1978
TL;DR: In this article, a denitration catalyst of high performance used for catalytic reduction of exhaust gas in the presence of NH3 by coating a porous ceramics substrate with a slurry obtd.
Abstract: PURPOSE:To produce a denitration catalyst of high performance used for catalytic reduction of exhaust gas in the presence of NH3 by coating a porous ceramics substrate with a slurry obtd. by suspending alumina (hydrate) and basic Al chloride as a binder in water; calcining the coated substrate; impregnating the calcined substrate with an aq. soln. contg. V; and drying the impregnated substrate.
TL;DR: In this paper, the formation of hydrogen cyanide during the catalytic reduction of nitric oxide (NO) with carbon monoxide and hydrogen was studied with a bench-scale flow reactor.
Abstract: The formation of hydrogen cyanide during the catalytic reduction of nitric oxide (NO) with carbon monoxide and hydrogen was studied with a bench-scale flow reactor. The previously reported inhibition by sulfur dioxide of the formation of hydrogen cyanide was found to be counteracted by transient admission of oxygen to the catalyst. These results are discussed in the context of the control of automotive emissions of NO and the prevention of hydrogen cyanide production during such control.
01 Jan 1978
TL;DR: In this paper, the selectivities of iridium (Ir), platinum (Pt) and rhodium (Rh) catalysts for reducing NO in the presence of excess O/sub 2/ in two synthetic fuel-lean exhaust gases have been determined, before and after a severe heat treatment.
Abstract: The selectivities of iridium (Ir), platinum (Pt) and rhodium (Rh) catalysts for reducing NO in the presence of excess O/sub 2/ in two synthetic fuel-lean exhaust gases have been determined, before and after a severe heat treatment. When tested at 500/sup 0/C, the order of selectivity was Ir >> Rh > Pt for fresh catalysts, and Pt > Rh for treated catalysts. When tested at 400/sup 0/C, the treated Pt and Rh catalysts were identical in selectivity to the fresh Ir catalyst. A catalyst called Leanox was developed which showed higher NO selectivity than the fresh Ir catalyst. The advantages of incorporating this catalyst upstream of a conventional three-component-control catalyst to improve NO conversion on the fuel-lean side of stoichiometry were demonstrated in laboratory tests.
Patent•
11 Oct 1978
TL;DR: In this article, a sythetic reduction of 2,4-diphenyl-2methylpentene with hydrogen at 240 deg.C or lower without solvent in the presence of a ruthenium catalyst is described.
Abstract: PURPOSE:To prepare the tiel cpd., useful as sythetic lubricants for transmissions, in high yield and high selectivity, by catalytic reduction of 2,4-diphenyl-2methylpentene with hydrogen at 240 deg.C or lower without solvent in the presence of a ruthenium catalyst.