Rhone-poulenc Specialites Chimiques

Rhone-poulenc Industries

L'institut Francais Du Petrole

Societe Nationale Elf Aquitaine

Rhone-poulenc Specialties Chimiques

Mitsui Miike Eng. Corp.

Thierry Dupin

Regis Poisson

Jean Lavina

Gilbert Bouge

Robert Voirin

Laurent Seigneurin

Bertrand Latourrette

Roland Jacques

Osamu Matsunaga

Georges Dupuy

Patrice Nortier

Kouichi Shirai

Susumu Chawanya

Takayuki Fujimoto

Morito Okamura

Provided is a process for preparing alumina agglomerates which comprises:

Alumina agglomerates and process for the preparation thereof

Process for the preparation of alumina agglomerates

Sulfur containing organics, e.g., carbon disulfide carbon oxysulfide, or a mercaptan, are oxidized to sulfur dioxide in gaseopus phase, whether alone or conjointly with hydrogen sulfide and/or elemental sulfur, per se, by passing a gaseous stream thereof, at elevated temperature, over a catalyst composition which comprises (i) a carrier substrate comprising titanium oxide, silica, zirconium oxide, silica-magnesia, silica-zirconia, silica-titanium oxide, zirconia-titanium oxide, or a zeolite, or admixture thereof, and (ii) a catalytically effective amount of at least one catalytically active element of Group Ib, IIb, IIIb, Vb, VIb, VIIb, VIII or Va of the Periodic Table, e.g., copper, silver, zinc, cadmium, yttrium, a lanthanide, chromium, molybdenum, tungsten, manganese, iron, cobalt, rhodium, iridium, nickel, palladium, platinum, tin and/or bismuth, but said catalyst composition being devoid of mixed oxide of spinel type.

Catalytic oxidation of sulfur compounds

An SO.sub.2 -containing gas, in particular, pre-stage gas for the Claus reaction to recover sulfur can effectively be purified by removing NH.sub.3 contained therein using a TiO.sub.2 catalyst.

Process for removing NH.sub.3 in an SO.sub.2 -containing gas

Durable, aging-resistant alumina-based catalyst carriers having improved mechanical strength are facilely prepared by (i) impregnating an alumina-based catalyst carrier with an aqueous solution of a quaternary ammonium silicate, (ii) drying said impregnated carrier, and (iii) calcining said dried carrier.

Alumina-based catalyst carriers having improved durability/mechanical

An improved oxidation catalyst, well adopted for the conversion of H.sub.2 S-containing acid gases at least in part to elemental sulfur, is facilely prepared by (i) hydrothermally treating at least a portion of an active alumina support, and (ii) then impregnating said at least partially hydrothermally treated support with a catalytically effective amount of a catalytically active oxide phase which comprises the oxides of at least one of the metals, Fe, Cu, Ag, W, Co, Ni, Bi, Cr and Cd, with the proviso (iii) that at least one rare earth oxide, alkaline earth metal oxide, zirconium oxide or silica compound, or any precursor compound thereof, is incorporated into the catalyst during either of the steps (i) or (ii).

Catalyst for the oxidation of hydrogen sulfide and process for the

Catalytic desulfurization process of an acid gas containing H.sub.2 S

Industrial waste gases containing objectionable/polluting compounds of sulfur, e.g., H.sub.2 S, SO.sub.2 and such organosulfur derivatives as COS, CS.sub.2 and mercaptans, are catalytically desulfurized, e.g., by Claus process, employing an improved catalyst comprising titanium dioxide and calcium, barium, strontium or magnesium sulfate.

Catalytic desulfurization of industrial waste gases

Aqueous alumina coating compositions well adopted for directly impregnating/coating both ceramic and metallic catalyst supports to provide integral, both macroporous and microporous coatings therefor, which coated supports are useful for the fabrication of a wide variety of catalysts for catalyzing a broad spectrum of reactions, including those characterized by highly limited internal diffusion or by progressive catalyst poisoning, e.g., the treatment of exhaust gases, are comprised of water and a particulate alumina binder fraction dispersed therein, and an undispersed particulate alumina filler fraction therefor, said particulate alumina fractions being from 10 to 60% dispersed in the water, with the grain size distribution of the alumina particles comprising said undispersed filler fraction being such that the average diameter of said alumina filler particles ranges from 1 to 15 microns, and with at least 70% of such alumina filler particles having diameters ranging from one-half of the average diameter to twice the average diameter.

Alumina coating compositions for catalyst supports and process for their

Spheroidal alumina particulates well adapted as catalysts or catalyst supports and having enhanced pore volumes are facilely prepared by drop coagulating an aqueous suspension or dispersion of alumina, or an aqueous solution of a basic aluminum salt, said suspension, dispersion or solution comprising an oil-in-water emulsion, and then recovering, drying and calcining the gelled particulates which result.

Preparation of spheroidal alumina particulates

Catalyst for the desulfurization of industrial waste gases and process

The hydrogen sulfide, and/or organosulfur compounds, and/or elemental sulfur contained in gaseous effluents is/are catalytically oxidized to sulfur dioxide, employing an improved oxidation catalyst comprising (i) titanium dioxide, or admixture of titanium dioxide with zirconia or silica, (ii) an alkaline earth metal sulfate, and (iii) at least one of the elements copper, silver, zinc, cadmium, yttrium, lanthanides, vanadium, chromium, molybdenum, tungsten, manganese, iron, cobalt, rhodium, irridium, nickel, palladium, platinum, tin and bismuth.

Catalyst for oxidation of hydrogen sulfide and/or organosulfur compounds

Industrial waste gases containing objectionable/polluting compounds of sulfur, e.g., H.sub.2 S, SO.sub.2 and such organo-sulfur derivatives as COS, CS.sub.2 and mercaptans, are catalytically desulfurized, e.g., by Claus process, employing an improved catalyst comprising titanium dioxide and calcium, barium, strontium or magnesium sulfate.

Catalyst for desulfurization of industrial waste gases and process for

Shaped titanium oxide catalysts/carriers useful, e.g., for sulfur recovery via Claus catalysis, are prepared by (i) intimately admixing powdered, poorly crystalline and/or amorphous titanium oxide, said titanium oxide powder being characterized by a weight loss on ignition ranging from 1 to 50%, water and from 0 to about 15% by weight of a shaping additive, (ii) next shaping the intimate admixture which results, and (iii) thence, optionally after drying, calcining the product shaped article.

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Garges/Les/Gonesse, France

Thierry Dupin