Abstract: A high activity catalyst is obtained by oxidizing and modifying the surface of zinc sulfide by hydrogen peroxide. An oxidation treatment is carried out in basic aqueous solution. The high activity photocatalyst is added to the basic aqueous solution in which hydrogen sulfide is dissolved to recover hydrogen and sulfur under low energy. Thus, the inexpensive high activity photocatalyst having a high catalytic activity and a long duration of life is realized and hydrogen gas is efficiently generated under little energy.

Abstract: A method is provided for removal of sulfur gases and recovery of elemental sulfur from sulfur gas containing supply streams, such as syngas or coal gas, by contacting the supply stream with a catalyst, that is either an activated carbon or an oxide based catalyst, and an oxidant, such as sulfur dioxide, in a reaction medium such as molten sulfur, to convert the sulfur gases in the supply stream to elemental sulfur, and recovering the elemental sulfur by separation from the reaction medium.

Abstract: Zinc oxide-based sorbents, and processes for preparing and using them are provided, wherein the sorbents are preferably used to remove one or more reduced sulfur species from gas streams. The sorbents contain an active zinc component, optionally in combination with one or more promoter components and/or one or more substantially inert components. The active zinc component is a two phase material, consisting essentially of a zinc oxide (ZnO) phase and a zinc aluminate (ZnAl2O4) phase. Each of the two phases is characterized by a relatively small crystallite size of typically less than about 500 Angstroms. Preferably the sorbents are prepared by converting a precursor mixture, containing a precipitated zinc oxide precursor and a precipitated aluminum oxide precursor, to the two-phase, active zinc oxide containing component.

Abstract: A gas stream containing at least one fluorine compound selected from the group consisting of compounds of carbon and fluorine, compounds of carbon, hydrogen and fluorine, compounds of sulfur and fluorine, compounds of nitrogen and fluorine and compounds of carbon, hydrogen, oxygen and fluorine is contacted with a catalyst comprising at least one of alumina, titania, zirconia and silica, preferably a catalyst comprising alumina and at least one of nickel oxide, zinc oxide and titania in the presence of steam, thereby hydrolyzing the fluorine compound at a relatively low temperature, e.g. 200°-800° C., to convert the fluorine of the fluorine compound to hydrogen fluoride.

Abstract: Provided is a method and plant for reducing SO2 emissions in which a catalyst for catalyzing the formation of cement clinker is extracted from kiln exhaust gas and recycled.

Abstract: An adsorbent for removing sulfur compounds from sulfur compounds-containing fuel gas contains a zeolite ion-exchanged with Ag and has an excellent performance when used to remove sulfur compounds from the fuel gas, irrespective of the moisture concentration in the fuel gas, and a method for removing sulfur compounds from sulfur compounds-containing fuel gas by use of an adsorbent of the above-mentioned type. The zeolite is a Na—+Y type zeolite.

Abstract: A NOx reduction catalyst for exhaust gas discharged from an automotive internal combustion engine operable in a lean region and in a range including a stoichiometric region and a rich region. The NOx reduction catalyst comprises a catalytic noble metal. Additionally, an oxygen adsorbable and releasable material is provided carrying at least a part of the catalytic noble metal. In this catalyst, the catalytic noble metal carried on the oxygen adsorbable and releasable material adsorbs SOx in the exhaust gas, in a form of at least one of sulfate and sulfite.

Abstract: A gas stream containing at least one fluorine compound selected from the group consisting of compounds of carbon and fluorine, compounds of carbon, hydrogen and fluorine, compounds of sulfur and fluorine, compounds of nitrogen and fluorine and compounds of carbon, hydrogen, oxygen and fluorine is contacted with a catalyst comprising at least one of alumina, titania, zirconia and silica, preferably a catalyst comprising alumina and at least one of nickel oxide, zinc oxide and titania in the presence of steam, thereby hydrolyzing the fluorine compound at a relatively low temperature, e.g. 200°-800° C., to convert the fluorine of the fluorine compound to hydrogen fluoride.

Abstract: The invention is directed to a process for the catalytic reduction of sulphur dioxide from a gas mixture at least containing 10 vol. % of water, in which process the gas mixture is passed over a sulphur resistant hydrogenation catalyst in sulphidic form, at a space velocity of at least 2000 h−1, in the presence of a reducing component, preferably at least partly consisting of hydrogen, in a molar ratio or reducing component to sulphur dioxide of more than 10 up to 100, at a temperature of 125° C. to 300° C., followed by passing the gas mixture, after the said reduction, through a dry oxidation bed for the oxidation of sulphur compounds, more in particular hydrogen sulphide, to elemental sulphur.

Abstract: In ridding fluids, including hydrocarbon fluids, both gaseous and liquid, of sulfur compounds including hydrogen sulfide, oxides of sulfur, and thiols, the present invention uses a small quantity of an activator, generally a noble metal oxide, preferably a copper species, along with a known oxide product, such as iron oxide or zinc oxide, to thoroughly remove sulfur contaminants in a short amount of time. The activator allows for the use of smaller reactor vessels and the production of hydrocarbon fluids substantially free of sulfur products.

Abstract: A hydrocarbon gas such as methane and LPG is desulfurized in the presence of oxygen and an oxidation catalyst to convert sulfur compounds in the gas to sulfur oxides. The sulfur oxides are then trapped downstream of the oxidation by an adsorbent. The amount of oxygen added to the hydrocarbon gas to promote oxidation is such that the sulfur compounds are selectively oxidized and the oxidation of the hydrocarbon gas is minimized to reduce hydrogen formation.

Abstract: A gas stream containing at least one fluorine compound selected from the group consisting of compounds of carbon and fluorine, compounds of carbon, hydrogen and fluorine, compounds of sulfur and fluorine, compounds of nitrogen and fluorine and compounds of carbon, hydrogen, oxygen and fluorine is contacted with a catalyst comprising at least one of alumina, titania, zirconia and silica, preferably a catalyst comprising alumina and at least one of nickel oxide, zinc oxide and titania in the presence of steam, thereby hydrolyzing the fluorine compound at a relatively low temperature, e.g. 200°-800° C., to convert the fluorine of the fluorine compound to hydrogen fluoride.

Abstract: The present invention relates to sulfur tolerant catalyst composites useful for reducing contaminants in exhaust gas streams, especially gaseous streams containing sulfur oxide contaminants. More specifically, the present invention is concerned with improved NOx trap catalysts for use in diesel engines as well as lean burn gasoline engines. The sulfur tolerant NOx trap catalyst composites comprise a platinum component, a support, and a NOx sorbent component prepared by hydrothermal synthesis. The NOx sorbent component comprises a first metal oxide and a second metal oxide. The metal in the first metal oxide is selected from the group consisting of aluminum, titanium, zirconium, silicon, and composites thereof, and the metal in the second metal oxide is selected from the group consisting of Group IIA metals, Group II metals, Group IV metals, rare earth metals, and transition metals. The metal in the first metal oxide is different from the metal in the second metal oxide.

Abstract: Carbon monoxide and carbonyl sulfide emissions are reduced in manufacturing processes, including titanium tetrachloride production processes. Gas is contacted with CO, COS, and an oxygen-containing gas with a suitable catalyst. The catalyst may be a metal oxide catalyst containing bismuth, cobalt and nickel, a xerogel or aerogel catalyst containing Au, Rh, Ru and Co in aluminum oxide/oxyhydroxide matrices, or a supported metal catalyst that contains at least one metal from the group Pd, Rh, Ru and Cu. In the latter case, the catalyst support is contains alumina or carbon. A catalyst composite of Au, Rh, Ru and Cr, and cerium oxide and lanthanum oxide may also be used.

Abstract: A catalytic composition and method of making the same in which a catalytic material has an average pore size distribution sufficiently large to substantially prevent capillary condensation.

Abstract: Methods for removing sulfur from syngas in a Fischer-Tropsch reactor, and reactors including means for removing sulfur from syngas are disclosed. Sulfur-reactive metals can be used in the Fischer-Tropsch unit to sequester the sulfur. For example, the Fischer-Tropsch unit can be run in stages, using a sacrificial catalyst in a first stage to adsorb the sulfur. The Fischer-Tropsch reactor can include internal baffles that separate the reactor into zones, with a sacrificial catalyst in one or more of the zones, that can be easily sequestered and regenerated or replaced. Sulfur adsorbents can be placed in the inlet gas manifold. A portion of the Fischer-Tropsch catalyst can be converted into larger size pellets that do not fluidize with the finer grain Fischer-Tropsch catalyst and remain near the gas inlet where they adsorb and sequester the sulfur. These embodiments can be combined in any suitable manner to lower the sulfur concentration in the syngas feed.

Abstract: Fluid/solids contacting in a fluidization reactor is enhanced by passing the fluidization fluid through a fine screen positioned below the fluidized bed of solid particulates, thereby decreasing axial dispersion in the reactor.

Abstract: A gas contaminant is filtered using fibers having internal cavities containing a chemically reactive oxidizing agent, an acid or base, a coordinating agent, a complexing agent, or a deliquescing agent. Where the contaminant is basic, the reagent is preferably an oxidizing agent. Where the contaminant is acidic, the reagent is preferably basic, and more preferably comprises a group 1 or group 2 metal cation. The reagent may also advantageously comprise a phosphate, chitosan, hypochlorite, borate, carbonate, hydroxide, or oxide. Where the contaminant is neutral, the reagent is preferably an oxidizing agent, complexing agent, coordinating agent, or deliquescing agent. The reagent is preferably impregnated into an adsorptive solid, including, for example, carbon powder, zeolite, aluminum oxide, or silica. The fibers are preferably multilobal, and most preferably either trilobal or quadrilobal. It is also preferred that the fibers contain a plurality of T shaped lobes.

Abstract: A high activity catalyst is obtained by oxidizing and modifying the surface of zinc sulfide by hydrogen peroxide. An oxidation treatment is carried out in basic aqueous solution. The high activity photocatalyst is added to the basic aqueous solution in which hydrogen sulfide is dissolved to recover hydrogen and sulfur under low energy. Thus, the inexpensive high activity photocatalyst having a high catalytic activity and a long duration of life is realized and hydrogen gas is efficiently generated under little energy.

Abstract: An ultra-efficient multilobal cross-sectioned fiber filter for chemical contaminant filtering applications is described. An absorptive chemically reactive reagent, preferably an acid or base and in liquid or an adsorptive chemically reactive reagent (an acid or base) in solid form, is disposed within longitudinal slots in each length of fiber. The reagent may be used alone or in conjunction with solid adsorptive particles which may also be utilized with the reagents in the longitudinal slots within the fibers. Reagents within the fibers remain exposed to a base-contaminated airstream passing through the filter. Base contaminants in the airstream, chemicals such as ammonium and amines (as well as particles), react with the acid reagent within the longitudinal slots of the fibers. As the contaminant and reagent react, the ammonium or amine becomes irreversibly absorbed (or adsorbed if reagent is a solid acid) to the liquid acid reagent and multilobal fiber.

Abstract: An integrated lean NOx trap. The integrated lean NOx trap includes a lean NOx trap containing a composite metal oxide mixture consisting essentially of about 80-100 wt % stoichiometric spinel MgAl2O4 and between about 0-20 wt % of CeO2 or CeO2—ZrO2. A method for removing NOx and SOx impurities from exhaust gases using the integrated lean NOx trap is also described.

Abstract: The present invention relates to sulfur tolerant catalyst composites useful for reducing contaminants in exhaust gas streams, especially gaseous streams containing sulfur oxide contaminants. More specifically, the present invention is concerned with improved NOx trap catalysts for use in diesel engines as well as lean burn gasoline engines. The sulfur tolerant NOx trap catalyst composites comprise a platinum component, a support, and a NOx sorbent component prepared by hydrothermal synthesis. The NOx sorbent component comprises a first metal oxide and a second metal oxide. The metal in the first metal oxide is selected from the group consisting of aluminum, titanium, zirconium, silicon, and composites thereof, and the metal in the second metal oxide is selected from the group consisting of Group IIA metals, Group III metals, Group IV metals, rare earth metals, and transition metals. The metal in the first metal oxide is different from the metal in the second metal oxide.

Abstract: A sorbent composition comprising a support and reduced-valence iron can be used to desulfurize a hydrocarbon-containing fluid such as cracked-gasoline or diesel fuel.

Abstract: A process for adjusting the ratio of sulfur dioxide to hydrogen disulfide from the regeneration of a catalytic system of a structured support for example a monolith coated with: (i) a metal oxide sorber component selected from the group consisting of Ti, Zr, Hf, Ce, Al, Si and mixtures thereof, for example Ti2O, (ii) a precious metal component, for example Pt metal and, optionally (iii) a modifier consisting of an oxide Ag, Cu, Bi, Sb, Sn, As, In, Pb, Au or mixtures thereof, such as Cu as copper oxide. The system first captures the gaseous sulfur compounds. Then the captured gaseous sulfur compounds are then desorbed as mainly H2S and SO, in higher concentrations in a separate isolated lower flow stream in a ratio determined by the amount of modifier in the catalyst. The higher concentrations may be processed to less noxious or useful sulfur materials and the catalyst/sorber is regenerated.

Abstract: A process is provided for the production of hydrogen from hydrogen sulfide by reacting carbon monoxide with hydrogen sulfide to produce hydrogen and carbonyl sulfide, and then reacting the carbonyl sulfide with oxygen to produce carbon monoxide and sulfur dioxide. The carbon monoxide is recycled back to the hydrogen sulfide reaction step. The catalyst used to promote the reaction between carbonyl sulfide and oxygen is an oxide of a metal, such as V, Nb, Mo, Cr, Re, Ti, W, Mn or Ta, which is supported on a support, such as TiO2, ZrO2, CeO2, Nb2O5 and Al2O3.

Abstract: A method of treating exhaust from an internal combustion engine having an emission reduction device, such as a lean NOx trap. Exhaust from the engine is directed to a first sulfur trap, which treats the exhaust and discharges exhaust that is substantially free of sulfur. The exhaust from the first sulfur trap is normally directed to the emission reduction device, but is diverted to a second sulfur trap when the first sulfur trap is saturated. During this diversion, a reducing agent introduced upstream of the first sulfur trap aids in purging the first sulfur trap and in reducing metal sulfates and metal sulfites in the first sulfur trap to hydrogen sulfides, which are then treated by the second sulfur trap. When the first sulfur trap is thus purged, the exhaust gas is again directed to the emission reduction device.

Abstract: In general, the invention provides methods and associated apparatuses for removing odorant and sulfur compounds from a gas stream such as natural gas. As an example, such systems are typically required by fuel processor systems adapted to convert natural gas into reformate for use in fuel cell systems, where the odorant and sulfur compounds might otherwise poison the fuel processor and fuel cell catalysts Systems under the present invention are based on the use of at least two filtration stages such that the odorant removal function is segregated from the general removal of H2S.

Abstract: A process for the reduction of gaseous sulfur compounds in gaseous streams. The gaseous stream is contacted with a sorber, e.g., zinc oxide, which is cable of sorbing the sulfur compounds under sulfur sorbing conditions. The sorber is present in the form of one or more layers on the surface of a monolith carrier, e.g., cordierite. The layers of the sorber have a total thickness of at least 3 g/in3 of the carrier. The process is especially useful for the removal of gaseous sulfur compounds such as H2S from gaseous streams.

Abstract: The present invention relates to sulfur tolerant catalyst composites useful for reducing contaminants in exhaust gas streams, especially gaseous streams containing sulfur oxide contaminants. More specifically, the present invention is concerned with improved NOx trap catalysts for use in diesel engines as well as lean burn gasoline engines. The sulfur tolerant NOx trap catalyst composites comprise a platinum component, a support, a NOx sorbent component, and a spinel material prepared by calcining an anionic clay material represented by the formula MmNn(OH)(2m+2n)Aa.bH2O, wherein the formula is defined herein. The sulfur tolerant NOx trap catalyst composites are highly effective with a sulfur containing fuel by trapping sulfur oxide contaminants which tend to poison conventional NOx trap catalysts used to abate other pollutants in the stream.

Abstract: Compounds having the formula A2B3O6±d wherein A is an alkaline-earth metal, an alkaline metal, a lanthanide, or a solid solution thereof, B is a transition metal, an element of group III, or a solid solution thereof, and d has a value between 0 and 1; a method for preparing the compounds; a method for producing composite materials on various matrices and thin or thick films deposited on various substrates which contain the compounds; their use; and a method for eliminating certain gases from a mixture that includes them by using the compounds.

Abstract: A process for removing hydrogen sulfide from a fluid stream by contacting a hydrogen sulfide-containing stream with a sorbent composition wherein said sorbent composition is produced by mixing at least one zinc component which is zinc oxide or a compound convertible to zinc oxide, at least one silica component where the silica component comprises silica or a compound convertible to silica, at least one colloidal metal oxide, and optionally at least one pore generator component so as to form a mixture, extruding the mixture, sphering the resulting extrudate to form spherical particles having a size of form about 0.5 to about 15 millimeters drying the resulting spherical particles, calcining the dried particles, steaming the resulting calcined particles, sulfiding the steamed particles by contacting them with sulfides or sulfur at a temperature of about 200° C. to 1400° C.

Abstract: A sulfur oxide storage material contains a magnesium-aluminum spinel (MgO.Al2O3) and can be used as a so-called “sulfur trap” to remove sulfur oxides from oxygen-containing exhaust gases of industrial processes. In particular, it can be used for the catalytic purification of exhaust gas from internal-combustion engines to remove the sulfur oxides from the exhaust gas in order to protect the exhaust gas catalysts from sulfur poisoning. The material displays a molar ratio of magnesium oxide to aluminum oxide in the range of over 1.1:1, and the magnesium oxide present in stoichiometric excess is homogeneously distributed in a highly disperse form in the storage material.

Abstract: A removal method of malodorous substance and deodorization device thereof enables un-treated gas containing soluble or insoluble malodorous substance contained complexly to be removed by only one treatment process as far as the degree of sensing nothing by organoleptic test. The un-treated gas containing soluble or insoluble malodorous substance contained complexly is flushed in compliance with necessity to remove insoluble malodorous substance, before converting insoluble malodorous substance into soluble substance by virtue of conversion catalyst to flush to be removed.

Abstract: The useful life of SOx additives having a SO2→SO3 oxidation catalyst component and a SO3 absorption component can be extended by employing each of these components as separate and distinct physical particles, pellets, etc.

Abstract: A catalyst system for deodorization and an apparatus for deodorization, each of which comprises a pretreating catalyst and a noble metal catalyst, the pretreating catalyst converting a sulfur atom of low oxidation state which deactivates the noble metal catalyst into a sulfur atom of high oxidation state which has little deactivation effects thereon, the noble metal catalyst oxidizing aldehyde, etc., wherein a material to be deodorized is brought into contact with the pretreating catalyst prior to being brought into contact with the noble metal catalyst. As the pretreating catalyst, a catalyst comprising at least one selected from the group consisting of vanadium, chromium, manganese, iron, cobalt, nickel, copper and oxides thereof is used, while as the noble metal catalyst, a catalyst comprising at least one selected from the group consisting of ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum and gold is used.

Abstract: The present invention relates to a &ggr;-Al2O3 sorbent impregnated with alkali salt and CuO, which has a superior SO2 sorption capacity and a high regeneration conversion rate. A &ggr;-Al2O3 sorbent of the present invention is impregnated with alkali salt and copper oxide, whose alkali salt and copper oxide(CuO) contents are 1 to 10 wt. % and 5 to 20 wt. % against 100 wt. % &ggr;-Al2O3 carrier, respectively. The &ggr;-Al2O3 sorbent of the invention has a superior SO2 sorption capacity and a high regeneration conversion rate, which facilitates efficient removal of SO2 by the conventional dry method.

Abstract: The invention provides a catalyst; a method for making the catalyst and a method for using the catalyst to promote the selective oxidation of hydrogen sulfide into elemental sulfur. The catalyst may be prepared by contacting a catalyst support, such as silica, with a solution containing ammonium metal salts, such as ammonium iron citrate and ammonium zinc citrate, and an amount of chloride (e.g., ammonium chloride) that is between about 0.1 and about 20 weight percent of the metal ions in the solution, to produce a support material impregnated with ammonium metal citrate salts and ammonium chloride. This impregnated catalyst support is then dried and calcined to produce a catalyst, such as iron and zinc oxide mixture supported on silica. It has been found that by adding chloride to the impregnated catalyst support prior to calcination and drying, that the sintering of the metal oxides can be controlled and the formation of a mixed metal oxide is promoted.