Abstract: There is provided a method for flue gas desulfurization which is capable of conducting minute control of oxidation and which is capable of maintaining the concentration of sulfurous acid in an absorbent liquid within a proper range in a highly reliable and efficient manner, even in the case where an abrupt change occurs in the operational conditions of the system. In the method for controlling the oxidation in flue gas desulfurization, the value of proportional sensitivity K in the feed back control process, which is based primarily on the oxidation-reduction potential, is increased depending on the deviation .epsilon. in a region where the detected oxidation reduction potential value PN is below the target oxidation reduction potential value SN in correspondence with the characteristic change of the oxidation-reduction potential against the concentration of sulfurous acid.

Abstract: A system is provided including an article having a surface and a catalytic metal atom, capable of oxidation, covalently immobilized at the surface via a plurality of covalent bonds, but being free of direct covalent bonding to the surface. In particular, the invention relates to inorganic surfaces including silica, alumina, niobium oxide, or tantalum oxide, or a combination thereof and catalytic metal atoms including Fe, Mn, Cr, Ni, Co, Ru, and Os. The catalytic metal atom, covalently immobilized at the surface via a plurality of covalent bonds, can be immobilized via bonding through at least one atom that is bonded directly to the surface. The article preferably is an inorganic, mesoporous structure, in the pores of which are covalently bonded a plurality of metalloporphyrins.

Abstract: This invention describes a process for the scrubbing of sulfur oxides from the effluent of conventional wet lime/limestone SOx reduction processes in coal or oil-fired plants. The sulfur oxides are oxidatively sorbed onto solid sorbents such as magnesium aluminate spinel. Reduction with the appropriate reducing gases (such as hydrogen) regenerates the catalyst, also yielding a process stream concentrated in SOx. This concentrated SOx stream can then be refed to the front end of the coal or oil-fired plants, with the SOx thus produced ultimately being removed in the conventional wet scrubbing technology.

Abstract: A method for removing a heavy metal from sludge, including the step of putting the sludge into contact with a treating liquid to dissolve the heavy metal contained in the sludge into the treating liquid. The treating liquid is formed of either A or B, where (A) is an aqueous solution of phosphoric acid, and (B) is an aqueous solution of phosphoric acid containing at least one of B1 and B2, where (B1) is at least one acid other than phosphoric acid, and (B2) is at least one oxidant. The concentration of the phosphoric acid in the treating liquid is 3% by weight or more. Alternatively, the sludge is put into contact with the treating liquid at a temperature of 40.degree. C. or higher.

Abstract: The present invention relates to a method for operating a catalyst for gases, especially for exhaust gases of stoichiometrically operated gasoline engines, wherein a catalyst is exposed to a gas stream and pollutants are catalytically converted. To improve the elimination of pollutants in the starting phase, hydrocarbons present in the gas are temporarily stored by the catalyst at temperatures below a response temperature of the catalyst, particularly below 200.degree. C., and preferably below 150.degree. C. The hydrocarbons are then released at temperatures above the response temperature and the pollutants, such as nitrogen oxides, are catalytically converted with reducing agents, such as hydrocarbons, carbon monoxide and mixtures thereof. The catalyst is a spinel, such as (MgCu)Al.sub.2 O.sub.4, which may also include a catalytically active species, such as WO.sub.3, V.sub.2 O.sub.5 and TiO.sub.2.

Abstract: Lithium compound and nickel oxyhydroxide containing a transition metal (Me) such as V, Cr, Mn, Fe, Zn and Co are suspended in water or in an organic solvent, and the solution is reacted with each other in an autoclave by a hydrothermal method to thereby synthesize transition metal-containing lithium nickelate.

Abstract: A catalyst composition, a process for producing the composition and a hydrocarbon conversion process for converting a C.sub.9 + aromatic compound to a C.sub.6 to C.sub.8 aromatic hydrocarbon such as a xylene are disclosed. The composition comprises an acid-treated zeolite having impregnated thereon a metal or metal oxide. The composition can be produced by incorporating the metal or metal oxide into the zeolite. The hydrocarbon conversion process comprises contacting a fluid which comprises a C.sub.9 + aromatic compound with the catalyst composition under a condition sufficient to effect the conversion of a C.sub.9 + aromatic compound to a C.sub.6 to C.sub.8 aromatic hydrocarbon.

Abstract: A process is provided for the production of a catalyst useful for removing nitrogen oxides out of exhaust gases from internal combustion engines operated under lean burn conditions. The catalyst is produced by supporting at least one catalytic metal, such as platinum, iridium, rhodium, other transition metals and alkaline earth metals, as the active component on a support, such as a zeolite, by either wash-coating a solution of the catalytic metal components onto the support; evaporating off solvent from a mixture of solvent, catalyst material and support, or rapidly drying droplets of support and catalyst material containing slurry with a hot gas. The supported catalyst is activated by heating to a temperature of 150 to 300.degree. C. for a period of time sufficient to desorb catalytic material components, such as water, chlorine and ammonia, out of the pores of the catalyst that adversely affect the activity and heat resistance of the catalyst.

Abstract: A process for the recovery of sulfur and carbon monoxide from metal sulfates in which the carbon monoxide is recycled as a reducing agent for reaction with the metal sulfate. Metal sulfates such as gypsum (calcium sulfate dihydrate) are processed to form sulfur dioxide. The sulfur dioxide is contacted with carbonaceous matter at sufficiently high temperature to form elemental sulfur and carbon monoxide. The carbon monoxide is then recycled for use as a reducing agent in the initial processing of the metal sulfate.

Abstract: The invention relates to a process for the direct oxidation of sulphur compounds into elemental sulphur and/or into sulphates at a temperature below 200.degree. C., in which a supported catalyst whose catalytically active phase comprises copper is used, the copper element being present in a content of at least 2% by weight relative to the catalyst and of at least 15 by weight relative to the sum of the elements of the catalytically active phase.The use of a catalyst of this type ensures a high conversion of the H.sub.2 S while at the same time minimizing the conversion into SO.sub.2.

Abstract: A method of producing sodium carbonate crystals from a sodium carbonate-containing solution including the steps of passing the sodium carbonate-containing solution to a precipitator, adding methanol to the sodium carbonate-containing solution in the precipitator such that a resultant liquor has methanol in a concentration of between 15% and 70% by volume, precipitating the sodium carbonate crystals from the resultant liquor, washing the precipitated sodium carbonate crystals with an alcohol-containing solution and drying the washed precipitated sodium carbonate crystals. The sodium carbonate-containing solution has a sodium carbonate concentration ranging between 100 g/l to saturation. The methanol is in residence with the sodium carbonate-containing solution for between 10 and 100 minutes. The alcohol-containing solution has an alcohol concentration ranging between 50% and 100%.

Abstract: A method for decomposing a perfluorocarbon in the presence of water vapor or water vapor and molecular oxygen in gas phase, in which a catalyst of a phosphate comprising at least one element selected from the group consisting of aluminum, boron, alkali earth metal, titanium, zirconium, lanthanum, cerium, yttrium, rare earth metal, vanadium, niobium, chromium, manganese, iron, cobalt and nickel, and phosphorus oxide, is used.

Abstract: The invention relates to a method of manufacturing compounds of the Monazite type, doped or not doped with actinides, to a method of packaging radioactive waste, high in actinides and in lanthanides by incorporating this waste in a confining matrix based on Monazite, and to a block for the packaging of radioactive waste that includes a Monazite matrix containing the radioactive elements. This method includes mixing, in the solid phase, reactants comprising an inactive compound of the lanthanide metaphosphate type Ln (PO.sub.3).sub.3 and one or more lanthanide oxides and/or one or more compounds capable of reacting with this oxide or these oxides during a thermal sintering process; the shaping of the mixture thus obtained, and the reaction sintering of said formed mixture, as a result of which a Monazite or a compound of the Monazite type is obtained.

Abstract: A titanium compound for photochemical reactions having a high catalytic activity per unit surface area and extremely good stability to heat treatment is made of a substitutional solid solution of titanium oxide in which aluminum atoms occupy titanium sites of the titanium oxide uniformly at a predetermined ratio. Aluminum atoms preferably occupy about 0.01 to 0.5% of the titanium sites. The titanium compound for photochemical reactions is obtained from a complex alkoxide of titanium and aluminum.

Abstract: The invention relates to a process for fractioning vinasse, in which process the pH value of the vinasse is lowered by adding acid, and the formed precipitate is separated in order to obtain an inorganic fraction, whereupon an organic fraction remains. The invention also relates to the products obtained. The inorganic fraction mainly contains potassium salt, and it is useful for example as a fertilizer. The organic fraction mainly contains organic acids, and it is useful for example as an additive in animal feed and in producing silage.

Abstract: A process is provided for destroying organic contaminants, such as oil mists from workshop rooms, formaldehyde and aromatics, out of exhaust gases by passing the exhaust gas through two reactors connected in a parallel arrangement to a contaminated exhaust gas inlet. Each of the two reactors is equipped with a plurality of serially arranged reaction zones, wherein each reaction zone contains an upstream catalyst (such as a commercial wire knit catalyst); a downstream absorbent (such as Y zeolite or H-ZSM) and a heater. A major portion of the contaminated exhaust gas is passed through one of the two reactors, while, simultaneously, a minor portion of the contaminated exhaust gas is passed through the other reactor.

Abstract: A process is provided for reducing the amount of hydrogen sulfide present in a tail gas from a sulfur recovery process. The hydrogen sulfide contaminated gas along with a gas containing free oxygen is passed through a series of hydrogen sulfide oxidation zones containing an oxidation catalyst, such as one or more oxides or salts of Ni, Co, Fe, Cu, Ag, Mn, Mo, Cr, W and V, deposited on a support, such as bauxite, activated alumina, titania and activated carbon. The initial and intermediate catalyst beds are operated adiabatically by injecting a substoichiometric amount of oxygen into the gas to be treated with respect to the amount of hydrogen sulfide present in the gas so that the temperature does not exceed 150.degree. C. The final catalyst bed is operated under conditions such that a superstoichiometric amount of oxygen is injected into the gas with respect to the hydrogen sulfide and cooling is provided so that the temperature does not exceed 150.degree. C.

Abstract: A process is provided for disposing of hydrogen sulfide contained in a gas stream, wherein a first gas feed stream having a hydrogen sulfide gas component, a second gas feed stream having an oxygen gas component, and an aqueous liquid feed stream are combined to form a reaction mixture. The aqueous liquid feed stream may be water available in remote oilfield locales, such as produced water, or sea water. The aqueous liquid feed stream may include a significant concentration of preexisting sulfate ions, in which case it is generally desirable to remove the preexisting sulfate ions using membrane separation before mixing the aqueous liquid feed stream with the first and second gas feed streams. The resultant low sulfate liquid may further comprise one or more of the following dissolved ions: Na.sup.+,K.sup.+, Mg.sup.2+, Cl.sup.-, Br.sup.-, HCO.sub.3.sup.-.

Abstract: A method for removing nitrogen oxides out of the exhaust gas from a combustion apparatus is provided by reducing the nitrogen oxides with injected ammonia or urea to produce nitrogen and water. The method further includes the provision of at least one, sensor placed downstream from the nitrogen oxides removal step for measuring the concentration of the residual ammonia and nitrogen oxides in the exhaust gas after the nitrogen oxides removal step. The method also further includes the provision of a controller for controlling the rate that the ammonia and/or urea is injected into the exhaust gas so that the rate of ammonia and/or urea injection is repeatedly increased and decreased in response to the signal generated by the sensor about a reference value plus the average of the increased and reduced rates of ammonia and urea injection.

Abstract: A catalyst composition and a process for converting a hydrocarbon stream such as, for example, a C.sub.9 +aromatic compound to C.sub.6 to C.sub.8 aromatic hydrocarbons such as xylenes are disclosed. The catalyst composition comprises an aluminosilicate, and a metal wherein the weight ratio of aluminum to silicon is in the range of from about 0.002:1 to about 0.6:1. The process comprises contacting a hydrocarbon stream with the catalyst composition under a condition sufficient to effect the conversion of a hydrocarbon to a C.sub.6 to C.sub.8 aromatic hydrocarbon.