Showing papers on "Partial oxidation published in 1979"

Polymer-anchored cobalt tetraarylporphyrin catalysts for the conversion of quadricyclane to norbornadiene

Abstract: Methods are described for the preparation of carboxamide- and sulfonamide-linked polystyrene-anchored cobalt (II) tetraarylporphyrins containing 0.28 to 0.44% cobalt, which are highly active catalysts for the conversion of quadricyclane to norbornadiene. These cobalt catalysts gradually lose some of their activity upon repeated recycling. This loss in catalytic activity apparently arises from partial oxidation, since the loss of catalytic activity can be partially restored by treatment with a strong reducing agent such as titanium(III). The apparent activities of these catalysts are increased if the catalyst is finely powdered, thereby suggesting diffusion limitation of the catalytic activity. Applications are discussed of these catalysts in a proposed solar energy storage system based on the reversible valence isomerization of norbornadiene to quadricyclane. 1 figure, 5 tables.

Process for the generation of power from carbonaceous fuels with minimal atmospheric pollution

Abstract: This invention relates to a process for the efficient production of power by the oxidation of carbonaceous or hydrocarbon fuels with minimal pollution of the atmosphere. In one of its more specific aspects, this object is accomplished by partial oxidation of the hydrocarbon or other carbon-containing fuels to produce a fuel gas, followed by partial oxidation of this fuel gas and finally complete combustion of the gaseous products of the second partial oxidation with the generation of power in stages following each of the oxidation steps such that the stack gas discharged to the atmosphere is low in oxides of nitrogen and is substantially free from sulfur compounds. The process is particularly suitable for use with sulfur-containing petroleum residua, shale oils and the like.

Process for producing hydrogen from synthesis gas containing COS

Abstract: Process for treating synthesis gas to recover a purified essentially sulfur-free hydrogen-rich stream. The novel sequence of operations employed comprises initially removing from the feed gas, such as from a synthesis gas derived from partial oxidation of coal or oil, the bulk of contained H 2 S and a substantial part of the contained COS, by physical absorption in a suitable solvent. The gas from the initial absorption is then subjected to water-gas shift reaction over a sulfur-resistant shift catalyst under conditions such that in addition to the conversion of CO to CO 2 most of the contained COS hydrolyzed to H 2 S. The gaseous shift product is then subjected to a second treatment with suitable solvent to remove by physical absorption essentially all of the remaining sulfur, which is then present as H 2 S. The thus desulfurized gas mixture is then sent to a CO 2 absorber, from which a H 2 -rich gas effluent is withdrawn. The H 2 S bearing solvent from the second treatment is used in the initial absorbtion. H 2 S is stripped from the initial rich absorption bottoms liquid to recover a Claus gas effluent of high H 2 S content, while the stripped liquid bottoms are recycled for further use in the process.

Method of converting liquid and/or solid fuel to a substantially inerts-free gas

Abstract: The invention relates to the conversion of fuel (solid and/or liquid) to reducing and/or synthesis gas by contacting the fuel in a fluidized conversion bed (13) with a solid oxygen donor (e.g. CaSO 4 ) at a fuel conversion temperature (e.g. 850° to 1150° C.) in the presence of at least one gas/vapor phase substance such as H 2 and/or H 2 O and/or CO and/or CO 2 which serves to promote and or mediate the transfer of oxygen from the donor to the fuel and preferably in the absence of non-reactive gases (e.g. N 2 ) whereby the fuel is converted to a reducing and/or synthesis gas product by (inter alia) partial oxidation employing the oxygen of the solid oxygen donor, the latter being reduced (e.g. CaS). The reduced donor is exothermically oxidized in a fluidized oxidation bed (35) by contact with an oxygen-containing gas (e.g. air) and re-used for converting further quantities of fuel. Moieties (e.g. sulfur/sulfur compounds) whose presence is undesirable in the gas product may be removed by a solid moiety-fixing agent (e.g. CaO) in the conversion bed (13). The moiety-fixing properties of the latter are at least partly regenerated in a fluidized regenerator bed (48) by treatment in a suitable regenerating atmosphere, and the regenerated moiety-fixing agent is returned to the conversion bed (13) directly and/or indirectly via the oxidation bed (35).

Ethylene oxide recovery

Abstract: In the manufacture of ethylene oxide by the partial oxidation of ethylene in the vapor phase, the effluent gases from the reaction are absorbed in water prior to separation and purification of the ethylene oxide. The present invention is the improvement in which ethylene carbonate is employed as the absorbing medium for the ethylene oxide.

Partial oxidation catalyst

Abstract: An improvement in the oxidation catalyst used for the partial oxidation of n-butane and containing vanadium and phosphorus mixed oxides which comprises adding a zinc compound in an amount of from about 0.15 to 0.001/l Zn/V to the catalyst during the digestion of the reduced vanadium component by concentrated phosphoric acid. The addition of zinc produces a catalyst which is more easily activated and which is very stable to heat upset of the reaction system. Small amounts of lithium and silicon compounds also have additional desirable catalytic effects without dimunition of the zinc compound benefit.

Oxidation of ethanol on platinum/alumina and copper oxide catalysts

Abstract: The oxidation of ethanol on CuO, CuO/Al2O3 and Pt/Al2O3 catalysts has been studied at various concentrations of alcohol, oxygen and water vapor in the reaction mixture. The reaction order and activation energies have been determined for both complete and partial oxidation processes. A consecutive oxidation scheme is suggested.

Disposition of a high nitrogen content oil stream

Abstract: A method of denitrogenating viscous oils containing a relatively high content of nitrogenous compounds and of disposing of a resulting high nitrogen content oil stream, characterized by forming a raw oil stream and a first viscous bottoms stream that would not be operably pumpable to a partial oxidation unit without the inclusion of viscosity lowering constituents; extracting the nitrogenous compounds from the raw oil stream with an operable acid solvent to produce a raffinate oil of low nitrogen content oil and an extract stream of low viscosity, high nitrogen content oil; recovering the acid solvent from the extract stream, simultaneously producing a small volume stream of low viscosity, high nitrogen content oil; admixing the low viscosity high nitrogen content oil with the high viscosity bottoms stream to provide a pumpable mixed stream; sending the mixed stream to a partial oxidation unit to produce hydrogen; employing the produced hydrogen for hydrogenation of the raffinate oil at mild conditions; and recycling the acid solvent to the extraction step Additional and alternative steps are also disclosed

Principles of oxidative dehydrodimerization of olefins on oxide catalysts

Abstract: Analysis of the available data shows that the main laws of the partial oxidation of hydrocarbons are valid for the oxidative dehydrodimerization of olefins. The problem of choosing the catalysts for the reaction of this type is discussed.

Process for purifying and cooling partial oxidation gases containing dust-like impurities

Abstract: The hot partial oxidation gases which are formed in a gasifier for solid or liquid fuel are passed first into a dust separator under conditions where 70 to 95% of the impurities are eliminated, whereupon the gases then are washed in a wet washer with an amount of water not higher than necessary to remove the residual dust impurities. The process has the particular advantage of a very low amount of drainage water and has a high safety factor and adaptability for different conditions.

Partial oxidation process with recovery of unconverted solid fuel from suspension in water

Abstract: Disclosed is a partial oxidation process including separation of particles high in carbon content from particles low in carbon content suspended in water used for quenching or scrubbing the gaseous products of the partial oxidation of a solid ash-containing carbonaceous fuel.

Catalytic partial oxidation of hydrogen sulfide on chabazite tuff

Abstract: The catalytic activity of a chabazite tuff in the partial oxidation of H2S to sulfur has been determined. The effects of temperature, feed concentration and chemical composition of the tuff on H2S conversion and selectivity to sulfur have been investigated. Encouraging results in view of a possible use in H2S removal processes have been obtained.

A Partial Oxidation Staging Concept for Gas Turbines Using Broadened Specification Fuels

Abstract: A concept is described for using a very fuel-rich partial oxidation process as the first stage of a two-stage combustion system for onboard processing of broadened specification fuels to improve their combustion characteristics. Results of an initial step in the experimental verification of the concept are presented, where the basic benefits of H2 enrichment are shown to provide extended lean-combustion limits and permit simultaneous achievement of ultralow levels of NOx, CO, and HC emissions. The H2 required to obtain these results is within the range available from a partial oxidation precombustion stage. Operation of a catalytic partial oxidation reactor using a conventional aviation turbine fuel (JP5) and an unconventional fuel (blend of JP5/xylene) is shown to produce a “fuel gas” stream with near-theoretical equilibrium H2 content. However, a number of design considerations indicate that the precombustion stage should be incorporated as a thermal reaction.Copyright © 1979 by ASME

Preparation of dimethylformamide

Abstract: PURPOSE:To obtain the title high-quality compound with a high selectivity and yield, by reacting a mixture comprising monomethylamine with Co in the presence of metallic iron as a catalyst and hydrogen. CONSTITUTION:Monomethylamine(M) and/or a mixture of monomethylformamide and trimethylamine or further M is reacted with Co and hydrogen in the presence of a metallic iron or its compound as a catalyst at a volume ratio of H2 to Co of 0.05- 3;1, preferably 0.1-2:1. EFFECT:An inexpensive and available mixture of Co and H2, obtained by partial oxidation or steam reforming of naphtha or methane, or H2-containing blast furnace gas of iron mills can be directly used to produce economic advantages.

Emission characteristics of a premix combustor fueled with a simulated partial-oxidation product gas

Abstract: A two-stage gas turbine combustor concept employing a very fuel-rich partial oxidation stage is being explored for broadening the combustion margin between ultralow emissions and the lean stability limit Combustion and emission results are presented for a series of experiments where a simulated partial oxidation product gas was used in a premix combustor operated with inlet air state conditions typical of cruise power for high-performance aviation engines (12 atm and 850 F) Ultralow NOx, CO, and HC emissions and an extended lean burning limit were achieved simultaneously

Hydrocarbon cracking process

Abstract: 57 The method for splitting of hydrocarbons can be employed as the thermal decomposition (9) of heavy hydrocarbons, which are subjected to a hydrogenating pretreatment (2). The pyrolytic residue (14) of the thermal cracking (9) is gasified by partial oxidation (15). The hydrogen formed is separated (19, 21) is supplied and the hydrogenating pretreatment (2). In a separation of polymeric constituents of the pyrolysis residue (14) only those are gasified, while the non-polymer components are recycled for the hydrogenation of (2).

IR spectra of catalysts and adsorbed molecules. 29. State of the water on the surface of copper-containing catalysts during the low-temperature conversion of carbon monoxide

Abstract: 1. Carbon monoxide is a “probe” for the interaction of water with the surface of copper-containing catalysts. 2. The state of the surface of the catalyst affects the form of the water adsorbed onto copper applied to γ-Al2O3. Adsorption in the molecular form is more probable on the surface containing oxygen, and in the dissociative form on the reduced surface. 3. The surface of copper reduced to the metallic state can undergo partial oxidation from the effect of a mixture of CO and water vapor.

Selectivity in heterogeneous catalytic oxidation

Abstract: Selectivity of the catalytic oxidation of hydrocarbons is discussed in terms of the type of intermediate complex formed. Two different intermediate complexes initiate two different routes of the reaction. Activation of oxygen leads to total oxidation through electrophilic attack on the double bond and formation of the complex of the peroxide or epoxide type, whereas partial oxidation requires activation of the hydrocarbon molecule resulting in the formation of the allyl species bonded as ligand in the intermediate complex. It proceeds then in a series of consecutive oxidative elementary steps, each of them requiring different active centers to be present at the catalyst surface. The type of product obtained and its selectivity depend thus on the type and mutual proportions of these centers. Oxidation is performed by the cationic active centers, whereas oxygen is inserted by a nucleophilic attack which may also be considered as an acid-base process. Mechanisms of these elementary steps is are discussed on the basis of the quantum chemical description of intermediate complexes.

Partial oxidation of methane to formaldehyde over halogen modified catalyst

Abstract: The partial oxidation of methane to formaldehyde over Pd-supported on Al2O3 in the presence of small amounts of halogen modifiers was investigated in an isothermal integral flow reactor at atmospheric pressure between 300 and 510°C. The effects of several variables, feed ratio of air to methane, reaction temperature, reciprocal of space velocity, and the type and amount of halogen modifiers on the conversion and product distribution, were determined by gas chromatography. Though 13 different mechanisms were postulated the rate of reaction was most satisfactorily correlated by a mechanism which assumes the rate controlling step to be the surface reaction between charged, adsorbed methane and oxygen.