Showing papers on "Methanol published in 1979"

Catalytic distillation process

Abstract: A method for conducting chemical reactions and fractionation of the reaction mixture comprising feeding reactants to a distillation column reactor into a feed zone and concurrently contracting the reactants with a fixed bed catalytic packing to concurrently carry out the reaction and fractionate the reaction mixture. For example, a method for preparing methyl tertiary butyl ether in high purity from a mixed feed stream of isobutene and normal butene comprising feeding the mixed feed stream to a distillation column reactor into a feed zone at the lower end of a distillation reaction zone, and methanol into the upper end of said distillation reaction zone, which is packed with a properly supported cationic ion exchange resin, contacting the C 4 feed and methanol with the catalytic distillation packing to react methanol and isobutene, and concurrently fractionating the ether from the column below the catalytic zone and removing normal butene overhead above the catalytic zone.

Formation and Catalytic Functionality of Synthetic Polymer-Noble Metal Colloid

Abstract: Colloidal dispersions of noble metals in synthetic polymers are prepared by reduction with alcohol. Reflux of a solution of rhodium(III) chloride and poly(vinyl alcohol) (PVA) in a methanol-water mixed solvent under argon or air for 4 hr gives a homogeneous solution of colloidal dispersion of rhodium (Rh-PVA-MeOH/H2O). The particle size of metallic rhodium is distributed n a narrow range of 30-70 A, and the average diameter is 40 A. The formation of colloidal rhodium proceeds through three steps: coordination of poly(vinyl alcohol) to rhodium(III) ion, reduction with methanol to form small particles (8 A in diameter), and growth of the small particle to large particle (40 A in diameter). Polyvinylpyrrolidone (PVP) and poly(methyl vinyl ether) (PMVE) can be used in place of poly(vinyl alcohol) and result in colloidal dispersions, respectively, similar to Rh-PVA-MeOH/H2O. Colloidal dispersions in nonaqueous solvent can be prepared by using ethanol instead of methanol-water (Rh-PVP-EtOH) and by usin...

A new method for the determination of the relative acidities of alcohols in alcoholic solutions. The nucleophilicities and competitive reactivities of alkoxides and phenoxides

Abstract: A new semiquantitative method has been developed for measuring the relative acidities of methanol, ethanol, isopropyl alcohol, and tert-butyl alcohol in mixed hydroxylic solvents. A solution of the...

Process for methanol production

Abstract: An improved methanol synthesis process is provided wherein synthesis gas containing hydrogen and carbon dioxide is passed over a methanol synthesis catalyst, cooled to condense methanol and water in the reacted gas, the liquids separated, a purge gas stream removed while the remaining reacted gas is recycled to the synthesis catalyst, the purge gas separated by contacting the outer surfaces of a plurality of hollow fiber membranes selectively permeable to hydrogen and carbon dioxide to form a permeant gas depleted in hydrogen and carbon dioxide and a permeate gas enriched in said gases and the enriched permeate gas is combined with the synthesis gas. In an optional embodiment, methanol vapor is first recovered from the purge gas prior to contacting the selectively permeable membranes, preferably by a water scrub.

NAD-dependent formate dehydrogenase from methylotrophic bacterium, strain 1. Purification and characterization.

Abstract: 1. NAD-dependent formate dehydrogenase was isolated from gram-negative methylotrophic bacteria, strain 1, grown on methanol. The purification procedure involved ammonium sulfate fractionation, ion-exchange chromatography and preparative isotachophoresis or gel filtration; it resulted in a yield of 40%. 2. The final enzyme preparations were homogeneous as judged by sedimentation in an ultracentrifuge. Formate dehydrogenase purified in the presence of EDTA reveals two bands on electrophoresis in polyacrylamide gel both after protein and activity staining. Two components are transformed into a single one after prolonged storage in the presence of 2-mercaptoethanol. 3. Formate dehydrogenase is a dimer composed of identical or very similar subunits. The molecular weight of the enzyme is about 80 000. 4. Amino acid composition and some other physico-chemical properties of the enzyme were studied. 5. Formate dehydrogenase is specific for formate and NAD as electron acceptor. The Michaelis constant was 0.11 mM for NAD and 15 mM for formate (pH 7.0, 37 degrees C). 6. Formate dehydrogenase was rapidly inactivated in the absence of -SH compounds. The enzyme retained full activity upon storage at ambient temperature in solution for half a year in the presence of 2-mercaptoethanol or EDTA.

Pyrazoles as inhibitors of alcohol oxidation and as important tools in alcohol research: an approach to therapy against methanol poisoning.

Abstract: 4-Methylpyrazole, in a dose producing inhibition of alcohol dehydrogenase (alcohol:NAD+ oxidoreductase, EC 1.1.1.1), was given alone or together with ethanol (10%) as sole drinking fluid to growing rats for up to 38 weeks. Their weight curves remained normal. Electron microscopy of liver, kidney, and heart revealed no changes related to treatment. Hematologic analysis showed normal values for blood and bone marrow. Several clinical chemical parameters showed no impairment of liver or kidney function, except for an enhancement of the microsomal drug-metabolizing activity after concurrent administration of 4-methylpyrazole and ethanol. A study on rats receiving 4-methylpyrazole and ethanol indicated a mutual interaction of the two compounds or the metabolites, leading to increased concentration in the blood of the compounds and reduced formation of 4-hydroxymethylpyrazole, the primary metabolite of 4-methylpyrazole. In monkeys, elimination of 4-methylpyrazole followed a linear course. 4-Hydroxymethylpyrazole accumulated to a level of at most 10% of that of 4-methylpyrazole. Concurrent administration of methanol inhibited the elimination of 4-methylpyrazole about 25%, and 4-methylpyrazole produced a profound inhibition of the oxidation of methanol. 4-Methylpyrazole, at a level in the plasma of more than 10 μM, prevented accumulation of the toxic metabolite formic acid in methanol-poisoned monkeys, and repeated injections of 4-methylpyrazole abolished methanol toxicity in monkeys receiving lethal doses of methanol. The present investigation indicates that 4-methylpyrazole, with its low toxicity and strong inhibition of alcohol oxidation, is a valuable tool for experimental studies of alcohol metabolism and its effects. It illustrates the usefulness of the monkey as a model to study 4-methylpyrazole activity and toxicity in light of its possible use for treating methanol poisoning in human beings.

Catalyst for the synthesis of methanol

Abstract: A methanol synthesis catalyst which comprises a major portion by weight of the oxides of copper and zinc and a minor portion by weight of a thermal stabilizing metal oxide is useful for the synthesis of methanol from the oxides of carbon and hydrogen at relatively low temperatures. The catalyst is characterized in that the ratio of copper oxide to zinc oxide, each expressed as a metal by weight, is in the range of from 2:1 to 3.5:1 and by the intimate association with each other of copper and zinc oxides and with said thermal stabilizing oxide. Further, the catalyst is characterized in that the amount of iron oxides, as an impurity, is less than 150 parts per million.

Process for the production of ethanol and/or acetaldehyde by reacting methanol with synthesis gas

Abstract: Ethanol and/or acetaldehyde is (are) produced by reacting methanol and synthesis gas at elevated temperature and pressure in the presenee of a catalyst consisting of (a) cobalt, (b) an iodide or a bromide and (c) a polydentate ligand wherein the donor atoms are selected from nitrogen, phosphorus, arsenic, antimony and bismuth, ethanol being the predominant product when the donor atoms are exclusively nitrogen or phosphorus, particularly phosphorus, and acetaldehyde being the major product when the donor atoms are exclusively arsenic, antimony or bismuth. A particularly effective polydentate ligand is one having the formula: (R') (R2)X-(C (R3) (R6)]n -Y(R3)(R4) (II) in which X and Y are independently nitrogen, phosphorus, arsenic, antimony or bismuth; n is an integer; (R'), (R2), (R3) and (R4) are independently saturated monovalent organic radicals containing from 1 to 20 carbon atoms. Examples of polydentate ligands which are effective in the production of ethanol are those having the formula (II) in which (R1), (R2), (R3) and (R4) are C6H5, X and Y are phosphorus and n has the value 4 to 6.

Microbial oxidation of gaseous hydrocarbons: production of methyl ketones from their corresponding secondary alcohols by methane- and methanol-grown microbes.

Abstract: Cultures of methane- or methanol-utilizing microbes, including obligate (both types I and II) and facultative methylotrophic bacteria, obligate methanol utilizers, and methanol-grown yeasts were isolated from lake water of Warinanco Park, Linden, N.J., and lake and soil samples of Bayway Refinery, Linden, N.J. Resting-cell suspensions of these, and of other known C1-utilizing microbes, oxidized secondary alcohols to their corresponding methyl ketones. The product methyl ketones accumulated extracellularly. Succinate-grown cells of facultative methylotrophs did not oxidize secondary alcohols. Among the secondary alcohols, 2-butanol was oxidized at the highest rate. The optimal conditions for in vivo methyl ketone formation were compared among five different types of C1-utilizing microbes. Some enzymatic degradation of 2-butanone was observed. The product, 2-butanone, did not inhibit the oxidation of 2-butanol. The rate of the 2-butanone production was linear for the first 4 h of incubation for all five cultures tested. A yeast culture had the highest production rate. The optimum temperature for the production of 2-butanone was 35°C for all the bacteria tested. The yeast culture had a higher temperature optimum (40°C), and there was a reasonably high 2-butanone production rate even at 45°C. Metal-chelating agents inhibit the production of 2-butanone, suggesting the involvement of metal(s) in the oxidation of secondary alcohols. Secondary alcohol dehydrogenase activity was found in the cell-free soluble extract of sonically disrupted cells. The cell-free system requires a cofactor, specifically nicotinamide adenine dinucleotide, for its activity. This is the first report of a nicotinamide adenine dinucleotide-dependent, secondary alcohol-specific enzyme.

Base-catalysed oxygenolysis of 3-hydroxyflavones

Abstract: 3-Hydroxyflavones, except those containing a 7-hydroxy-group, undergo base-catalysed oxygenolysis under mild conditions leading to oxidative cleavage of the heterocyclic ring to give the corresponding depsides and carbon monoxide in excellent yields. The same result is obtained in the reaction of quercetinase, a dioxygenase. The oxygenation of 3,4′,7-trihydroxyflavone in aqueous solution gave p-hydroxyphenylglyoxylic acid and 2,4-dihydroxybenzoic acid; in absolute methanol containing sodium methoxide methyl 4-hydroxyphenylglyoxylate and methyl 2,4-dihydroxybenzoate as well as 4-hydroxyphenylglyoxylic acid were obtained. The formation of these products is rationalized by assuming that 2-hydroperoxy-4′,7-dihydroxyflavan-3,4-dione is formed first and is reduced with the intervention of the 7-hydroxy-group to give 2,4′,7-trihydroxyflavan-3,4-dione, which is solvated and oxidized under the reaction conditions. 2′-Substituted-3-hydroxyflavones were not susceptible to oxygenolysis.

Further Study of Methanol Carbonylation Catalyzed by Cobalt, Rhodium, and Iridium Catalysts

Abstract: The effect of iodide ion was examined in methanol carbonylation with use of Co-, Rh-, and Ir-catalysts. Sodium iodide gives no noticeable effect on carbonylation catalyzed by Rh-catalyst to give acetic acid, and retards that catalyzed by Ir-catalyst. Methyl iodide is effective for methanol carbonylation with Co-catalyst in the presence of hydrogen to give mainly acetaldehyde, which is readily hydrogenated to ethanol during the course of carbonylation on addition of a catalytic amount of Ru3(CO)12. Sodium iodide is also effective for acetaldehyde formation, although it strongly retards the hydrogenation of acetaldehyde with Ru-catalyst. The different effect of iodide ion on methanol carbonylation catalyzed by Co-, Rh-, or Ir-catalyst is discussed in terms of neucleophilicity of the active catalyst species.

Isolation of a Methanol Dehydrogenase with a Functional Coupling to Cytochrome c

Abstract: Summary: A methanol dehydrogenase containing cytochrome c which was reduced on addition of methanol was isolated from Hyphomicrobium X. Metal-chelators or oxygen blocked this electron transport. Oxygen changed the coupling irreversibly, transforming the enzyme in the complex into the already known, NH4 +-requiring enzyme form. This ‘classical’ methanol dehydrogenase differs in several respects from the more natural enzyme reported here.

Method for producing microbial cells and use thereof to produce oxidation products

Abstract: Disclosed are newly discovered and isolated methylotrophic microorganism strains and their natural and/or artificial mutants which grow well under aerobic conditions in a culture medium in the presence of methane as the major carbon and energy source. The methane-grown microbial cells possess a high content of protein and can be utilized as such as feedstuffs. The methane-grown microbial cells or enzyme preparations thereof are also useful in converting C 1 -C 6 alkanes to alcohols, particularly methane to methanol, C 3 -C 6 alkanes to the corresponding C 3 -C 6 sec. alcohols and methyl ketones, C 3 -C 6 sec. alcohols to the corresponding methyl ketones, cyclic hydrocarbons to cyclic hydrocarbyl alcohols (e.g., cyclohexane to cyclohexanol) C 2 -C 4 alkenes selected from the group consisting of ethylene, propylene, butene-1 and butadiene to 1,2-epoxides, styrene to styrene oxide, and converting other oxidizable substrates to oxidized products. The newly discovered and isolated methylotrophic microorganism strains may be aerobically grown on a plurality of methyl-radical donating carbon-containing compounds, such as methanol, methylamine, methyl formate, methyl carbonate, dimethyl ether, etc., to produce microbial cells or enzyme preparations capable of aerobically converting C 3 -C 6 linear secondary alcohols to the corresponding methyl ketones.