Showing papers on "Methanol published in 1976"

Purification and properties of formaldehyde dehydrogenase and formate dehydrogenase from Candida boidinii.

Abstract: Formaldehyde hydrogenase and formate dehydrogenase were purified 130-fold and 19-fold respectively from Candida boidinii grown on methanol. The final enzyme preparations were homogenous as judged by acrylamide gel electrophoresis and by sedimentation in an ultracentrifuge. The molecular weights of the enzymes were determined by sedimentation equilibrium studies and calculated as 80000 and 74000 respectively. Dissociation into subunits was observed by treatment with sodium dodecylsulfate. The molecular weights of the polypeptide chains were estimated to be 40000 and 36000 respectively. The NAD-linked formaldehyde dehydrogenase specifically requires reduced glutathione for activity. Besides formaldehyde only methylglyoxal served as a substrate but no other aldehyde tested. The Km values were found to be 0.25 mM for formaldehyde, 1.2 mM for methylglyoxal, 0.09 mM for NAD and 0.13 mM for glutathione. Evidence is presented which demonstrates that the reaction product of the formaldehyde-dehydrogenase-catalyzed oxidation of formaldehyde is S-formylglutathione rather than formate. The NAD-linked formate dehydrogenase catalyzes specifically the oxidation of formate to carbon dioxide. The Km values were found to be 13 mM for formate and 0.09 mM for NAD.

Conversion of synthesis gas to hydrocarbon mixtures

Abstract: Synthesis gas is contacted with an intimate mixture of a carbon monoxide hydrogen reduction catalyst, comprising a methanol synthesis catalyst in combination with a selective class of acidic crystalline aluminosilicate having a silica/alumina ratio greater than 12, a pore dimension greater than about 5 Angstroms to produce hydrocarbon mixtures useful in the manufacture of heating fuels, gasoline, aromatic hydrocarbons, and chemicals intermediates

Growth of hansenula-polymorpha in a methanol-limited chemostat - physiological-responses due to involvement of methanol oxidase as a key enzyme in methanol metabolism

Abstract: Hansenula polymorpha has been grown in a methanol-limited continuous culture at a variety of dilution rates. Cell suspensions of the yeast grown at a dilution rate of 0.16 h-1 showed a maximal capacity to oxidize excess methanol (QO 2 max ) which was 1.6 times higher than the rate required to sustain the growth rate (Q O2). When the dilution rate was decreased to 0.03 h-1, QO 2 max of the cells increased to a value of more than 20 times that of Q O2. The enzymatic basis for this tremendous overcapacity for the oxidation of excess methanol at low growth rates was found to be the methanol oxidase content of the cells. The level of this enzyme increased from 7% to approximately 20% of the soluble protein when the growth rate was decreased from 0.16 to 0.03 h-1. These results were explained on the basis of the poor affinity of methanol oxidase for its substrates. Methanol oxidase purified from Hansenula polymorpha showed an apparent K mfor methanol of 1.3 mM in air saturated reaction mixtures and the apparent K mof the enzyme for oxygen was 0.4 mM at a methanol concentration of 100 mM. The involvement of an oxygen dependent methanol oxidase in the dissimilation of methanol in Hansenula polymorpha was also reflected in the growth yield of the organism. The maximal yield of the yeast was found to be low (0.38 g cells/g methanol). This was not due to a very high maintenance energy requirement which was estimated to be 17 mg methanol/g cells x h.

Isothermal Vapor-Liquid Equilibrium Data for Binary Systems Containing Carbon Dioxide at High Pressures: Methanol-Carbon Dioxide, n-Hexane-Carbon Dioxide, and Benzene-Carbon Dioxide Systems

Abstract: Isothermal vapor-liquid equilibrium data for the systems methanol-carbon dioxide, n-hexane-carbon dioxide, and benzene-carbon dioxide were measured by a static method at 25' and 4OoC. By use of the Lewis rule and the RedlichKwong equation of state for carbon dioxide in the vapor phase, the activity coefficients in the liquid phase and the fugacity coefficients in the vapor phase were evaluated from thermodynamic relationships. The isothermal vapor-liquid equilibria at high pressures for binary systems containing carbon dioxide were reported in previous papers, in which methanol-carbon dioxide and acetone-carbon dioxide systems were measured by a vapor recirculation method (3), and ethyl ether-carbon dioxide and methyl acetate-carbon dioxide systems by a static method In this study the vapor-liquid equilibria for three binary systems of methanol-carbon dioxide, n-hexane-carbon dioxide, and benzene-carbon dioxide were measured at 25' and 4OoC by the static method. The activity coefficients in the liquid phase and fugacity coefficients in the vapor phase were determined by using the Lewis rule and the Redlich-Kwong equation of state for carbon dioxide in the vapor phase. The liquid activity coefficients in the methanol-carbon dioxide system are the largest of the three systems, though those in n-hexane-carbon dioxide and benzene-carbon dioxide are also considerably large. Experimental

Isothermal vapor-liquid equilibrium data for binary systems containing ethane at high pressures

Abstract: Isothermal vapor-liquid equilibrium data for binary systems containing carbon dioxide at high pressure have been reported previously. In those studies, methanol, acetone, methyl acetate, ethyl ether, n-hexane, and benzene were chosen as the solvent components. In this study, the same solvent components were used and carbon dioxide was replaced with ethane having similar critical temperature to that of carbon dioxide. The nonidealities of vapor and liquid phases of the ethane systems were determined with thermodynamic procedures and were compared between these 6 systems. By use of the Redlick-Kwong equation of state and the Lewis rule for ethane in the vapor phase, the activity coefficients in the liquid phase and the fugacity coefficients in the vapor phase were evaluated. (10 refs.)

Conversion of methanol to gasoline components

Abstract: A method and sequence of process steps is described for effecting the conversion of lower alcohols comprising methanol, ethanol and propanol to gasoline boiling range component arranged to significantly extract reaction heat and selectively control the restricting of the alcohol feed through the production of ethers and olefins prior to isomerizing and aromatizing the formed olefins. A tubular reactor section is particularly relied upon for the highly exothermic olefin forming step of the combination operation.

Colloidal rhodium in polyvinyl alcohol as hydrogenation catalyst of olefins

Abstract: A colloidal rhodium has been prepared by reduction of rhodium(III) chloride with methanol in the presence of polyvinyl alcohol. The particle size distribution of the metallic rhodium is narrow ranging from 30 to 70 A with a maximum at 35 A. The colloidal dispersions in methanol-water solutions are effective for the hydrogenation of olefins at 30°C under an atmospheric hydrogen pressure.

A new method of quaternizing amines and its use in amino acid and peptide chemistry

Abstract: Methyl iodide and potassium bicarbonate in methanol is presented as a mild, efficient, and selective reagent for the quaternization of amino groups. It does not attack hydroxyl groups. Its use with...

Bacterial yields on methanol, methylamine, formaldehyde, and formate

Abstract: Several bacteria utilizing C1-compounds as sole carbon sources were grown on these substrates in continuous culture. The molar yield values (g of cell dry wt/mol of substrate utilized) of bacteria which utilize C1-compounds via the ribulose monophosphate pathway were between 15.7 to 17.3 when grown on methanol; while the molar yield values of bacteria which use the serine pathway for the assimilation of C1-compounds varied between 9.8 and 13.1. The molar yield values of different bacteria which use the serine pathway decreased as the oxidation levels of the C1-growth substrates increased. On formaldehyde the values were between 7.2 to 9.6, whereas on formate the values varied from 3.3 to 6.9. It appears that bacteria utilize Cl-compounds more efficiently via the ribulose monophosphate pathway than via the serine pathway. The oxidation step from methanol to formaldehyde (and from methylamine to formaldehyde) in the bacteria studied may be energy yielding. A comparison has been made between the experimental yield values obtained and theoretical values.

N‐acetylchitosan gel: A polyhydrate of chitin

Abstract: N-Acetylchitosan gel, a polyhydrate of chitin, and partially O-acetylated N-acetylchitosan gel were produced by a facile acetylation of chitosan with acetic anhydride in 10% acetic acid and in aqueous acetic acid/methanol at room temperature. Under the same conditions, a series of N-acylchitosan gels was produced in reaction with the other carboxylic anhydrides. The gels thus produced were colorless, transparent and rigid, and stable on heating. The gels were insoluble in cold and boiling water, formic acid, aqueous acids, and the other solvents examined. Significant changes in specific rotation occurred in the acylation of chitosan and its aggregation.

Zeolite catalyst containing oxide of boron or magnesium

Abstract: A catalytic process is provided for converting lower monohydric alcohols and their ethers, especially methanol and dimethyl ethers, to a hydrocarbon mixture rich in C 2 -C 3 olefins and mononuclear aromatics with high selectivity for para-xylene production by contact, under conversion conditions, with a catalyst comprising a crystalline aluminosilicate zeolite, said zeolite having a silica to alumina ratio of at least about 12 and a constraint index, as hereinafter defined, within the approximate range of 1 to 12, said catalyst having been modified by the addition thereto of a minor proportion of an oxide of boron or magnesium either alone or in combination, or in further combination with an oxide of phosphorus

Manufacture of light olefins

Abstract: A catalytic process is provided for converting a charge consisting essentially of methanol, dimethyl ether or mixtures thereof to a hydrocarbon product rich in ethylene and propylene by contact, under conversion conditions, with a catalyst comprising the crystalline aluminosilicate zeolite designated "ZSM-34".

S-formylglutathione - substrate for formate dehydrogenase in methanol-utilizing yeasts

Abstract: Formaldehyde dehydrogenase and formate dehydrogenase were purified 45- and 16-fold, respectively, from Hansenula polymorpha grown on methanol. Formaldehyde dehydrogenase was strictly dependent on NAD and glutathione for activity. The Kmvalues of the enzyme were found to be 0.18 mM for glutathione, 0.21 mM for formaldehyde and 0.15 mM for NAD. The enzyme catalyzed the glutathine-dependent oxidation of formaldehyde to S-formylglutathione. The reaction was shown to be reversible: at pH 8.0 a Kmof 1 mM for S-formylglutathione was estimated for the reduction of the thiol ester with NADH. The enzyme did not catalyze the reduction of formate with NADH. The NAD-dependent formate dehydrogenase of H. polymorpha showed a low affinity for formate (Kmof 40 mM) but a relatively high affinity for S-formylglutathione (Kmof 1.1 mM). The Kmvalues of formate dehydrogenase in cell-free extracts of methanol-grown Candida boidinii and Pichia pinus for S-formylglutathione were also an order of magnitude lower than those for formate. It is concluded that S-formylglutathione rather than free formate is an intermediate in the oxidation of methanol by yeasts.

Metabolism of methanol by Rhodopseudomonas acidophila.

Abstract: Summary: Rhodopseudomonas acidophila strain 10050, grown anaerobically in the light on methanol, contained a methanol and formaldehyde dehydrogenase which could be coupled to phenazine methosulphate; an NAD-linked formaldehyde dehydrogenase which required GSH for activity; and an NAD-linked formate dehydrogenase. The specific activities of these enzymes varied in a non-coordinate manner when the organism was grown on different alcohols, formate or succinate. The affinity of the phenazine methosulphate linked methanol dehydrogenase for methanol was increased 10-fold if the cell-free extract was prepared and assayed in the absence of oxygen. Pulse-labelling experiments with [14C]methanol and [14C]bicarbonate indicated that fixation of carbon dioxide occurred via the ribulose diphosphate cycle and C3 + CO2 fixation reaction(s). No evidence was obtained for operation of a reduced C1 fixation sequence. This conclusion was borne out by the enzyme content of cell-free extracts of the organism.

Microbial oxidation of methane and methanol: crystallization and properties of methanol dehydrogenase from Methylosinus sporium.

Abstract: Obligate methylotrophs are divisible into two types on the basis of ultrastructural biochemical characteristics. Both groups possess a soluble phenazine methosulfate (PMS)-dependent methanol dehydrogenase. In addition, particulate PMS-dependent methanol dehydrogenase and PMS-independent methanol oxidase have been found in the type I membrane group. A procedure was developed for the crystallization of methanol dehydrogenase from the soluble fraction of the type II obligate methylotroph Methylosinus sporium. This is the first report of a crystalline methanol dehydrogenase from a methylotrophic bacterium. The crystallized enzyme is homogeneous as judged by ultracentrifugation and by acrylamide gel electrophoresis. In the presence of an electron acceptor (phenazine or phenazinium compound) and an activator (ammonium compound), the crystallized enzyme catalyzed the oxidation of primary alcohols and formaldehyde. Secondary, tertiary, and aromatic alcohols were not oxidized. The molecular weight of the enzyme as estimated by gel filtration is approximately 60,000, and as estimated by sedimentation equilibrium analysis it is 62,000. The sedimentation constant (S20,W) is 2.9. The subunit size determined by sodium dodecyl sulfate-gel electrophoresis is approximately 60,000. The amino acid composition and spectral properties of the enzyme are also presented. Antisera prepared against the crystalline enzyme are nonspecific, they cross-reacted and inhibited isofunctional enzymes from other obligate methylotrophic bacteria.

Conversion of methanol to olefinic components

Abstract: A method and sequence of process steps is described for effecting the conversion of lower alcohols comprising methanol, ethanol, and propanol to primarily olefin boiling range component under conditions to significantly extract reaction heat and selectively control the restructuring of the alcohol feed through the production of ethers and particularly olefins.

A facile method for the oxidation of alcohols.

Abstract: Trialkyltin alkoxides, prepared from alcohols and trialkyltin methoxide by azeotropical removal of methanol, are easily oxidized by bromine in the presence of trialkyltin methoxide, a hydrogen bromide captor, to give the corresponding aldehydes or ketones in good yields. Alcohols are oxidized directly in one step to the corresponding carbonyl compounds by utilizing bis(tributyltin) oxide and bromine.

A Single-Cylinder Engine Study of Methanol Fuel-Emphasis on Organic Emissions

Abstract: Exhaust emission and performance characteristics of a single-cylinder engine fueled with methanol are compared to those obtained either with gasoline or a methanol-water blend. Our measurements of engine efficiency and power, and CO and NO/sub x/ emissions agree with trends established in the literature. Consequently, the emphasis is placed on organic emissions (unburned fuel including hydrocarbons, and aldehydes), an area in which there is no consensus in the literature. In all cases with methanol fueling, the unburned fuel (UBF) emissions were virtually all methanol as opposed to hydrocarbon compounds. Without special measures to overcome methanol's large heat of vaporization, UBF emissions were four times greater with methanol than those with gasoline. Similarly, aldehyde emissions were an order of magnitude greater with methanol. These high levels of organic emissions with methanol were related to inadequate fuel-air mixture preparation, which was caused by methanol's large heat of vaporization. Modifying the single-cylinder engine intake system to improve vaporization reduced UBF emissions 80 to 90% with methanol and 30 to 50% with gasoline. Aldehyde emissions were also significantly reduced by improving mixture preparation, but remained three to four times greater for methanol than for gasoline. Blending 10% water with methanol resulted in: (1) reducedmore » engine efficiency and power, (2) increased UBF emissions, (3) no measurable effect on aldehyde and CO emissions, and (4) reduced NO/sub x/ emissions. Our tests indicate that the advantages of blending water with methanol are outweighed by the disadvantages.« less

Free acid, anion, alkali, and alkaline earth complexes of lasalocid a (X537A) in methanol: structural and kinetic studies at the monomer level

Abstract: We report below on nuclear magnetic resonance investigations of the structure and exchange kinetics for the free acid, anion, sodium complex, and barium complex of the ionophore lasalocid A (X537A) in methanol solution. A comparison between the proton and carbon longitudinal relaxation times of lasalocid in nonpolar and polar solvents demonstrates that the free acid (HX) is a monomer in methanol solution. Parallel proton and carbon relaxation measurements demonstrate that the anion (X-), sodium complex (NaX), and barium complex (BaX+) are also monomeric in methanol solution. These results are in contrast to the Na2X2 dimer and the BaX2-H20 dimer observed in crystals and in nonpolar (cyclohexane and methylene chloride) solutions. Large downfield shifts on complex formation (X- to NaX and BaX+) are detected for protons located on the polar face of the ionophore with their C-H bonds directed towards and proximal to the metal ion. The exchange of lasalocid anion between free (X-) and complexed (BaX+) states in methanol can be monitored from the temperature-dependent line shapes of the proton resonances at superconducting fields. The exchange rates are independent of the reactant concentrations and are characteristic of a rate-determining dissociation of BaX+ in methanol solution with activation parameters delta H++ = 6.5 kcal mol-1 (25 degrees) and delta S++ = -20.0 cal mol-1 degree -1 (1 cal = 4.184 J). The rate constants for dissociation and formation of BaX+ complex in methanol, 25 degrees, are 5.2 X 10(3) sec-1 and 1.5 X 10(10) M-1 sec-1, respectively. These studies were extended to derive the activation parameters for the exchange of lasalocid anion between BaX+ and NaX and between BaX+ and HX in methanol, while the exchange among HX, X-, and NaX is too rapid to be monitored on the time scale of nuclear magnetic resonance.

Process for preparing trihydrocarbyl (2,5-dihydroxyphenyl) phosphonium salts

Abstract: The title compounds are prepared by reacting (a) a trihydrocarbylphosphine, (b) p-benzoquinone, and (c) a protic acid in a liquid reaction medium comprising a lower alkanol of from 1 to 4 carbon atoms, a 1,2-alkylene glycol, dialkylene glycol or trialkylene glycol or a lower alkyl mono-ether of said glycols. The glycols are either ethylene glycol, propylene glycol, or the indicated oligomers thereof. Methanol is the solvent of choice. As an example, tri-n-butyl (2,5-dihydroxyphenyl)phosphonium chloroacetate was prepared in excellent yields by slowly adding tri-n-butylphosphine, precooled to about 0° C, to a vigorously stirred suspension of p-benzoquinone in a methanol solution of chloroacetic acid at a temperature of approximately -10° C. A precatalyzed epoxy resin was obtained by merely adding the methanol solution of the phosphonium chloroacetate to a liquid epoxy resin (e.g., the diglycidyl ether of bisphenol-A).

Mordenite conversion of alkanols to penta- and hexamethyl benzenes

Abstract: By catalytic contact with the crystalline alumino-silicate zeolite, mordenite, having a silica to alumina ratio greater than about 15, methanol and/or methyl ethers are catalytically condensed to a mixture of hydrocarbons including polyalkylated aromatic hydrocarbons.

Process for production of hydrogen

Abstract: Catalytic compositions particularly useful in the production of hydrogen from methanol, especially by steam reforming, which comprises a mixture of zinc oxide, copper oxide, thorium oxide and aluminum oxide whereby the activity and activity maintenance of the catalytic composition is superior relative to a composition otherwise substantially the same but lacking thoria.