Showing papers on "Methanol published in 1982"

Methanol from coal and natural gas

Abstract: The present invention is directed to a process which uses the methanol synthesis gas from steam reforming in a first methanol plant and effectively integrates a second methanol plant which uses as the methanol synthesis gas (a) the purge gas from the first methanol plant and (b) the clean syn-gas produced by partial oxidation.

The adsorption and reaction of methanol on Pd(100). I. Chemisorption and condensation

Abstract: The adsorption, desorption, and condensation of methanol on a clean Pd(100) surface has been studied in UHV at 77 K using high‐resolution electron energy loss spectroscopy, thermal desorption spectroscopy, UV photoemission, work function measurements, and low energy electron diffraction. CH3OH adsorbed readily with a high initial sticking probability which remains nearly constant up to monolayer coverages (∼6×1014/cm2) indicating precursor state adsorption kinetics. The first 20% of this methanol spontaneously decomposes, but can largely recombine to desorb as methanol. The nature of this species and other decomposition products are discussed in part II. The remaining methanol chemisorbs nondissociatively having a bonding energy of 10.8 kcal/mol; no long‐range order can be observed. The first physisorbed and later condensed layers are readily distinguishable and have desorption energies of 9.0 and 7.2 kcal/mode, respectively. The adsorption of methanol is accompanied by a continuous work function decrease...

Continuous production of ethanol and plural stage distillation of the same

Abstract: Ethanol is produced continuously via the carbonylation of methanol, by (a) carbonylating methanol, in a reactor R, in the presence of a carbonyl complex of a metal of group VIII of the periodic table and of a halogen compound, (b) separating, in a distillation column D1, the reactor discharge, into a top fraction comprising methyl acetate, methanol, dimethyl ether and an organohalogen compound, and into a bottom fraction comprising water, small quantities of acetic acid and the catalyst, if the latter is not in a fixed bed, the residence time being so adjusted that the greater part of the acetic acid reacts with the methanol present to give methyl acetate, (c) separating the top fraction from D1, in a distillation column D2, into a top fraction comprising small quantities of methyl acetate, methanol, dimethyl ether and the organo-halogen compound, and a bottom fraction comprising methyl acetate and methanol, and recycling the top fraction to reactor R, (d) distilling off, via the top of distillation column D3, the greater part of the water from the bottom fraction from D1and removing this water from circulation, and recycling to reactor R the bottom fraction consisting of small quantities of water, acetic acid and the catalyst, (e) using hydrogen to hydrogenate, in the hydrogenation reactor H, the bottom fraction from D2, in a conventional manner, to give a mixture of methanol and ethanol, and (f) separating the mixture into ethanol and methanol in a distillation column D4, and recycling the methanol to reactor R.

Aromatic acids produced during degradation of lignin in spruce wood by Phanerochaete chrysosporium

Abstract: Spruce wood was pre-extracted, decayed with the white-rot fungus Phanerochaete chrysosporium to a 20% loss in lignin content, and then extracted successively with solvents of increasing polarity (pet. ether, chloroform, acetone, methanol, and aqueous dioxane). The methanol extract (0.5% of the decayed wood) was divided into acid and phenol fractions, and these further into high and low molecular weight components. The low molecular weight acid fraction was examined by high performance liquid chromatography and, after acetylation and methylation, by gas chromatography/mass spectrometry. The following compounds were identified: 4-hydroxybenzoic acid (I), vanillic acid (2), isovanillic acid (3), veratric acid (4), 4-hydroxy- 5-methoxyphthalic acid (7), m-hemipinic acid (8), dehydrodivanillic acid (9), and 2'-hydroxy-2,3'-dimethoxydiphenylether-4,5'- dicarboxylic acid (10), 4-Hydroxy-3-methoxymandelic acid (11) was also tentatively identified. Compounds 2, 3, 4, 8, and 9 were the most abundant. Vanillic acid (2), homovanillic acid, and acetovanillone were 4-O-methylated by ligninolytic cultures of Ph. chrysosporium, with methionine serving as methyl donor. Thus compounds 4, 6, and 8 (and possibly 3), containing 4-O-methyl groups, probably arose via fungal methylation. Results establish that lignin is degraded by white-rot fungi in part via low molecular weight aromatic acids, formation of which involves C alpha-C beta side chain cleavage with C alpha oxidation. (Refs. 32).

Reactive distillation process for the production of methyl acetate

Abstract: The present invention provides a process for the production of high purity methyl acetate from methanol and glacial acetic acid wherein the acetic acid functions both as a reactant and as an extractive agent The process comprises countercurrently flowing approximately stoichiometric quantities of acetic acid and methanol through a single reactive distillation column in the presence of an acidic catalyst which is preferably sulfuric acid The column provides intimate contact between the acetic acid and the methanol and between the acetic acid and the azeotropes (methyl acetate/water and methyl acetate/methanol) which are formed in the column At preferred catalyst concentrations, the residence time in the column is at least about two hours The process further comprises continuously removing high purity methyl acetate from the top of the column and continuously removing water from the bottom of the column In preferred embodiments, the process further comprises removing intermediate boiling compounds, such as methyl propionate, methyl butyrate, isopropyl acetate, and mixtures thereof, from a vapor sidedraw stream The invention further comprises in preferred embodiments the use of a temperature control scheme whereby the overhead and the bottoms compositions are controlled by using two temperature control loops

Methanol fuel cell

Abstract: A methanol fuel cell wherein a positive electrode (2) and a negative electrode (1) are disposed in contact with a solid film (3) which exhibits a hydrogen ion- and/ or hydronium ion-conductivity. The methanol permeability coefficient of the solid film (3) of the methanol fuel cell is at most 1 x 10-6 mol/mol/l).min.cm2.

[76] Alcohol dehydrogenase from acetic acid bacteria, membrane-bound

Abstract: Publisher Summary This chapter describes the assay method, purification, and properties of alcohol dehydrogenase isolated from acetic acid bacteria. Alcohol dehydrogenase of acetic acid bacteria acts on a wide range of primary alcohols, except methanol. The enzyme acts as a vinegar producer by coupling with aldehyde dehydrogenase. The enzyme is localized on the outer surface of the cytoplasmic membrane and the oxidation of substrate is linked to its respiratory chain. The enzyme differs from alcohol dehydrogenase of methanol utilizing bacteria, which without exception requires ammonia for full activity. The reaction rate is estimated (a) by spectrophotometry in the presence of 2,6-dichlorophenolindophenol and phenazine methosulfate; (b) by colorimetry in the presence of potassium ferricyanide; (c) by polarography with an oxygen electrode; or (d) by manometry in a conventional Warburg apparatus. The assay method with potassium ferricyanide is employed because of its simplicity for routine assay. The steps involved in the purification of alcohol dehydrogenase from G. suboxydans and A. aceti are (1) the preparation of membrane fraction, (2) the solubilization of enzyme, (3) diethylaminoethyl (DEAE)-Sephadex column chromatography I and II, and (4) hydroxyapatite column chromatography.

Regulatory flexibility of methylotrophic yeasts in chemostat cultures: Simultaneous assimilation of glucose and methanol at a fixed dilution rate

Abstract: The influence of the composition of methanol/glucose-mixtures as only sources of carbon and energy on growth and regulation of the synthesis of enzymes involved in methanol-dissimilation was studied under chemostat conditions at a fixed dilution rate with the methylotrophic yeasts Hansenula polymorpha and Kloeckera sp. 2201. Both carbon sources were found to be utilized completely independently of the composition of the C1/C6 mixture. Using mixtures of 14C-labelled methanol and glucose the growth yield for glucose was found to be constant for all C1/C6-mixtures tested and both yeasts. The growth yield for methanol, however, was reduced by up to 25% when the proportion of methanol in the inflowing medium was lower than 20% (w/w with respect to glucose) for H. polymorpha and 50% (w/w with respect to glucose) for Kloeckera sp. 2201 respectively. During growth with C1/C6-mixtures containing higher C1-proportions of methanol regular growth yields for methanol were recorded which corresponded to the growth yields found with methanol as the only carbon source.

Partial oxidation of methane by nitrous oxide over molybdenum oxide supported on silica

Abstract: Methanol and formaldehyde were formed as major products at a moderate conversion level (16%) in the partial oxidation of methane by nitrous oxide in the presence of water over molybdenum oxide supported on silica.

Temperature-programmed reaction studies of the interaction of methyl formate and ethanol with polycrystalline zinc oxide

Abstract: The reactive nature of the polycrystalline zinc oxide surface has been investigated using methyl formate and ethanol as probe molecules; these have shown the dominant influence of the cation–anion dual site. Methyl formate decomposes during adsorption at the dual site to adsorbed methoxy and formate species. On temperature programming these show identical kinetics and reaction pathways to the methoxy and formate species observed previously after the adsorption of formaldehyde or methanol. Adsorption of ethanol at the dual site results in the formation of an adsorbed ethoxy species. On temperature programming, at 510 K, the zinc oxide surface abstracts one of the β-hydrogen atoms to form an unstable C2H4O fragment which decomposes mainly (90%) to ethylene; a small amount (ca. 10%) of the desorbing material which is either acetaldehyde or ethylene oxide (these cannot be distinguished by mass spectrometry) is desorbed coincidently at this temperature in an isomerization/desorption step. Despite the ethylene formation being a dehydration reaction, no water is observed in the desorption spectrum, the ethoxy oxygen species being left on the surface during decomposition.

SYNTHESIS OF METHYL-t-BUTYL ETHER FROM METHANOL AND ISOBUTENE USING A CLAY CATALYST

Abstract: The acid-catalyzed reaction between methanol and isobutene to give methyl-t-butyl ether may be carried out using a cation-exchanged smectite as the catalyst. In 1,4-dioxan solvent at 60°C smectites exchanged with Al3+, Fe3+, or Cr3+ give yields of ∼60% after 4 hr, whereas smectites exchanged with Cu2+, Pb2+, Ni2+, Co2+, Ca2+, and Na+ give less than ∼8% yield. The reaction is efficient only when certain solvents are used, e.g., with Al3+-smectite the yield is ∼5% when using 1,2-dimethoxyethane, diethyleneglycol diethylether, n-pentane, tetrahydropyran, N-methylmorpholine, or tetrahydrofuran solvents compared with ∼60% using 1,4-dioxan solvent (4 hr). Moreover, the effective solvents depend somewhat on the clay interlayer cation. The use of tetrahydrofuran and tetrahydropyran gives ∼35% yields at 60°C (4 hr) with Fe3+- or Cr3+-smectites but ∼4% yield with Al3+-smectite.