Abstract: A process for polymerizing oxiranes, oxetanes, oxepanes, dioxolanes, trioxanes, and tetrahydrofurans to their respective polymers by contacting them with a selected metal compound is disclosed; and also a process for depolymerizing polytetrahydrofurans to monomeric tetrahydrofurans by contacting the polymer with a selected metal compound at a temperature of about 100.degree. C. to about 250.degree. C. The catalysts may be in solution or part of a heterogeneous solid, and selected organic compounds are used as accelerators in the polymerizations. The polymeric products, some of which are novel, may be used as polyether monomers for further polymerization, as by reaction with isocyanates to produce polyurethanes, and other useful polymers. Some of the polymeric products are relatively high in molecular weight and are suitable for direct use, for instance as spandex fibers.

Abstract: Maleic acid, maleic anhydride or other hydrogenatable precursor are catalytically hydrogenated to 1,4-butanediol and tetrahydrofuran. It has been discovered that high yields of 1,4-butanediol are achieved when the hydrogenation catalyst comprises palladium, silver and rhenium on a carbon support and is prepared by the steps of(i) impregnating a carbon support with a source of palladium, silver and rhenium, wherein the source of palladium, silver and rhenium is at least one solution,(ii) after each impregnation step, drying the impregnated carbon support to remove solvent,(iii) heating the impregnated carbon support at a temperature of about 120.degree. C. to about 350.degree. C. under reducing conditions.The palladium in the catalyst is present in the form of crystallites having a particle size of less than 10 nm.

Abstract: A process for the preparation of tetrahydrofuran or tetrahydrofuran and .gamma.-butyrolactone from the product of the hydrogenation of maleic acid, succinic acid, maleic anhydride, succinic anhydride and/or fumaric acid, by treating the crude hydrogenation product, without prior work-up, at from 100.degree. to 300.degree. C. with a protic acid, and isolating pure tetrahydrofuran and .gamma.-butyrolactone from the resultant reaction mixture by distillation.

Abstract: A process for producing tetrahydrofuran, 1,4-butanediol, and 2-methyl-1,3,-propanediol is disclosed. A mixture containing 4-hydroxybutanal and 3-hydroxy-2-methylpropanal is hydrogenated in the presence of a transition metal supported on a weakly acidic ion-exchange resin or zeolite-type material to give tetrahydrofuran as the major product, and 1,4-butanediol and 2-methyl-1,3-propanediol as minor products. High yields of 2-methyl-1,3-propanediol can be obtained.

Abstract: A process for hydrogenating feeds into their corresponding alcohols by contact with a coprecipitated catalyst comprising copper, aluminum, and a metal (X) selected from the group consisting of magnesium, zinc, titanium, zirconium, tin, nickel, cobalt and mixtures thereof; that has been reduced with an increasing temperature during the reduction.

Abstract: A process is described for isolating tetrahydrofuran from mixtures containing tetrahydrofuran, 1,4-butanediol, -butyrolactone and succinic acid esters, in which the mixtures are heated to from 150.degree. to 250.degree. C. in the presence of phyllosilicates, the resultant tetrahydrofuran and water of reaction are removed from the reaction mixture by distillation, and the tetrahydrofuran is separated from the distillate.

Abstract: A process for converting 1,4-butanediol to tetrahydrofuran using polybenzimidazole to catalyze the reaction. The conversion is accomplished by heating the 1,4-butanediol in the presence of the PBI. The THF product may be distilled from the reaction solution as an azeotrope with water. To function as the catalyst, the PBI must first be pre-treated with a strong aqueous acid such as sulfuric acid. The catalyst may be in the form of microporous resin beads, hollow fibers, or other forms of PBI. This process exhibits a high selectivity for producing THF without side reactions.

Abstract: Mixtures which contain 1,4-butanediol and tetrahydrofuran are prepared by heating 4-hydroxybutyraldehyde of the formula ##STR1## at 20.degree.-300.degree. C. in the presence or absence of 1,4-butanediol and subjecting the resulting acetals of the formulae ##STR2## to a catalytic hydrogenation at 50.degree.-300.degree. C. and 1-350 bar.

Abstract: Tetrahydrofuran is recovered by a two stage distillation procedure from a crude hydrogenation product resulting from vapor phase hydrogenation of diethyl maleate and containing water, ethanol and a minor amount of n-butanol, and possibly also dissolved hydrogen, in addition to butane-1,4-diol, gamma-butyrolactone and "heavies" such as diethyl ethoxysuccinate. In the first distillation stage, conveniently operated substantially at atmospheric pressure, ethanol, water, and tetrahydrofuran are recovered as overhead product, are condensed to separate the condensible components from a hydrogen stream which can be vented, and then redistilled in the presence of a molar excess of a hydroxylic solvent containing at least two hydroxyl groups, such as butane-1,4-diol, in a second distillation zone.

Abstract: Purification of tetrahydrofuran from the dehydrocyclization of 1,4-butanediol in the presence of an organic acid catalyst has been accomplished by the extractive distillation of crude tetrahydrofuran containing water using monopropylene glycol as an extractive solvent.

Abstract: Crude water-containing tetrahydrofuran is purified by distillation by a process in which the crude tetrahydrofuran is passed through three distillation columns, water being removed from the bottom of the first column, water-containing tetrahydrofuran being recycled from the top of the second column into the first column, the top product of the third column being recycled to the first column, a distillate being removed at the top of the first column, and pure tetrahydrofuran being distilled off from the bottom product of the second column, in the third column, and the pure tetrahydrofuran being removed from the side take-off of the third column.

Abstract: Tetrahydrofurans are prepared in the gas phase from butane-1,4-diols which may be substituted by alkyl, alkenyl and/or aryl radicals in the carbon skeleton. The reaction is carried out in the presence of a borosilicate and/or iron silicate zeolite, preferably of the pentasil type, as catalyst.Other catalysts which may be used are zeolites doped with alkali metals and/or alkaline earth metals and/or transition metals and/or rare earth metals and/or noble metals.

Abstract: Process for preparing 2-alkyl-1,4-butanediols and mixtures with 1,4-butanediol which comprises bringing together, at an initial alkaline pH, and at a temperature and pressure suitable for reaction, a mixture of 4-hydroxybutyraldehyde and/or its cyclic acetal, 2-hydroxytetrahydrofuran, hydrogen, an unsubstituted aliphatic aldehyde, especially formaldehyde, and a hydrogenation catalyst. Also processes for preparing mixtures of tetrahydrofuran and 3-alkyltetrahydrofuran from the diol mixtures, and copolymers from the tetrahydrofuran mixtures.

Abstract: Process for preparing 2-alkyl-1,4-butanediols and mixtures with 1,4-butanediol which comprises bringing together, at an initial alkaline pH, and at a temperature and pressure suitable for reaction, 2,3-dihydrofuran, hydrogen, an unsubstituted aliphatic aldehyde, especially formaldehyde, and a hydrogenation catalyst. Also processes for preparing mixtures of tetrahydrofuran and 3-alkyltetrahydrofuran from the diol mixtures, and copolymers from the tetrahydrofuran mixtures.

Abstract: A process for preparing tetrahydrofuran which comprises steps of;(i) subjecting 1,4-butanediol to dehydration reaction, and(ii) subjecting the reaction product obtained from the dehydration reaction in step (i) to extractive distillation, while supplying 1,4-butanediol as the extraction solvent to the system.

Abstract: A mixture of 1,4-butanediol and 2-alkyl-1,4-butanediol is produced by catalytic hydrogenation and reaction with an aldehyde. Such mixture is cyclized to a mixture of tetrahydrofuran and 3-alkyl tetrahydrofuran. Copolymers can then be made from such mixtures of furans.

Abstract: 2-Alkyl-1,4-butanediols are prepared from 1,4-butynediol or 1,4-butenediol by catalytic hydrogenation and reaction with an aldehyde.

Abstract: Tetrahydrofuran is prepared from a crude alkaline aqueous solution of butane-1,4-diol, as obtained by reaction of acetylene with aqueous formaldehyde and catylytic hydrogenation of the resulting but-2-yne-1,4-diol solution by a process in which the alkaline solution is first neutralized with sulfuric acid and water is then eliminated in the liquid phase at from 200.degree. to 260.degree. C., under superatmospheric pressure and in the presence of phosphoric acid.

Abstract: A process is provided for the thermochemical conversion of biomass to useful gaseous and liquid organic products. The inventive process utilizes a catalyst to obtain increased yields of gaseous and liquid organic products and decreased yields, if any, of solid and semisolid tar/oils.

Abstract: A coproduct continuous dealkylation process is described in which 4-t-butoxy-n-butanol is contacted with acidic silica-alumina catalyst at temperatures in the 160.degree.-200.degree. C. range (reactor wall temperature) in the liquid hourly space velocity regime of 2:0 to 6:0 liter/liter catalyst/hr. to produce in a single reactor a mixture in which the ultimate product of conversion of the 4-t-butoxy-n-butanol is 1,4-butanediol (1,4-diol) and tetrahydrofuran (THF) present in a preselected ratio (mole %) of 1,4-diol to THF ranging from 7:3 to 3:7. The 1,4-diol produced is useful in the preparation of polyesters, e.g. polybutylene terephthalates, and THF is a useful intermediate in the manufacture of certain chemicals and plastics.

Abstract: The amount of methacrolein impurity in tetrahydrofuran made from acetylene and formaldehyde can be significantly reduced by treating it with hydrogen peroxide during an interval in the multi-stage distillation tetrahydrofuran refining procedure.

Abstract: A process of removing solids from an aqueous redox catalyst system which solids are formed in the production of furan compounds from butadiene or a butadiene derivative by heating at 180.degree.-280.degree. C. in the presence of sufficient cupric ion or oxygen to oxidize the solids. The redox catalyst system contains iodine ions, copper at an oxidation state between 1 and 2, a solubilizing agent for cuprous ion which is soluble in water and forms a water-soluble complex with cuprous ion and, at least 20 moles per liter of water the medium havine a pH of less than 2.

Abstract: Alkanols are converted to ethers by contact at temperature of 150.degree. C.-550.degree. C. with a novel siliceous composition prepared by impregnating porous silica with aluminum hydride and subsequently heating the impregnated silica to a temperature of from about 300.degree. C. to about 900.degree. C. in a non-oxidizing environment.

Abstract: A process for depolymerizing polytetramethylene glycol ethers, wherein the latter are heated at from 90.degree. to 180.degree. C. in the presence of a bleaching earth.