E.i. Dupont De Nemours and Company

Harry B Copelin

Richard E Ernst

Thomas D Canby

The oligomeric cyclic ether content of a tetrahydrofuran-, an alkylene oxide-, or a tetrahydrofuran/alkylene oxide polymerizate can be reduced by bringing the polymerizate into contact with an aliphatic- or cycloaliphatic hydrocarbon of 6-8 carbon atoms, and separating the polymerizate and the hydrocarbon phases.

Method for reducing oligomeric cyclic ether content of a polymerizate

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.

Purification of tetrahydrofuran

The oligomeric cyclic ether content of a tetrahydrofuran-, an alkylene oxide- or a tetrahydrofuran/alkylene oxide polymerizate can be reduced by bringing the polymerizate into contact with a gas in the supercritical state.

A process for the purification of crude 1,4-butanediol by crystallizing said crude in a solution comprising tetrahydrofuran at a temperature of from 10.degree. to -10.degree. C. and a pressure of from 16-26 mm of mercury to form a slurry of crystallized 1,4-butanediol in a liquid, and then separating the crystallized 1,4-butanediol from the liquid.

Preparation of high purity 1,4-butanediol

An amorphous silica supported palladium catalyst is provided which also contains a small amount of an additive metal compound selected from an oxide, hydroxide and carbonate of zirconium, thorium, hafnium, cerium, titanium and aluminum. By use of particular preparation conditions and the amount of additive metal salt raw material used, the additive metal compound deposits from solution before or simultaneously with a palladium compound. The additive metal compound deposits on the silica support and serves as a base for the subsequently deposited palladium compound which is later reduced to palladium metal. The described catalyst is particularly suitable as a hydrogenation catalyst in a cyclic process for the manufacture of hydrogen peroxide.

Pd/SiO.sub.2 Hydrogenation catalyst suitable for H.sub.2 O.sub.2

A process for reducing the chemical oxygen demand of water removed from a mixture of crude tetrahydrofuran and water, said process comprising contacting said mixture in the vapor phase with a dilute sodium hydroxide solution, then optionally contacting the tetrahydrofuran-water mixture after condensation with a concentrated sodium hydroxide solution and separating water from the thus treated mixture, said water having reduced chemical oxygen demand over water that is removed from said mixture merely by distillation.

Reduction in chemical oxygen demand of water from crude tetrahydrofuran

A process for separating one or more aliphatic alcohols selected from the group consisting of methanol, ethanol, isopropanol and tertiary butanol from a tetrahydrofuran stream comprising tetrahydrofuran, one or more of said alcohols and optionally water by extractive distillation with water.

Separation of alcohol from tetrahydrofuran

A process for preparing an acetal from acrolein and a 1,3-diol whereby substantially complete conversion of the acrolein to acetal is attained, by simultaneously reacting and separating by extraction the acetal and water formed from said diol and acrolein reaction, said process comprising continuously feeding a 1,3-diol and an acid catalyst countercurrent to a solvent while continuously feeding acrolein to the solvent and diol, separating the acetal-solvent from the diol-water, optionally separating the acetal and solvent and optionally separating the diol and water.

Preparation of an acetal from a diol and acrolein

A method is provided for simultaneously hydrolyzing and hydrogenating compounds containing one six-membered acetal ring and one aldehyde functional group with a water insoluble strongly acid ion exchange resin and a nickel hydrogenation catalyst.

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Wilmington, DE, United States of America

Harry B Copelin