Alliedsignal Inc.

Allied Chemical Corporation

Allied Corporation

Theodore J Jenczewski

Lamberto Crescentini

Richard Eugene Mayer

Alan B Gancy

James A Kweeder

Robert A Smith

Thomas R Morgan

Barry J Boghean

William H Skinner, Jr

Donald C Butt

Robert L Sturtevant

Audie J Patterson

Process for the purification of caprolactam obtained from the depolymerization of polyamide-containing carpet

The present invention provides a process for the preparation of purified caprolactam comprising the steps of:

Process for the purification of caprolactam obtained from the

A process for recovering monomer from multi-component waste material that includes a hydrolyzable polymer, includes contacting the multi-component waste material with water and subjecting the resulting mixture to heat and pressure to form a liquid aqueous portion and a water insoluble portion. The liquid aqueous portion mainly includes depolymerization products of the hydrolyzable polymer, and the water insoluble portion mainly includes components other than the depolymerization products. This mixture is cooled and the liquid aqueous portion and the water insoluble portion are separated. Monomer that formed the hydrolyzable polymer is recovered from the liquid aqueous solution.

Monomer recovery from multi-component materials

A process for the reduction of methylbenzofuran (MBF) impurities in phenol obtained from the decomposition product of cumene hydroperoxide requires treating the phenol to reduce the level of acetol, contacting the phenol containing a low level of acetol with an acid resin at sufficient temperature and residence time to reduce the level of MBF by conversion to higher boiling compounds, then distilling the phenol to separate phenol from higher boiling compounds. The phenol may be treated in known ways, such as by treatment with an amine, to reduce the level of acetol. The phenol containing a low level of acetol is contacted with a strong acid resin to reduce the level MBF.

Phenol with low levels of methylbenzofuran

A method is provided wherein the equilibrium HF concentration in the mixture of HF, sulfuric acid and water fed to an HF reaction furnace is greatly reduced by injecting a controlled amount of steam into an HF-removal process wherein the sulfuric acid mixture is also contacted with the hot HF gas leaving the HF reaction furnace. Reducing the HF concentration in this manner significantly improves furnace performance. The purpose of injecting steam is to adjust the water content of the mixture to the optimum value (about 12.5 weight percent) for HF removal, as well as to supply the heat required for HF removal without the need for an indirect heat exchanger. An additional advantage to this method is that since direct steam injection adds water to the process, in order to keep the furnace feed acid water concentration at the desirable level of less than 1%, oleum or SO.sub.3 must be added to react with the excess water. Since the reaction of water and SO.sub.3 is exothermic, this supplies additional heat to the process and no indirect heat exchanger is needed to achieve the desired high furnace feed acid temperature (&gt;100.degree. C.).

Furnace gas - sulfuric acid contact process for HF manufacture

A process for manufacturing high purity anhydrous hydrogen fluoride (HF) having low levels of arsenic impurity by contacting anhydrous hydrogen fluoride product, or an intermediate product obtained during the manufacture of HF, with hydrogen peroxide in the presence of a catalyst which comprises effective amounts of molybdenum or an inorganic molybdenum compound and a phosphate compound. The volatile trivalent arsenic impurity in the anhydrous hydrogen fluoride is oxidized to a non-volatile pentavalent arsenic compound and the resultant mixture is distilled to recover high purity anhydrous hydrogen fluoride with reduced levels of arsenic impurity. In one embodiment, an oxidizing agent such as nitric acid or a nitrate salt is added to the reaction mixture to oxidize organic contaminants.

Manufacture of high purity low arsenic anhydrous hydrogen fluoride

Methods for removal of sulfur oxides, e.g., SO.sub.2 and SO.sub.3, from sulfuric acid tail gases by alkaline solution scrubbing, acidification of the alkaline scrubbing solution containing absorbed sulfur valves, liberation of concentrated SO.sub.2 from the acidified solution and regeneration of the alkaline scrubbing solution by means of two- or three-compartment electrodialytic water splitters are disclosed. A completely closed loop method suitable for continuous removal of sulfur oxides from sulfuric acid tail gas, recovery of concentrated SO.sub.2 for use in sulfuric acid plants, regeneration of alkaline scrubbing process solution and improvement in the water balance in sulfuric acid plant by use of two- and three-compartment electrodialytic water splitters is also disclosed.

Electrodialytic methods for removal of sulfur oxides from waste gases

An electrodialytic process for the conversion of soda sources containing anionic and optionally nonionic impurities to high purity, high strength sodium hydroxide and carbon dioxide gas is disclosed.

Electrodialytic process for the conversion of impure soda values to

An improved process for the electrodialysis of aqueous NaCl which operates at high current efficiency and low unit cell voltage drop to produce high strength, high purity Na.sub.2 CO.sub.3 and either high purity HCl or CaCl.sub.2 by utilizing cation permselective, anion permselective and bipolar membranes wherein the solutions on both sides of the anion permselective membrane are acidic.

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Sherrill, NY, United States of America

Theodore J Jenczewski