Abstract: Polychlorinated phenols (e.g., pentachlorophenol) of improved color are made by vacuum distilling polychlorinated phenols containing dark color-forming impurities in the presence of a color inhibitor such as free radical-acting substances (e.g., free radical-acting compounds of the phenol, hydroquinone, organic sulfur derivative, organic phosphite, amine and aldehyde type). In addition, the chlorodioxin content of the impure pentachlorophenol (generally about) 2,000 p.p.m.) is reduced to a residual chlorodioxin content of less than 25 p.p.m. during distillation.
Abstract: Recovery of pure propylene oxide from propylene oxide which is contaminated by C.sub.6 hydrocarbons and methyl formate, by distillation with the addition of more methyl formate so that the amount of methyl formate is four times that of the 2-methylpentane present.
Abstract: A process for treating an adipic acid bleed stream obtained in the manufacture of adipic acid, said adipic acid bleed stream consisting mainly of nitric, adipic, glutaric, and succinic acids and a catalyst; the process comprising maintaining said adipic acid bleed stream in aqueous solution, and stripping nitric acid from said aqueous solution with steam at a temperature of about 100.degree.-110.degree. C. while maintaining in said aqueous solution a water to nitric acid weight ratio of at least 6, to remove substantially all of the nitric acid therefrom, thereby forming an aqueous nitric acid free mixture of said dibasic acids and said catalyst which can be safely dehydrated and distilled to produce useful chemicals.
Abstract: A process for the production of linear fiber-forming polyesters, especially polyethylene terephthalate, wherein vaporous reaction products are separated in an improved manner by suction withdrawal from the polymerization reactor through the action of a fluid vacuum jet or aspirator which is supplied with recirculated glycol vapor as the propellant or jet fluid for the aspirator and also by further suction through the action of a recirculated glycol liquid operating a liquid circulating vacuum pump in a final separation of non-condensable gases such as nitrogen from residual condensable vapors. The process is especially useful in preventing the discharge of the vaporous by-products into the surrounding environment during the production of the polyester product.
Type:
Grant
Filed:
February 27, 1975
Date of Patent:
March 8, 1977
Assignee:
Akzona Incorporated
Inventors:
Karl Ebner, Franz Ettinger, Rudolf Fuchs, Helmut Schnorr
Abstract: A low boiling water immiscible fluid containing two or more molecular species and having a variable boiling point is contacted in the liquid state with relatively hot or warm water such as surface sea water or geothermal water, thereby generating vapor of immiscible fluid (together with a certain amount of water vapor) which is used to drive a prime mover such as a gas turbine and thereby produce mechanical energy; the exhaust vapor from the prime mover is condensed by direct contact with a relatively cool or cold liquid aqueous phase such as deep sea water or water from a lake or stream or cooling tower to condense the vapor; and the condensate is recycled. Provision is made for ridding water discharged from the system of entrained and dissolved immiscible fluid. By countercurrent flow of the liquid phases and by suitable matching techniques greater efficiency is obtained. The invention is also applicable to heat pumps.
Abstract: A process for isolating carboxylic acids from residues of the oxo reaction which are obtained as residues, on hydroformylation of ethylene or propylene, optionally after removing a part of the aldehydes produced, subsequent hydrogenation, treatment with aqueous alkali metal hydroxide solutions and subsequent distillation, wherein the residues are acidified with strong mineral acids to a pH of from 2-4, the acidified mixture not containing more than 5 parts by weight of water per part by weight of the carboxylic acids contained in the mixture, the organic phase is then separated off and the carboxylic acids are isolated therefrom by distillation at pressures below 150 mbar. The carboxylic acids obtained can be used as solvents or for the manufacture of esters.
Type:
Grant
Filed:
September 23, 1974
Date of Patent:
January 11, 1977
Assignee:
BASF Aktiengesellschaft
Inventors:
Max Strohmeyer, Werner Hagen, Heinz Hohenschutz
Abstract: Diisopropylbenzene monohydroperoxide which is usable for the oxidation of diisopropylbenzene without prevention of the oxidation, is recovered from an oxidation product solution of diisopropylbenzene by steam-distilling the oxidation product solution at pH 6 to 9 and at a solution temperature of 80.degree. to 130.degree. C under a reduced pressure.
Abstract: A process for recovering alkyl sulfonic acid from a photosulfoxidation reaction mixture of an alkane comprising the steps of: separating a major portion of the unreacted alkane contained in said reaction mixture by settling; subjecting thus treated reaction mixture to steam-distillation to remove the remaining portion of the unreacted alkane together with the sulfur dioxide therefrom; subsequently separating the sulfuric acid without heating from the resulting mixture by settling, thereby recovering the alkyl sulfonic acids.
Abstract: Process for the purification of adiponitrile containing chloride impurities by contacting said adiponitrile with a high boiling amine and recovering the purified adiponitrile containing lower amounts of chloride impurities.
Abstract: A process for recovering purified 4-hydroxy-2,4,6-trimethyl-2,5-cyclohexadiene-1-one by distilling crude 4-hydroxy-,2,4,6-trimethyl-2,5-cyclohexadien-1-one. Preferably, the distillation is performed at a temperature of 40.degree. to 250.degree.C. using crude 4-hydroxy-2,4,6-trimethyl-2,5-cyclohexadien-1-one having a pH of 4 to 11.5. Thus, 4-hydroxy-2,4,6-trimethyl-2,5-cyclohexadien-1-one of high purity and reduced coloration can be recovered at a high recovery ratio.
Abstract: A method and apparatus for cooling aqueous alkali metal hydroxide liquors such as, for example, caustic soda liquors, involving the vacuum cooling of a body of such liquor in an evaporating chamber having a overhead vapor outlet which communicates with a direct-contact barometric condenser supplied with a stream of cooled alkali metal hydroxide liquor. The cooled alkali metal hydroxide liquor has a vapor pressure below the absolute pressure of water vapor evolved from the body of liquor in the evaporating chamber and condenses the water vapor upon contact therewith. A stream of cooled concentrated alkali metal hydroxide liquor withdrawn from the evaporating chamber is, in accordance with a preferred embodiment of the present invention, further cooled and solids contained therein, such as, for example, sodium chloride crystals, are then removed in a suitable liquid-solids separation device.
Abstract: Crude phosphate ester products resulting from the phosphorylation of phenol, lower alkyl phenols and mixtures of same are purified to prepare triaryl phosphates substantially free of unreacted phenols by the sequential steps of flash distillation and fractional distillation under controlled conditions with removal of the phosphate ester product as a liquid underflow.
Type:
Grant
Filed:
June 20, 1974
Date of Patent:
March 23, 1976
Assignee:
FMC Corporation
Inventors:
Robert A. Aal, Norman H. C. Chen, James K. Chapman, Jr.
Abstract: Methyl tertiary butyl ether may be recovered from etherification reaction effluent by azeotropic distillation to recover methanol-ether azeotrope overhead which latter is azeotropically distilled in the presence of n-pentane to give pure ether bottoms substantially free of water and methanol.
Abstract: A process is disclosed for the purification of crude dehydroacetic acid by means of simple vacuum or reduced pressure distillation wherein activated charcoal is added to the still. The term reduced pressure is used in the sense that it excludes complicated distillations such as fractional distillation and it is synonymous with simple vacuum distillation. Preferably a pressure of about 10 to about 20 torr is maintained in the vacuum distillation still. Preferably, 0.1 to 1 percent by weight, relative to the total amount of the crude dehydroacetic acid, of activated charcoal is added to the still before the distillation occurs. Crude dehydroacetic acid, particularly that obtained from diketene, is quite impure and discolored. The process of this invention produces a pure dehydroacetic acid, which is pure white, has a transparency of 96 percent and which has a purity of greater than 99.9 percent.