Abstract: Improved method by control of excess bromine in reaction between bromine and cyclododecatriene to form hexabromocyclododecane provides increased product yield. A novel reaction mass is obtained and maintained.
Abstract: A process for obtaining a substantially dry alcohol from a mixture comprising alcohol and water in a non-azeotropic amount by utilizing at least a portion of the alcohol in the mixture as the stripping medium.
Abstract: A flame retardant product predominant in hexabromocyclododecane is prepared and dried by a process wherein gaseous ammonia is injected into the dryer system to prevent the formation of color bodies which contaminant the product.
Type:
Grant
Filed:
November 15, 1990
Date of Patent:
December 31, 1991
Assignee:
Ethyl Corporation
Inventors:
George W. Cook, Jr., George H. Ransford
Abstract: 1,2,5,6,9,10-Hexabromocyclododecane (HBCD) is prepared in an anhydrous process in polar solvents, by the bromination of 1,5,9-cis, trans, trans-cyclododecatriene at relatively high temperatures.
Type:
Grant
Filed:
June 2, 1988
Date of Patent:
April 17, 1990
Assignee:
Bromine Compounds Limited
Inventors:
Joshua Hermolin, Amiram Groweiss, Aaron R. McMurray
Abstract: A method for producing dichloroethane (EDC) by reacting ethylene and chlorine in a liquid reaction medium composed mainly of EDC at a temperature of not less than the boiling point of EDC measured at ordinary pressure, characterized by leading the vapor of the reaction medium generated in a reactor from the top of the reactor to a heat exchanger so as to recover and utilize the latent heat resulting from condensation of the vapor in the heat exchanger. According to the present invention, high heat utilization efficiency can be attained with advantages as compared with conventional EDC production methods.
Abstract: Hexabromocyclododecane may be synthesized at a high yield in pure form by brominating 1,5,9-cyclododecatriene with bromine in a C.sub.4 -C.sub.8 saturated aliphatic alcohol in the presence of a boron trifluoride complex, neutralizing the reaction mixture with a non-aqueous base, and recovering the resulting crystals of hexabromocyclododecane.
Abstract: A method for producing dichloroethane (EDC) from ethylene and chlorine in high selectivity, yield and efficiency and in high safety wherein the unreacted ethylene and oxygen included in an exhaust gas discharged from a reactor are prevented from forming an explosive gas mixture by diluting the exhaust gas with a dichloroethane vapor.
Abstract: Hydrogen chloride is recovered from a mixture with propylene by extractive distillation with an inert extraction solvent to minimize reaction between hydrogen chloride and propylene during such distillation. The temperature and pressure conditions are coordinated with the extraction solvent and amount thereof to prevent the presence of hydrogen chloride in a liquid state. The process is particularly suitable for recovering hydrogen chloride in the production of allyl chloride by thermal chlorination of propylene.
Type:
Grant
Filed:
August 1, 1983
Date of Patent:
December 10, 1985
Assignee:
The Lummus Company
Inventors:
Herbert Riegel, Chiung-Yuan Huang, Vincent A. Strangio
Abstract: The invention is a process for the purification of hydrogen chloride formed during the thermal cracking of 1,2-dichloroethane, by hydrogenating the acetylene impurities with excess hydrogen, at pressures of from 8 to 20 bar absolute and at temperatures of from 120.degree. to 180.degree. C., using platinum or palladium supported catalysts, wherein, according to the invention, carrier materials having a specific surface area of not more than 5 m.sup.2 /g are used, the hydrogen excess used is a function of the acetylene content, the gas mixture, after reaching a temperature of approximately 70.degree. C., is permitted a dwell time of not more than 0.8 second before it enters the catalyst, and the temperature, pressure and volume flow rates are dependent on one another within narrow limits.The purified hydrogen chloride is used for oxychlorination.
Type:
Grant
Filed:
October 29, 1981
Date of Patent:
June 14, 1983
Assignee:
Wacker Chemie GmbH
Inventors:
Ludwig Schmidhammer, Gerhard Dummer, Rudolf Straszer
Abstract: A supported catalyst containing copper and alkali metals, wherein the content of copper is from 1.0 to 12% by weight, based on total catalyst and expressed as metal, and the total content of the alkali metals potassium, lithium and sodium is from 0.3 to 9% by weight, based on total catalyst.The novel catalyst is useful for the preparation of 1,2-dichloroethane by oxychlorination of ethylene.
Type:
Grant
Filed:
November 25, 1981
Date of Patent:
May 3, 1983
Assignee:
BASF Aktiengesellschaft
Inventors:
Peter R. Laurer, Gerd Krome, Luc Cordemans, Reinhard Seifert, Eckehard Danz
Abstract: An improved process for production of allyl chloride which comprises (1) thermally chlorinating propylene above 300.degree. C., but below that at which substantial carbon formation is effected, (2) separating the allyl chloride from its by-products, (3) subjecting the unsaturated compounds in said by-products to a low temperature chlorination, (4) separating the 1,2-dichloropropane from the products of said low temperature chlorination, and (5) passing said 1,2-dichloropropane to a cracking furnace. The effluent from the cracking furnace can be recycled to the allyl chloride finishing system by adding it to the high temperature propylene chlorination reactor effluent. Reaction temperatures are optimized to eliminate problems caused by carbon formation in the high temperature chlorination reactor, while overall yields of allyl chloride are increased and effluents which are ecologically and economically undesirable are reduced.
Type:
Grant
Filed:
April 17, 1978
Date of Patent:
March 9, 1982
Assignee:
The Dow Chemical Company
Inventors:
Theodore S. Boozalis, John B. Ivy, Gordon G. Willis
Abstract: Hexachlorocyclopentadiene is produced by the use of a molten salt mixture of cuprous and cupric chloride, with the reaction effluent including the product, chlorine, hydrogen chloride, unreacted feed and organic byproduct, as well as entrained molten salt. The effluent is cooled at a temperature and pressure to effect condensation of organics, with the salt being present in the condensate. The salt is then separated from the organics for re-use in the process. Hydrogen chloride and chlorine present in the effluent are also recovered for re-use in the process.