Albemarle Corporation

Other

Ethyl Corporation

Robert E Williams

Gary L Sharp

Bonnie G McKinnie

William B Harrod

Alireza M Dadgar

Steven G Karseboom

John M Harden

William J Cranston, Iii

Helen M Williams

Rhett P Heeb

Processes of and systems for removing free bromine from gaseous anhydrous HBr contaminated with free bromine are described. In one type of process the gaseous contaminated HBr is fed into countercurrent contact with at least one liquid alkylaromatic hydrocarbon within a packed section of a column while maintaining the packed section under free radical bromination conditions so that one or more than one liquid a-bromoalkylaromatic compound is produced along with one mole of gaseous HBr per mole of a-bromoalkylaromatic compound produced. In another type of process the gaseous anhydrous HBr is fed into countercurrent contact through at least two scrubbers so that the gaseous anhydrous HBr is scrubbed substantially free of bromine by passage through these at least two scrubbers, each of which contains a different specified type of scrubbing liquid. In one embodiment the liquid alkylaromatic hydrocarbon comprises 1,2-diphenylethane.

Removal of bromine from gaseous hydrogen bromide

Bisphenol-A-bis(neopentylglycolphosphate) products of enhanced properties and processes for preparing them are described. One of the processes includes (a) mixing and reacting neopentyl glycol and bisphenol-A-bis(dichlorophosphate) in an inert polar organic solvent which (1) if mixed by itself with an equal volume of water at 25&#xb0; C., will form a separate phase, (2) the solvent by itself will dissolve at least about 10 wt % of bisphenol-A-bis(neopentylglycolphosphate) at a temperature in the range of 25 to 50&#xb0; C., and optionally but preferably (3) the solvent by itself can be completely vaporized at a temperature below about 180&#xb0; C.; (b) washing bisphenol-A-bis(neopentylglycolphosphate) product formed in a) while dissolved in inert organic solvent having such characteristics at least once with an aqueous alkaline washing solution; and (c) optionally but preferably, recovering bisphenol-A-bis(neopentylglycolphosphate) product from organic solvent having such characteristics. The reaction of (a) can be conducted in an inert non-polar solvent if that solvent is replaced by an inert polar organic solvent satisfying (1) and (2), and preferably (3). A solvent satisfying (1), (2), and (3) is used when (c) is conducted by distilling or vaporizing off the solvent to recover the bisphenol-A-bis(neopentylglycolphosphate) product as such. The product has a low acid number or a high thermal stability, and usually both.

Separation process

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This invention provides an environmentally acceptable method for recovery of phenolic and brominated phenolic compounds, alcohol solvent, and bromide values from the a reaction medium liquid mixture formed in the production of a tetrabromobisphenol-A predominant product. The process comprises (a) separating the tetrabromobisphenol-A predominant product and alkyl bromide from the reaction medium thereby forming a liquid mixture containing alcohol, phenolic and brominated phenolic compounds, HBr, and water; (b) treating the liquid mixture with a sufficient amount of alkaline or alkaline earth metal hydroxide so as to form a treated aqueous mixture having a pH in the range of from about 9.5 to about 14.0, and containing MBr.sub.n, water, alcohol, and soluble salts of the phenolic and brominated phenolic compounds, wherein M is an alkaline or alkaline earth metal ion, and n is the valence of M; (c) distilling alcohol from the treated aqueous mixture of (b); (d) acidifying the treated aqueous mixture from (c) subsequent to distillation with a sufficient amount of acid to precipitate the phenolic and brominated phenolic compounds therefrom; and (e) separating the precipitated phenolic and brominated phenolic compounds from the acidified aqueous mixture of (d).

Method for recovering methanol solvent

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This invention relates to a process for preparing a flame retardant product predominant in tetrabromobisphenol-A. The process comprises: (a) dissolving bisphenol-A in a methanol solvent containing up to about 5 weight percent water, wherein the ratio of methanol to bisphenol-A ranges from about 25 to about 43 moles of methanol per mole of bisphenol-A based on the total amount of methanol used and the total amount of bisphenol-A to be brominated; (b) adding to the solution in (a) from about 3.9 to about 4.2 moles of bromine per mole of bisphenol-A to be brominated while maintaining a reaction temperature in the range of from about 0.degree. to about 40.degree. C.; (c) after the bromination is substantially complete, adding water to precipitate the tetrabromobisphenol-A thus formed; and (d) purifying the precipitated tetrabromobisphenol-A so as to obtain a product predominant in tetrabromobisphenol-A containing less than about 20 ppm total ionic impurity.

Process for high purity tetrabromobisphenol-A

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Boles, AR, United States of America

Robert E Williams