Process for the production epichlorohydrin
First Claim
1. A continuous process for the production of epichlorohydrin which comprises in sequence(a) reacting allyl chloride, chlorine and water in a first reaction zone to produce an aqueous solution of dichlorohydrin,(b) reacting said dichlorohydrin solution with an excess of a basic substance in a second reaction zone under conditions of temperature and contact time of the reactants whereby the dichlorohydrin is substantially converted to epichlorohydrin,(c) separating the formed epichlorohydrin rapidly and substantially completely from the aqueous reaction mixture as overhead by flash distillation,(d) cooling said reaction mixture depleted in epichlorohyrin to a temperature below about 70°
- C.,(e) electrodialyzing said cooled reaction mixture in an electrodialysis zone to afford;
(1) an electrodialysis concentrate stream having an inorganic chloride content higher than said cooled reaction mixture feed to the electrodialysis zone, and (2) a diluate stream containing organic chloride compounds and having a lower inorganic chloride content than said reaction mixture feed,(f) removing said concentrate stream of step (e),(g) subjecting said diluate stream to a reverse osmosis to form a retentate stream having a higher content of organic and inorganic chlorides than said diluate stream, and a permeate stream substantially depleted in both organic and inorganic chlorides,(h) removing said retentate stream, and(i) recycling at least part of said permeate stream to said first reaction zone.
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Accused Products
Abstract
A process for the production of epichlorohydrin is disclosed which comprises reacting allyl chloride, chlorine and water to form an intermediate, then rapid conversion and separation of epichlorohydrin product; the epichlorohydrin-depleted reaction mixture is cooled and subjected to electrodialysis then reverse osmosis to concentrate and remove deleterious by-products, and at least a substantial portion of the resultant permeate is recycled to the reaction zone, thereby enabling reduced operating costs and/or improved yield.
7 Citations
8 Claims
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1. A continuous process for the production of epichlorohydrin which comprises in sequence
(a) reacting allyl chloride, chlorine and water in a first reaction zone to produce an aqueous solution of dichlorohydrin, (b) reacting said dichlorohydrin solution with an excess of a basic substance in a second reaction zone under conditions of temperature and contact time of the reactants whereby the dichlorohydrin is substantially converted to epichlorohydrin, (c) separating the formed epichlorohydrin rapidly and substantially completely from the aqueous reaction mixture as overhead by flash distillation, (d) cooling said reaction mixture depleted in epichlorohyrin to a temperature below about 70° - C.,
(e) electrodialyzing said cooled reaction mixture in an electrodialysis zone to afford;
(1) an electrodialysis concentrate stream having an inorganic chloride content higher than said cooled reaction mixture feed to the electrodialysis zone, and (2) a diluate stream containing organic chloride compounds and having a lower inorganic chloride content than said reaction mixture feed,(f) removing said concentrate stream of step (e), (g) subjecting said diluate stream to a reverse osmosis to form a retentate stream having a higher content of organic and inorganic chlorides than said diluate stream, and a permeate stream substantially depleted in both organic and inorganic chlorides, (h) removing said retentate stream, and (i) recycling at least part of said permeate stream to said first reaction zone. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
- C.,
Specification