Method for continuously producing a dialkyl carbonate and a diol

Organic compounds -- part of the class 532-570 series – Organic compounds – Carbonate esters

Patent

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

558275, C07C 6806

Patent

active

058471898

DESCRIPTION:

BRIEF SUMMARY
This application is a 371 of PCT/JP96/03746, filed Dec. 20, 1996.


BACKGROUND OF THE INVENTION

1. Field of The Invention
The present invention relates to a method for continuously producing a dialkyl carbonate and a diol from a cyclic carbonate and an aliphatic monohydric alcohol. More particularly, the present invention is concerned with a method for continuously producing a dialkyl carbonate and a diol, comprising: (1) feeding a cyclic carbonate and an aliphatic monohydric alcohol containing 0 to 40% by weight of a concomitant dialkyl carbonate to a continuous multi-stage distillation column, and effecting a transesterification between the cyclic carbonate and the aliphatic monohydric alcohol in the presence of a catalyst in at least one reaction zone selected from the group consisting of the multi-stage distillation column and at least one transesterification reactor which is disposed outside of the multi-stage distillation column and which communicates fluid-tightly with the multi-stage distillation column so that a liquid flowing-down inside the distillation column can be continuously introduced to the transesterification reactor and the resultant reaction mixture can be continuously recycled to the distillation column, while continuously withdrawing a low boiling point mixture containing the produced dialkyl carbonate in a gaseous form from an upper portion of the distillation column and continuously withdrawing a high boiling point mixture containing the produced diol and unreacted cyclic carbonate in a liquid form from a lower portion of the distillation column; and (2) continuously feeding water and the high boiling point mixture withdrawn from a lower portion of the distillation column to a continuous hydrolysis reactor, to thereby effect a continuous hydrolysis of the unreacted cyclic carbonate and produce a diol and carbon dioxide, while continuously withdrawing the resultant hydrolysis reaction mixture containing the produced diol from the continuous hydrolysis reactor.
By the method of the present invention, it becomes possible to produce a dialkyl carbonate and a high purity diol with high productivity from a cyclic carbonate and an aliphatic monohydric alcohol containing 0 to 40% by weight of a concomitant dialkyl carbonate.
2. Prior Art
With respect to the method for producing a dialkyl carbonate and a diol by reacting a cyclic carbonate with an aliphatic monohydric alcohol, various proposals have been made. Most of those proposals relate to the development of catalysts for the above reaction. Examples of such catalysts include alkali metals or basic compounds containing alkali Application Laid-Open Specification No. 54-48715 (corresponding to U.S. Patent Application Laid-Open Specification No. 51-122025 (corresponding to Patent Application Laid-Open Specification No. 54-48716 (corresponding to U.S. Pat. No. 4,307,032)!, tin alkoxides (see Unexamined Japanese Patent Application Laid-Open Specification No. 54-63023), alkoxides of zinc, aluminum and titanium (see Unexamined Japanese Patent Application Laid-Open Specification No. 54-148726), a mixture of a Lewis acid with an nitrogen-containing organic base (see Unexamined Japanese Patent Application Laid-Open Specification No. 55-64550), phosphine compounds (see Unexamined Japanese Patent Application Laid-Open Specification No. 55-64551), quaternary phosphonium salts (see Unexamined Japanese Patent Unexamined Japanese Patent Application Laid-Open Specification No. 59-106436 (corresponding to U.S. Pat. No. 4,681,967, EP-110629B, and Japanese Patent Application Laid-Open Specification No. 63-41432 (corresponding to U.S. Pat. No. 4,616,609, EP-255252B1 and DE-3781742)!, a quaternary ammonium group-containing strongly basic anion-exchange solid material (see Unexamined Japanese Patent Application Laid-Open Specification No. 63-238043), a solid catalyst selected from the group consisting of a tertiary amine- or quaternary ammonium group-containing ion-exchange resin, a strongly acidic or a weakly acidic ion-exchange resin, a mixture of an alkal

REFERENCES:
patent: 4691041 (1987-09-01), Duranleau et al.
patent: 5231212 (1993-07-01), Buysch et al.
patent: 5359118 (1994-10-01), Wagner et al.

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Method for continuously producing a dialkyl carbonate and a diol does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Method for continuously producing a dialkyl carbonate and a diol, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for continuously producing a dialkyl carbonate and a diol will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-179106

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.