Method for continuously producing cyclic carbonate

Patent metadata

Field	Value
Publication number	US-9586927-B2
Application number	US-201414903225-A
Country	US
Kind code	B2
Filing date	Jul 18, 2014
Priority date	Jul 19, 2013
Publication date	Mar 7, 2017
Grant date	Mar 7, 2017

Abstract

Provided is a method for continuously producing a cyclic carbonate, by which generation of a glycol in a reaction for synthesizing a cyclic carbonate is suppressed, and a cyclic carbonate having a high purity can be efficiently obtained even by simple purification.
A method for continuously producing a cyclic carbonate, including filling a catalyst in a fixed-bed tube reactor, and continuously feeding carbon dioxide and an epoxide to the fixed-bed tube reactor to thereby bringing the carbon dioxide and the epoxide into contact with the catalyst, while continuously withdrawing the reaction liquid in the fixed-bed tube reactor, wherein the method includes a pre-treatment step in which a pre-treatment liquid containing a cyclic carbonate is brought into contact with the catalyst before feeding the carbon dioxide and the epoxide to the fixed-bed tube reactor, and the generated glycol is removed out of the system.

First claim

The invention claimed is:

1. A method for continuously producing a cyclic carbonate, the method comprising:
filling a tributylphosphonium bromide surface-modified silica gel catalyst in a fixed bed tube reactor,
contacting a pre-treatment liquid comprising a sacrificial cyclic carbonate with the catalyst to form a glycol,
removing the glycol from the fixed-bed tube reactor, and
continuously feeding carbon dioxide, 2-bromoethanol and ethylene oxide to the fixed-bed tube reactor to thereby bring the carbon dioxide and the ethylene oxide into contact with the tributylphosphonium bromide surface-modified silica gel catalyst to form a reaction liquid comprising the cyclic carbonate, while continuously withdrawing the reaction liquid from the fixed-bed tube reactor,
wherein the sacrificial cyclic carbonate and the cyclic carbonate in the reaction liquid are identical.

2. The method according to claim 1 , wherein the pre-treatment liquid and the catalyst are brought into contact until a total amount of the glycol in an effluent from the fixed-bed tube reactor is 100 ppm or lower.

3. The method according to claim 1 , wherein the pre-treatment liquid and the catalyst are brought into contact at a temperature in a range of 20° C. to 140° C.

4. The method according to claim 1 , further comprising feeding a part of the reaction liquid that has been withdrawn to the fixed-bed tube reactor.

5. The method according to claim 1 , further comprising drying said tributylphosphonium bromide surface-modified silica gel catalyst in said fixed-bed tube reactor by vacuum exhausting and/or by contact with an inert gas prior to said contacting said pre-treatment liquid with the catalyst.

Assignees

• Maruzen Petrochem Co Ltd
• Nat Inst Advanced Ind Science & Tech

Inventors

• Naniki Takashi
• Hayashi Yasunori
• Sawada Goro
• Furukawa Takuro
• Haruna Takeshi
• Takahashi Toshikazu
• Yasuda Hiroyuki
• Yamamoto Shouji

Classifications

• B01J31/0268

  Phosphonium compounds, i.e. phosphine with an additional hydrogen or carbon atom bonded to phosphorous so as to result in a formal positive charge on phosphorous · CPC title

• B01J31/0231

  Halogen-containing compounds · CPC title

• B01J31/0239

  Quaternary ammonium compounds · CPC title

• C07D317/38 Primary

  Ethylene carbonate · CPC title

• B01J2231/341

  1,2-additions, e.g. aldol or Knoevenagel condensations · CPC title