Process for the production of dialkyl carbonate
AssigneeMitsubishi Gas Chemical Company, Inc.
InventorsMasaharu Doya, Ken-ichi Kimizuka, Yutaka Kanbara
Life of this patent
Estimating the term…
Abstract
A process for the production of a dialkyl carbonate comprising a first step of reacting an alkylene glycol, or an alkanediol, with urea in the presence of a catalyst to form an alkylene carbonate or a six-membered cyclic carbonate, and a second step of reacting the alkylene carbonate or the six-membered cyclic carbonate with an alcohol in the presence of a catalyst to obtain a dialkyl carbonate and an alkylene glycol, or a dialkyl carbonate and an alkanediol, wherein the alkylene glycol or the alkanediol obtained in the second step is recycled to the first step.
Claims10
A process for the production of a dialkyl carbonate, which comprises
- a first step of reacting an alkylene glycol of the formula (1),
- R.sup.1 CH(OH)CH(OH)R.sup.2 (1)
- wherein each of R.sup.1 and R.sup.2 is independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms,
- or an alkanediol of the formula (2), ##STR5## wherein each of R.sup.3 to R.sup.6 is independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, with urea in the presence of a catalyst to form an alkylene carbonate derived from the alkylene glycol of the formula (1) or six-membered cyclic carbonate derived from the alkanediol of the formula (2),
- and
- a second step of reacting the alkylene carbonate or the six-membered cyclic carbonate with an alcohol in the presence of a catalyst to obtain a dialkyl carbonate and an alkylene glycol, or a dialkyl carbonate and an alkanediol,
- wherein the alkylene glycol or the alkanediol obtained in the second step is recycled to the first step, the catalyst used in the first step is the same as the catalyst used in the second step, and a catalyst-containing reaction mixture obtained in the second step from which the dialkyl carbonate and unreacted alcohol are separated is recycled to the first step.
Dependencies are inferred from the claim text.