Synthesis process of trimethylene carbonate from 1,3-propanediol and urea by heterogeneous catalysis

摘要

The invention relates to the synthesis of trimethylene carbonate by reaction of alcoholysis of urea with 1,3-propanediol in liquid phase catalyzed by a mixed metal oxide comprising Zn and La.;The catalyst used in the process of the invention is an intimate mixture of Zinc oxide (ZnO) and Lanthanum oxide (La₂O₃) leading, according to the molar ratio La:Zn ranging from 0.01 to 1.5, to a new mixed metal oxide comprising a solid solution of Lanthanum or Zinc in Zinc oxide or Lanthanum oxide, respectively, or to a spinel like structure when the molar ratio La/Zn is equal to 1.;The solid mixed catalyst La:Zn improves both yield and selectivity of the reaction and makes easier the further step of separating the compounds of the reaction medium with an improved recovering rate in trimethylene carbonate.