Produção de carbonato de glicerol e glicidol empregando catalisadores a base de Zn e Al

Abstract

Nowadays, the increasing demand for biodiesel makes the byproduct glycerol available in large amounts at decreasing prices. Among the valuable chemicals produced by valorization of glycerol, glycerol carbonate and glycidol are the more prominent. As the glycidol produced from the decomposition of glycerol carbonate.They are the raw materials for the preparation of polyglycerols, glycidyl ethers, polyurethanes and pharmaceuticals. One of the most promising routes for industrial application would be transesterification between glycerol and dimethyl carbonate. Because of the low toxicity, medium volatility and high polar property dimethyl carbonate is an emerging chemical and its usage is increasing as a green solvent. Base solid catalysis is more attractive than acid solid catalysis, because higher conversion can be achieved using base catalysts. In this work was investigated the production of glycerol carbonate and glycidol from transesterification of glycerol and dimethyl carbonate, using ZnAl mixed oxides as solid basic catalysts. The catalytic behavior of this material was studied by the influence of variables such as reaction and calcination temperature, concentration of catalyst and DMC/Glycerol molar ratio. The catalysts prepared showed predominantly basic sites and were active for the studied reaction. The mixed oxide with Al/(Al+Zn) molar ratio 0.50 showed the most promising results. The best condition of reaction were the heat treatment at 550 °C, DMC/Glycerol molar ratio equal 4/1, 10 % of catalyst and reaction temperature equal 100 °C. These conditions were responsible for 93 % conversion of glycerol, and showed yields of glycerol carbonate and glycidol up to 66 % and 27 %, respectively