金属醋酸盐复配催化剂催化超临界CO2一步法合成碳酸二甲酯

由CO2合成碳酸二甲酯(DMC)是CO2资源化的重要途径之一。超临界CO2因具有独特的溶解和传递性能,在合成反应中可既作反应物,又作反应溶剂。本实验以超临界CO2、环氧丙烷和甲醇作为反应物,选用金属醋酸盐与K2CO3、KI复合催化一步合成DMC。在温度130~170℃、CO2压力2~14 MPa条件下,考察了催化剂用量、物料配比、温度、压力、反应时间等条件对DMC产率的影响,产物采用气相色谱以内标法进行定量分析。结果表明,当醋酸锌复合催化剂配比为K2CO3:KI:Zn(CH3COO)2=1:1:2时,在合适的反应条件下(催化剂用量4%,物料配比8:1,160℃、7.4MPa,反应4 h),环氧丙烷转化率可达95%,DMC产率可达54.3%。

One-Pot Synthesis of Dimethyl Carbonate from Supercritical CO2 Catalyzed by Using Metal Acetates Formulation Catalyst

The synthesis of dimethyl carbonate(DMC) from carbon dioxide is one of the important routes of the resourcization of carbon dioxide.Because of its particular solubility and transitivity,the supercritical carbon dioxide(SC-CO2) can be used as both reagent and solvent in the reaction.In this experiment,metal acetates K2CO3 and KI were used as catalysts for the one-pot synthesis of DMC with SC-CO2,propylene oxide(PO) and methanol(CH3OH) as raw materials.The influences of catalyst dosage,VCH3OH:VPO,temperature(from 130℃ to 170℃),pressure(from 2 to 14 MPa) and reaction time were investigated.Products were analyzed by gas chromatography with the use of internal standard method.When the multiplex catalyst with the mass ratio of K2CO3:KI:Zn(CH3COO)2=1:1:2 was used,under the suitable reaction conditions(catalyst dosage 4%,VCH3OH:VPO=8:1,160℃,7.4 MPa,reaction time 4 hours),the conversion of propylene oxide could reach 95% and the yield of DMC could reach 54.3%.