摘要
以二氧化碳为原料合成碳酸二甲酯(DMC)不仅可以实现二氧化碳的资源化利用,而且对碳减排具有重要意义。酯交换法是目前国内外生产DMC的主要方法,近年来DMC的合成研究主要集中在二氧化碳与甲醇直接合成及尿素醇解法两个方向。酯交换法、尿素醇解法是以二氧化碳与CH3OH为原料间接合成DMC,以二氧化碳和CH3OH为原料直接合成DMC属于典型的绿色化学反应,目前仍处于实验室研究阶段。研究有效活化二氧化碳及CH3OH的催化剂及耦合反应,提高DMC的产率和选择性,是开发以二氧化碳和甲醇为原料制备DMC技术的关键。目前关于甲醇与二氧化碳合成DMC的催化机理基本可以归纳为两类:直接活化二氧化碳的反应机理和先活化甲醇再活化二氧化碳的反应机理。已报道的催化剂主要有有机金属催化剂、碱催化剂、金属氧化物催化剂、负载金属催化剂、醋酸盐催化剂、杂多酸催化剂、光助催化剂。以季铵盐和叔胺为协同催化剂,以PO为耦合剂,采用连续反应工艺,从而实现甲醇的高转化率和DMC的高收率,或许是直接合成DMC工艺实现突破的有效途径。在电场作用下,可以很好地活化二氧化碳。加大电催化研究力度,尽快构建电催化中试装置,或许可以为电化学催化直接合成DMC带来发展机遇。
The synthesis of dimethyl carbonate(DMC)from carbon dioxide can not only realize the resource utilization of carbon dioxide,but also has important significance for carbon emission reduction.Transesterification is the main method for DMC production at home and abroad.In recent years,the research on synthesis of DMC has focused on the direct synthesis of carbon dioxide and methanol and the alcoholysis of urea.The transesterification method and the urea alcoholysis method indirectly synthesize DMC from carbon dioxide and CH3OH.The direct synthesis of DMC from carbon dioxide and CH3OH is typical green chemical reaction and still in the stage of laboratory research.Studying the catalysts and coupling reactions that effectively activate carbon dioxide and CH3OH to improve the yield and selectivity of DMC is the key to developing technologies for producing DMC from carbon dioxide and methanol.Currently the catalytic mechanism for the synthesis of DMC from methanol and carbon dioxide can be roughly classified into two categories,i.e.the reaction mechanism of directly activating carbon dioxide and the reaction mechanism of first activating methanol and then activating carbon dioxide.The reported catalysts mainly include organometallic catalyst,alkali catalyst,metal oxide catalyst,supported metal catalyst,acetate catalyst,heteropolyacid catalyst and photo-cocatalyst.Using quaternary ammonium salt and tertiary amine as synergistic catalysts and PO as coupling agent and adopting continuous reaction process to obtain high conversion of methanol and high yield of DMC may be an effective way to achieve breakthroughs in the direct synthesis of DMC.Carbon dioxide can be well activated in the electric field.Strengthening the research on electrocatalysis and building electrocatalysis pilot plant as soon as possible may bring development opportunities for the direct synthesis of DMC by electrochemical catalysis.
作者
史建公
刘志坚
刘春生
Shi Jiangong;Liu Zhijian;Liu Chunsheng(Engineering and Technology Research Institute,SINOPEC Catalyst Co.,Ltd.,Beijing 101111;SINOPEC Catalyst Co.,Ltd.,Beijing 100029;Sino-Global Energy,Beijing 100011)
出处
《中外能源》
CAS
2019年第10期49-71,共23页
Sino-Global Energy
关键词
二氧化碳
甲醇
碳酸二甲酯
直接合成
催化剂
电催化
carbon dioxide
methanol
dimethyl carbonate
direct synthesis
catalyst
electrocatalysis
