基于低温等离子体的CO_(2)催化加氢制甲醇研究进展

Research progress on carbon dioxide catalytic hydrogenation to methanol based on low-temperature plasma

社会快速发展在带来富足生活的同时,也造成温室效应、环境恶化等一系列负面影响。“碳达峰、碳中和”作为八项重点任务之一不断被提及,对环境保护提出了更高要求。因此控制CO_(2)排放量,对其进行回收、固定、利用及资源化利用,降低大气中CO_(2)浓度,已成为世界各国十分关注的问题。但CO_(2)分子十分稳定,分解活化通常需要高温、催化剂和光、电等能量的输入,而高温易导致催化剂失活。目前CO_(2)转化技术如催化转化和生化过程均存在催化剂失活、能量消耗高等缺点。相比上述技术,等离子体技术具有操作条件简单、易升级、能量成本低等优点。利用等离子体技术,可在室温、常压下,将CO_(2)转化为具有高附加值的燃料和化学品。当等离子体技术联合催化剂后,CO_(2)转化率进一步提高。在诸多CO_(2)利用技术中,CO_(2)氢化有利于生成高能效增值产品,具有现实意义和广阔前景。对等离子体催化CO_(2)加氢制甲醇过程中催化剂类型、反应器结构及操作条件的影响进行研究和综述,可为CO_(2)资源化利用提供更好的参考。研究表明,当等离子体与催化剂联合时,更有利于甲醇合成,因此后续需关注活性更高、成本更低、制备方法更简便的催化剂。同时,反应器结构也会影响CO_(2)转化率,可以考虑进一步优化反应器,目前具有较冷催化剂床的低温等离子体反应器更适合CO_(2)加氢制甲醇。但低温等离子体催化CO_(2)加氢制甲醇反应过程较复杂,对CO_(2)转化机理的探索需要进行更多建模。

While the rapid development of society has brought people a prosperous life,it also brings people a series of negative impacts such as the greenhouse effect and environmental degradation.As one of the eight key tasks,"carbon neutralization and carbon peaking"is constantly being mentioned,which puts forward higher requirements for environmental protection.Therefore,the control of CO_(2) emissions,its recovery,fixation,utilization and recycle,as well as the reduction of the concentration of CO_(2) in the atmosphere,has become the issues of great concern for all countries in the world.However,the CO_(2) molecule is very stable,and its decomposition and activation usually requires the input of high temperature,catalyst and energy such as light and electricity,and high temperature can easily lead to the deactivation of the catalyst.Current CO_(2)conversion technologies,such as catalytic conversion and biochemical processes,have disadvantages of catalyst deactivation and high energy input.Compared with the above technologies,plasma technology has the advantages of simple operating conditions,easy upgrading,and low energy cost.Using plasma technology,CO_(2)can be converted into fuels and chemicals with high added value at room temperature and atmospheric pressure.When the plasma technology is combined with the catalyst,the CO_(2)conversion rate is further improved.Among many CO_(2)utilization technologies,the hydrogenation of CO_(2)is conducive to the generation of high-energy-efficiency value-added products,which has practical significance and broad prospects.By investigating and reviewing the influence of catalyst type,reactor structure and operating conditions in the process of plasma catalytic CO_(2)hydrogenation to methanol,it can provide a better reference for CO_(2)resource utilization.Studies have shown that when plasma is combined with catalysts,it is more conducive to methanol synthesis,so more attention should be paid to catalysts with higher activity,lower cost,and simpler preparation methods in the future.At the same time,the structure of the reactor will also affect the CO_(2)conversion rate.Further innovation of the reactor can be considered.At present,the low-temperature plasma reactor with a cooler catalyst bed is more suitable for CO_(2)hydrogenation to methanol.However,the low-temperature plasma catalytic CO_(2)hydrogenation to methanol reaction process is relatively complex,and the exploration of the CO_(2)conversion mechanism requires more modeling.