Sorption-Enhanced CO2 Hydrogenation to Methanol under Dynamic Reaction Conditions

高效的碳捕获和利用（CCU）是可持续碳中和经济的关键要素。目前的CO2分离技术（即，变压吸附）以及可再生能量的动态可用性要求开发能够在反应物浓度和可再生能量的可用性的动态变化期间操作的方法。在这个项目中，我们调查的组合CO2捕集，然后加氢为甲醇与绿色H2在反应（定期）再生的吸附剂，以利用CO2作为丰富的碳源生产甲醇。为了获得成功，需要在低温下的动态操作和对甲醇的高选择性以达到足够的甲醇产率。与多步反应系统相比，其中CO2在吸附温度（或仅略微提高的温度）下被相同的催化剂捕获和转化的集成系统允许减少总能量输入。在该项目的第一阶段，二氧化碳捕获/转化概念被证明是可行的。它基于一种催化剂，该催化剂包含用于CO2吸附的胺官能化多孔固体和用于将CO2氢化成甲醇的贵金属。在阶段II中，将增强CO2与胺基的相互作用以及与贵金属颗粒的局部接近性，以增加CO2的结合，从而增加与MeOH的反应速率。微观动力学建模和多尺度反应器模拟将应用于研究反应机理，这将使合理开发的新的催化材料所需的提高甲醇的产率。

Efficient carbon capture and utilization (CCU) is a key element for a sustainable carbon neutral economy. The current CO2 separation technology (i.e., pressure swing adsorption) as well as the dynamic availability of renewable energy requires the development of processes able to operate during dynamic changes in the reactant concentrations and in the availability of renewable energy. In this project we investigate the combination of CO2 capture followed by hydrogenation to methanol with green H2 during a reactive (periodic) regeneration of the sorbent in order to utilize CO2 as abundant carbon source for the production of methanol. For being successful, dynamic operation at low temperatures and high selectivity to methanol are required to reach a sufficient methanol yield. The integrated system, in which CO2 is captured and converted by the same catalyst at the sorption temperature (or only slightly enhanced temperatures) allows to reduce the overall energy input compared to a multistep reaction system. In phase I of the project, the CO2 capture/conversion concept was shown to be feasible. It is based on a catalyst comprising an amine functionalized porous solid for CO2 sorption and a noble metal for the hydrogenation of CO2 to methanol. In phase II, the interaction of CO2 with the amine groups and the local proximity to the noble metal particles will be enhanced in order to increase the binding of CO2 and hence the rate of the reaction to MeOH. Microkinetic modeling and multiscale reactor simulations will be applied study the reaction mechanism, which will enable the rational development of novel catalytic materials required for enhancing the MeOH yield.