Methanol is recognized today as an important and valuable energy carrier with a high potential in replacing fossil resources . A sustainable and carbon-neutral approach to produce methanol is by hydrogenation of carbon dioxide by using hydrogen from solar water splitting. The challenge of this reaction is that CO2 is a rather inert molecule and typically, high pressure and temperature and the use of expensive catalysts with loadings are needed . Further, a CO2-capture system is needed if one wants to use CO2 from the environment. As shown in Figure 1, we developed a capture method using amines to form CO2-based ionic liquids that can then be further hydrogenated to methanol.
Here, we present our work on the process intensification and optimization of the hydrogenation steps of CO2-based ionic liquids. We discuss our DoE studies on the influence of reaction parameters, optimization of the work-up and isolation of the methanol, and of the scale-up.
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