(Bio)Catalytic Continuous Flow Processes in scCO2 and/or ILs: Towards Sustainable (Bio)Catalytic Synthetic Platforms

This review highlights the tool box for the development of continuous green/sustainable processes aimed at the synthesis of fine chemicals. By combining either chemical and/or biological catalysts with biphasic systems based on neoteric solvents, e.g. ionic liquids (ILs) and supercritical carbon dioxide (scCO2), interesting alternatives to organic solvents for designing continuous clean (bio)transformations methods are growing that directly provide pure products. The classical advantages of scCO2 -its ability to extract, dissolve and transport chemicals- are complemented by the high catalytic efficiency of enzymes in ILs. Enzyme behavior in scCO2 and ILs, as well as the phase behavior of ILs/scCO2, are key parameters for carrying out integral green bioprocesses in continuous operation. The preparation, main characteristics and advantages of monolithic microreactors and miniflow reactors for the synthesis of fine chemicals by continuous flow (bio)catalytic processes are underlined. Examples where the use of continuous flow techniques for multi-step synthesis enables multiple reaction steps to be combined into a single continuous operation are provided.