Cleaning Porous Materials Using Supercritical Fluids

In this work, processes for cleaning porous materials using supercritical fluids as cleaning media are considered. In the first part of the work, a literature review is provided, showing examples of successful development of such processes. In the literature review, the processes are characterized and advantages resulting from application of supercritical fluids are explained. The advantages and disadvantages of using supercritical fluids as cleaning media are discussed. In the second part of the work, practical guidelines for development of novel processes for cleaning porous materials, in which supercritical fluids can be applied, are formulated. The guidelines include the review of references processes as a starting point for process design, the analysis of the physical properties of the investigated system, investigation of potential negative effect of treatment with SCFs on the porous material’s key properties, experimental investigation of the process, as well as process optimization and scale-up. The guidelines are illustrated with an exemplary process—cleaning microfiltration membranes using supercritical carbon dioxide instead of liquid organic solvents. Despite some technological challenges and limitations, supercritical fluids can be applied in many processes for cleaning porous materials, leading often to safer and more environmentally friendly processes, as well as to products of superior quality.