CO2 conversion Pd-based membrane Z-scheme advanced separations clarification desalination ethanol fouling renewable heat sources gas/liquid separation hydrogel composite membranes hydrogen hydrogen production ionic liquids membranes membrane configuration membrane distillation membrane engineering membrane reactor methane micro channel micro contactor micro direct methanol fuel cell (μDMFC) microfiltration (MF) modeling multivariate analysis on-board orange press liquor palladium photocatalysis photocatalytic membrane reactor porous membranes