Hydrophilic and organophilic pervaporation of industrially important α,β and α,ω-diols

The distillation-based purification of α,β and α,ω-diols is energy and resource intensive, as well as time consuming.

Separation of Alcohol-Water Mixtures by a Combination of Distillation, Hydrophilic and Organophilic Pervaporation Processes

It can be stated that in the fine chemical industries, especially in the pharmaceutical industry, large amounts of liquid waste and industrial waste solvents are generated during the production technology. Addressing these is a key issue because their disposal often accounts for the largest proportion of the cost of the entire technology. There is need to develop regeneration processes that are financially beneficial to the plant and, if possible, reuse the liquid waste in the spirit of a circular economy, in a particular technology, or possibly elsewhere. The distillation technique proves to be a good solution in many cases, but in the case of mixtures with high water content and few volatile components, this process is often not cost-effective due to its high steam consumption, and in the case of azeotropic mixtures there are separation constraints. In the present work, the membrane process considered as an alternative; pervaporation is demonstrated through the treatment of low alcohol (methanol and ethanol) aqueous mixtures. Alcohol-containing process wastewaters were investigated in professional process simulator environment with user-added pervaporation modules. Eight different methods were built up in ChemCAD flowsheet simulator: organophilic pervaporation (OPV), hydrophilic pervaporation (HPV), hydrophilic pervaporation with recirculation (R-HPV), dynamic organophilic pervaporation (Dyn-OPV), dynamic hydronophilic pervaporation (Dyn-HPV), hybrid distillation-organophilic pervaporation (D + OPV), hybrid distillation-hydrophilic pervaporation (D + HPV), and finally hybrid distillation-hydrophilic pervaporation with recirculation (R-D + HPV). It can be stated the last solution in line was the most suitable in the terms of composition, however distillation of mixture with high water content has significant heat consumption. Furthermore, the pervaporation supplemented with dynamic tanks is not favourable due to the high recirculation rate in the case of tested mixtures and compositions.

Platform Molecule Removal from Aqueous Mixture with Organophilic Pervaporation: Experiments and Modelling

The work is motivated by a separation problem, which is ethanol removal from aqueous mixtures with membranes. Ethanol can be considered as promising biomass based platform molecule. The platform molecule includes several building-block chemicals grouped together, resulting in a range of downstream chemical products. To solve the target, organophilic pervaporation system is investigated using benchmarked Sulzer PERVAP™ 4060 membranes. Separation factors, total permeation fluxes, permeances and selectivities are experimentally determined. The target of this work is to parameter estimation for semi-empirical pervaporation model. The measured data are evaluated with improved pervaporation model by Valentinyi et al. [1]. Three different polymeric flat sheet membranes are investigated, PERVAP™ 4060, PERVAP™ 1060 and CELFA-CMG-OG010. It is found that the model can be applied also for each organophilic separation case.