BORSIG Pervaporation

Ethanol is used as solvent in pharmaceutical and nutraceutical processes as well as in the fine chemical industry. The used Ethanol needs to be dehydrated before recycling into the process. By combining distillation and vapor permeation the ethanol can be dehydrated down to water contents of 0.3 wt-% without the use of entrainer or molecular sieves.

For use in biofuel production the water contents in ethanol has to be significantly reduced. Pervaporation plants allow for reduction of water contents down to 0.3 wt-%.

IPA is used as solvent in pharmaceutical and fine chemical production processes, e.g. for the synthesis and purification of pharmaceuticals. The used IPA often contains water and impurities which need to be removed for recycling and reuse.

Liquid feeds consisting of more than 50 wt-% IPA and water can be efficiently dehydrated in pervaporation, vapour permeation or hybrid (distillation combined with vapour permeation) plants.

For synthesis of pharmaceuticals such as Active Pharmaceutical Ingredients (APIs) different solvents are used. Those solvent need to be purified from water for reuse. Multipurpose plants are designed for dehydration of different solvents like ethanol, isopropanol, acetone, tetrahydrofuran (THF), methyl ethyl ketone (MEK) or ethyl acetate by using the same membrane and plant.

In the production of Polyvinyl Alcohol (PVA) a large amount of methyl actetate/methanol mixture is formed in the second production step. 

In conventional processing an energy-intensive extractive distillation step is applied to separate methanol from methyl acetate.

By combining distillation with pervaporation the separation process is significantly simplified and no third component needs to be introduced.

In trimethyl borate production process the reaction mixtures is distilled producing a trimethyl borate / methanol azeotrope as the top product of the column. In conventional process, the azeotrope is washed out with a complicated alkali salt process, followed by another distillation step. The addition of a vapour permeation unit in between these two distillation columns is today’s state of the art optimized process with the final product free of salt impurities.