Ethanol Dehydration

MTR uses SolvSep™ membrane systems to dehydrate organic solvents widely used in the pharmaceuticals and fine chemicals industries.

Ethanol forms an azeotrope with water at 95 wt% ethanol and 5 wt% water. As a consequence, simple distillation can easily dehydrate wet ethanol to about 90% ethanol. However, removing the remaining water requires another technique, most commonly extractive distillation with an entrainer or molecular siev based temperature and pressure swing adsorption. These processes are complex and energy intensive. Membrane vapor permeation or pervaporation with robust zeolitic membranes are simple, low cost and compact alternatives.

Figure 1: Typical PFD of dehydration system operating in Vapor Permeation Mode

 

Figure 2: Typical PFD of dehydration system operating in Pervaporation Mode

Photographs of compact zeolite membrane plants processing 1,000 to 3,000 gallons per day of wet ethanol.