Abstract
Economy of vapor phase gas separation and pervaporation can be improved by the use of vapor compression method, which can give the necessary pressure difference for the permeation and at the same time can rise the permeate and residual gas temperature by the adiabatic compression. Thus the latent and sensible heat can be recovered to preheat or vaporize the feed.
A example is shown, where the 979kg/hr of 8.07wt % ethanol solution made by the biomass conversion is separated to 457.7kg/hr of 17.2wt% solution and 521kg/hr of 845ppm ethanol solution. In this case only 57.48kcal/hr is required as shown in Fig. 1, which is only 19% of the heat used for vaporization. And ethanol loss is 0.56% of the feed.
A next example is the production of 40.55kg/hr of 99wt% and 2.38kg/hr of 33.8wt% ethanol solution from 42.92kg/hr of 95.4wt% solution without dehydration agent as shown in Fig. 3.
Also the permselective membranes for organic vapor mixture can be used in this system, which also can be the revolutional technique, when combined with the rectification.
