Distillation is the common process for the separation and purification of ethanol after fermentation. It is a thermal process which can consume large amounts of energy, and can also contribute significantly to the cost of production. Scientists from the Minnesota Institute of Technology (United States) have developed an energy-efficient (low cost) membrane separation process "that could revolutionize processes in the petrochemical and biofuels industries". The membrane process involves the use of high performance membranes created from crystal sieves (zeolites) by rapid thermal treatment. The rapid heating treatment was made "to remove structural defects in zeolite membranes that limit their performance, a problem that has plagued the technology for decades." According to Program Officer Rosemarie Wesson, of the National Science Foundation (provider of the research grant), the use of membranes rather than energy-intensive processes (such as distillation and crystallization) could have a major impact in the industry." It can also increase energy efficiency in the production of biofuels, like ethanol and butanol..