A University of Saskatchewan PhD chemistry student has devised a new and more energy-efficient way to separate water from ethanol.
Leila Dehabadi is using starch-based materials such as corn, and can extract the water without using additional energy to isolate the ethanol, which could reduce the cost of biofuels.
“Compared to distillation, this new approach based on green chemistry and engineering will be a significant saving to biofuel and alcohol production in Saskatchewan and globally by changing the way water is separated from ethanol mixtures,” said Lee Wilson, U of S chemistry professor and Dehabadi’s supervisor.
In traditional distillation methods, fermented plants create a mixture of water and ethanol which is then heated to separate out the ethanol. However, some water remains, Dehabadi said.
She solved this problem by using non-toxic starch-based materials that do not require energy to remove water. Published in ACS Sustainable Chemistry & Engineering, her results show the new technology is 40 times more effective than materials previously studied and achieves an efficiency comparable to traditional distillation.
Dehabadi has modified different types of starch (corn) and cellulose (plants) to create materials with varying chemical compositions and textural properties.
During trials, she found that her materials act like “selective sponges,” and remove water better than cellulose-based ones.
When immersed in a mixture of water and ethanol, her new materials suck up 80 times more water than ethanol.
“You can repeat the process in a ‘loop’ to get more ethanol,” said Wilson.