Development of chemical property and process models for a new fermentation approach
Bioethanol is well-established as an alternative to petroleum-based fuels. A current roadblock in ethanol fermentation is end-product inhibition: where the increasing concentration of ethanol slows the growth of the yeast cells and their ability to ferment biomass. There is work being done to use existing separation technologies to remove ethanol throughout the reaction to avoid end-product inhibition, however these methods are often energy-intensive and therefore not feasible on a commercial scale. Drystill has proposed a novel separation technique called “Concurrent Alcohol Removal and Fermentation” (CARAF) that is able to perform this separation at a low temperature, conserving the yeast, while at a lower energy cost. In order to clearly demonstrate the advantages CARAF has over more traditional separation methods, a robust process simulation is required. Aspen Plus and OLI will be used to thoroughly evaluate and optimize the performance of the CARAF process in terms of ethanol production, separation performance, energy requirements, as well as capital and operating costs.