In order to obtain high-purity bioethanol, solids and other aqueous components associated with the bioethanol need to be removed by clarification and distillation respectively. This separation process, however, has not yet been demonstrated for microalgal-bioethanol broth. The residual biomass produced after the separation process can theoretically be concentrated and converted to other products, such as animal feeds or fertilizers. The purity of bioethanol must satisfy international stan­dards for fuel specifications, ASTM D5798—09B. The produced bioethanol can be either blended with gasoline to form E10 (10% bioethanol) and E85 (85% bioetha­nol) or used directly in vehicles as a substitute for gasoline. Each of the blends has its own specifications which vary from one country to another. The overall cost of bioethanol production from microalgae should be made low enough to compete with existing commercial fuels. Due to the lack of any existing pilot-scale produc­tion facility of bioethanol from microalgae, practical information on operating and production costs is not readily available.

Acknowledgement This work was supported by an Australian Research Council (ARC) Linkage grant between Bio-Fuel Pty Ltd (Victoria, Australia) and Monash University Department of Chemical Engineering (Victoria, Australia).