Biobutanol extraction and dehydration with eucalyptus oil yielding linear and cyclic biofuel blends

Abstract The biobutanol‐based biofuel fermentation is hindered by the challenge of inadequate fermentation broth concentration and the azeotropic systems of water. The application of eucalyptus oil in diesel fuel makes it a promising extractant for biobutanol extraction and dehydration, thus resulting in product recovery and the development of fuel blend technology. Eucalyptus oil‐derived 1,8‐cineole was applied to acetone‐butanol‐ethanol (ABE) and isobutanol systems to enhance the butanol recovery and dehydration. The recovery of n‐butanol and isobutanol reached 92% and 95%, respectively, while the water removal in a 2% butanol system exceeded 99%. These results demonstrated that 1,8‐cineole exhibited a high selectivity toward butanol, thus providing a robust theoretical foundation for the fermentation‐based biofuel recovery and the elimination of azeotropic systems. The introduction of high‐density diesel‐fuel‐like eucalyptus oil into low‐energy‐density biobutanol will increase the energy density of fermentation‐based alcohols, yielding linear and cyclic biofuel blends.