Past practices and current trends in the recovery and purification of first generation ethanol: A learning curve for lignocellulosic ethanol

Due to the negative health and environmental consequences of fossil fuels, lignocellulosic ethanol has garnered a great interest as a clean and potent renewable energy resource. The presence of excess amount of water hinders the application of ethanol produced, necessitating the implication of robust recovery and purification techniques. Typically, ethanol recovery starts with a conventional distillation process yielding azeotropic ethanol. Further, dehydration and purification steps are employed to achieve fuel-grade ethanol, which consumes tremendous amount of energy and incur high operational cost; eventually limits the economic feasibility of lignocellulosic ethanol on commercial scale. Therefore, to overcome such obstacles, the synergetic application of distillation or adsorption with membrane mediated processes seems to be a promising approach in terms of energy conservation, costeffectiveness, and environmental security. In this review article, we have made an appraisal of the past and current purification and recovery technologies for first generation ethanol, which can be a learning trend for the recovery of lignocellulosic ethanol from the fermented broth, with desired purity. (C) 2020 Elsevier Ltd. All rights reserved.