In past few years, world is facing the unexpected rise in the crude oil prices. On tracking the rise in these prices, it is observed that depletion in fossil fuel reserves is the main reason behind it. This fact motivated the scientist across the globe to find out the alternatives for the fossil fuels. The study in this field reveals that, alternative energy sources like solar, wind and hydrogen can serve the purpose to certain extent but surely they has not a potential to meet the global demands. Further research concluded that, biofuels especially ethanol has a great potential to serve as an alternative to conventional fossil fuels with minimal impact on the environment. It demands the high scale production of ethanol which is possible from renewable biomass. This paper in detail describes the production of ethanol from cane molasses in distillery. The major concern in distillery is the energy consumption in distillation arising through the low thermodynamic efficiency of columns. The paper in detail explains the implementation of different techniques like direct vapor recompression (DVR), heat integrated distillation column (HIDiC), multi-pressure distillation (MPRD) in order to reduce the energy consumption in a process. The paper significantly elaborates how the energy consumption in distillery could be reduced from 3.2 to 3.0 kg of steam/liter of ethanol produced through internal and external heat integration in columns. Heat integration achieves the reduction in steam consumption by applying MPRD.

Keywords: Bio-ethanol; Heat Integrated Distillation Column (HIDiC); Multi-Pressure Distillation (MPRD); Direct Vapor Recompression (DVR); Energy Optimization;