Cellulosic ethanol production process involves a series of steps including preprocessing of feedstock (transportation, grinding, sieving), pretreatment (chemical or biological to remove lignin), enzyme hydrolysis (to produce fermentable sugars), fermentation (for production of ethanol, biomass) and downstream processing (separation of biomass from product, distillation, purification). The cost of ethanol production using lignocellulosic feedstock is relatively high with lower yield based on the current technologies. The main challenges are with pretreatment, enzyme hydrolysis cost, fermentation and downstream processing of lignocellulosic feedstock.