Process Design and Economic Analysis of Bio-Butanol Process

Owing to depletion of fossil fuels, increase in crude prices, and large scale environmental pollutions forced to shift current research focus on renewable resources like biomass for production of fuels and chemicals. The bio-butanol is one such alternative fuel for application in existing internal combustion engines that can be produced by fermentation of biomass. The bio-butanol provides an alternative to butanol produced from petrochemical pathways. Thus there is a need to develop the process for large scale production of bio-butanol from biomass in cost effective manner. The objective of the present study is to design processes to produce bio-butanol from various feedstock including sugarcane, corn, and lignocellulosic biomass using aspen plus. The economic estimation of fixed capital investment and production costs has been carried out for a plant capacity of 10,000 tonne per year butanol. The yield of 0.39 g ABE/g glucose with ABE solvents in the ratio 3:6:1 has been considered in entire analysis. It has been found that the fixed capital investment for corn as feedstock was much higher compared to sugarcane and lignocellulosic biomass. This is because of the additional pretreatment required to extract starch from corn and medium preparation. Byproduct credits for gases and chemicals are taken into consideration to calculate the production cost of butanol. For a yield of 0.39 g ABE/g glucose, the bio-butanol production cost was estimated as $1.04, $1.89, $1.42 for sugarcane, corn, and lignocellulosic biomass respectively. These costs are sensitive to changes in feedstock cost which can change the butanol price significantly