Evaluation of recent advances in butanol fermentation, upstream, and downstream processing

Abstract

Four different processes for butanol production from corn, namely, batch fermentation and distillative recovery (BFDR), batch fermentation and pervaporative recovery (BFPR), fed-batch fermentation and pervaporative recovery (FBFPR), and immobilized cell continuous fermentation and pervaporative recovery (ICCFPR) were evaluated. Pervaporative recovery signi®cantly reduces the cost of butanol production. Depending upon the byproduct credit, which is approximately 3.7 times that of the amount of butanol produced, BFDR, BFPR, FBFPR, and ICCFPR result in a butanol price of $0.55, $0.14±0.39, $0.12±0.37, and $0.11±0.36´kg ±1 , respectively. The price of butanol was recently reported at $1.21´kg ±1 by Chemical Marketing Reporter. It should be noted that all three components (acetone, butanol, and ethanol: ABE) diffuse through the pervaporation membrane. Further separation and puri®cation of the solvents would require distillation, which has been considered in this exercise. This article also details the impact of byproduct credit, rate of return, and tax on butanol price.

Optimization Strategies Based on Sequential Quadratic Programming Applied for a Fermentation Process for Butanol Production

“…Mainly because of these problems and due to high costs related to the distillation of dilute product streams, the production of biobutanol on a commercial scale has been considered to be uneconomical [1,2], when compared to the conventional petrochemical route, which is currently responsible for all butanol produced worldwide. In order to turn the butanol fermentation viable, experts suggest that the production cost must be less than US $0.44 kg −1 [3]. Recently, DuPont (US) and BP (UK) announced their plans to produce biobutanol.…”

“…These recovery techniques reduce the effect of product inhibition, allowing an increase in the substrate concentration which results in a reduction in the process streams, higher productivity, and lower distillation costs [4]. According to Qureshi and Blaschek [3], pervaporative recovery significantly reduces the price of butanol production from corn. From US$0.55 kg −1 when employing the batch fermentation and distillative recovery, the production cost can drop to US$0.11-0.36 kg −1 .…”