Butanol

Applied Energy 88 (2011) 1999–2012

Contents lists available at ScienceDirect

Applied Energy
journal homepage: www.elsevier.com/locate/apenergy

Developments in biobutanol production: New insights
Manish Kumar, Kalyan Gayen ⇑
Department of Chemical Engineering, Indian Institute of Technology Gandhinagar, VGEC Complex, Chandkheda, Ahmedabad 382 424, Gujarat, India

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a b s t r a c t
Biobutanol will become an attractive, economic and sustainable fuel as petroleum oil leads towards expensive fuel due to diminishing oil reserves and an increase of green house gases in the atmosphere. The major challenges in biobutanol production are low butanol titer, availability of compatible feedstocks, and product inhibition. These hurdles are being resolved usingseveral genetic engineering techniques, metabolic engineering strategies, and promising integrated continuous fermentation processes with efficient product recovery techniques (like gas stripping). Adequate success in utilizing renewable and cost-effective cellulosic materials as feedstocks has opened up novel grounds for the advancement in economic biobutanol production. In this direction,Clostridium beijerinckii is being explored as promising strain to produce biobutanol from cellulosic materials. Moreover, high biobutanol titer is being focused through genetic modifications of Clostridia and non-Clostridia organisms (e.g., Escherichia coli, Saccharomyces cerevisiae, Pseudomonas putida, and Bacillus subtilis) in both aerobic and anaerobic fermentation. Further, application of various novelgenetic tools and genome sequencing of hyper-butanolproducing Clostridial organism will enhance the scope of genetic engineering for biobutanol production. Therefore, consolidation of academic and industrial research towards economic synthesis of biobutanol illustrates the possibility of substantial breakthrough in future. In this review, we focus on (i) selection of suitable bacterial strain (ii)availability of cheaper biomass to produce butanol (iii) metabolic engineering strategies of various microorganisms (iv) attempts at process development and (v) biobutanol recovery techniques that provide future direction of economical biobutanol fermentation. Ó 2010 Elsevier Ltd. All rights reserved.

Article history: Received 2 October 2010 Received in revised form 16 December 2010 Accepted18 December 2010 Available online 13 January 2011 Keywords: Biobutanol Lignocellulosic material Process development Metabolic engineering Economic feasibility

Contents 1. 2. 3. 4. 5. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Microorganisms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . Biomass selection for butanol production . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Development in fermentation processes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . 5.1. Batch and fed-batch fermentation processes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2. Continuous fermentation processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ....