Biobutanol - Biotechnology in China: Biofuels and Bioenergy - page 86

Contents

1 Introduction.......................................................................................................................... 86

2 Advances in Butanol-Producing Microorganisms.............................................................. 87

2.1 Strains Used for Biobutanol Industry and Research ................................................. 87

2.2 Genetic Manipulation Methods .................................................................................. 88

2.3 Strain Improvement .................................................................................................... 90

2.4 New Insights into Genome-Scale Analysis of Physiology of C. acetobutylicum

and Solvent Production Using Omics Technologies ................................................. 93

3 Progress in ABE Fermentation Process.............................................................................. 95

3.1 Substrates .................................................................................................................... 95

3.2 Fermentation Process .................................................................................................. 95

3.3 Separation.................................................................................................................... 96

4 Conclusions.......................................................................................................................... 97

References ................................................................................................................................. 98

1 Introduction

ABE fermentation means the production of acetone, butanol, and ethanol via
fermentation, usually using the clostridial strains. It was initiated in the early part
of the twentieth century in the UK, and achieved its peak in the 1950s. The driving
forces for ABE fermentation development were different in different historical
periods, including the artificial synthesis of rubber at the beginning of the
twentieth century, the manufacture of cordite in World Wars I and II, and the
development of nitrocellulose lacquer for the automobile industry after World War
I. Along with the rapid development of the petroleum industry, ABE fermentation
lost its economic competitiveness for producing acetone or butanol, which resulted
in a dramatic decline in ABE fermentation in the last half of the twentieth century
[ 26 ]. In China, the ABE industry was initiated in 1950s and reached its peak in the
1980s. All ABE plants in China were closed at the end of the last century owing to
the severe competitive impact of petro-based butanol [ 38 ].
The oil crisis in the 1970s warned that humanity's dependence on oil was not
sustainable and that industrial processes based on renewable resources must be
developed. The current serious shortage of oil re-stimulates governments and
scientists to find substitutes for petrochemical products from renewable biomass.
Butanol (butyl alcohol or 1-butanol, C 4 H 9 OH, MW 74.12), is an important
chemical and solvent. It is mainly used to synthesize butyl acrylate and methac-
rylate esters for latex surface coating, enamels and lacquers, and butyl glycol ether,
butyl acetate and plasticizers. Additionally, butanol can be used directly as the
diluent for brake fluid formulations, and as solvent for the production of hormones,
vitamins, and antibiotics. Although ethanol has been extensively recognized as
the typical biofuel, butanol, as an alternative biofuel, has several significant
advantages over ethanol, such as higher energy content, lower water absorption,