Environmental Engineering Reference
In-Depth Information
29
Sugarbeet
Pawan Kumar, Anjanabha Bhattacharya, and Rippy Singh
University of Georgia
contents
29.1 Introduction ........................................................................................................................ 709
29.2 Sugarbeet as a Sugar Crop .................................................................................................. 710
29.3 Extraction of Sugar ............................................................................................................ 710
29.4 Bioethanol Production from Sugars ................................................................................... 710
29.5 Sugarbeet Improvement ...................................................................................................... 711
29.6 Alternative Uses .................................................................................................................... 713
29.7 Further Discussions and Conclusions ................................................................................... 713
References ...................................................................................................................................... 714
29.1 IntroductIon
The world population is growing at an alarming rate, and with this growth the demand for energy is
also increasing at a rapid pace. It is projected that there will be more than a 50% increase in energy
demand in 2025, with most coming from rapidly developing nations. This increased demand cannot
be met with finite fossil energy sources like petroleum and coal. Therefore, the present-day energy
scenario and concerns for global warming have stimulated the search for an alternative to fossil fuel
energy which ought to not only be renewable but also ecofriendly with low emission of greenhouse
gases (GHGs). Bioenergy from plants is one such source that has the potential to reduce dependence
on fossil fuels.
Ethanol produced from plants can be used as an energy source in its pure state or it can
be used by blending with petroleum fuel in engines. It offers several advantages over fossil
fuel: it has a high octane number (the higher the number, the more efficient the energy usage)
(Balat 2009), low toxicity to humans, low volatility, and low evaporation (Hira and de Oliveira
2009). Bioethanol is being produced from sugar-rich crops such as sugarcane and sugarbeet
(Wegner and Hagnefelt 2008). Bioethanol production from sugarbeet is of recent origin. It
helps to stabilize falling sugar prices in addition to bridging global energy demands. It is more
cost-efficient to convert sugars to ethanol than unlocking complex polysaccharides from plant
sources because to date there has been limited success in separating lignin from plant material
that prevents access of cellulose (polysaccharides) to trap the source molecules needed as raw
material in bioethanol production.
Sugarcane is adapted to tropical regions of the world, whereas sugarbeet is predominately
grown in temperate regions; therefore, the two sugar-rich crops occupy different geographical
niches. Sugarbeet was identified as a crop of choice for sugar production in the temperate regions
in the early nineteenth century, when sugar was largely imported from the tropical and subtropical
countries and so was considered to be a luxury item that few could afford. Sugar was used largely
as a base in traditional medicine such as homeopathy and was a very expensive product that was
only derived from cane sugar. Although sugarbeet contains less sugar (17%; Milford and Watson
1971) than sugarcane (18-22%), and it is a poor transformer of sugars from the photoassimilate, it
had advantages because it could be grown in temperate climate and the foliage could be used as a
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