Agriculture Reference
In-Depth Information
Due to some flexibility, steam consumptions in processes could also be reduced to the
detriment of electricity requirement. Electricity would be then imported from the grid at a
lower cost owing to its production from nuclear energy.
Ethanol from sugar cane is produced through identical or similar operations. Conse-
quently, direct consumptions can be also close if the same efficient processes are used (a
typical Brazilian is still far from this situation). However, cane yields a large amount of
residue - 15% of cane mass against 5.5% for beet -, which is dry enough to be used as
fuel in order to supply all factory requirements and even electricity surplus to the grid.
Ironically, this higher overall efficiency stems partly from cane stalk having a lower sugar
content than beet root and, subsequently, a lower ethanol yield. As a result, even by taking
into account the consumption of importation by ship, cane industry can compete with beet
one for the local ethanol market as the industry is doing for sugar market.
We have not dealt with the emission of fossil greenhouse gases resulting from beet
processing into ethanol. From the energy consumptions of natural gas and crude oil by
the industry we can infer that the balance is not favorable. Moreover, there is also the
production of N
2
O, a potent greenhouse gas, during plant cultivation. The released quantity
is difficult to assess.
Of course, use of ethanol to substitute for fossil fuels would improve markedly this
balance. On the other hand, emission resulting from land use change would be three time
as high as without self-reliance. However, as residues of the industry is either restored to
soil or, in the case of beet pulp, used as a substitute for wheat as animal feed, the impact is
a bit low.
Acknowledgment
The authors thank prof. J.-P. Frangi, director of the Institut Universitaire Professionnel
Génie de l'Environnement, without whom this work would not have been possible.
They are also grateful to P. Dumas researcher at Centre International de Recherche
Agronomique pour le Développement (France) for his remarks.
References
[1]
Bruce Dorminey.
Ethanol from energy beets: A viable option?
Renewable Energy
World, April 2014.
[2]
D. Ballerini. Les biocarburants: état des lieux, perspectives et enjeux du développe-
ment. IFP publication, Editions Technip, 2006. 375 pp (In French).
[3]
Confédération Générale des planteurs de Betteraves. La betterave en 2014, fév. 2014.
163 pp (In French).
[4]
Renewable Fuel Association. 2014 ethanol industry outlook, February 18th, 2014. 40
pp.
