Journal of Fundamentals of Renewable Energy and Applications
Open Access
ISSN: 2090-4541
+44 1300 500008
ISSN: 2090-4541
+44 1300 500008
S Farzad, M Ali Mandegari and J F Gorgens
Scientific Tracks Abstracts: J Fundam Renewable Energy Appl
The South African sugar industry which has significant impact on the national economy is currently facing problems due
to increasing energy price and low global sugar price. The available bagasse is already combusted in low efficiency boilers
of the sugar mills while bagasse is generally recognized as promising feedstock for second generation bioethanol production.
Establishment of biorefinery annexed to the existing sugar mills, as an alternative for re-vitalisation of sugar industry producing
biofuel and electricity has been proposed and considered in this study. Since scale is an important issue in feasibility of the
technology, this study has taken into account a typical sugar mill with 300 ton/hr sugar cane capacity. The biorefinery simulation
is carried out using Aspen PlusTM V8.6, in which the sugar mill’s power and steam demand has been considered. Hence sugar
mills in South Africa can be categorized as highly efficient, efficient and not efficient with steam consumption of 33, 40 and
60 tons of steam per ton of cane and electric power demand of 10 MW, three different scenarios are studied. The sugar cane
bagasse and tops/trash are supplied to the biorefinery process and the wastes/residues (mostly lignin) from the process are
burnt in the CHP plant in order to produce steam and electricity for the biorefinery and sugar mill as well. Considering the
efficient sugar mill, the CHP plant has generated 5 MW surplus electric power but the obtained energy is not enough for selfsufficiency
of the plant (Biorefinery and Sugar mill) due to lack of 34 MW heat. One of the advantages of second generation
biorefinery is its low impact on the environment and carbon footprint, thus the plant should be self-sufficient in energy without
using fossil fuels. For this reason, a portion of fresh bagasse should be sent to the CHP plant to meet the energy requirements.
An optimisation procedure was carried out to find out the appropriate portion to be burnt in the combustor. As a result, 20%
of the bagasse is re-routed to the combustor which leads to 5 tonnes of LP Steam and 8.6 MW electric power surplus.
S Farzad is currently a Postdoctoral researcher at Process Engineering Department of Stellenbosch University. Besides supervision of Postgraduate students, her current
research involves biorefinery techno-economic analysis and also environmentally friendly tire production. Her PhD thesis and previous expertise were focused on petroleum
industry in which she has 7 ISI published papers and three papers in progress. She supervised three master students while working as “Assistant Professor” at University
of Environment. Apart from academic activities, she has more than 6 years industrial experience in gas and petrochemical plants as R&D manager and project engineer.