An assessment of the renewable energy export potential of the Mauritian sugar cane industry with new practices and prospective technologies
Code (CO)MSI08P4292
Author (AU)Lau Ah Wing, A. F.
Organisation (OR)School of the Built Environment, University of Ulster
Title - English (ET)An assessment of the renewable energy export potential of the Mauritian sugar cane industry with new practices and prospective technologies
Thesis-Parent title (TH)Thesis, MSc Energy Management
Document Type(DT)thesis
Date of publication (DP)2008
Source (SO)126 p.: 52 figs, 31 tbls, 6 appen.
Language of text (LT)en
Language of summaries (LS)En
Abstract (AB)This study assesses current and prospective technologies or new practices that can further increase exportable energy from the sugar cane industry in Mauritius. It shows the potential of the first and second generation bio-fuel technologies. Accurate predictions of likely performance will guide research activities at the Mauritius Sugar Industry Research Institute (MSIRI). An energy efficient virtual plant was assembled for a simulation program, VCogen, written on a spreadsheet. It includes a high pressure boiler, a condensing extraction turbo alternator (CETA), a cane diffuser station and a Sextuple effect evaporator station, all considered as leading technologies to maximize electricity export. The energy requirement of a sugar refinery and distillery was also considered as they will be included in new factories. Net electricity export of the virtual plant was 530 GWh/year, assuming 1.69 million tonnes bagasse available (880,000t fibre equivalent). Without the refinery and distillery it would have been 690 GWh. Practices believed to have an impact on electricity export were simulated in VCogen. The gain with a Sextuple (with cane diffuser station) instead of the typical Quintuple effect evaporator station (with typical mill tandem) was around 60 GWh. The impact of recovering heat from hot condensate to heat juice and boiler make-up water was insignificant, i.e. a rise of only 5 GWh. For every 100,000t bagasse equivalent of trash recovered (47,500t fibre) the gain was 57 GWh. High fibre cane, 20 per cent can increase net electricity export to 640 GWh compared to 530 GWh in our virtual plant; achieved even if the cane yield remains 72 t/ha, the average performance in Mauritius. Bagasse drying may add 43 GWh/year but is not advisable because boiler furnaces are designed to operate at 48 per cent humidity. Heat recovery using flue gas will not have a significant impact on net electricity export. The 2G bio-fuel technologies using the thermo or bio-chemical route has the potential to produce more exportable energy compared to the conventional technologies. Between 1,005 and 2018 GWh electricity can be exported from the BIG-GT cycle. Alternatively syngas from bagasse gasification can be used in fuel cell, with electricity export ranging between 930 and 1060 GWh. The hydrogen and carbon monoxide (CO) component in the syngas can be used to produce F-T fuels, e.g. Octane, ranging between 60,032t and 138,187t. It appears that in all these three cases where 975,000t fibre was assumed, steam demand for juice processing will not be fully satisfied. In the short term, 3 to 5 years, only trash recovery can have a drastic impact on net electricity export, considering that 774,000t dry matter (fibre) is left in the fields. A comprehensive agronomic, technical and economic study is recommended if more than 200,000t of bagasse equivalent of trash (75,000t fibre) is to be recovered from the fields.
Descriptors - English (DE)sugarcane
sugar cane industry
sugar industry
energy
renewable energy
export potential
ethanol
electricity
molasses
bagasse
sugarcane byproducts
high fibre cane
sugarcane trash
flue gas
biofuels
energy usage
enzymatic hydrolysis
gasification
Descriptors - Geographic (DG)Mauritius
Sort Key 1(K1)Cane sugar manufacture
Sort Key 2 (K2)Sugarcane byproducts: Energy
Date record entered (DA)2008-07-10
Language of analysis (LA)en
Location (LO)LIB
Processing status (PS)CAT
Number of copies (NC)1
MSIRI Staff (MS)ST