Workshop on Global Fuel Economy Initiative 22 & 23 July 2013, Maritim Hotel, Balaclava Bio-ethanol CO 2 reduction For Mauritius Abdel Khoodaruth Mechanical and Production Engineering Department, University of Mauritius 1
Overview Introduction Ethanol production stages Carbon Dioxide emissions of ethanol pathways Implications Conclusion 2
Introduction Global warming is a major component in the energy scenario of many countries Policy makers are facing a growing need to reduce CO 2 Bio-ethanol is produced from biomass and is suitable for use as fuel in motor-vehicles Ethanol can be produced from corn, sugarcane, and maize Sugar cane ethanol is being promoted as an important component of global energy and climate change mitigation policy Sugar cane ethanol(molasses or cane juice) 3
Bio-Ethanol Clear advantages over gasoline in reducing greenhouse gases emissions and improving air quality Substitute for automotive fuel Although ethanol has lower energy content than conventional gasoline, its higher octane value results in higher compression ratios and consequently more efficient thermodynamic operation in internal combustion engines(nguyen et al, 2007). Very low emissions of ozone-forming hydrocarbons and toxics Made from renewable sources Can be domestically produced 4
Sugar cane in Mauritius Mauritius is a small island of 1865km 2 Agriculture accounts 43% of land use and sugar cultivation represents 38.6%. 90% of agriculture land is under sugar cultivation Sugar cultivation and production has contributed significantly to the socio-economic progress for more than a century By-product of sugar cultivation=sugar, bagasse and molasses 5
Sugarcane production statistics 2006 2007 2008 2009 2010 2011 Area harvested (ha) 66,732 65,259 62,024 60,380 58,709 56,668 Cane production (000tonnes) 4,749 4,236 4,533 4,667 4,366 4,230 Molasses(tonnes) 139621 130917 145113 147568 143515 138579 Source: Statistics Mauritius: Digest of Agricultural Statistics. October 2012 6
CO 2 emissions - Mauritius 5% 0% 25% 9% 61% Energy industries (electricity) Manufacturing industries Transport Other sectors Industrial processes Source: Statistics Mauritius: Digest of Environmental Statistics. December 2012 7
The Issue evaluating ethanol CO 2 emissions when producing sugar cane ethanol Quantify the CO 2 emissions in the ethanol production pathways 8
Ethanol production stages(molasses) Fertiliser and herbicide production transport Fossil fuel Cane Cultivation and Harvest transport Sugar Processing and Electricity Generation Sugar Electricity Molasses 9 Bio-fuel transport Ethanol transport
Ethanol production stages(sugar juice) Fertiliser and herbicide production transport Fossil fuel Cane Cultivation and Harvest transport Sugarcane Processing Electricity Ethanol transport 10 Bio-fuel
Transportation from harbour to factory 11
Parameters Area harvested(2011) 56668 Sugar cane(tonne) 4 230 000 1 tonne of molasses 215 L of ethanol 1 tonne of sugar cane 86 Litres of ethanol Functional Unit 1 litre of ethanol, 1 tonne of sugar cane 12
Calculations Area harvested(2011) 56668 Sugar cane(tonne) 4 230 000 Molasses(tonne) 138579 Ethanol production(ml) molasses Ethanol production(ml) Sugar cane juice 31 364 13
CO 2 emissions of ethanol pathways 14 CO 2 kg per tonne of sugar cane Production of fertilisers 8.158 0.0949 Production of herbicide 2.163 0.0252 Transportation of fertilisers 0.110 0.0013 Transportation of herbicide 0.002 0.0000 Farming and cultivation 2.185 0.0254 Irrigation 0.480 0.0056 Harvesting 0.724 0.0084 Loading of cane 1.249 0.0145 Transportation of sugar cane to factory 3.362 0.0391 Sub-total 18.435 0.2144 Ethanol conversion 0.980 0.0110 Transportation of ethanol to admixture plant 1.436 0.0160 Total 20.828 0.2422 CO 2 kg per litre of ethanol
CO 2 emissions of ethanol pathways(%) 5% 7% Production of fertilisers 16% 39% Production of herbicide Transportation of fertilisers Transportation of herbicide 6% 3% 2% 11% 10% Farming and cultivation Irrigation Harvesting Loading of cane Transportation of sugar cane to factory Ethanol conversion Transportation of ethanol to admixture plant 0% 1% Transport = 24% 15
Implications To produce one litre of anhydrous ethanol, 242.2g of CO 2 emitted one litre of gasoline emits 2325g of CO 2 Blend of gasoline and anhydrous ethanol is now being used and is even considered mandatory in many countries such as Brazil, United States and Europe E-10 means 90% gasoline and 10% ethanol E-10: no modification in engine 16
Implications One litre of E10 = 0.967 litres of gasoline* One litre E20 = 0.935 litres of gasoline* One litre of E85 = 0.725 litres of gasoline* E10, E20 and E85, will cause an over consumption of 3.4%, 6.95% and 37.9% respectively. To replace one litre of gasoline, we need more than one litre of ethanol This is because ethanol has a lower calorific value * Source: Bell et al. (2011) 17
Implications 152 ML of gasoline = 350 000 tonnes of CO 2 E10: 15.7 ML of ethanol + 141.45ML of gasoline = 330 000 of CO 2 = -20 000 tonnes of CO 2 E85: 178.2 ML of ethanol + 31.4ML of gasoline = 117 000 of CO 2 = -233 000 tonnes of CO 2 18
Conclusion Ethanol production = 242.2 g of CO 2 Gasoline to E10 = -20 000 tonnes of CO 2 More in case of higher proportion of ethanol blended with gasoline Price structure The potential reduction of CO 2 emissions is one of the sustainability indicators which can be used to bridge the gap between economic competiveness and environmental benefits. 19
20 Thank you!!