Biofuels, Solar and Wind as Renewable Energy Systems_Benefits and Risks Episode 2 Part 5 pdf

13 Bio-Ethanol Production in Brazil 339 Buildings are regarded as having a useful life of 50 years and a maintenance en- ergy cost of 4% per yr (Macedo, 1997). As the greatest energy input is in cement the energy value of this material is used. As fuel costs are such a large part of manufac- turing costs, most cement companies have aggressive energy conservation programs and according to the International Energy Program (IEA, 1999) new manufacturing plants have reduced energy use by between 25 and 40% compared to 10–15 years ago. The report by the IEA (1999) gives a value of 6.61 GJ for the energy required to produced 1 Mg of cement, and other recent reports (Young et al., 2002 and Wor- rell and Galitsky, 2004) give somewhat lower values of 4.35 and 6.1 GJMg −1 .We use the former higher value of 6.61 GJMg −1 . So allowing for a 4% annual main- tenance cost the total embodied energy for all buildings over a 50 year period is (1,600 + (0.04 ×50 ×1,600)) ´ U 6.61 GJ which becomes 31,730 MJ or 634.6 MJ yr −1 . As we assume that the mill serves to grind one third of 2 million Mg of cane per year, this becomes 0.952 MJMg cane milled, or 75.9 MJ ha −1 yr −1 (Table 13.7). For the mild steel in the mill/distillery we have assumed that one third is in light equipment and thus subject to more wear and will have a lower useful life Table 13.7 Energy in the buildings and construction of a standard mill/distillery. Design capacity 2 million Mg year, running at 33% capacity. Methodology for the calculation of the fossil, energy inputs follows that of Pimentel (2007) Mass a Useful life b Including maintenance c Including on-site energy utilisation d per year kg/ha/ year Total energy Mg yr Mg Mg kg kg MJ/ha/yr Cement in buildings 1600 50 4800.0 5000.0 100000 11.49 75.9 Mild steel (structural) 2873 25 5746.0 6105.1 244205 28.06 841.8 Mild steel in light equipment 1437 10 2011.8 2191.4 201180 23.12 693.5 Stainless steel 410 25 820.0 871.3 34850 4.00 287.1 1898.3 Basic data on standard cane Factory Mg cane harvested by factory 666667 yr −1 Area harvested by factory 8703.2 ha Energy in cement (MJ/kg) e 6.61 Energy in Steel (MJ/kg) f 30.0 Energy in stainless steel (MJ/kg) g 71.7 a Data from Dedini S.A Piracicaba. S ˜ ao Paulo. b According to Macedo et al. (2003). c Maintenance energy cost of 4% per year. d 12.5% of mass of each component (Hannon et al. 1978). e From IEA (1999). f From Worrel et al. (1997). g Embodied energy in stainless steel = 2.39 ×energy in mild steel (Pimentel and Patzek, 2007). 340 R.M. Boddey et al. (10 yrs – Macedo, 1997). The remaining two thirds is considered to be in the struc- ture of the mill, equipment and distillery, and thus will have a longer useful life (25 years). The same calculations have been made in the same way as for the cement in buildings but the embodied energy in mild steel was considered to be 30 MJ kg −1 as justified in Section 13.3.1.4 above. The data for the standard mill provided by Dedini S.A. show that 410 Mg of stain- less steel was used, mainly in the distillery columns. Pimentel and Patzek (2007) give the embodied energy in stainless steel to be 2.39 times that in mild steel, so the value of 71.7 MJ kg −1 was used for this material. The useful life of this material was assumed to be 25 years. The energy input for stainless steel in the factory was again calculated using the same procedure as for cement (Table 13.7). Finally to account for on-site energy utilised in the construction, all values were increased by 12.5% as suggested by Hannon et al. (1978). The total energy require- ment for factory buildings and equipment totalled 1898 MJ ha −1 yr −1 (Table 13.7). 13.3.1.7 Energy Balance The details of all fossil energy inputs calculated as described in Sections 13.3.1.1– 13.3.1.6 above, are displayed in Table 13.4. The total energy yield of the annual mean per ha ethanol yield of 6,281 L, becomes 134,815 MJha −1 (1 L of ethanol yields 21.46 MJL −1 – Pimentel, 1980). Within the fossil energy inputs in the agricultural operations, fertilisers, espe- cially N fertiliser, are responsible for the largest contributions. The fact that in Brazil N fertiliser use is far lower than in just about any other cane growing area in the world, makes an important economy. If for example 150 kgN ha −1 yr −1 (typical of most other countries) were used instead of the estimated 56.7 kg, the energy input would rise from 3060 to 8100 MJha −1 yr −1 increasing the total energy input in agri- cultural operations (including transport of cane and consumables) by 43%. Because of their complicated synthesis herbicides are extremely energy intensive and even though only a mean of 3.2 kg a.i. ha −1 yr −1 are applied, this is the second most important consumables input after fertilisers. Brazil is fortunate in that most of the country has over 1,000 mm of rainfall a year, and the most productive cane-growing areas have over 1,300 mm of rain. For this reason only a very small area is irrigated so that there is effectively no energy input for irrigation. The comparatively large input of fossil energy in the manufacture of agricultural machinery, and to a lesser extent, of human labour, show the importance of includ- ing these inputs, which is not universal practice in computing such balances (e.g. Sheehan et al., 1998; Shapouri et al., 2002) As all factory energy is supplied by bagasse, the main fossil energy input (es- timated to be ∼1,900 MJ ha −1 yr −1 ) is in the infrastructure of the construction and maintenance of structure and equipment of the factory. All factories are built near abundant water supplies (usually rivers) and pumping comes from electricity gener- ated from bagasse, and thus involves minimal fossil energy inputs. 13 Bio-Ethanol Production in Brazil 341 The total energy balance is the Total Energy Yield (TEY) of the biofuel divided by the Fossil Energy Invested (FEI). For today’s production levels and practice we calculate this to be approximately 8.8, which is close to the value of 9.2 calcu- lated for ethanol production S ˜ ao Paulo by Macedo (1998), and of 8.3 by Macedo et al. (2003). The main differences between these studies are that (a) we included the manual labour energy input, which was not included in the studies by Macedo and his colleagues, and (b) we used a much more recent estimate for the energy em- bodied in steel (30 MJ kg −1 – Worrell et al., 1997), rather than that cited by Macedo et al. (2003) of 38–63 MJ kg −1 which are estimates that date from the 1970s. When the energy balance (TEY/FEI) is high, differences of 1 or 2 units in the this ratio make only small differences in the proportion of energy saved. This is illustrated in Fig. 13.3, which displays the relationship between the economy in fossil energy (% Fossil energy saved) and the energy balance. Thus if a biofuel has an energy balance of 5, this represents an economy in fossil energy of 80%. It might take a lot of ingenuity and expenditure to halve fossil energy inputs to raise the balance to 10, but this would only represent economy in fossil energy inputs of a further 10%. Pimentel and Patzek (2007) estimated the input of fossil energy to produce Brazilian bioethanol was 13,286 MJ m −3 (3,177 Mcal m −3 ) and a total energy yield of 21,454 MJ m −3 (5,130 Mcal m −3 ). The resulting energy balance of 1.66 is in wide disparity of those calculated by Macedo (1998) and Macedo et al. (2003) and by us in this present study. A comparison of our estimates with those of Pimentel and Patzek (2007) is given in Table 13.8. Energy Balance 123456789101112131415 % Fossil energy saved 0 20 40 60 80 100 Fig. 13.3 The relationship for biofuel production between energy balance and fossil energy saved 342 R.M. Boddey et al. Table 13.8 Comparison of estimates of fossil energy and energy balance computed in this study and that of Pimentel and Patzek (2007) This study Pimentel and Patzek (2007) Input Quantity unit MJ/unit MJ/ha/yr Quantity unit MJ/unit MJ/ha/yr Field operations Labour 128.0h 7.84 1003.5 128 h 3.1 656.6 Machinery 136.6kg 13.07 1785.6 156 kg 112.9 2668.1 Diesel 22.3L 47.73 1064.4 22.3 L 4.1 1062.2 Nitrogen 56.7kg 54.00 3061.8 58.3 kg 66.9 3901.8 Phosphorus 16.0kg 3.19 51.016kg17.4 250.9 Potassium 83.0kg 5.89 488.983kg13.6 1129.1 Lime 367.0kg 1.31 478.9 367 kg 1.3 476.7 Seeds a 2000.0 kg 252.2 21000 kg 5.3 865.7 Herbicides 3.20 kg 451.66 1445.3 5 kg 418.2 2091.0 Insecticides 0.24 kg 363.83 87.3 2 kg 418.2 836.4 Transport of consumables b 820.0 kg 276.8 650 kg 3.5 2258.3 Cane transport c 76,7L15.37 2058.0 77 Mg 499.8 32977.4 Total field operations 12709.7 49174.2 13 Bio-Ethanol Production in Brazil 343 Table 13.8 (continued) This study Pimentel and Patzek (2007) Input Quantity unit MJ/unit MJ/ha/yr Quantity unit MJ/unit MJ/ha/yr Factory inputs Chemicals used in factory d 487.6 Water L 0.0 115500 L 0.0 2070.1 Cement 11.5kg 6.675.9 44 kg 200.7 8832.4 Mild steel 51.2kg 30.0 1535.322kg 96.2 2116.1 Stainless steel 4.0kg 71.8 287.1 16.5 kg 230.0 3795.2 95% ethanol to 99.5% 225.3 188.2 Sewage effluent 0 0.0 110 kg BOD 14.4 1587.1 Total Factory inputs 2611.3 18589.1 Distribution 3411.9 Total all fossil energy inputs 15320.8 71175.2 Output Sugarcane yield 76.7 Mg/ha 77.0 Mg/ha Total ethanol yield 6281.0L/ha 21.45 134750.4 5499 21.45 117973.7 Final Energy Balance 8.8 Final Energy Balance 1,66 For footnotes see Table 13.4. 344 R.M. Boddey et al. There is a huge disparity in the estimates of the energy attributed to transport of consumables (fertilisers and chemicals for the factory) and of hauling cane from the field to the mill, the estimates of Pimentel and Patzek (2007) being respectively 10 and 33 times higher than ours. The consumption of diesel oil estimated by these authors seems totally unrealistic in that if a truck and trailer can carry 34 Mg of cane for a 16 km round trip (their value) then the consumption of diesel at 47.7 MJ L −1 would be 21.6 L km −1 . The other large difference is in the specific constants used for the cement and steel used in the construction of the factory, which are, respectively, 30.4 and 3 times greater than those used in our study and justified in Sections 13.1.3.6 and 13.1.3.4. The energy balance computed by de Oliveira et al. (2005) of 3.7 is also consider- ably lower than that computed in this present study or Macedo (1998) and Macedo et al. (2003), and again the large difference comes in the utilisation of diesel fuel in the field operations and cane transport. These authors cite a report from the Uni- versity of Campinas (Unicamp, Campinas, S ˜ ao Paulo State) for a value of 600 L of diesel fuel consumed per ha per year compared to a total of 71.2 L ha −1 yr −1 (43.1 L for cane transport, 22.3 L for field operations and 5.8 L for transport of consumables to the plantation/mill) in our study. Substituting our value for diesel consumption in the energy balance of de Oliveira et al. (2005) becomes 7.0. 13.3.2 Greenhouse Gas Emissions For the ethanol production, fossil fuel is used directly and indirectly for construction of the infrastructure of machinery and consumables together with other chemical and biological processes which are used in sugarcane production. The use of these fossil fuels results in the generation of greenhouse gases (GHGs). The energy data and amounts of material for factories, consumables, machinery, fuels and labour involved in the ethanol life cycle (Table 13.4) were used to estimate GHGs emis- sions based on emission factors for each component. A summary of the results is displayed in Table 13.9. Inputs for agricultural operations are calculated from energy in labour, herbi- cides, insecticides and seeds which come from many different sources and they were assumed to be best represented by crude oil. From IPCC (1996) 1 GJ of crude oil emits 73.3 kg CO 2 , 0.003 kg CH 4 and 0.0006 kg N 2 O. Estimates from machinery were based on the energy contained in the steel, which was assumed to come from steel factories fuelled by coking coal (1 GJ is equivalent to 94.6 kg CO 2 , 0.001 kg CH 4 and 0.0015 kg N 2 O). Diesel oil was the energy source for transport of consumables and cane to the factory, fuel for machines and irrigation, which meant each GJ employed emitted 74.1 kg CO 2 , 0.003 kg CH 4 and 0.0006 kg N 2 O (IPCC, 2006). Fertilisers and lime complete the components of sugarcane produc- tion. In the absence of information regarding the type of lime used in sugarcane areas (proportions of calcitic and dolomitic) emissions of CO 2 from lime addition were estimated by the amount of lime multiplied by the emission factor of 0.75, proposed 13 Bio-Ethanol Production in Brazil 345 Table 13.9 Emissions and avoided emissions of greenhouse gases (CO 2 ,N 2 OandCH 4 ) during ethanol production phases Ethanol production phase Greenhouse gases emitted (per ha) CH 4 N 2 OCO 2 CO 2 eq a gofCH 4 or N 2 Oha −1 yr −1 kg ha −1 yr −1 Sugarcane planting b + 8.9 + 1.8 + 718.0 + 718.7 Crop management c + 2.7 + 1,570.5 + 86.9 + 573.8 Harvesting d + 28007.1 + 381.9 + 253.8 + 960.2 Ethanol production e – – + 107.6 + 107.6 Total fossil GG emission + 2,360.3 Ethanol consumption f –– −9580.6 −9580.6 Net greenhouse gas emissions −7220.3 a Each mol of N 2 OandCH 4 is considered equivalent to 310 and 21 mol CO 2 , respectively (IPCC, 2006). Positive values refer to emissions, and avoided emissions when negative. b Machinery and diesel (50% of total), transportation, labour (20% total), herbicide, soil liming, fertiliser addition and planting operation. c Machinery and diesel (10% of total), labour (20% total), insecticides, irrigation and soil emis- sions. d Machinery and diesel (40% of total) , labour (60% total), emissions from residues after burning to harvest 80% of the area, and transportation. e Ethanol installations and processing. f Assuming ethanol (52% C) is fully burned. by the IPCC (2006), tier 1. For fertiliser emissions, urea, triple superphosphate and potassium chloride were considered to best represent the NPK formulation used in sugarcane areas. The contribution of each source was estimated by the emission factors proposed by Kongshaug (1998). Assuming the average for this technology in Europe, the production of 1 kg of urea, 1 kg of triple superphosphate and 1 kg of potassium chloride represent 0.61, 0.17 and 0.34 kg CO 2 emitted to the atmosphere, respectively. After N fertiliser placement (56.7 kg N ha −1 ) and vinasse application (23kgNha −1 ), it was assumed no NH + 4 volatilisation occurs, so the total N added was substrate for nitrification and denitrification processes for N 2 O emissions. No significant CH 4 production was considered to occur in the sugarcane areas during cropping phase (Macedo, 1998). The harvested area after burning was assumed to be 80% of the whole cropped area. In this case, fractions of 0.005 of total C (5.25Mgha −1 ) and 0.007 of total N (30 kg N ha −1 ) in burned trash were considered to evolve as CH 4 and N 2 O, respectively (IPCC, 2006). For the remaining 20% in unburned areas, the 30 kg N ha −1 were considered to be in harvest residues left to decompose in the field which meant a fraction of 0.0125 of this N was emitted as N 2 O. For factory construction and function the emissions coming from cement, steel and chemicals were accounted for, all based on emission factors from the IPCC guidelines (IPCC, 1996). For cement a factor of 0.95 was applied to calculate clinker content from the total cement used. According to Tier 1 this carries an emission 346 R.M. Boddey et al. Appendix 13.1 Calculation of fossil energy inputs to agricultural machinery. Data on a per ha per year basis Equipment Mass of equipment a Proportion of steel Total Steel Total Tyres Energy ha −1 Steel b,c Tyres d All Fabrication e Maintenance f Total g per year h kg ha −1 kg ha −1 MJ ha −1 Tractors 41.80.82 34.37.48 1029.5 641.2 1670.8 501.4 496.2 2489 497.8 Implements 12.41.00 12.4 0 472.40.0 472.4 106.9 146.0 680 85.0 Trucks 82.40.94 77.54.94 2951.1 1412.5 4363.6 1131.6 881.4 6014 1202.9 136.6 1785.6 a Mass of equipment per ha adapted from Macedo et al. (2003). b Energy intensity of steel in tractors rated at 30 MJ kg −1 (See Section 13.3.1.4). c Steel in Implements (ploughs etc.) and trucks rated at 1.27 × 30 MJ (Factor from Pimentel, 1980) = 38.1 MJ kg −1 d Tyres rated at 85,7 MJ kg −1 (Macedo et al., 2003). e Fabrication energy = 14.61, 8,62 and 14.61 MJ kg steel for Tractors, Implements and Trucks, respectively. f Maintenance energy cost over working life = 0.297, 0.309 and 0.202 kg total mass for tractors, implements and trucks respectively. g Total adjusted to “reliable life” (TARL) according to Pimentel (1980) is 0.82 × (total embodied + fabrication energy). Hence this Total energy = TARL energy + Maintenance energy. h Working life of Tractors, implement and trucks were rated as 5, 8 and 5 years, respectively. 13 Bio-Ethanol Production in Brazil 347 factor of 0.507, with a 2% correction for cement kiln dust, and this was used to calculate the CO 2 emission. In the case of structural and mild steel, emissions of CO 2 were calculated on the basis of the global average emission factor for iron and steel production (1.06 kg CO 2 kg −1 steel produced). For stainless steel, the emission factor for ferrochromium of 1.6 kg CO 2 kg −1 steel produced was used (IPCC, 2006). Energy in the production agro–chemicals was considered to be from crude oil for which the emission factors for CO 2 ,N 2 O and CH 4 were mentioned above. To explain the impact of ethanol from sugarcane produced under Brazilian condi- tions the agricultural activities were broken down into three different phases: plant- ing, crop management and harvesting, the latter including transportation of cane to mill. The factory phase was also included to close the cycle (Table 13.9). Emissions of CO 2 predominated at planting and were explained by the fossil fuel energy used in consumables, machinery and transportation of consumables. During plant development N 2 O production was derived from fertiliser and vinasse N and nitrification/denitrification gained importance and represented a large share (85%) of the emissions expressed as equivalents of CO 2 . Again, the trace gases CH 4 and N 2 O represented most of the emissions at harvest, the former was emitted mostly from burning trash at harvest and the latter, partially from burning, but also from decomposition of N in residues in unburned areas (20% of all Brazilian cane). The most important greenhouse gas (GG) emissions are incurred during pre-harvest burning, and amount to 82 kg and 588 kg ha −1 yr −1 of CO 2 equivalents, as N 2 O and CH 4 , respectively, 34% of all GG emissions. The conversion from manual harvesting of burned cane to machine harvesting of green cane would eliminate these emissions as well as approximately 70% of the yearly manual labour input (0.7 × 1004 MJ ha −1 or 52 kg CO 2 equivalents ha −1 ). However, the decomposing trash emits 183 kg CO 2 equivalents ha −1 yr −1 as N 2 O from the 30 kg N left in the cane trash. Furthermore, the harvester (70 Mg of cane harvested per h, machine weight 19 Mg) consumes 40 L of diesel per h (data from Sr. Aureo Tasch, John Deere S.A., Catal ˜ ao, Goi ´ as) giving a fossil energy input of 2089 MJ ha −1 yr −1 (155 kg CO 2 equivalents ha −1 yr −1 ). Embodied energy in the machine (effectively 100% steel, 5.5 kg ha −1 yr −1 ) is equivalent to 54.2 MJ (5.1 kg CO 2 equivalents ha −1 yr −1 ). In summary, under manual harvesting annual GG emis- sions amount to 722 kg CO 2 equivalents ha −1 and this falls to 343 kg CO 2 equiva- lents ha −1 if the cane is harvested green with machine harvesting. It is also reported that full ground cover with trash during the year reduces the requirement of her- bicide by at least 50% (Ant ˆ onio Gondim, Usina Cruangi, Timba ´ uba, Pernambuco; pers. comm.) equivalent to 60 kg CO 2 equivalents ha −1 yr −1 . Emissions derived from the factory infrastructure and chemicals for ethanol pro- duction from milled cane accounted for less than 5% of the emissions calculated for the whole cycle. Summing up: all emissions in terms of CO 2 equivalents amount to approximately 2.36 Mg CO 2 ha −1 yr −1 , close to one fourth of the total emissions avoided whether burning ethanol as a fuel (9.58 Mg CO 2 ha −1 yr −1 ), assuming 100% is converted to CO 2 . 348 R.M. Boddey et al. 13.3.3 Local and Regional Impacts 13.3.3.1 Atmospheric Pollution Harvesting of cane occurs mainly in the dry season. The pre-harvest burning of the cane facilitates the manual harvest and diminishes the risks of injury to workers from snakes and poisonous spiders. The burning releases inhalable particles with a great number of components, most of all are carbon-rich alumino-silicate based, causing a typical overcast fog-like atmosphere, widespread in the cane districts in this season. However, the occurrence, composition and persistence of the smoke is highly depen- dent on specific weather conditions and this coincides with admission to hospitals of children and elderly people with respiratory problems (Godoi et al., 2004; Arbex et al., 2007). Some studies state that this effect is regarded as similar to what could be observed in urban areas exposed to industrial and automotive pollution, but also acknowledge that the ethanol addition to gasoline has contributed to decreasing air pollution, at least in the last twenty years, in the urban centres (Canc¸ado et al., 2006). As mentioned before (Section 13.2.6) biggest cane producer, S ˜ ao Paulo State has passed a law to regulate cane burning since 2003. The law defines what areas are able to use mechanical harvesting due to field slope, and sets a timetable. All the plantations under 12% of inclination should be totally mechanised by 2022. Cane burning in the other areas should be eliminated by 2032, when all areas ought to be harvested without burning. 13.3.3.2 Water Pollution In the early years most distillery waste was disposed of without treatment into local rivers. As the waste usually contains approximately 1% soluble C and high levels of K, S and N and some P, the results were disastrous. Many rivers became eutrophic, there was massive death of fish and all other aquatic organisms, and the stench of this disposed waste could be scented many kilometres before arriving at a distillery. At first the factory owners were loath to return these wastes to the field as there was often an initial wilting of the cane leaves and signs of damage to the plants (Boddey, 1993). However, it was shown in many experiments that the plants soon recovered and benefited from the extra nutrients, and pumping the waste out onto the fields diluted with other wash water from the mills (which also had significant BOD), was a cheaper source of nutrients than synthetic fertilisers. Today almost all vinhac¸a is disposed of by pumping onto the fields, and where State and/or Municipal governments have effective environmental protection agen- cies, significant water pollution is a thing of the past. 13.3.3.3 Soil Erosion Several authors have stated that soil erosion in sugarcane fields is major problem. Pimentel and Patzek (2007) write “Sugarcane production causes more intense soil erosion than any crop produced in Brazil because the total sugarcane biomass is [...]... Phosphorus Potassium Lime Sulfur Sets Herbicides Insecticides Transportation 128 ha 156 kga 22 .3 La 58 .3 kgb 16 kgb 83 kgb 367 kga 2 kgf 21 ,000 kgh 5 kgi 2 kgf 650 kgj 157 a 638a 25 4a 933c 60d 27 0e 114a 53 g 20 7h 50 0c 20 0c 54 0k TOTAL Sugarcane yield Sugar yield 3, 926 77,000 kg/hal 5, 789 kg/hal 94,000,000 kcal input:output 1 :23 .94 a Macedo et al., 20 04 Boddey, 19 95 c Pimentel and Patzek, 20 05 d Input 3,7 62 kcal/kg... 444k 603m 96o 53 p 20 7r 58 0s 25 0s 59 3t 52 0 .00c 26 4.44f 860.00h 107.80j 73.16l 57 .35n 4.74o 27 .00h 23 0.00h 116.00h 50 .00h 21 3.80h 13,4 02 $2, 52 4 .29 107,000,000 kcal input:output 1:7.98 TOTAL Sugarcane yield Sugar a 88,000 kg/haa 6,600 kg/haa Breaux and Salassi, 20 03 It is assumed that a person works 2, 000 h per year and utilizes an average of 8,000 L of oil equivalents per year c It is assumed that labor... of Brazilian gasohol Based on data presented in Table 13.9, the 10 L of ethanol would emit ( 95% of 3.76 kg of fossil CO2 ) 3 .57 kg of fossil CO2 The same distance covered with gasohol would mean an emission of 13. 45 kg CO2 (1.87 kg CO2 L−1 in the mixture gasoline:alcohol (23 %) (3 .57 kg CO2 L alcohol (our data) and 2. 32 kg CO2 L gasoline – IPCC, 20 06), even without considering the fossil energy expended... Agriculture and Life Sciences, Cornell University, 5 126 Comstock Hall, Ithaca, NY 158 50, e-mail: Dp18@cornell.edu T.W Patzek Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94 720 , 4 25 David Hall, MC1716, e-mail: patzek@patzek.ce.berkeley.edu D Pimentel (ed.), Biofuels, Solar and Wind as Renewable Energy Systems, C Springer Science+Business Media B.V 20 08 357 358 D... al., 20 04 g Estimated h Newton, 20 01 i Illinois Corn, 20 04 j Bagasse was used as a substitute fuel to generate steam and also as the fuel to generate electricity The bagasse with 45 55 % moisture has an energy value of about 1,900 kcal/kg (Liu and Helyar, 20 03) k 95% ethanol converted to 99 .5% ethanol for the addition to gasoline (T Patzek, personal communication, University of California, Berkeley, 20 04)... juice f Pimentel et al., 20 04 g Estimated h Newton, 20 01 i Illinois Corn, 20 04 j Bagasse was used as a substitute fuel to generate steam and also as the fuel to generate electricity The bagasse with 45% to 55 % moisture has an energy value of about 1,900 kcal/kg (Liu and Helyar, 20 03) k Although there was charge for the fuel, the manipulations of using the fuel to generate steam and produce electricity... kgb 12, 000 kgc 21 ,000 Le 3 kgg 4 kgg 8 kgg 2, 54 6,000 kcali 3 92 kWhi 9 kcal/Lk 20 kg BODl 331 kcal/Ln 612b 490d 90f 165h 92h 384h 0j 0j 9k 69m 331 TOTAL 2, 2 42 26 c/litero a Output: 1 L of ethanol = 5, 130 kcal Data from Table 14 .2 c Calculated for 16 km roundtrip d R.M Boddey, Senior Scientist, Empresa Brasileira de Pesquisa Agropecuaria (Embrapa), Brasil, personal communication, 20 07 e 1 .5 L of water... Distribution 12, 000 kgb 12, 000 kgc 21 ,000 Le 3 kgg 4 kgg 8 kgg 2, 54 6,000 kcali 3 92 kWhi 9 kcal/Ll 20 kg BODm 331 kcal/Lo 1, 828 b 490c 90f 165h 92h 384h 0j 0j 9l 69n 331 363.95b 80.00d 19.04f 10.60d 10.60d 10.60d 21 .00k 27 .44k 0.60 6.00 20 .00o 3, 458 $56 9.83 TOTAL a Output: 1 L of ethanol = 5, 130 kcal Data from Table 14.1 c Calculated for 16 km roundtrip d Pimentel, 20 03 e 1 .5 L of water mixed with each... Agriculture, Ecosystems and Environment, 32, 25 7 27 2 Globo Rural (20 07) Television Program Rede Globo, 26 , August, 20 07 Full text retreived 27 , August, 20 07 http://globoruraltv.globo.com/GRural/0 ,27 0 62, LTO0-4370 -29 8116-1,00.html Godoi, R H M., Godoi, A F L., Worobiec, A., Andrade, S J., de Hoog, J., Santiago-Silva, M R., & Van Grieken, R (20 04) Characterisation of Sugar Cane Combustion Particles in the Araraquara... 14 .2) 14 Ethanol Production 359 Table 14.1 Energy inputs and costs of sugarcane production per hectare in Louisiana Inputs Quantity kcal × 1000 Costs $ Labor Machinery Diesel Nitrogen Phosphorus Potassium Lime Sulfur Sets Herbicides Insecticides Transportation 40 ha 70 kgd 430 La 196 kga 118 kga 1 85 kga 23 7 kga 27 kga 12, 000 kgq 5. 8 kga 2. 5 kga 7 15 kgt 1, 621 b 917e 4,902g 3,136i 444k 603m 96o 53 p 20 7r . 476.7 Seeds a 20 00.0 kg 25 2 .2 21000 kg 5. 3 8 65. 7 Herbicides 3 .20 kg 451 .66 14 45. 3 5 kg 418 .2 2091.0 Insecticides 0 .24 kg 363.83 87.3 2 kg 418 .2 836.4 Transport of consumables b 820 .0 kg 27 6.8 650 kg 3 .5 22 58 .3 Cane. 11.49 75. 9 Mild steel (structural) 28 73 25 57 46.0 61 05. 1 24 420 5 28 .06 841.8 Mild steel in light equipment 1437 10 20 11.8 21 91.4 20 1180 23 . 12 693 .5 Stainless steel 410 25 820 .0 871.3 34 850 4.00 28 7.1 1898.3 Basic. 20 0.7 88 32. 4 Mild steel 51 .2kg 30.0 153 5. 322 kg 96 .2 2116.1 Stainless steel 4.0kg 71.8 28 7.1 16 .5 kg 23 0.0 37 95 .2 95% ethanol to 99 .5% 22 5. 3 188 .2 Sewage effluent 0 0.0 110 kg BOD 14.4 158 7.1 Total