18 CCSCarbon Capture and Sequestration 24 Is there
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CCS=Carbon Capture and Sequestration 24
以上の条件から、バイオエネルギーと藻類を考える Is there any roles of Microbiology to contribute to Climate Change? n n How about Bio-Fuel? Because of its “Carbon. Neutral” characteristics. It must be a good idea! We have to consider almost everything including carbon debt, adverse effects on biological diversity, energy balance and so on. It may be dangerous to depend only on ecosystem fully. Because nobody knows what happens if we neglect the fragility of ecosystem! 27
From the view point of Carbon Debt Time of repay biofuel carbon debt (years) Published Online February 7 2008 Science 29 February 2008: Vol. 319 no. 5867 pp. 1235 -1238 http: //www. sciencemag. org/content/319/5867/1235. abstract Recommendation by the J. Fargione(the author): 1. biofuels made from waste biomass 2. or from biomass grown on degraded and abandoned agricultural lands planted with perennials 28
Comparison of Productivities of Bio-diesel Fuel from Several Sources Productivities+ Area Required Mha# Corn 0. 2 1540 Soy 0. 4 594 Jatrofa 1. 9 144 Oil Palm 6. 0 45 136. 9 2 Micro Algae* ? ? ? ? +Productivity: in tons/ha #Area Required: To produce 50% of fuel for transportation in USA *Micro Algae containing oil of 70% in weight Biodiesel from microalgae Yusuf Christi Biotechnology Advances Volume 25, Issue 3, May-June 2007, Pages 294 -306 29
From the view point of cost and productivity n 1. Kind of Water n n n Fresh water = expensive and insufficient(0. 8%) Better to use Marine Water 2. Required Water n n n Corn 1900 m 3 fresh water/ton of fuel Soy 2500 m 3 fresh water/ton of fuel Micro Algae 125 m 3 marine water/ton of fuel Really? ? ? ? But maybe Ok, if use only marine water. 30
Tentative Results obtained so far Can be improved! Open Pond w/ Raceway Type ■Basic Data Biomass Density Oil Content Scale ■Reactor Parameter ・days in year ・number of Reactors ・days for one operation cycle ・cycles per year ■Area used for Reactors Oil Productivity 0. 5 g/L 20% 170 k. L 250 days 35 (80 m x 18 m) 7 days 35 cycles/year 7 ha 3 ton/ha/year Less than the Value Reported =136. 9 ton/ha/year 31
Energy Balance : Most Important Point! Energy Consumed to Move Paddles: 41. 4 MJ Energy Recovered by Algae: 6. 7 MJ Growth: 0. 5 g/L、 Oil Contents: 20% EPR 6. 7 MJ / 41. 4 MJ = 0. 16 EPR=Energy Profit Ratio Shorter Time for Paddling EPR = 0. 16 x 2 = 0. 32 Change Design ( 200 L 300 L) EPR = 0. 32 x 1. 5 = 0. 48 Tentative Conclusion: It is necessary to find new types of Algae with high efficiency! Dr. T. Tanaka (Tokyo University of Agriculture and Technology) will try to enhance the efficiency of oil production by means of genetic modification etc. 32
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