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Research paper : Bioethanol production from woods with the aid of nanotechnology (T. Endo)−280−Synthesiology - English edition Vol.2 No.4 (2010) E. Farrell, R. J. Plevin, B. T. Turner, A. D. Jones, M. O'Hare and D. M. Kammen: Ethanol can contribute to energy and environmental goals, Science, 311, 506-508 (2006).J. F. Saeman: Kinetics of wood saccharification - Hydrolysis of cellulose and decomposition of sugars in dilute acid at high temperature, Ind. Eng. Chem. Res., 37, 43-52 (1945).K. Shimizu: Serurosu kei busshitsu no koso kasui bunkai (Enzymatic hydrolysis of cellulose substance), Kinosei Serurosu (Functional Cellulose), 195-229, CMC Publishing, Tokyo, (1985) (in Japanese).T. Endo: Mechano-chemical preparation of novel cellulose composite, Cellu. Commun. (Journal of the Cellulose Society of Japan), 7 (2), 63-66 (2000) (in Japanese).T. Endo, F. R. Zhang and Y. Shinohara: Cellulose as molding material, Cellu. Commun. (Journal of the Cellulose Society of Japan), 9 (2), 86-92 (2002) (in Japanese).T. Endo and M. Ago: Mechano-chemical modification of cellulose structure, Cellu. Commun. (Journal of the Cellulose Society of Japan), 11 (2), 74-78 (2004) (in Japanese).T. Endo and A. Isogai, eds: Bifunsaika serurosu to purasuchikku no fukugoka (Compositing of finely milled cellulose and plastic), Serurose Riyo Gijutsu No Saisentan (Advanced Technologies of Cellulose Utilization), 298-309, CMC Publishing, Tokyo, (2008) (in Japanese).R. Tanaka, F. Yaku, E. Murai and T. Koshijima: Enzymatic degradation on finely divided wood meal of Pinus densiflora, Cell. Chem. Technol., 14, 859-868 (1980).T. Endo, R. Kitagawa and J. Hosokawa: Kikaiteki funsai niyoru serurosu sen’i no biryushi keisei kyodo (Fine particle formation behavior of cellulose fibers by mechanical milling), Kobunshi Ronbunshu (Japanese Journal of Polymer Science and Technology), 56 (3), 166-173 (1999) (in Japanese).S. Fujimoto, H. Inoue, S. Yano, T. Sakaki, T. Minowa, T. Endo, S. Sawayama and K. Sakanishi: Bioethanol production from lignocellulosic biomass requiring no sulfuric acid: mechanochemical pretreatment and enzymic saccharification, Sekiyu Gakkaishi (Journal of the Japan Petroleum Institute), 51 (5), 264-273 (2008) (in Japanese).D. Ishii, D. Tatsumi and T. Matsumoto: Effect of solvent exchange on the solid structure and dissolution behavior of cellulose, Biomacromol., 4, 1238-1243 (2003).M. Ago, T. Endo and T. Hirotsu: Crystalline transformation of native cellulose from cellulose I to cellulose II polymorph by a ball-milling method with a specific amount of water, Cellulose, 11 (2), 163-167 (2004).H. Ando, T. Sasaki, T. Kokusho, M. Shibata, Y. Uemura and Y. Hatate: Decomposition behavior of plant biomass in hot-compressed water, Ind. Eng. Chem. Res., 39 (10), 3688-3693 (2000).H. Inoue, S. Yano, T. Endo, T. Sakaki and S. Sawayama: Combining hot-compressed water and ball milling pretreatments to improve the efficiency of the enzymatic hydrolysis of eucalyptus, Biotechnol. Biofuels 1:2 1-9 (2008).H. Yano and A. Isogai eds: Serurose nano faiba fukugo zairyo (Cellulose nanofiber composite material), Serurose Riyo Gijutsu No Saisentan (Advanced Technologies of Cellulose Utilization), 258-269, CMC Publishing, Tokyo, (2008) (in Japanese).[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]AuthorTakashi EndoCompleted the doctorate course at the Department of Chemistry, Graduate School of Science, Hiroshima University in 1992. Doctor (Science). Joined the Shikoku National Industrial Research Institute, Agency of Industrial Science and Technology in April 1992. Engaged in research for the pulverization of cellulose and wood using the milling technology and high added-value technology. Worked mainly in the field of materials to 2003. After transferring to the current institute in 2004, has conducted R&D for bioethanol. Leader of the research team of the Biomass Technology Research Center from 2006 to present. This paper is a summary of part of the research results for cellulose milling that has been the subject of study since joining the institute.Discussion with Reviewers1 Advantages compared to conventional treatment methods (cooking, steam explosion, and hydrothermal methods)Question (Koichi Mizuno, Research Institute for Environmental Management Technology, AIST)In the conversion process from wood to ethanol when limited to enzymatic saccharification, Fig. 2 shows the comparison of the developed method combining the wet cutter mill, autoclave, and wet disk mill treatments to other conventional methods (cooking, steam explosion, and hydrothermal treatments). Please indicate quantitatively or qualitatively how much the advantages and strengths have been progressed and to what degree the disadvantages and problematic issues have been overcome.Answer (Takashi Endo)The advantage of the combination treatment we developed is that a pretreated product with high degree of saccharification can be obtained with low environmental load and with no dependency on wood species. Compared to ball milling, the conventional technology, the consumption energy is 1:10~20 or less. Also, in our pretreatment method, saccharification occurs with a small amount of enzymes, so the cost of enzymes can be reduced. Woods with high moisture content immediately after lumbering can be used as raw materials. Since there is no use of chemicals in large amounts, I think there is high potential for commercial bioethanol production at the site of raw material harvesting in the future (such as in Southeast Asia). At the Biomass Technology Research Center where I work, there is a research team that specializes in assessing economic feasibility. We conducted some economic projections at large-scale commercial levels (raw material 1500 ton/day) using the data for pretreatment and saccharification-fermentation processes that we actually conducted in the lab. As a result, there was the possibility for decreasing the cost of bioethanol final product to a level lower than the NEDO’s concentrated sulfuric acid method that was considered to have the lowest cost (sufficiently accurate data for economic feasibility are not disclosed for other methods). Since the combination treatment is a multi-step treatment, the cost of the facilities may be higher, but the facility depreciation can be actually the same as the concentrated sulfuric acid method. For example, there is a hydrothermal process in our pretreatment, and the temperature needed is about 150 ºC (0.48 MPa) which will not be subject to the strict regulation of the High Pressure Gas Safety References

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