2004 Fiscal Year Final Research Report Summary
Saccharification of plant biomass by pyrolytic molecular distillation
| Project/Area Number |
15310046
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Environmental technology/Environmental materials
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| Research Institution | THE UNIVERSITY OF TOKYO |
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Principal Investigator |
KUGA Shigenori The University of Tokyo, Graduate School of Agricultural and Life Sciences, Professor, 大学院・農学生命科学研究科, 教授 (60012051)
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| Co-Investigator(Kenkyū-buntansha) |
WADA Masahisa The University of Tokyo, Graduate School of Agricultural and Life Sciences, Associate Professor, 大学院・農学生命科学研究科, 助教授 (40270897)
HATTORI Nobuaki Tokyo University of Agriculture and Technology, Dept. of Agriculture, Professor, 農学部, 教授 (90115915)
ANDO Keisuke Tokyo University of Agriculture and Technology, Dept. of Agriculture, Assistant, 農学部, 助手 (70262227)
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| Project Period (FY) |
2003 – 2004
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| Keywords | cellulose / pyrolysis / levoglucosan / anhydrosugar / laser / biomass / caffine / extraction |
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| Research Abstract |
For improving anhydrosugar (levoglucosan, LG) yield from thermal decomposition of cellulose, laser pyrolysis which can heat the material from its open surface. Minimum laser irradiation condition for causing fast pyrolysis was determined as : 75〜100W, pulse length more than 14 ms ; 150〜250W, pulse length more than 8 ms. Pyrolysis under vacuum caused significant generation of aerosol (white smoke), which remained for a long time and obstructed efficient recovery by trap. Flushing by atmospheric inert gases was effective in expelling the aerosol into cotton trap at exit. Maximum LG yield by this method was 20〜25%, max. 35%. Batch-type vacuum pyrolysis in glass bottle for comparison gave LG yield of 35〜56%. This variation was caused by the method of cold trapping, and close placing of trap to the heated area was found very important. Based on this finding, a novel pyrolyzer was designed and tested extensively. The apparatus consisted of a pair of metal belt conveyers, arranged parallel and facing with each other. The lower belt was heated to pyrolysis temperature from beneath, and the upper belt was cooled from above. The LG yield by this apparatus strongly depended on the vacuum level, and the low level of residual air was advantageous for higher yields. Optimal pressure was approx. 5 KPa, which gave maximum yield of 70% from pure cellulose and 50% from corn starch. The value for cellulose significantly exceeded the highest reported value of 55%. Since this pyrolyzer can operate continuously, it can be used for industrial production of LG from cellulose. As a side application of this pyrolyzer, thermal extraction of caffeine from coffee and green tea was attempted. The results showed high efficiency, i.e. approx. 80〜90% of caffeine was recovered from ground materials at 350℃ treatment. These results showed advantages of the novel pyrolyzer in extracting useful components from biomass materials.
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