1998 Fiscal Year Final Research Report Summary
Efficient treatment and energy recovery for supercritical water oxidation of wastes
| Project/Area Number |
09450294
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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 |
反応・分離工学
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| Research Institution | Kumamoto University |
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Principal Investigator |
GOTO Motonobu Kumamoto University, Dept of Applied Chemistry and Biochemistry, Associate Professor, 工学部, 助教授 (80170471)
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| Co-Investigator(Kenkyū-buntansha) |
HIROSE Tsutomu Kumamoto University, Dept of Applied Chemistry and Biochemistry, Professor, 工学部, 教授 (40037841)
KODAMA Akio Kumamoto University, Dept of Applied Chemistry and Biochemistry, Assistant Profe, 工学部, 助手 (30274690)
GOTO Motonobu Kumamoto University, Dept of Applied Chemistry and Biochemistry, Associate Profe (80170471)
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| Project Period (FY) |
1997 – 1998
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| Keywords | Supercritical water oxidation / Wastes treatment / Sewage sludge / Distillery wastewater / Kinetic analysis / Activation energy / Catalyst |
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| Research Abstract |
Supercritical water oxidation has been focused as an environmentally attractive technology where organic materials are oxidized to carbon dioxide, water, and N_2. We have applied the supercritical water oxidation to municipal excess sludge and alcohol distillery wastewater of molasses. The reaction was carried out in a batch reactor or a flow reactor with hydrogen peroxide as an oxidant in the temperature range of 473K-873K.The liquid phase products were colorless and odorless. The reaction products were analyzed in terms of total organic carbon (TOG), organic acids, and ammonium ion. TOG decreased with temperature and the oxidant amount. Acetic acid and ammonia were detected as major refractory intermediates in the product. When more than stoichiometric demand of oxidant was used, organic carbon in liquid phase was almost completely destroyed. Complete destruction of ammonia produced in the reaction required higher temperature than that of acetic acid. A tube-type flow reactor (1/8 inch-l.7 m) was constructed for the continuous treatment of wastes. The sludge was efficiently destructed by the flow reactor. Total organic carbon was measured as a function of reaction time. The kinetic data were analyzed by a single first order reaction model and two generalized models including refractory intermediate such as acetic acid. The rate constant in first order reaction model coincides with those reported in literature. The reaction rate constant for the decomposition of refractory intermediate in the generalized model was comparable to decomposition rate of acetic acid.
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