2003 Fiscal Year Final Research Report Summary
ZERO FORMATION OF DIOXINS AND SUPPRESSION OF DE NOVE SYNTHESIS
| Project/Area Number |
14205110
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Metal making engineering
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| Research Institution | OSAKA UNIVERSITY |
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Principal Investigator |
USUI Tateo OSAKA UNIVERSITY, GRADUATE SCHOOL OF ENGINEERING, PROFESSOR, 大学院・工学研究科, 教授 (90029348)
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| Co-Investigator(Kenkyū-buntansha) |
ONO-NAKAZATO Hideki OSAKA UNIVERSITY, GRADUATE SCHOOL OF ENGINEERING, ASSOCIATE PROFESSOR, 大学院・工学研究科, 講師 (30283716)
TANAKA Tishihiro OSAKA UNIVERSITY, GRADUATE SCHOOL OF ENGINEERING, PROFESSOR, 大学院・工学研究科, 教授 (10179773)
HARA Shigeta OSAKA UNIVERSITY, GRADUATE SCHOOL OF ENGINEERING, PROFESSOR, 大学院・工学研究科, 教授 (90029116)
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| Project Period (FY) |
2002 – 2003
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| Keywords | CaO chips / dechlorination / dioxins / furans (Dioxins) / Electromagnetic wave / fly carbonaceous matters / high CO / CO_2 ratio / zero formation of Dioxins |
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| Research Abstract |
From our fundamental studies on combustion experiments and thermodynamic evaluations, it is clarified that dioxins/furans (Dioxins) are mainly formed at the thermodynamically heterogeneous site with high CO/CO_2 ratio, which is the boundary layer on the surface of the fly carbonaceous (C^*) matters remaining in combustion gas. Therefore, it is considered that Dioxins are hardly formed by the decomposition or the disappearance of the fly C^* matters and by the dechlorination from the fly C^* matters. The present study has investigated whether zero formation of Dioxins was achieved or not by the dechlorination from the fly C^* matters with CaO, and by the dispersion of the boundary layer with high CO/CO_2 ratio around the fly C^* matters through an irradiation of electromagnetic wave with high energy density to combustion gas.
Electromagnetic wave was irradiated to an exhaust gas of PVC combustion, in which Dioxins concentration was 85 ng-TEQ/m^3 (s.t.p.). The irradiation conditions were the power of 1.8 kW, the frequency of 915 MHz, the irradiation time of 6 s, and the temperature of 423 K. Dioxins concentration after the irradiation of electromagnetic wave decreased to be 2.4 ng-TEQ/m3 (s.t.p.), the decomposition rate of about 97 %. It is regarded that a lot of Dioxins is decomposed by the dispersion of the boundary layer around the fly C^* matters, where Dioxins are formed, and by the decomposition or the burning out of the fly C^* matters with heating up. Decomposition rate of Dioxins are expected to improve more at higher temperature zone.
By setting CaO chips bed in the high temperature zone, Dioxins extremely decreased from 1 ng-TEQ/m^3 (s.t.p.) to 0.007 ng-TEQ/m^3 (s.t.p.) because chlorine in and around the fly C* matters was dechlorinated to thermodynamically stable CaCl2. The dechlorination at the high temperature zone is very effective for zero formation of Dioxins.
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Research Products
(6 results)
