2007 Fiscal Year Final Research Report Summary
Environmental safety on recycling process using pyrolysis gasification and reforming technology
| Project/Area Number |
17360438
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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 |
Recycling engineering
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| Research Institution | National Institute for Environmental Studies |
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Principal Investigator |
KATSUYA Kawamoto National Institute for Environmental Studies, Research Center for Material Cycles and Waste Management, Chief (50257325)
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| Co-Investigator(Kenkyū-buntansha) |
KOBAYASHI Jun National Institute for Environment Studies, Research Center for Material Cycles and Waste Management, Researcher (60314035)
KASAI Eiki Tohoku University, Institute of Multidisciplinary Research for Advanced Materials Research Center for Sustainable Materials Engineering, Professor (50134044)
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| Project Period (FY) |
2005 – 2007
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| Keywords | Pyrolvsis gasification and reforming / Recycling process / Environmental load substances / Environmental safety / Volatile organic comnounds / Polv-aromatic hydrocarbons / Dioxins / Catalyst |
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| Research Abstract |
The aim of this study is to clarify emission characteristics of substances, especially dioxins and poly-aromatic hydrocarbons (PAHs) that may cause negative effects to the environment and gas utilization equipment after the gasification and reforming process currently developing. The experiments employed two kinds of test equipments, which are a small-scale equipment (Process capacity for raw materials: 〜2 kg/h) and a bench-scale equipment (〜15kg/h).
The results showed that dioxins were generated from waste woods, refuse derived fuel made from municipal solid waste and refuse paper and plastic fuel (RPF) even under oxygen deficient conditions. The measured concentrations were in the range of 0.1〜several ng-TEQ/m^3N in gas. The formation occurred at low temperatures around 650 -C and it decreased to low level over 700℃. The result also suggested that the formed dioxins were decomposed during the gasification and reforming processes probably because of the effect of catalyst and of the increase of gas residence time. The concentrations were differed between the kinds of raw material, and the amount of dioxins from woody biomass was smaller than that of from RPF.
PAHs were significantly generated in high concentrations in the range of 1 mg/m^3〜several hundred mg/m^3N. Among those, benzene formed in the concentration range of typically 100〜5000mg/m^3N. Therefore, investigation was concentrated on the development of reduction technology of benzene exhaust. Several catalysts were applied for the reduction of the compound and a nickel catalyst was found to be effective on high benzene conversion to methane at 300℃. The coexistence of moisture and hydrocarbons such as ethylene did not affect on the reaction. The results suggested that an effective gas cleaning technology could be developed by using catalyst process even at low temperatures after the reforming process.
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