Studies2

Research

Studies2

Recycling Municipal Solid Waste Incineration Residues as Secondary Cement Resources, and Its Application to Asian Regions

fig

Characterization of municipal solid
waste incineration residues
(SEM and microscope images)


fig

Semi-plant scale lysimeters for
chlorine removal experiments
in Japan and China


fig

Chlorine removal of municipal
solid waste incineration bottom
ash using an organic
dechlorination promoter

ABSTRACT:
Fully 78% of municipal solid waste is combusted, and incinerated residues (MSWIR) are deposited in landfills in Japan. The limited disposal capacity of landfill sites means that recycling of MSWIR is urgently needed. The elemental composition of MSWIR is similar to that of cement clinker, and this has spurred the effort to recycle MSWIR for application as a secondary cement resource. In this study, the efficient removal of harmful or unnecessary elements, toxic heavy metals and especially chlorine from MSWIR has been investigated with consideration given to chemical, mineralogical and biological characteristics and reactions. Applications of this innovative technology in Asia, where waste management problems are emerging and cement production is growing, are also studied.

DETAILED:
Fully 78% of municipal solid waste is combusted, and incinerated residues (MSWIR) are deposited in landfills in Japan. The limited disposal capacity of landfill sites means that recycling of MSWIR is urgently needed. The elemental composition of MSWIR is similar to that of cement clinker, and this has spurred the effort to recycle MSWIR for application as a secondary cement resource, which is a promising technology that may contribute to the reduction of both waste disposal and natural resource consumption for cement manufacturing. In this study, the low-cost, environmentally friendly and efficient removal of harmful or unnecessary elements, toxic heavy metals and especially chlorine from MSWIR have been investigated. Chlorine conversion and leaching were studied based on mineralogical conversions or deformation, and on chemical interactions between chlorine types and other soluble compounds. A low-cost dechlorination promoter was also developed by focusing on biological reactions and the effect of their intermediates on dechlorination. An innovative dechlorination system using a landfill site as a huge chlorine removal reactor, called a recyclable landfill system, has been suggested, and semi-plant scale lysimeters have been constructed to monitor dechlorination efficiency, investigate dechlorination mechanisms, and evaluate the feasibility of this technology.

Waste management is emerging as a pressing social issue, as is the increasing consumption of natural resources for cement production in growing Asian nations. Because this technology can contribute to overcoming both problems at the same time, applications within the Asian region are also being studied. As a first step, semi-plant scale lysimeters have been constructed in Shanghai, China to study technical feasibility.

Laboratory of Environmental Systems Analysis and Control Engineering,
Department of Urban and Environmental Engineering, Faculty of Engineering, Kyushu University
Professor Takayuki Shimaoka
Associate Professor Hirofumi Nakayama
Assistant Professor Teppei Komiya
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