Chemitec Consulting has been working on developing a concept process of clearing old waste open dumpsites/unmanaged landfills by recovering still available value in the waste. The value is recovered in the form of energy recovery (electricity, heat) and construction material recovery for specific/dedicated constructing applications. However, major value of clearing old waste open dumpsites/unmanaged landfills is recovered from the land area cleared from waste material making it available for other valuable uses for the society.
Open old waste dumpsites/unmanaged landfills where municipal solid waste (MSW) has been dumped without any proper pre-treatment for last many years (ten, fifteen, twenty or more) may be considered as potential sources of serious environmental issues such as greenhouse gases (especially CH4) emissions directly into atmosphere, leaking leachate (containing hazardous and toxic elements) into ground water deteriorating quality of drinking water, spreading dust into air and causing bad smell for residents living nearby. Apart from these mentioned issues, there is potential risk of dumpsite/landfill land sliding. Moreover, the old waste dumpsites/unmanaged landfills occupies significant land areas in urban cities which may be used for better purposes to benefit society.
In the mentioned old dumpsites/unmanaged landfills, biofraction (kitchen waste and related), paper and cardboard, natural fibre etc. are most likely completely decomposed within the mentioned time period (ten years or more and even earlier). However, components such as plastic, rubber (synthetic), metal and glass etc. are most likely still remain there in the waste material containing value to be recovered in the form of energy (electricity and heat, for instance), material recycling (metal, glass) and construction material for specific/dedicated construction applications. In the concept process developed at Chemitec, the waste material is excavated/mined from old dumpsites/landfills at first stage, which is then processed in mechanical treatment based waste sorting plant recovering the valuables i.e. combustible (plastic, rubber etc.) containing high calorific value and recyclable (metal, glass etc.). The combustible fraction is transformed (shredded, homogenized) into RDF to be utilized in Waste to Energy plant and recyclable (metals, glass) can be used as recycling material. The rest non-combustible and non-recyclable fraction obtained after sorting process is treated with in post sorting material’s processing section (further sorting if needed, heating, grinding and mixing etc.) which partly can be used as construction material in specific/dedicated construction applications, and partly as reject to be disposed properly in sanitary landfills. The simplified schematic of the concept process developed at Chemitec is shown in the Figure below.
Figure: Simplified schematic of the concept process for clearing old waste open dumpsites/landfills
It depends on the original composition of waste material dumped in dumpsites/landfills, however, the estimated amount of combustible and recyclable maybe in the range of 5 – 15 wt % and that of non-combustible in the range of 85 – 95 wt %. In case, certain amount of energy (electricity, heat) is required to be produced from the process, new waste material (textile waste, commercial and industrial waste or some other related waste stream) would be required to be utilized as fuel for the process which can be conveniently adjusted within the developed process.
Please contact with Chemitec Consulting Oy for techno-economical details of the process to be implemented as commercial scale project.