Turning municipal solid waste incineration into eco-bricks production

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While the incineration of municipal solid wastes (MSW) produces heat and electricity to the serviced community, the generated residues still pose an environmental challenge for this waste management option. The residues normally amass in specialized landfill sites, contributing to considerable disposal costs and raising pollution concerns. Moreover, approximately one ton of carbon dioxide is emitted for every ton of MSW incinerated. Even though incineration substantially reduces waste volume by up to 90% and destroys organic contaminants, the technique's associated hazardous residues and carbon emissions limit its popularity. To maximize the benefits of incineration and minimize its environmental impact, it becomes imperative that harmful by-products be reduced to a minimum, and, where possible, converted to value-added products. This proposed research aims to investigate whether three incineration by-products, namely, heat, ash residues and carbon dioxide, can be utilized to produce environmentally friendly building products: "eco-bricks". The methodologies adopted herein involve the production of "eco-cement" using incinerator heat and residues, and the subsequent production of "eco-bricks" by combining the eco-cement, bottom ash as sand, and flue gas carbon dioxide as the activation agent. The incineration-turned-production innovatively utilizes all incineration by-products to their best: eco-cement is synthesized inside the incinerator furnace at a maximum temperature of 1000 degree C by combining calcium-rich APC residues and silica-rich bottom ash. The cement produced at this temperature is latent hydraulic or non-hydraulic. However, this cement can develop significant strength upon carbonation activation. In addition, carbonation helps immobilize heavy metals in cement and convert gaseous CO2 into solid carbonates for carbon storage. Computerized thermodynamic database will be used to predict the complex phase equilibrium in the multi-component ash system to maximize the formation of reactive phases. The closed-loop system will turn incineration as a waste management option into a value-added production. In this system, the input is municipal solid wastes and the output is eco-products.