Comprehensive assessment of cement kiln co-processing under MSW sustainable management requirements

Abstract

Although cement kiln co-processing (CKC) has been considered an important municipal solid waste (MSW) treatment method in recent years, there however still exist obstacles such as unclear technical feasibility and ambiguous legislation that impede its further development. Addressing these barriers remains difficult as a comprehensive understanding of CKC from an MSW management perspective (which is a major challenge for policy makers) is lacking in existing studies.Therefore, this study adopted Material Flow Analysis, Life Cycle Assessment and Net Present Value evaluation methods to quantitatively analyze the waste reduction effect, energy efficiency, environmental impact and economic performance of CKC in order to provide an important basis for determining its feasibility and policy direction in comparison to existing MSW treatment technologies.The results showed that CKC had a waste reduction rate of up to 99.5%, and 90% lower environmental emissions than incineration. However, from a life cycle perspective, the net environmental impact of CKC was not as significant as incineration and mechanical biological treatment because its coal saving effect has a relatively lower environmental impact mitigation potential compared to the potential from electricity generation brought by incineration. Furthermore, the proposed MSW treatment fee subsidy for CKC was 59 CNY/tonne, reflecting a 34% reduction from current incineration subsidy fee.These findings are important for many countries since the main barriers to CKC development are similar. Improving the comprehensive understanding of CKC could help policymakers formulate precise promotion planning and reasonable incentive policies.