INTEGRATED WASTE-TO-ENERGY SYSTEMS: ENVIRONMENTAL TRADE-OFFS AND CIRCULAR ECONOMY POTENTIAL

Abstract

The waste-to-energy (WtE) processes, as an integrated waste management system, are emerging as an important component of sustainable waste management as not only do they eliminate the problem of landfills but also generate renewable energy.  This paper explores in detail current WtE technologies assessing their effectiveness in terms of energy savings, emission reduction, material recovery and compatibility with the concepts of a circular economy.  It was based on a mixed-methodology, and some experimental tests on 25 other types of garbage were made, along with assessment of possible environmental and economic impact.  The findings demonstrated that the waste of the trash had varied a lot with the organic material representing between 30 and 65 per cent and plastics representing up to 25 per cent. This influenced the technological selection and the calorific value.  The higher heating values were up to 28 MJ/kg and optimised systems delivered 6.0 kWh/kg of energy.  Between 25 and 75 percent of conversion efficiency occurred. Incineration and gasification sucked more energy per mass compared to anaerobic digestion with increased emissions of CO 2 and PM emissions compared to AD.  To assess the performance of circular economy, the indicators demonstrated that the top performing facilities recovered more than 90% of the material and a circularity of 0.89. This evidences the fact that the resource loop has great potential in being closed.  Lifecycle greenhouse gas emissions were attributed largely to the conversion stage and this demonstrates the need to have increased control of emissions and the integration of green energy sources.  Economical studies established that certain plants could gain as much as 25 percent of their investments, and more importantly, those that conducted combined heat and power (CHP) systems.  Survey results on the perception of the people on matters revealed that the citizens were mildly familiar with the issue of policy integration but strongly favored it. This goes in line with the view that WtE is viable in the society.  Overall, the findings demonstrate that when properly installed and managed, integrated WtE systems may become effective instruments of diversifying energy foundation, minimize emissions, and advancing the circular economy in general.  The research indicates the ultimate value of utilizing data to optimize systems, develop mechanisms to reduce the emissions and engage the stakeholders in achieving the sustainable potential of the Waste-to-Energy technologies to the full.