Feasibility of refuse derived fuel production from fresh and legacy waste in Indian cities: enabling business viability through circular economy

Abstract

Refuse-derived fuel is a type of fuel created from renewable energy sources that helps to reduce greenhouse gas emissions and address environmental and health concerns. Using RDF as a secondary fuel can decrease our dependence on fossil fuels and promote the use of renewable energy. The compositional data of urban MSW from 18 Indian cities revealed that the average plastic content in RDF is 39.93% in the southern zone, 24.58% in the northern zone, 25.05% in the central zone, 30.63% in the western zone, and 35.97% in the eastern zone. The average amount of paper and cardboard material in the RDF sample was 27.12% in the southern zone, 14.86% in the northern zone, 17.25% in the central zone, 19.51% in the western zone, and 16.27% in the eastern zone. The average amount of textile material in the RDF sample was 32.25% in the southern zone, 21.01% in the northern zone, 40.55% in the central zone, 36.56% in the western zone, and 32.33% in the eastern zone. The average amount of other combustible material (wood, coconut shell, dry leaves) in the RDF sample was 35.07% in the southern zone, 54.69% in the northern zone, 25.73% in the central zone, 38.22% in the western zone, and 23.14% in the eastern zone. Based on the study, the average RDF processing rate in India is approximately 12.32 weight percent of total fresh MSW generation, with an average NCV of 4,741.68 kcal/kg. Based on the daily amount of MSW, which is 48501 tonnes, approximately 5975.1 tonnes of RDF are produced each day in India. This study reveals that fresh RDF in India can be produced with varying heating values depending on the region. The southern zone has an average heating value of 5151.8 kcal/kg, while the northern zone has 4844.6 kcal/kg, the central zone has 4785kcal/kg, the western zone has 4080.38 kcal/kg, and the eastern zone has 4640.7kcal/kg. Additionally, the moisture content differs by region, with an average of 9.7% in the southern zone, 9.6% in the northern zone, 7.4% in the central zone, 9.4% in the western zone, and 10.7% in the eastern zone. An exemplary examination of the combustible waste percentage in Vellore found that the combustible waste percentage meets the recommended limit values for critical parameters such as chlorine, sulfur (0.24%), and nitrogen (0.35%). This suggests that the NCV of the MSW may be enhanced more easily by size screening. On average, the chlorine and sulfur contents were found to be 0.6% and 0.3%, respectively.In the case of RDF from recovered aged MSW fractions, the availability of RDF will be around 16 to 18% (with the removal of 20 to 22% moisture). The principal components of the prospective RDF were found to be plastic (~61.02%), Textiles and rags (~11.08%), rubber (~3.19%), paper (~6.79%), Cardboard (~12.97%), wood (~0.42%), thermal (~1.08%), and coconut shell (~3.45%). The average moisture content in the existing RDF is about 18%. During the summer, the calorific value of the existing RDF is about 3536.5 kcal/kg, while during the winter it is 3127 kcal/kg. In contrast, during the monsoon season, its calorific value drops to 1870 kcal/kg. The viability of the business model depends on several factors, such as the quality and quantity of RDF produced, CAPEX, OPEX, RDF transport costs, and the Government's willingness to invest in CAPEX. The profitability rate will also increase by Selling RDF in the form of pellets as compared to selling it in fluffy or loose form. An exemplary observation for the city of Jaipur, it was found that the profitability rate for RDF pellets increased by 72.64% of the total revenue than fluffy or loose RDF. To ensure the viability of the business model, transportation costs are a crucial factor. In an exemplary study in Kolkata, it was found that transport costs for 100 TPD RDF that bears ULB are exceedingly high at around Rs. 181640.00 due to the 578km distance. As a result, most of the business models are unfeasible for Kolkata. For Kolkata, the production of RDF pellets can only be feasible if the government invests in CAPEX. This would lead to a profit of 15.98% of the total revenue. ULB can supply fluffy or loose fresh RDF up to 400km without government investments in CAPEX, even if there is minimal profit (8% of the total revenue). For legacy RDF, they can deliver RDF up to 100km with a minimum profit of 13.6%.