The evaluation of energy consumption in transportation and processing of municipal waste for recovery in a waste-to-energy plant: a case study of Poland

Refuse-derived fuel (RDF) can be produced from combustible materials contained in municipal waste. This article investigates energy and material flow of waste in different scenarios for production of RDF from bulky waste, separately collected waste, and mixed municipal solid waste (MSW). We compare the proportion of energy consumption in transportation, handling waste, and processing using data from the waste collection company in South Poland. The findings show the components of the reverse supply chain consuming the highest value of energy. A model of material and energy flow has taken into consideration collection of waste and transportation by two categories of waste collection vehicles: light commercial vehicles and garbage trucks. The shipping of RDF from pre-treatment facilities uses tipper semi-trailers and walking floor trailers. The findings of the study show production of RDF from municipal solid waste consumes almost 10% of energy potential in RDF. Less energy is required for the production of RDF from bulky waste (2.2-4.8%) or separately collected waste (1.7-4.1%) depending on the efficiency of collection and selected vehicles. Transportation consumes the greatest portion of energy. For mixed municipal solid waste (MSW), it can reach 79%; for separated collection waste, 90%; and for bulky waste, up to 92% of the total energy consumed. Comparing emissions for two categories of the collection vehicles, no significant difference was found for the bulky waste collections. For mixed MSW and separately collected waste, the emissions are higher for garbage trucks. A recommendation for practitioners is optimization of routing to achieve a higher collection rate at a minimized route length. For transportation of RDF to WtE plants, vehicles with higher loading capacity are essential.