A realistic performance assessment for pilot-scale biodrying application: AHP-PROMETHEE approach

OpenAlex İngilizce

Tremendous amounts of generated municipal solid wastes (MSWs) and limited energy sources make utilization of sustainable waste management strategies mandatory. Lower efficiency of recycling practices especially in developing countries compels authorities to search for novel sustainable solutions. Biodrying is a promising technology for producing solid recovered fuel (SRF) from partially stabilized waste. However, accurate evaluation of biodrying performance remains challenging due to the complexity of microbial heat generation processes. On the other hand, basic biodrying indices are found to be insufficient for evaluating the overall efficiency. Multi-criteria decision-making techniques providing accurate and comprehensive information may serve as useful tools to interpret efficiency of such complex systems. The major aim of this work was to observe a meaningful ranking of biodrying efficiency by using AHP-PROMETHEE, considering all treatment and cost parameters. With this aim, first batch biodrying experiments were performed in a pilot-scale reactor with a volume of 0.8 m3 for a 7-day period. Eight trials including varying waste compositions weighing 70 ± 7 kg were tested under different air flow rates (AFR). Temperature and weight loss profiles together with moisture removal and leachate generation rates were determined for each of the trials. Energy contents (lower heating value (LHV)) were also analyzed after and before biodrying. The experimental results indicated that the higher food waste and lower AFR (Trial 4) increased volatile solids (VS) reductions along with the observed peak temperature (up to 60°C). In contrast, high AFR and low organic content (Trial 5), resulted in the lowest VS (6.86%) reduction and provided the highest biodrying index (6.76). The most crucial material in increasing the energy content of the waste matrix was plastic wastes with low biodegradability. As the proportion of plastic waste increased, the bioheat production capacity decreased and applied AFR became the most important factor in obtaining SRF (Trial 1). AHP results highlight energy content increase as the key factor (33% weight), while leachate production had minimal influence (6%). PROMETHEE ranked Trial 1 the first with the highest net flow value (Phi) of 0.32. Briefly, the study offers a novel approach to achieve an easy, informative, and accurate performance assessment for biodrying processes.