The Potential of Bio-drying Process in Improving Quality of the Processed Waste from the Mechanical Biological Treatment for Industrial Heating Systems

Abstract

This research has an objective to improve quality of theprocessed waste from the mechanical biological treatment (MBT) by using bio-drying process. The processed waste has high moisture content and low heating value because municipality solid waste (MSW), a major source of the waste, lacks of proper waste segregation. These properties make the processed waste not suitable for being used as refuse-derived fuel in waste-to-energy generation and industrial heating systems. Bio-drying is the process that utilizes aerobic decomposition of microbes such as bacteria and fungi on biomass content of the processed waste. We studied effects of operational parameters such as temperature, humidity and heating value of the processed waste before and after applying the bio-drying process. High-quality RDF should have minimum heating value of 5,000 kcal/kg and maximum moisture content of 30%. We found that the processed waste before applying the bio-drying process has the lower heating value (LHV) of 2,451 kcal/kg and moisture content of 53%, while after applying the bio-drying process, with airflow rate of 840 m²/hour every 3 hours for 20 days in a closed system, has the LHV of 9,047 kcal/kg and moisture content of 5%. The power used in these experiments was equivalent to electricity charge of 351 THB, while the revenue generated from selling the processed waste as RDF for waste-to-power generation is 750 THB/ton. Summarily, the bio-drying process can improve the quality of the processed waste with low power consumption within a short period of time. The bio-drying process is a solution for tackling waste management crisis and global warming by providing sustainable waste management model for the future.