Material and moisture balance in a full-scale bio-drying MBT system for solid recovered fuel production

Bio-drying MBT is a type of mechanical biological treatment (MBT) system and reduces moisture content of the MSW to improve the separation of combustible fractions. In this study, a full-scale biocell-type bio-drying MBT system was investigated. The mass balance of waste component was estimated by composition and characterization of waste and tonnage data. During separation of biodried outputs, 62% of plastics and 54% of paper were recovered as RPF material. Wood was decreased by reduction in particle size and 90% of biodried wood is returned to next reactor. Changes of mixed fine caused by fine wood particle and the loss of organic matters and 60% of it were returned. Daily water removal during 17-days of bio-drying was simulated through the model using the operation data. Among the four operation phases, the longest stabilization phase was expected to main water removal period, but half of water removal occurred at initial two stages and phase IV for only 6 days in total due to the high waste temperature for sanitization (phase I and II) and high airflow rate for cooling. Decreasing waste temperature at phase III resulted in low water evaporation.