(200b) Mechanical Preprocessing of Non-Recyclable Municipal Solid Wastes Towards Advanced Biorefinery Feedstock

Because of accelerated urbanization and development of global economy, a large quantity of municipal solid waste (MSW) has been disposed of by the municipalities. Currently, about 50% of the total MSW generated in the United States has been utilized through various recycling, combustion, and composting technologies while the remaining 50%, often known as non-recyclable MSW (nMSW), is sent to landfills. As nMSW is physically and chemically heterogeneous, it consolidates during feeding to a biorefinery. Thus, preprocessing is required to ensure a smooth feeding process. This study focused on how mechanical pre-processing advanced the physical and chemical properties (e.g., bulk density, permeability, higher heating value (HHV), etc.) of nMSW. In addition, combustion properties were examined in terms of ignition temperature, peak heat release rate, and combustion efficiency. Results show that the variability of physical and chemical properties of nMSW can be reduced by mechanical preprocessing. For example, the variability of the bulk density of the as-received nMSW was about 17.3%, while it reduced to 5.8% when the sample was size-reduced to 2 mm. Similarly, the variability of ash and HHV reduced from 49.2% to 11.0% and from 13.4% to 4.2%, respectively. Combustion thermograms showed that the size reduction positively improves the combustion properties, while the consolidation behavior of the nMSW showed a well-fitted log-linear relationship to the permeability with applied stress. Overall, mechanical preprocessing reduced the variability of physical and chemical properties in addition to the improvement of combustion behavior of the nMSW which is one step forward toward biorefinery feedstock.