Risk of spontaneous fires at temporary storages sites for organic material, waste fuels and recyclables: Quantification and mitigation

Sammanfattning: Economic and environmental constraints have created increasing demand for (material and energy recovery) and recycling of waste generated from households, commercial and industrial activities. A wide variety of materials waiting for sorting, recovery, recycling and disposal are stored at temporary storage sites (TSS) where physical, biotic and abiotic processes can lead the stored material to spontaneous ignition. Spontaneous fires at TSS are associated with severe social health economic and environmental implications.The objective of the present thesis was to access, quantify and mitigate the risk of spontaneous fires at temporary storage sites. It was found that during the period from 2000 to 2010, spontaneous fires have caused losses of about 49 million SEK (about 5 million Euros) to the Swedish waste and recycling industry. A comparison of two groups of waste operators (non-seasonal storage sites at private companies and seasonal storage sites at municipality owned companies) showed that the number of fire incidents per storage site was higher for the former one.Furthermore, it was found that there is a need to improve the behavior of environmental managers related to safety issues as a group of managers was found to be under the influence of optimism, attribution and availability biases. The managers under the influence of optimism bias preferred to follow low cost risk averting strategies and fire incidents were more frequently reported at their storage sites.The ArcGIS spatial analysis using Boolean and Weighted Linear Combination approach and open burn/open detonation model was used to provide the screening level guidelines for siting new storage sites with a due consideration given to potential off-site consequences of spontaneous fires on downwind population. Furthermore, experiments were conducted to investigate the combustion characteristics of MSW bales. The data suggested that the unwrapped bales might pose higher hazards for adjacently stored material to catch fire than bales wrapped with low density polyethylene (LDPE) plastic sheets. For future, interdisciplinary research with focus on technical solutions (e.g. development of performance based design using fire simulations and methods for early detection and extinction of fires) and economic, political and organizational solutions that ensure risk of spontaneous fires not to be trivialized is recommended.Keywords: temporary storage, risk of fires, spontaneous ignition, biofuels, recyclables, waste fuels