Physical and chemical processes in baled waste fuel,with emphasis on gaseous emissions

Abstract

Over a period of seven months, the temperature and the emissions from six cylindrical and two rectangular stored bales containing waste for later use as fuel were measured. The bales were kept at two different ranges of temperatures: 30-35°C and 20-25°C respectively. It was found that only the rectangular bales showed significant production of CO₂. The increase of emission for one of the rectangular bales kept at 30-35°C, was 0.246% vol. CO₂ per day for a 2-week period, after which there was a decrease of CO₂ concentrations at a rate of 0.0224% vol. during a 32-week period. The other rectangular bale kept at 20-25°C, exhibited a similar trend. However, the increase of CO₂ concentrations was less at a rate of 0.0259% vol. per day during a 8-week period, after which the CO₂ emission decreased at a rate of 0.0224% vol. per day during a 25-week period. All the bales exhibited aerobic decomposition in the sampling point. However on measuring the leachate concentrations, it was evident that the bales were actually in the equivalent acid-generating phase of a young landfill. The temperature inside the bales did not increase higher than the ambient air temperature.