Substitution effects of forest aggregates for bottom ash based on the economic value for forestry and carbon dioxide emissions

Abstract

The number of coal-fired power plants has recently increased in an effort to solve the power shortage in South Korea. The increase of thermal power plants has increased the occurrence of bottom ash, and interest in recycling bottom ash has increased because such by-products affect the efficient management of the land and the environment. Many aspects are considered when selecting materials, and indirect effects such as carbon dioxide[CO2] emissions and deforestation should be considered for an accurate description of the total benefit because the collection of natural aggregates not only increases the emissions of CO2 resulting from energy use but also damages forests. The objective of this research is to analyze the effects of bottom ash use through estimating the economic value of CO2 emissions and deforestation. The total economic benefit was estimated using the economic value for forestry and the trading price of CO2 emissions in 2008 and 2010. The estimation of the economic value showed that the economic value for forestry in Korea increased over time while the trading price of CO2 emissions varied greatly during the observation period, because the trading price influences many economic factors, and the price in 2010 was lower than in 2008. Using economic values of CO2 emissions and forestry, the total economic benefit for environmental effects was estimated depending on the volume of aggregates. The total economic value and volume of aggregates were proportional in 2008 and 2010 and were expressed as polynomial functions of involution related to the volume of aggregates. In conclusion, recycling bottom ash is shown to bring both direct and indirect economic benefits. For CO2 emissions and deforestation, the volume of aggregates used must be considered because the ratios of CO2 emissions and deforestation to the total indirect economic benefit vary based on the volume of the aggregates used.