Potential reduction of greenhouse gas emission through the use of sugarcane ash in cement-based industries: A case in the Philippines

Abstract

Abstract Sugarcane ashes are wastes generated during the combustion of sugarcane residues in cogeneration plants. With sugarcane being the Philippine's top produced crop and a renewable energy resource, generation of sugarcane ash is inevitable. The aims of this study are to assess the potential amount of sugarcane ashes the Philippines can generate, and evaluate the potential greenhouse gas reduction in the utilization of ashes as partial cement replacement in mortar and concrete. The annual potential ash generation could reach to ∼366 kt, ∼125 kt is sugarcane bagasse ash and ∼241 kt is sugarcane leaves ash. Only 68% (∼85 kt) of the sugarcane bagasse ash and 4% (∼9 kt) of the sugarcane leaves ash could be generated by existing cogeneration plants. The utilization of these ashes can reduce the emissions by ∼273 kt CO2-eq annually, while addressing its disposal issues. With the unique archipelagic situation of the Philippines, the distribution of sugarcane ash was investigated, considering the transport emissions when later adopted as raw material in formulating mortar and concrete. Critical distances for transport of sugarcane ash without incurring additional emissions were 1,851 to 4,770 km by land and 5,500 km by sea due to their different corresponding emission factors. The return trip of a given transport vehicle was accounted in the determination of the critical distance to provide realistic estimates. This study provides a quantitative basis for the use of renewable biomass-based resource, like sugarcane ash, to further reduce greenhouse gas emissions in the Philippines.