Potential of cofiring at coal power plant with Sabah sawn timber waste

Coal constitutes almost 60% of the electricity generation mix in Malaysia and they are experiencing an inflation in the price of their imported coal. Cofiring with biomass such as sawn timber waste (STW) in existing coal power plants (CPP) can improve the supply and fuel security in Malaysia and at the same time reduce overall greenhouse gas (GHG) emission. It can also lessen the landfill crisis currently being experienced in Sabah. This study investigated the feasibility of cofiring at a CPP in Peninsular Malaysia with STW collected from Sabah. Proximate analysis using thermogravimetric analysis (TGA) and ultimate analysis was carried out to obtain the fuel characteristics of STW and fired coal blend. The quantity of STW available and its potential substitution in a 700 MWe CPP boiler unit were calculated. Due to inefficient collection, transportation and pelletization process, the recommended substitution of STW was set to 4%. More carbon dioxide (CO₂) is released during combustion when cofiring CPP with 4% STW compared to combustion of only coal. However, for every kilogram of wood grown, 1.5 kg of CO₂ is removed from the atmosphere, while coal introduces new GHG gases that has not been present for millions of years. Furthermore, using locally sourced STW, would reduce GHG in the transportation of coal during importation.