STUDY OF RENEWABLE ENERGY AND ECONOMIC IMPROVEMENT FROM UTILIZING RICE HUSK WASTE THROUGH BIOMASS CO-FIRING

Abstract

Utilizing rice husk waste as a renewable energy source has significant potential to support national energy security while providing added economic value to the community. Indonesia, with rice production reaching 53.14 million tons in 2024, has a potential rice husk waste of 10.63 million tons. With an average calorific value of 14 MJ/kg, the theoretical energy potential of rice husk reaches 148.8×10⁹ MJ, equivalent to 41.33 GWh per year. The use of rice husks as a fuel mixture (co-firing) in coal-fired power plants significantly contributes to increasing the renewable energy mix and reducing greenhouse gas emissions. According to PLN data, the biomass co-firing program has been implemented in 46 PLTUs by 2023, with biomass usage reaching 1 million tons and emissions reductions of approximately 1.05 million tons of CO₂e. Rice husk co-firing trials at several coal-fired power plants, such as Jeranjang, Paiton, and Suralaya, demonstrated stable operation with high efficiency and a reduction in SO₂ emissions of up to 29.22%. Despite its lower calorific value than coal and high ash content (up to 20.67%), rice husk still has the potential to be used at a ratio of 20–30% of the energy mass. Its silica (SiO₂) content, which reaches 95.52%, poses challenges such as slagging and fouling, but the ash residue can be used as a cement mixture or silica powder. Utilizing rice husks through the direct co-firing method is considered most suitable for coal-fired power plants in Indonesia because it is inexpensive and easy to implement without significant modifications. Overall, rice husk co-firing can support the clean energy transition, reduce dependence on coal, improve the rural circular economy, and contribute to Indonesia's 2060 Net Zero Emission target.