Kajian Integrasi Pembangkit Listrik Tenaga Biomassa Berbasis Limbah Bauksit sebagai Substitusi Energi Fosil pada Operasional PT “X” Alumina Refinery, Kalimantan Barat

Integration Study of Bauxite Residue-Based Biomass Power Plant as Fossil Energy

Abstract

The increasing energy consumption in alumina refinery industrial operations drives the need for diversification of more sustainable energy sources. PT “X” Alumina Refinery (PT.”X”) in West Kalimantan consumes large amounts of fossil energy for the Bayer process including digestion, evaporation, and calcination stages. This study examines the potential integration of biomass power plants based on bauxite residue (red mud and oversize bauxite) and local West Kalimantan biomass (palm shell, wood powder, and rice husk) as partial fossil energy substitutes through co-firing and gasification technologies. The study was conducted using a techno-economic analysis approach with mathematical models of energy balance, thermal efficiency, and life cycle cost analysis. Results show that total energy potential from bauxite residue and local biomass reaches 319,009 GJ/year (10.11 MW equivalent) within the operational radius, and 485,600 GJ/year (42.7 MW equivalent) at the provincial scale. Implementation of 30% biomass co-firing in existing boilers can reduce coal consumption by 89,250 tons/year and save net energy costs of IDR 87.3 billion per year. Environmental assessment shows CO? emission reductions of 198,450 tons/year (63.8% of baseline emissions). Economic feasibility analysis yields NPV = IDR 412.8 billion, IRR = 18.7%, and a payback period of 5.3 years, confirming the project's financial viability and contribution to Indonesia's 2060 Net Zero Emission target