Prioritizing Alternative Fuels for Co-firing in an Indonesian Cement Plant: A Techno-Economic Analysis Using Integrated AHP-TOPSIS

Abstract

The cement industry faces a dual challenge stemming from global decarbonization requirements and fossil fuel price volatility. Increasing environmental regulatory pressure and sustainability targets compel cement producers to accelerate the energy transition through the substitution of alternative fuels (co-firing). This study aims to identify the factors influencing alternative fuel selection for cement production, determine the optimal fuel option for PT Semen ABC, West Java, and establish a ranking of the best alternative fuels by balancing technical and economic considerations. Using an MCDM framework, this research integrates the AHP to weight decision criteria and the TOPSIS method to rank the alternatives. Six materials were evaluated: rice husk, sawdust, wood chips, rice husk pellets, carbon rubber, and RDF. The AHP results indicate that technical quality dominates decision preferences at 56.5% (calorific value weight: 28.26%; moisture content weight: 28.16%), exceeding the influence of material price, transportation cost, supplier capacity, and number of suppliers. Based on the TOPSIS analysis, carbon rubber ranks first as the most ideal solution, achieving the highest preference value (V = 0.7266), with a calorific value of 6.363 kcal/kg and a moisture content of 2.44%. The subsequent ranking is: rice husk pellets, rice husk, RDF, wood chips, and sawdust, with sawdust identified as the least-recommended fuel. This study concludes that kiln operational stability, which is strongly affected by material quality, constitutes the primary priority compared with procurement cost and supplier capability. Empirical research on integrated AHP–TOPSIS MCDM using techno-economic assessments based on operational data from Indonesian cement plants remains scarce. Most prior studies emphasize co-firing in power plants, making this application to the cement sector a key novel contribution.