Multicriteria Decision-Making Tools for the Selection of Biomasses as Supplementary Cementitious Materials

Abstract

Using biomass ash to partially replace cement reduces the cement industry’s environmental impact and prevents these agro-industrial wastes from ending up in landfills, eroding soils, or being openly burned. This research aims to select three biomasses to produce supplementary cementitious materials (SCM) through the analytic hierarchy process, considering expert judgments from different domains. Complementary to up-to-date research, we evaluated biomasses taking into account biomass production, ash obtained from combustion, and logistics processes for supplying concrete plants with SCM. We also dealt with an industrial context instead of a laboratory one and validated our approach on a real case study using Colombian data. The results indicate experts count the technical viability of biomass (concrete properties) as the most crucial criteria, followed by the availability and transport characteristics of the waste (production criteria) and the combustion process as the least important criteria. In the baseline scenario (all experts’ judgments having the same weights), we found that cane bagasse is the best alternative, thanks to its large and highly concentrated production, even if it is not the biomass with the best pozzolanic properties. We also analyzed other scenarios in which we changed the weights of the experts’ judgments and the importance of the criteria. We found that cane bagasse, rice husk, and palm rachis remain the three biomasses selected as SCM, showing the robustness of the proposed multicriteria decision-making (MCDM) methodology. The results provide a methodological reference to appraise biomasses for SCM nationally, using a MCDM framework in a group decision-making context.