Multicriteria analysis as a supporting decision tool for expanding the use of the 3T method for waste-to-energy technologies and biorefineries

The advancement of Circular Economy practices has accelerated the development of recovery operations in waste management. Moreover, novel Waste-to-Energy (WtE) plants go well beyond the conventional framework of Combined Heat and Power (CHP) production and have also focused on the recovery of metals or the secondary production of other products. Thus, an integrated methodology needs to be utilised for the holistic assessment of novel WtE plants. The previously introduced 3T Method is a thermodynamic approach that assesses not only the CHP efficiency but also the quality of the recovered materials/products. Nonetheless, this method operates optimally in net energy producing facilities. This study introduces an outranking multicriteria decision analysis (MCDA) method that incorporates the 3T method and can be used for the assessment of WtE plants that produce valuable materials (like gasification plants) and biorefineries. The thermodynamic parameters that are used in the 3T Method were integrated in a MCDA tool based on the PROMETHEE-GAIA methods and five WtE plants were analysed. The proposed tool successfully assessed the production of materials from Plant D with Phi flows of 0.4583 and 0.3682 for scenarios 1 & 2, while also evaluating positively the high CHP efficiency of Plant C with Phi flows of 0.0417 and 0.0864, respectively. Overall, the PROMETHEE-GAIA MCDA tool kept most of the positive attributes of the 3T Method, while enhancing at the same time the role of materials in the assessment process. This proposed tool can develop to be a useful method for assessment for biorefineries.