Cooperative game-based anchor process allocation within sustainable palm oil based complex for environment-food-energy-water nexus evaluation

The challenge in clean palm oil production falls on the management of palm oil mill effluent which is a notable source of greenhouse gas emissions and water pollution. To address these critics against edible palm oil, an integrated palm oil-based complex (POBC) considering effluent elimination and refinery integration is suitable for environmental-food-energy-water (EFEW) nexus development. Optimal retrofit of palm oil mill into EFEW nexus-integrated POBC requires multi-objective considerations to balance the trade-offs between profitability, energy contribution, greenhouse gas, water and land footprints via fuzzy optimisation. With limited practical knowledge, potential flowsheet modifications should be investigated for flexible POBC design. In a cooperative game context, interconnecting processes act as multiple players cooperating to achieve the goal of the game, i.e., POBC performance, where each player has a distinctive impact on the outcome. In this work, such process performance was suggested to be distributed using cooperative game model, to target the EFEW-based anchor process, i.e., the process stage of greatest contribution in the weighted EFEW nexus, for desired flowsheet advancement. Considering these aspects, an integrated fuzzy and cooperative game optimisation framework was developed to identify the anchor process of an EFEW nexus-integrated POBC. EFEW objective-based process performance allocation in the fuzzy optimal POBC was weighted by the decision-maker to allocate the anchor process using developed models and Excel tools. Nut/kernel separation and cogeneration stage is the EFEW-based anchor process in the fuzzy optimal POBC with EFEW nexus score of 41% in this work. A comparative analysis between the proposed method with other approach was done. The favourability of EFEW contributions by POBC in terms of benefit-drawback ratio increased with the percentage of boiler efficiency increment within the targeted anchor process. Targeting anchor process aids planning for process maintenance and advancement to avoid resource wastage on sub-critical processes.