Fuzzy multi-objective approach for designing of biomass supply chain for polygeneration with triple footprint constraints

Polygeneration systems produce multiple energy products (i.e. electricity, heat, cooling), and other biochemical products (biofuels and syngas). Such systems offer a sustainable approach in meeting the ever-growing demand of energy, while reducing its environmental impact. The optimal design of such systems should consider the design of the supply-chain in producing the targeted energy products to reduce the resource consumption and waste generation and to maximize its economic potential. One of the important considerations in designing such a system is whether to out-source its raw materials or to produce them in-house. The criteria for such decision strategies are assessed through economics, product demand, and environmental impact. One holistic way to measure the environmental impact of such system is to consider the triple footprint: carbon, water, and land. The objective of this work is to maximize the economic potential while maintaining the footprints at acceptable levels and simultaneously meeting product demands. In this study, an adoption of fuzzy multi-objective approach is presented wherein the economic potential is introduced as a constraint. Moreover, predefined fuzzy trapezoidalshaped limits for the product demand constraints are used which mimics the probabilistic demand scenario for each of the product streams. Lastly, the triple footprint constrains is utilized to assess the environmental impact of the polygeneration. The technique is demonstrated using a modified industrial case study of a polygeneration system.