Multi-objective programming for designing sustainable biogas supply chain: a case study in North Dakota, USA

ABSTRACT This study considers the environmental and social impacts of an animal waste sourced biogas supply chain, along with economic factors for making tactical and strategic decisions. A multi-objective optimisation model is introduced to determine: 1) the best locations and capacities of biogas plants to treat cattle manure from dairy farms, and 2) the best transportation assignments from each farm to a subset of the opened biogas plants. This study formulates three objectives that include minimising total supply chain cost, carbon emissions, and social rejection. An augmented ε-constraint method is employed as a solution approach to solve the multi-objective problem. The results indicate the implementation of the proposed optimisation model has the potential to provide significant economic, environmental, and social benefits. In addition, the study finds that the allowed maximum transport distance contributes to the number and size of biogas plants used.