A methodology for designing biogas pipelines

Dependence on fossil fuels has heightened global energy security issues. Anaerobic digestion (AD) is a technology that can produce biogas to reduce fossil fuel consumption. Transportation of biogas to end users may be achieved using low pressure biogas pipelines. A methodology containing two heuristics (connection based on proximity or output flowrate) is developed to optimise biogas pipeline layouts. A case study of pipeline networks serving up to 10 AD plants and 1 biogas end user is presented. A road network minimum spanning tree (MST) connecting 10 AD plants to the biogas end user is calculated to cost 26% more than a Steiner MST. Multi-criteria decision analysis (MCDA) is used to rank biogas pipeline layouts considering pipeline material cost and biogas flow-rate to the end user. In this analysis, Steiner MSTs always outperform road network MSTs, except when pipeline material cost is disregarded. Scenarios that connected via the proximity heuristic almost always outperformed those which connected via the output heuristic.