Linearized model of pipeline distribution of gas to a local market

Natural gas is considered as a bridge fuel substituting the less environmentally friendly fossil fuels (coal and oil) on the way to a low emission future. The consumption of natural gas in the power generation and transportation is anticipated to increase as new gas sources emerge and new gas processing technologies are developed. Ecological gas sources, e.g., biogas or synthetic natural gas, are also steadily gaining popularity in local distributed production. A potential injection of gas from such sources to a gas pipeline should be considered in the design and operation of new gas networks. Mathematical modelling and optimization can contribute to the decision making in such tasks. A linearized model of a pipeline distribution problem has been developed for optimal network design and operation, providing information about the structure of the gas distribution network and its operation conditions. The model, which is based on a mixed integer linear programming (MILP) formulation, is illustrated by studying a future gas network, with the option of connecting new gas suppliers and consumers, minimizing the overall costs (including cost of fuel, cost of new pipeline connections, and cost of compression). Seasonal variations in the demand and supply are considered by a multi-period formulation of the problem. The results give information about the optimal connections and gas flows, including the flow directions in the pipe segments, gas supply rates and pressure level in the pipeline. The results for a case study are presented and analyzed, paying special attention to the effect of constrained gas sources on the optimal design of the network.