Modelling of gas pipeline networks: impact of hydrogen injection in natural gas infrastructures

Confronting more and more urgent today’s environmental challenges, such as the control of the discharges of the gas with greenhouse effect, and facing with the ever-increasing shortage in the fossil resources, the radical changes in energy policies seem now inevitable. Among the various domains, hydrogen is one of the most energy alternatives full of promise. Preliminary studies have shown that the transport of a mixture of natural gas and hydrogen is possible without modification of the network and perturbs little the fluid mechanics constraints of the system as long as the mass fraction of hydrogen remains sufficiently low. This work interested exclusively in the transmission pipeline of hydrogen gas and more exactly in the adaptation of the current transmission networks of the natural gas to its transport. The study is aimed to develop a mathematical model for such transmission networks. The quantitative estimation and analysis of the maximal hydrogen contents that are acceptable in the transported gas passing through the existing infrastructures of the natural gas distribution are proposed in this paper. The optimization procedure has been implemented by means of a nonlinear programming method involving the CONOPT resolution module within the General Algebraic Modelling System (GAMS) environment. Some typical results are then presented and discussed