Reliability assurance of gas-hydrogen mixture transportation by gas pipeline system

Abstract

The gas transmission system (GTS) of Ukraine is currently operating under underloading conditions. The utilization rate obtained by gas pipelines productivity/ their capacity proportion is approximately 50 percent. In the following years, this proportion will be decreasing to 30 percent. Therefore, the search for alternative kinds of products aimed at pipelines load increase as well as the search for alternative ways of GTS idle components use has been a very important problem. In particular, some possibilities of using the pipelines taken out of service for the mixture of natural gas and hydrogen transportation have been considered in recent years. As for environmental decarbonization, the problem of hydrogen use for both domestic and industrial needs is getting more and more topical as fossil mineral resources substitution for hydrogen is ecologically safe and energy saving. Nowadays, Ukraine has not only the considerable resources to generate wind and solar power which can be used whilst receiving “green” hydrogen but also the powerful GTS which is underloaded. Therefore, to increase its load level the Operator GTS of Ukraine has considered any possibilities of some hydrogen transportation (up to 20 percent) in mixture with natural gas. Nevertheless, a number of unsolved problems arise which require a scientific approach, namely: the study of the GTS operating modes while some hydrogen is being admixed, hydrogen impact on mechanical properties of the pipe steel, and determination of the hydrogen loss while it is transmitted by the system whose service life is more than 40 years, etc. Thus, one of the most essential problems for Ukraine is to determine the possibilities of renewable gases (hydrogen, in particular) transportation and storage. The choice of separate GTS objects for the further use of gas-hydrogen mixture transportation in the system or their removal has to be scientifically substantiated. Therefore, a mathematical model has been developed in the paper under consideration to determine and forecast the specified object technical position based on the diagnostic examination, mechanical tests, and stochastic study.