Analysis of the efficiency of reducing hydrogen losses in a pipeline made of various austenitic stainless steels

In order to reduce emissions of carbon dioxide into the atmosphere, which is formed as a result of production petroleum products use, it is proposed to use hydrogen as an environmentally friendly energy resource. At the same time, hydrogen has a high permeability through materials, which leads to its inevitable diffusion losses through the pipeline wall during hydrogen transportation and storage. Based on the literature data and mathematical transformations, a computational model was proposed to estimate hydrogen leakage during transportation by a pipeline at a pressure up to 1.2 MPa and at a temperature from 300 to 600 K. Using tabular literature data on permeability coefficients based on the calculation model, possible losses of hydrogen during its transportation through a pipeline made of different grades of austenitic corrosion-resistant steels (304, 304L, 310, 316, 316L, 316LN, 321, 21-6-9, 21-9-9) at temperatures from 300 to 600 K were determined. Based on the results of calculations, it was concluded that 304L steel is the most effective material for reducing hydrogen permeability (maximum losses ~69 l/year at a temperature of 600 K). At the same time, the largest losses of hydrogen are observed in a pipeline made of steel 310 (903 l/year at a temperature of 600 K). In other steels, the volume of losses varies in the range of ~200-300 l/year. The analysis of the steel compositions showed that a decrease in the concentration of carbon, nitrogen, sulfur and phosphorus leads to an increase in its resistance to hydrogen penetration.