Energy, Vol.167, 235-245, 2019
Investigating the effect of hydrogen injection on natural gas thermo-physical properties with various compositions
Blending of produced hydrogen from renewable energy resources into the natural gas (NG) grid has been promoted as a viable means of energy transportation and long-time storage in large-scales. However, variation of thermo-physical properties of hydrogen-NG admixture can impact the performance of the measuring devices, accessories, and end-use appliances. Therefore, present work investigates the effect of the hydrogen addition on the thermo-physical properties of NG from gas fields with different compositions. The permissible hydrogen concentration, which obviates the need for alteration or modification of the equipment, is considered to be between 1 and 10 vol%. The investigations are conducted on the most important characteristics of the mixture, and it is observed that hydrogen injection into NG increases the upper and lower flammability limits and compressibility factor, while both lower and higher heating values, lower and higher Wobbe indices, along with the relative density decrease with hydrogen concentration increase. Results show that although injecting up to 10 vol% hydrogen into NG causes a reduction of about 7% in lower heating value for investigated compositions, the NG consumption with the NG + H-2 admixture is reduced about 3.5%. Energy consumption of the compressors increases by around 9-14%, depending on the composition of the NG. (C) 2018 Elsevier Ltd. All rights reserved.