Study assessment of water electrolysis systems for green production of pure hydrogen and natural gas blending

Abstract

Hydrogen and hydrogen blended energy carriers are considered the main decisions for production of low-carbon and carbon-free energy. The green hydrogen production is still a small share compared to other hydrogen production methods and necessity of water electrolysis’s improvements is needed. This article aims to introduce the most developed electrolyzers as alkaline (AWE), proton exchange membrane (PEM) and solid oxide water electrolysis (SOWE) comparing them in different categories in order to assess advantages and disadvantages of each one. Comparing the most used method of hydrogen production such as steam reforming with water electrolysis shows that using hydrogen generated by natural gas steam reforming does not really reduce overall CO2. Mixing hydrogen with up to 20 % with natural gas does not require infrastructure changes and leads to 6.5 % reduction in CO2 emissions. The fuel characteristics of hydrogen and its influence on the properties of natural gas blending were also summarized.