The Blue Hydrogen Economy: A Promising Option for the Near-to-Mid-Term Energy Transition

Hydrogen is recently being promoted immensely as the primary energy carrier to replace fossil fuels for the envisioned environmentally friendly and sustainable future energy system, given its peculiar properties and advantages over conventional fuels and other alternative energy sources. Hydrogen is classified into various color categories based on the type of feedstock, technology, and CO₂ emissions in its production pathway. This paper focuses on blue hydrogen, discussing its potential as the most promising hydrogen production pathway for the near-to-mid-term transition into a hydrogen economy. First, a comprehensive overview of the hydrogen economy is given with a detailed description of hydrogen's color-code categorization. Blue hydrogen production methods are explained, and blue and green hydrogen are compared on the subject of the grand energy transition. Furthermore, the arguments favoring blue hydrogen as the most promising alternative for the near-to-mid-term energy transition are explained. Finally, a comparative life cycle analysis (LCA) of environmental emissions and resource usage in blue hydrogen and other selected commonly used fuel production pathways is conducted using the greenhouse gases, regulated emissions, and energy use in technologies (GREET) model to analyze the potentials of the blue hydrogen production pathway. The LCA results showed that more efforts need to be committed to reducing nitrous and sulfur oxides in the blue hydrogen production pathway and improving energy and CO₂ capturing efficiencies in carbon capture and storage (CCS) plants.