Sustainable hydrogen production: Technological advancements and economic analysis

Hydrogen (H 2 ) is pivotal to phasing out fossil fuel-based energy systems. It can be produced from different sources and using different technologies. Very few studies comprehensively discuss all available state-of-the-art technologies for H 2 production, the challenges facing each process, and their economic feasibility and sustainability. The current study thus addresses these gaps to effectively direct future research towards improving H 2 production techniques. Many conventional methods contribute to large greenhouse gas footprints, with high production costs and low efficiency. Steam methane reforming and coal gasification dominate the supply side of H 2 , due to their low production costs (<$3.50/kg). Water-splitting offers one of the most environmentally benign production methods when integrated with renewable energy sources. However, it is considerably expensive and ridden with the flaw of production of harmful by-products that affect efficiency. Fossil fuel processing technologies remain one of the most efficient forms of H 2 production sources, with yields exceeding 80% and reaching up to 100%, with the lowest cost despite their high reliance on expensive catalysts. Whereas solar-driven power systems cost slightly less than $10 kg −1 , coal gasification and steam reforming cost below $3.05 kg −1 . Future research thus needs to be directed towards cost reduction of renewable energy-based H 2 production systems, as well as in their decarbonization and designing more robust H 2 storage systems that are compatible with long-distance distribution networks with adequate fuelling stations. • H 2 production technologies, their economic feasibility and sustainability are reviewed. • Low-cost steam methane reforming and coal gasification dominate the supply side of H 2 . • Water-splitting coupled with renewable sources offers one of the most eco-friendly methods. • Future research should focus on decarbonizing and lowering renewable H 2 production cost.