Energy and environmental assessment of industrial-scale hydrogen production: Comparison of steam methane reforming, electrolysis, and Cu-Cl cycles

This study evaluated the environmental impacts of various hydrogen production methods at an industrial scale of 50 tonnes per day (TPD), vis-a-vis the six-step copper-chlorine (Cu-Cl) cycle developed by the Institute of Chemical Technology - ONGC Energy Centre (ICT-OEC). Comparative life cycle assessments (LCA) were conducted using GaBi 8 and SimaPro 9.3 software, examining four hydrogen production processes such as the Sorption Enhanced Steam Methane Reforming (SE-SMR) process, Proton Exchange Membrane (PEM) electrolysis, and Cu-Cl thermochemical cycles (both four-step and six-step). Results show that PEM electrolysis requires the highest energy input, while the Cu-Cl cycles demonstrate significantly lower environmental impacts. Notably, nuclear energy integration in Cu-Cl cycles result in minimum environmental impacts, with Global Warming Potential (GWP) values of 649 kg CO2e (four-step) and 665 kg CO2e (six-step). In contrast, water electrolysis with an electric grid mix generates a GWP of 146,000 kg CO2e, while SE-SMR produces 131,000 kg CO2e. The work provides a comparison of hydrogen production processes highlighting the impact of energy allocation on emissions, aiding sustainable decision-making for industrial-scale applications.