Comparision of the climate impacts of different hydrogen production routes in Finland

Abstract

Hydrogen is a favourable energy carrier and can serve as a feedstock for decarbonizing the energy, chemical and transport sectors and reducing the impact of global warming. However, identifying and realizing eco-friendly hydrogen production pathways is difficult since the production routes are very different. This study carries out the life cycle assessment based on the current status of hydrogen production technologies. Hydrogen production in Finland is considered using different process technologies, namely steam methane reforming, steam methane reforming with carbon capture and storage, thermal decomposition of methane and polymer electrolyte membrane electrolysis. The hydrogen in these technologies is often associated with the colours as grey, blue, turquoise, and green respectively. The critical technology comparison is objective and quantified using the life cycle assessment methodology. Three of these technologies are largely driven by natural gas and one of the technologies is driven by an electricity grid, all of which have negative environmental impacts, and which is why conducting and comparing their life cycle assessment needs to be undertaken. Both US LNG and the pipeline route from Russia are considered for the natural gas supply chain. For this purpose, the environmental impacts of hydrogen generation technologies are surveyed and simulated on LCA and the most promising solutions with regard to the ongoing energy transition are identified as, for grey hydrogen 11.44 kgCO2eq/kgH2 from pipeline and 11.73 kgCO2eq/kgH2 from USA LNG, for blue hydrogen 7.89 kgCO2eq/kgH2 from pipeline and 8.06 kgCO2eq/kgH2 from USA LNG, for turquoise hydrogen 5.09 kgCO2eq/kgH2 from pipeline and 5.59 kgCO2eq/kgH2 from USA LNG and for green hydrogen 1.6 kgCO2eq/kgH2.