Comparative life cycle assessment of hydrogen production methods: eucalyptus biomass gasification vs natural gas steam reforming in brazilian conditions

Abstract

Hydrogen is increasingly recognized as a promising alternative to conventional fuels, offering significant potential to drive the energy transition and reduce carbon emissions. However, the majority of hydrogen (H2) production still depends on fossil fuel sources, highlighting the urgent need to explore more sustainable alternatives. Among these, hydrogen production through the gasification of biomass, particularly eucalyptus, has garnered considerable attention. To evaluate the environmental impacts of this approach, a life cycle assessment (LCA) was conducted, comparing it to the most common method, steam methane reforming (SMR) of natural gas, under Brazilian conditions. The study assessed three distinct scenarios to provide a comprehensive analysis of their environmental performance. i) SMR of natural gas, ii) SMR-CCS - SMR integrated with carbon capture and storage (CCS), and iii) Gasification-WGS - eucalyptus gasification coupled with the water-gas shift reaction. Using ReCiPe's midpoint (H) method, nine key impact categories were analyzed, with global warming (GW) identified as the most critical. Results revealed that SMR and SMR-CCS produce 17.5 kg and 10.5 kg of CO2 equivalent emissions, respectively, while the Gasification-WGS scenario emits only 1.84 kg of CO2 equivalent, reducing emissions by approximately 89% compared to SMR. Despite its lower GW impact, the SMR-CCS scenario showed higher impacts in other categories, whereas the Gasification-WGS scenario had increased eutrophication due to nutrient runoff from eucalyptus cultivation. These findings underscore the importance of assessing hydrogen production pathways comprehensively to ensure their sustainability and environmental viability. Biomass gasification, supported by photosynthesis and CCS technologies, demonstrates significant potential as a clean energy vector in the decarbonization scenario.