Environmental performance of hydrogen production via eucalyptus biomass gasification and natural gas steam reforming: A life cycle assessment approach

Abstract

A life cycle assessment (LCA) was conducted to compare hydrogen production via steam methane reforming (SMR) of natural gas and eucalyptus biomass gasification under Brazilian conditions. Three scenarios were evaluated for the production of 1 kg of hydrogen: (i) SMR, (ii) SMR with carbon capture and storage (SMR-CCS), and (iii) Gasification-WGS (eucalyptus gasification with water–gas shift reaction). The ReCiPe 2016 midpoint method was applied, with normalization used to identify the most relevant impact categories. Global warming potential (GWP) was confirmed as the most critical category by both midpoint and endpoint results. SMR generated 10.13 kg CO 2 -eq, SMR-CCS 6.40 kg CO 2 -eq, and Gasification–WGS 1.30 kg CO 2 -eq per kg of hydrogen, corresponding to reductions of 36.8% and 87.2% relative to conventional SMR, respectively. Carbon capture reduced the climate impact of the fossil route but did not result in net-negative emissions. SMR-CCS showed higher burdens than conventional SMR in seventeen of the eighteen impact categories assessed, most markedly in water consumption (14.1-fold) and land use (8.5-fold), the latter arising from the biomass-fired cogeneration supplying MEA regeneration heat. Gasification-WGS achieved the lowest climate impact but did not dominate across all indicators: it outperformed conventional SMR in nine of the eighteen categories and underperformed in the remaining nine, most notably in land use (37-fold), water consumption (3.8-fold), marine eutrophication (2.3-fold) and freshwater ecotoxicity (2.2-fold). The comparison therefore describes a trade-off in which the biomass route exchanges carbon and fossil resources for land, water and nutrient pressure. Overall, the results indicate that the preferred pathway depends on which environmental priority dominates in a given region: eucalyptus gasification offers the largest climate and fossil-resource benefit, while carbon capture on the fossil route delivers a smaller climate gain at the cost of increased impacts in nearly every other category. By addressing both climate mitigation and resource sustainability, this study provides guidance for policymakers and industry in developing low-carbon hydrogen pathways adapted to regional conditions.