Role of low carbon emission H2 in the energy transition of Colombia: Environmental assessment of H2 production pathways for a certification scheme

Hydrogen (H2) is a low-carbon carrier. Hence, measuring the impact of its supply chain is key to guaranteeing environmental benefits. This research proposes a classification of H2 in Colombia based on its carbon footprint and source. Such environmental characterization enables the design of regulatory instruments to incentivize the demand for low carbon-H2. Life cycle assessment (LCA) was used to determine the carbon footprint of H2 production technologies. Based on our LCA, four classes of H2 were defined based on the emission threshold: (i) gray-H2 (21.8–17.0 kg CO2-eq/kg H2), (ii) low-carbon-H2 (4.13 – 17.0 kg CO2-eq/kg H2), (iii) blue-H2 (<4.13 kg CO2-eq/kg H2), and (iv) green-H2 (<4.13 kg CO2-eq/kg H2). While low-carbon-H2 could be employed to reduce 22 % of the national greenhouse gas (GHG) emissions as defined in the Nationally Determined Contribution (NDC), both blue and green-H2 could be employed for national and international trade since the standard emissions are aligned with international schemes such as CertifHy and the Chinese model. Besides, gasification of biomass results in environmental savings, indicating that biomass is a promising feedstock for international and local trade. Furthermore, combinations of H2 production technologies such as renewable-based electrolysis, natural gas steam reforming with CCS, and ethanol conversion were evaluated to explore the production of a combination of green- and blue-H2 to meet the current and future demand of low-carbon emission H2 in Colombia. However, to comply with the proposed carbon emission threshold, the installed capacities of solar and wind energies must be increase.