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

Abstract

• Carbon footprint threshold for H 2 production in Colombia. • Stakeholders for the low carbon emission, high-quality H 2 certification scheme in Colombia. • Emission threshold of green-H 2 determined as 4.13 kg CO 2 -eq/kg H 2. • Green-H 2 from biomass gasification is environmentally friendly. • Installed wind and solar energy capacities must be increased to meet the low carbon-H 2 demand. Hydrogen (H 2 ) 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 H 2 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-H 2 . Life cycle assessment (LCA) was used to determine the carbon footprint of H 2 production technologies. Based on our LCA, four classes of H 2 were defined based on the emission threshold: (i) gray-H 2 (21.8 - 17.0 kg CO 2 -eq/kg H 2 ), (ii) low carbon-H 2 (4.13 – 17.0 kg CO 2 -eq/kg H 2 ), (iii) blue-H 2 (<4.13 kg CO 2 -eq/kg H 2 ), and (iv) green-H 2 (<4.13 kg CO 2 -eq/kg H 2 ). While low carbon-H 2 could be employed to reduce 22% of the national greenhouse gas (GHG) emissions as defined in the National Determined Contribution (NDC), both blue and green-H 2 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 H 2 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-H 2 to meet the current and future demand of low carbon emission H 2 in Colombia. However, to comply with the proposed carbon emission threshold, the installed capacities of solar and wind energies must be increase.