This study evaluated the decarbonization of a high (HC) and a medium complexity (MC) Colombian refinery, considering three potential roles of biogenic CO 2 : carbon capture and utilization (CCU) for CO 2 -based products; generating carbon dioxide removal (CDR) credits via the storage of biogenic CO 2 to offset residual fossil emissions, or selling CDR credits. The study also considered renewable energy use and fossil CO 2 storage in the technology portfolio. Refinery performance was evaluated using techno-economic optimization from 2030 to 2050. By 2050, both refineries achieve carbon neutrality for direct emissions and purchased energy emissions, with total system emissions slightly below business-as-usual (BAU) levels. However, without CDR, CCU alone may raise total emissions. Results also showed that achieving carbon neutrality requires 39% more biogenic CO₂ in the MC refinery than in the HC case, and is highly sensitive to the availability of CO 2 storage and biomass feedstock. CO 2 conversion technologies demand large amounts of hydrogen, significantly increasing electricity (7–13 times), water (4–6 times), and steam (3–4 times) requirements, potentially exceeding local resources availability and exposing supply chain constraints. These added costs reduce total cash flow compared with BAU, lowering net margins to <1€/bbl in 2035, though recovery and improvement are projected by 2050. Overall, our findings underscore the importance of refinery complexity and resource availability in CCUS performance, the tension between direct and indirect emissions, and the need for further research on integrating hydrogen supply, CCU, and CDR to enable sustainable low-carbon refinery transitions.
López-Basto et al. (Sun,) studied this question.