Carbon accounting tool for greenhouse gas emission sources in hydrogen production facilities

Abstract. Hydrogen production facility stands out as one of the major CO2 contributors in oil and gas industry. As hydrogen has emerged as a clean energy source in the future, this research is conducted to focus on carbon footprint assessment in hydrogen production facilities. This study aims to quantify amount of carbon dioxide through direct and indirect emissions which comprised of stationary combustion, process emissions and energy consumption. A comparative analysis has been done between SMR facility in Hydrogen production plant in company A, partial oxidation (POX) and alkaline electrolysis (AEL). The study revealed that gridline-based electrolysis shows the highest CO2 emissions per production of 18 tCO2e/tH2, whereas hydropower-based electrolysis had the lowest emissions of 0 tCO2e/tH2. The study concluded that SMR exhibited the best efficiency among POX and AEL due to its overall low emissions per production of 8.6 tCO2e/tH2, high product throughput, and relatively low investment cost. Reforming technologies emit high amount of CO2 emissions due to large fuel consumption as feedstock, but greater hydrogen throughput compared to electrolysis. As SMR emerged as the most efficient technology, the study recommended implementing CO2 mitigation at process emissions, which accounted for the largest CO2 emissions.