Perpustakaan Digital ITB

As global efforts intensify to find clean energy alternatives, hydrogen has emerged as a promising energy carrier. Chemical Looping Hydrogen (CLH) systems offer an innovative pathway for clean hydrogen production with inherent CO2 capture, a process driven by the performance of solid oxygen carriers (OCs). While synthetic OCs exhibit high reactivity, their significant cost hinders large-scale application. This research evaluates the performance of low-cost natural OCs with high abundance in Indonesia's mineral reserves, specifically limonite, iron sand, ilmenite, chromite, and laterite. The methodology involved reactivity screening via thermogravimetric analysis, performance evaluation in a fixed-bed reactor over 10 redox cycles, and a comprehensive techno-economic assessment. The screening identified ilmenite, chromite, and laterite as inert under CLH conditions. Performance analysis revealed that limonite possessed a high initial hydrogen production capacity (45.5 mL/g OC) but suffered from poor cyclability, retaining only 7.0% of its capacity due to liquid-phase sintering. Conversely, iron sand exhibited a lower initial capacity (18.4 mL/g OC) but demonstrated excellent stability, retaining 52.6% of its performance. The synthetic Fe2O3 benchmark yielded an initial capacity of 84.2 mL/g OC but retained only 36.5%. The addition of a 5 wt% CeO2 promoter did not significantly impact initial capacity but improved the long-term cyclability of both limonite and iron sand. The techno-economic analysis concluded that the synthetic OC yielded the lowest minimum selling price of hydrogen at 2.62 USD/kg, followed by limonite at 2.89 USD/kg, while iron sand was the least economically viable at 3.69 USD/kg due to significantly higher capital costs. Despite the less favorable economic results, the utilization of domestic natural OCs offers a significant strategic advantage for Indonesia, supporting the national goal of adding value to its mineral wealth to enhance economic sovereignty, build technological capacity, increase employment rate, and ensure national energy security.