Title : Development of industrial scale turquoise hydrogen production system via methane pyrolysis using metal beads
Abstract:
Hydrogen is emerging as a breakthrough of the clean energy transition, with its environmental impact strongly governed by the production route. Among the various hydrogen production pathways, turquoise hydrogen, derived from CH4 pyrolysis, stands out as a promising option by producing CO2-free hydrogen and solid carbon, which can be stored or utilized. However, achieving energy efficiency and catalyst stability at industrial scale remains a key challenge. This study explores the use of SUJ2 steel beads as a regenerable and cost-effective catalyst for CH4 pyrolysis in a 1-meter tubular reactor at atmospheric-pressure. The catalytic performance was evaluated under different conditions of temperature, flow rate, and bed configuration. Using 5 mm beads, CH4 conversion reached 99% at 1000 °C with a flow rate of 0.1 LPM but dropped to 20% at 1 LPM. A critical advancement in this work is the simple air-based regeneration process, where spent SUJ2 beads oxidized in air recovered their activity completely. Post-regeneration, the catalyst achieved 100% conversion even at lower temperatures (~900 °C) with higher flow rates, enhancing the process’s energy efficiency and operational viability for continuous use. To further improve the sustainability and carbon footprint of the system, this proposal integrates a simultaneous Dry Methane Reforming (DMR) unit, which utilizes the CO2 generated during catalyst regeneration along with CH4 to produce syngas (CO + H2). This approach not only mitigates CO2 emissions from the regeneration cycle but also co-produces valuable syngas, enhancing overall process efficiency. This integrated strategy enables a closed-loop, low-carbon hydrogen production system that converts CH4into high-purity hydrogen and solid carbon while utilizing CO2, paving the way for scalable and sustainable turquoise hydrogen plants.
