Process Design Optimizes Hydrogen Production via Sorption-Enhanced Chemical Looping Steam Methane Reforming.
TUM.PtX News |
The study investigates two reactor arrangements for the sorption-enhanced chemical looping steam methane reforming (SE-CL-SMR) process: reforming-oxidation-calcination (R-O-C) and reforming-calcination-oxidation (R-C-O), employing NiO as oxygen carrier and CaO as CO2 sorbent. Thermodynamic analysis via Aspen Plus V.14, combined with experimental validation using a one-body NiO/CaO–Ca5Al6O14 multifunctional material, reveals that the R-O-C configuration delivers higher H2 yield and thermal efficiency than R-C-O, primarily due to favorable heat transfer through circulating solids between oxidation and calcination reactors. At S/C = 3, CaO/C = 1, NiO/C = 0.5, 600 °C and 1 bar, the reforming reactor achieves 99 % H2 purity with 97 % CH4 conversion. Thermal self-sufficiency is achieved by including a combustion unit fueled by either CH4 or H2. Using CH4 as combustible gas, the R-O-C system requires only 22 mol% of the feed for combustion and achieves 2.61 mol H2/mol CH4 with 75 % process thermal efficiency, though additional CO2 capture units are needed. With H2 as combustible gas, no CO2 is generated after combustion, but thermal efficiency drops to 69 % (R-O-C) and 66 % (R-C-O). Pinch analysis shows that heat exchanger networks with eight units eliminate hot utility demand across all configurations. The study demonstrates that the SE-CL-SMR technology offers a promising pathway toward environmentally friendly hydrogen production with inherent CO2 capture capability, bridging established SMR infrastructure and future green hydrogen technologies.
[1] N. Hemsap, et al. “Process design for sorption-enhanced chemical looping steam methane reforming: Selection of process configuration and combustible gas type.” International Journal of Hydrogen Energy 217 (2026) 153899