Simple CaO based dual functional materials for ICCU-RWGS

https://doi.org/10.1016/j.ccst.2021.100001

“Here we report a novel ICCU process using environmental-friendly, and cost-effective CaCO₃ derived CaO as both effective adsorbent and highly efficient catalyst to produce high purity syngas. The proposed process vastly reduces the material cost for ICCU and effectively mitigates the challenges in the deactivation of transition-metal-based DFMs in conventional CCU processes. As an adsorbent and catalyst, CaO experimentally achieved impressive carbon processing throughput, CO₂ conversion (> 75%) and CO yield (Fig. 1). In this work, the reaction temperature has shown a significant effect on the ICCU performance. A higher temperature is more active for CO generation, yielding 0.34, 1.53 and 4.15 mmol/g_CaO at 600, 650 and 700 °C in 28 mins, respectively. In contrast, CO₂ conversion is slightly decreased with the increase of reaction temperature, from 88.09% at 600 °C to 75.48% at 700 °C (Fig. 1) due to the enhanced CO₂ desorption kinetics. Furthermore, CH₄ is not detected in the overall conversion process and CO₂ was completely converted to CO.”

“Fig. 1. The yield, conversion and selectivity of CO₂ and CO in ICCU using CaO-alone. (ICCU over CaO: 500ml/min 15%CO₂/N₂ carbonation for 30 min, N₂ purge for 2 min, 500ml/min H₂ regeneration for 28 min, cat.= 5.0g CaO; RWGS over CaO: H₂/CO₂=4:1, cat.= 5.0g CaO)”