Conversion calculations for ICCU-RWGS using online gas analyser

In ICCU-RWGS, the composition of gases is determined normally by an online gas analyser. Key performance indicators include CO₂ conversion, the capacity of CO₂ capture, the yield of CO, the selectivity to CO, and the stability of materials. The following information is obtained from literature regarding the calculation of performance indicators.

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

Typically, CaO was heated to 600 ˚C with a rate of 10 ˚C/min in N₂ (500 ml/min). After the temperature is stabilized, switch N₂ to 15% CO₂/N₂ (500 ml/min) for 30 minutes adsorption and record the real-time data. The adsorbed samples were purged in N₂ (500 ml/min) for 2 mins, following with isothermal desorption in 100% H₂ (500 ml/min) for 28 mins. The comparison tests used the same parameters except replacing the 100% H₂ with N₂ in the desorption stage. Raise temperature to 650 ˚C and then 700 ˚C with a rate of 10 ˚C/min in N₂ (500 ml/min) for the following tests. Take Fig. S2 as an example to calculate the CO₂ and CO amount and CO₂ conversion by integrating real-time reaction data:

Y_CO (mmol/g_CaO), Y_CO2 (mmol/g_CaO), C_CO2 (%) and S_CO (%) represent CO yield, CO₂ yield, CO₂ conversion and CO selectivity, respectively.

Fig. S2.  Schematic diagram of reaction calculation area of isothermal CaL in H₂. (example taken from H₂ calcination test under 650 ˚C) https://doi.org/10.1016/j.ccst.2021.100001