CO2adsorption and desorption performance measurement

https://doi.org/10.1093/ce/zkac020

“The adsorption of CO₂ was carried out at 25°C and atmospheric pressure using 15/85 vol% CO₂/N₂ as a feed gas representing the concentration of CO₂ in the flue gas from the coal-fired power plant. In a typical run, 0.5 g of adsorbent was packed into a stainless-steel tube reactor (12 mm id) supported by glass wool. Before measurement, the adsorbent was pre-treated at 100°C using heating tape (±2°C) under an N₂ flow rate of 20 mL/minute for 1 hour to remove physically adsorbed moisture and remaining CO₂ in the adsorbent and then it was cooled to room temperature (25°C), which was measured using a thermometer (±2°C). CO₂ adsorption was begun by switching to the 15% CO₂ at 20 mL/minute. The flow rate of the feed gas was controlled using a mass flow controller (AALBORG, GFC-17 with a range of 0–200 mL/minute) and accurately measured using a volumetric (bubble) flowmeter (Agilent Optiflow Digital Flowmeter) with an accuracy of within ±3%. When 15% CO₂ was purged to the reactor, the CO₂ concentration at the outlet of the reactor was continuously detected using a gas chromatograph equipped with a thermal conductivity detector (GC-TCD, Agilent, model 7280A, USA) fitted with Porapak-Q column (0.32 mm id × 60 m l dimension) until saturation (i.e. the CO₂ concentration in the effluent gas was equal to the feed concentration).

The desorption experiment was further carried out after the adsorption was complete by switching the CO₂ feed gas to the N₂ gas at the same flow rate and applying heat at 100°C. It was performed by continuously detecting the CO₂ concentration until no more CO₂ peak was observed in the gas chromatogram. The experimental set-up for the CO₂ adsorption–desorption is shown in Fig. 2.”