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© 2020 Elsevier B.V. Polyethyleneimine (PEI)/silica adsorbents have been considered as a promising candidate for post-combustion CO2 capture, but the limited process study has been performed on a pilot-scale unit. Herein we report the 150 h continuous test results using a 100 kg sample of silica-PEI on a fluidized bed continuous unit. The CO2 removal efficiency and dynamic sorption capacity were evaluated continuously by changing a number of variables. For the sorption reactor, the changing variables were inlet H2O concentrations of 0–8.3 vol%, inlet CO2 concentrations of 12.0–21.5 vol%, bed temperatures of 50–70 °C and the bed differential pressures of 176–370 mmH2O. For the desorption reactor operated at the bed temperature of 129–130 °C, inlet H2O concentrations of 8.0–13.5 vol%, inlet CO2 concentrations of 14.6–81.2 vol% and bed differential pressures of 430–580 mmH2O were used. During continuous operation, CO2 removal efficiencies of over 90% were achieved with dynamic sorption capacities of 7.5 wt%. Solid sample collected during continuous operation were analyzed by TGA and 13C NMR to identity the decrease of CO2 adsorption capacity and the extent of thermo-oxidative side reactions. Slow oxidative degradation of the silica-PEI occurred because the transporting adsorbent was exposure to the non-humidified air in the solid transport system.

In this study, the hydrogen chloride removal using K-based dry sorbents (K2CO3/Al2O3, KEPRI, Korea) was studied with varying the pressure in a fixed bed reactor (15 cm tall bed with 0.5 cm I.d.). Working temperature was 400℃ and feed gas concentration was 750 ppm (HCl vol%, N2 balance). The chloride sorption capacity of sorbent increases with increasing pressure (1, 5, 10, 15 and 20 bar). Also, after forming KCl crystal by reaction with K2CO3 and HCl, owing to the strong bonding energy, sorbent regeneration was practically impossible. Its optical, physical and chemical characterizations were evaluated by SEM, EDAX, BET, TGA and XRD. At 400 ℃ and 20 bar condition, working condition for the dehalogenation process after gasification, K-based dry sor- bent showed high HCl sorption capacity and HCl/N2 separation performances comparing with Ca-based and Mg-based dry sorbents.