Polyethyleneimine modified porous wood ceramics for efficient and high-capacity adsorption of CO2 in simulated gases

In this study, porous wood ceramics with enhanced pore structures and mechanical properties were synthesized by treating natural wood with resin. The ceramics were used as matrices for organic amines to generate aminemodified ceramic adsorbents. An orthogonal experiment revealed that the polyethyleneimine-to-ethanol mass ratio was the primary influencing factor, leading to a maximum sorption capacity of 3.06 mmol/g (N-2, 15 vol% CO2). Furthermore, the synthesized amine-modified materials had a 2.2-fold higher adsorption capacity than the wood ceramics. The experimental analysis focused on examining the influence of temperature and humidity on the sorption capacity of the wood ceramic adsorbents in four simulated gases. It was discovered that an increase in temperature had a negative effect on the sorption capacity, whereas a humidity level below 50% had a positive effect on the adsorption of CO2 . At a relative humidity of 50%, the presence of moisture increased the CO2 absorption capacity, resulting in maximum absorption capacities of 3.61 and 2.65 mmol/g in N-2 at CO2 concentrations of 15 vol% and 400 ppm, respectively. The findings of the study indicate that the CO2 adsorption kinetics of amine-impregnated wood ceramics may be accurately described by both the Avrami and pseudosecond-order models. Furthermore, it was observed that the CO2 adsorption capacity of the amineimpregnated wood ceramics decreased by < 6% after they underwent 30 adsorption-desorption cycles in the presence of four simulated gases.