Evaluating the performance and kinetics of amine-modified NaY zeolites from rice husk for direct air CO<inf>2</inf> capture

Abstract

High-purity silica derived from rice husk, a low-cost and abundant agricultural byproduct, was utilized to synthesize NaY zeolite via hydrothermal. The resulting NaY zeolite, with a specific surface area of 666 m2/g, was modified with various amines to enhance direct air CO2 capture performance. 30 wt% MEA/NaY sorbent exhibited the highest CO2 uptake, achieving approximately 14.5 mgCO2/g at 30 °C. Sorbent retained about 96 percent of its initial capacity after ten cycles. Kinetic analysis using Avrami's model indicated a low activation energy of 9.01 kJ/mol. Also, cost analysis showed that 13 USD/kg is needed to produce NaY zeolite from rice husk.