CO2 removal using amine-functionalized kenaf in pressure swing adsorption system

Abstract

An agro-based adsorbent from kenaf (Hibiscus cannabinus L.) for CO2 removal was prepared by functionalizing it with amine. Amine functionalization improves the adsorbates–adsorbent interaction through the presence of basic active sites on the adsorbent surfaces. Several amines (MEA, DEA, MDEA, AMP, PEI, DETA, TETA, TEPA, DIPA, PEHA, TEA, and DGA) have been selected for the amine-screening process. The result revealed that adsorption capacity of raw kenaf is only 0.624 mmol/g, whereas TEPA attained the highest CO2 capture capacity (0.914 mmol/g). Further study on the effect of amine loadings was conducted using two types of amine (MEA and TEPA) and it was found that the highest CO2 adsorption capacity for is 2.070 mmol/g for MEA to kenaf ratio of 1:1 and 2.086 mmol/g for TEPA to kenaf ratio of 2:1. The regeneration study also showed that kenaf sorbent can be used for repeated cycle operations. Due to the presence of amine on kenaf, the regeneration values of MEA–kenaf (82.15%) and TEPA–kenaf (75.62%) were lower than the raw kenaf (99.07%).