عليرضا تركاشوند

As one of the microporous polymers, hypercrosslinked polymers (HCP) have attracted a lot of attention in CO2 adsorption due to their low density, chemical stability, high surface area, and high specific surface area. Preliminary experiment on CO2 adsorption by carbazole-based HCP adsorbent showed that this adsorbent has a high potential due to the presence of an amine functional group in its structure. Considering the structure of carbazole and the presence of two benzene rings in its structure, the ability of carbazole to be hypercross-linked through the cross-linker formaldehyde dimethyl acetal is justified. On the other hand, amine modification of the adsorbent is known to improve it. Therefore, research on amine modification of HCP adsorbents is increasing. The aim of this study was the synthesis of hypercrosslinked adsorbent based on carbazole monomer using Friedel-Craft reaction for CO2 adsorption. The tests of CO2 gas adsorption were performed in a batch reactor on a laboratory scale in a temperature range between 298 K and 328 K and a pressure of 1 bar to 9 bar. Modification of carbazole-based HCP adsorbent surface by grafting ethyl group (CH3-CH2-) and then in the second step ethyl groups (CH3-CH2-) attached to aromatic rings are replaced by carboxylic acid and finally carboxylated adsorbent with ethylene Diamine (C2H8N2) was mixed and the amine group of the first and second types was added to the base adsorbent. In addition, the adsorption capacity was increased by post-synthesis modification using the amine modification process. The structural characteristics of the adsorbent are provided by various techniques such as FTIR, BET, and EDS. A higher specific surface area was obtained for the amine-modified adsorbent (N-HCP) with a value of 705.35 (m2/g) compared to the HCP adsorbent with a value of 384.21 (m2/g). The carbon dioxide adsorption capacity of carbazole-based (HCP) and amine-modified samples (N-HCP) was eva‎luated in different conditions. The adsorption capacity of the modified sample (N-HCP) at 5 bar pressure and temperature of 273 K is 236.37 (mg/g), which is higher than the HCP sample with a value of 182.13 (mg/g). In order to better understand the adsorption process, experiments were conducted to investigate the isotherm, kinetic and thermodynamic process.

دي اكسيد كربن , جذب سطحي , پليمر هايپر كراس‌لينك شده , كربازول , اصلاح آميني

Carbon dioxide , adsorption , hyper cross-linked polymer , carbazole , amine modification

Alireza Torkashvand

ahad ghaemi