Study of CO2 Adsorption on Chemically Modified Activated Carbon With Nitric Acid and Ammonium Aqueous

Abstract

The study of CO 2 adsorption on adsorbent materials is a current topic of research interest. Although in real operating circumstances, the removal conditions of this gas is carried out at temperatures between 290 and 303 K and 1 Bar of pressure or high pressures, it is useful, as a preliminary approach, to determine CO 2 adsorption capacity at 273K and 1 Bar and perform a thermodynamic study of the CO 2 adsorption heats on carbonaceous materials prepared by chemical activation from African palm shell with CaCl 2 and H 3 PO 4 solutions, later modified with HNO 3 and NH 4 OH, with the aim to establish the influence that these treatments have on the textural and chemical properties of the activated carbons and their relationship with the CO 2 adsorption capacity. The carbonaceous materials were characterized by physical adsorption of N 2 at 77K, CO 2 at 273K, proximate analysis, Boehm titrations and immersion calorimetry in water and benzene. Activated carbons had a BET area between 634 and 865 m 2 g −1 , with a micropore volume between 0.25 and 0.34 cm 3 g −1 . The experimental results indicated that the modification of activated carbon with HNO 3 and NH 4 OH generated a decrease in the surface area and pore volume of the material, as well as an increase in surface groups that favored the adsorption of CO 2 , which was evidenced by an increase in the adsorption capacity and the heat of adsorption.

Nitrogen doped activated carbon derived from chitosan/hexamethylenetetramine: structural and CO2 adsorption properties

“…Among the three samples C-0 showed that maximum adsorption capacity with adsorption values of 97.98, 97.55, 96.34, 97.45, 95.34 mg/g respectively. It was expected an increase in the CO 2 adsorption for N-doped activated carbons as reported in previous studies [44,45]. The basic nitrogen functionalities react with the Lewis acidic CO 2 to increase the chemisorption to a greater extent.…”

Water Treatment Using High Performance Antifouling Ultrafiltration Polyether Sulfone Membranes Incorporated with Activated Carbon

“…Concerning to the modification of AC with APTMS, a decrease in BET area and pore volume of mAC up to 188 m 2 /g and 0.490570 cm 3 /g respectively, in relation to non- chemically modified AC. The formation of new surface functional groups attributed as the major obstruction for the drastic decrease in surface area [ 60 ]. Similar results have shown that formation of surface functional groups like nitriles, amides, amines, among others block the existing pores and reduce the surface are upon chemical modification of carbonaceous material [ 61 , 62 ].…”

Synthesis of exopolysaccharide-based organo-montmorillonite with improved affinity towards carbon dioxide and hydrophilic character

“…20-21 µmol•m −2 as defined by the CRC/Surface area ratio [17]. Compared to various highly porous materials [9][10][11][12][13][14][15][16]41] this value is lower than that of activated carbons (ca.…”

“…Other CO 2 capture attempts were performed with materials such metal-inorganic-organic core-shell material [9], chemically modified activated carbon with nitric acid and ammonium aqueous solutions [10], cupric nitrate [11] or polyacrylonitrile [12], functionalized carbonaceous and silica-based materials [13], zeolites and layered double hydroxides [14][15][16], metal-organic frameworks (MOFs), mesoporous silica, clay, porous carbons, porous organic polymers (POP), and metal oxides (MO) [16]. Most of these materials involve costly/sophisticated synthesis procedures but low surface affinity as reported to their specific surface area as defined earlier [17].…”