title: CO2capture performance of bi-functional activated bleaching earth modified with basic-alcoholic solution and functionalization with monoethanolamine: isotherms, kinetics and thermodynamics.
abstract: CO2capture performance of bifunctional activated bleaching earth (ABE) was investigated at atmospheric pressure. The sorbents were characterized by means of X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), Caron-Hydrogen-Nitrogen analysis (CHN), Fourier transform infrared (FT-IR) and thermal gravimetric analysis (TGA). The CO2capacity was enhanced via basic-modification and monoethanolamine (MEA) loading of the ABE sorbent to obtain a bifunctional surface property. Here, basic-modified calcined ABE with a 30wt.% MEA loading (SAB-30) showed the highest CO2capture capacity, but this was decreased with excess MEA loading (>30wt.%). At a 10% (V/V) initial CO2concentration feed, the maximum capacity of SAB-30 increased from 2.71mmol/g at 30°C (without adding moisture to the feed) to 3.3mmol/g at 50°C when adding 10% (V/V) moisture to the feed. Increasing the moisture concentration further reduced the maximum CO2capacity due to the blocking effect of the excess moisture on the sorbent surface. However, SAB-30 could completely capture CO2even in a 100% (V/V) initial CO2concentration feed. A maximum CO2capacity of 5.7mmol/g for SAB-30 was achieved at 30°C. Varying the ratio of sorbent weight to total flow rate of the gas stream had no discernible effect on the equilibrium CO2capture capacity. Avrami's equation and Toth's isotherm model provided a good fitting for the data and suggested the presence of more than one reaction pathway in the CO2capture process and the heterogeneous adsorption surface of SAB-30. Thermodynamics studies revealed that CO2capture on the bifunctional SAB-30 is feasible, spontaneous and exothermic in nature.
authors.affiliation: Department of Chemical Technology, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Patumwan, Bangkok 10330, Thailand; Center of Excellence on Petrochemical and Materials Technology, Chulalongkorn University, Phayathai Road, Patumwan, Bangkok 10330, Thailand. Electronic address: sangobtip.p@chula.ac.th.
authors.forename: Sangobtip
authors.initials: S
authors.lastname: Pongstabodee
authors.affiliation: Department of Chemical Technology, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Patumwan, Bangkok 10330, Thailand.
authors.forename: Phuwadej
authors.initials: P
authors.lastname: Pornaroontham
authors.affiliation: Department of Chemical Technology, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Patumwan, Bangkok 10330, Thailand; Center of Excellence on Petrochemical and Materials Technology, Chulalongkorn University, Phayathai Road, Patumwan, Bangkok 10330, Thailand.
authors.forename: Nuthapol
authors.initials: N
authors.lastname: Pintuyothin
authors.affiliation: Department of Chemical Technology, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Patumwan, Bangkok 10330, Thailand; Center of Excellence on Petrochemical and Materials Technology, Chulalongkorn University, Phayathai Road, Patumwan, Bangkok 10330, Thailand.
authors.forename: Nuttapol
authors.initials: N
authors.lastname: Pootrakulchote
authors.affiliation: Department of Chemical Technology, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Patumwan, Bangkok 10330, Thailand.
authors.forename: Nutthavich
authors.initials: N
authors.lastname: Thouchprasitchai
mesh_terms: D065966:Absorption, Physicochemical; D000327:Adsorption; D002245:Carbon Dioxide / Q000737:chemistry*; D019856:Ethanolamine / Q000737:chemistry*; D006859:Hydrogen; D007700:Kinetics; D008956:Models, Chemical; D009584:Nitrogen; D013499:Surface Properties; D013816:Thermodynamics
chemical_list: D002245:Carbon Dioxide; D019856:Ethanolamine; D006859:Hydrogen; D009584:Nitrogen
keywords: Activated bleaching earth; Bifunctional surface; Capture; Carbon dioxide