LAPSE:2022.0045
Published Article
LAPSE:2022.0045
Equilibrium and Kinetics of CO2 Adsorption by Coconut Shell Activated Carbon Impregnated with Sodium Hydroxide
Chaiyot Tangsathitkulchai, Suravit Naksusuk, Atichat Wongkoblap, Poomiwat Phadungbut, Prapassorn Borisut
October 12, 2022
The equilibrium and kinetics of CO2 adsorption at 273 K by coconut-shell activated carbon impregnated with sodium hydroxide (NaOH) was investigated. Based on nitrogen adsorption isotherms, porous properties of the tested activated carbons decreased with the increase of NaOH loading, with the decrease resulting primarily from the reduction of pore space available for nitrogen adsorption. Equilibrium isotherms of CO2 adsorption by activated carbons impregnated with NaOH at 273 K and the pressure up to 100 kPa displayed an initial part of Type I isotherm with most adsorption taking place in micropores in the range of 0.7−0.9 nm by pore-filling mechanisms. The amount of CO2 adsorbed increased with the increase of NaOH loading and passed through a maximum at the optimum NaOH loading of 180 mg/g. The CO2 isotherm data were best fitted with the three-parameter Sips equation, followed by Freundlich and Langmuir equations. The pore diffusion model, characterized by the effective pore diffusivity (De), could well describe the adsorption kinetics of CO2 in activated carbons impregnated with NaOH. The variation of De with the amount of CO2 adsorbed showed three consecutive regions, consisting of a rapid decrease of De for CO2 loading less than 40 mg/g, a relatively constant value of De for the CO2 loading of 40−80 mg/g and a slow decrease of De for the CO2 loading of 80−200 mg/g. The maximum De occurred at the optimum NaOH loading of 180 mg/g, in line with the equilibrium adsorption results. The values of De varied from 1.1 × 10−9 to 5.5 × 10−9 m2/s, which are about four orders of magnitude smaller than the molecular diffusion of CO2 in air. An empirical correlation was developed for predicting the effective pore diffusivity with the amount of CO2 adsorbed and NaOH loading.
Keywords
activated carbon, adsorption isotherms, adsorption kinetics, alkali impregnation, carbon dioxide adsorption
Subject
Suggested Citation
Tangsathitkulchai C, Naksusuk S, Wongkoblap A, Phadungbut P, Borisut P. Equilibrium and Kinetics of CO2 Adsorption by Coconut Shell Activated Carbon Impregnated with Sodium Hydroxide. (2022). LAPSE:2022.0045
Author Affiliations
Tangsathitkulchai C: School of Chemical Engineering, Institute of Engineering, Suranaree University of Technology, Muang District, Nakhon Ratchasima 30000, Thailand
Naksusuk S: School of Chemical Engineering, Institute of Engineering, Suranaree University of Technology, Muang District, Nakhon Ratchasima 30000, Thailand
Wongkoblap A: School of Chemical Engineering, Institute of Engineering, Suranaree University of Technology, Muang District, Nakhon Ratchasima 30000, Thailand [ORCID]
Phadungbut P: Department of Chemical Engineering, Faculty of Engineering, Mahidol University, Nakhon Pathom 73170, Thailand
Borisut P: School of Chemical Engineering, Institute of Engineering, Suranaree University of Technology, Muang District, Nakhon Ratchasima 30000, Thailand [ORCID]
Journal Name
Processes
Volume
9
Issue
2
First Page
201
Year
2021
Publication Date
2021-01-21
Published Version
ISSN
2227-9717
Version Comments
Original Submission
Other Meta
PII: pr9020201, Publication Type: Journal Article
Record Map
Published Article

LAPSE:2022.0045
This Record
External Link

doi:10.3390/pr9020201
Publisher Version
Download
Files
[Download 1v1.pdf] (17.2 MB)
Oct 12, 2022
Main Article
License
CC BY 4.0
Meta
Record Statistics
Record Views
140
Version History
[v1] (Original Submission)
Oct 12, 2022
 
Verified by curator on
Oct 12, 2022
This Version Number
v1
Citations
Most Recent
This Version
URL Here
https://psecommunity.org/LAPSE:2022.0045
 
Original Submitter
Thomas A. Adams II
Links to Related Works
Directly Related to This Work
Publisher Version