Affiliation:
1. Chemical Engineering Studies, College of Engineering, Universiti Teknologi MARA, Johor Branch, Pasir Gudang Campus, Masai, Johor 81750, Malaysia
Abstract
Introduction:
Carbon capture and storage (CCS) is the most mature technology to
capture CO2 from flue gas stream through the adsorption process. The commercial adsorbent,
though efficient, is cost-inhibitive. An alternative adsorption approach is by utilizing a palm
kernel shell (PKS) as adsorbent. To enhance the adsorption capacity of CO2, impregnation
with Tetraethylenepentamine (TEPA) and imidazoles (Ims) were introduced to increase the
selectivity and capacity of CO2. The response surface methodology (RSM) technique was utilized
to optimize the operating conditions for the preparation of modified AC-PKS for carbon
capture applications.
Method:
The main process variables for this study were impregnation ratio (TEPA: Ims) and
impregnation temperature. The 2 Factorial 1 model was developed for iodine number which
was selected as the investigated response. The optimum conditions for modified AC-PKS had
been identified to be an impregnation ratio 0.17 and a temperature of 90°C which gave a maximum
of iodine number 1062.95 mg/g. Based on this optimum condition, the experimental
value of iodine number is 1027.58 mg/g and is found to agree adequately with that (1062.95
mg/g) predicted from the model. The higher the iodine number, the greater the surface area
available for adsorption. With the high surface area of activated carbon allows it to have more
adsorption sites, increasing its capacity to remove contaminants from liquids or gases. According
to Scanning electron microscope (SEM), TEPA and Ims molecules were attached to
the surface of ACs and stimulated the chemisorption process for excellent adsorption process.
Result:
Two prominent adsorption peaks were also observed at 3100 cm-1 and 2800 cm-1, corresponding
to the stretching of the N-H functional group and confirmed the successfulness of impregnation
between TEPA and Ims. Based on elemental analysis (EA), the addition of TEPA and
imidazole resulted in an increase in the number of amine groups on the surface of the adsorbent.
Conclusion:
Hence, this modified AC-PKS with optimum impregnation ratio and temperature
increased the adsorption capacity and selectivity of CO2 adsorption from the simulated
flue gas with 4.239 mol/kg AC compared to the previous study reported for unmodified ACPKS
only 1.005 mol/kg AC.
Funder
University Teknologi MARA, Cawangan Johor
Publisher
Bentham Science Publishers Ltd.
Subject
General Chemical Engineering