Comparison of Optimized Isotherm Models and Error Functions for Carbon Dioxide Adsorption on Activated Carbon

Abstract

The adsorption of CO2 on commercial activated carbon WG12 and WG12 modified by ZnCl2 and KOH was investigated using a high pressure Sievert’s apparatus. The experimental data were analyzed using Langmuir, Freundlich, Sips, Toth, Unilan, Ftitz–Schlunder, and Redlich–Peterson equations. An error analysis was performed to examine the effect of using different error criteria for the isotherm parameters determination. Five error analysis methods were used: the sum of the squares of errors, the hybrid fractional error function, the average relative error, the Marquardt’s percent standard deviation, and the sum of the absolute errors. The Sips isotherm provided the best quality of fitting for all the experimental data. Error function analysis found that sum of the squares of the errors and hybrid fractional error function provided the best overall results.

Modification of Commercial Activated Carbons for CO2Adsorption

“…• C. Mathematical methods are very useful for thermodynamics [3] and kinetics model [25] solving. CO 2 adsorption data on activated carbons were fitted to the Langmuir, Freundlich, Sips and Toth standard isotherm models.…”

“…The increased CO 2 concentration in the atmosphere due to emissions from fossil fuel combustion has caused concerns about climate changes [1]. Now, a wide range of techniques including, conversion to useful chemicals [2] adsorption [3], absorption [4] and membranes [5] have been suggested to sequestrate CO 2 from fuel gases. Adsorption is thought by many scientists to be a promising and economical technique due to its low energy requirement, cost effectiveness, and ease of use at a wide variety of temperatures and pressures [6].…”

“…* corresponding author; e-mail: jsrenscek@zut.edu.pl Physical activation is usually carried out using carbon dioxide, steam, air, or their mixture. Chemical activation involves various agents such as ZnCl 2 [9], KOH [3,10,11] and K 2 CO 3 [12]. Adsorption performance of AC depends on the pore structure and surface properties.…”

Activated Carbons from Molasses as CO2Sorbents

“…One of the best gas-adsorbing materials is activated carbon (AC). Vast surface area and porosity makes ACs potential highly impressive [4,5]. It is plausible to produce AC materials from almost every organic material, with relatively high content of carbon.…”

Preparation of Activated Carbon from Beet Molasses and TiO2as the Adsorption of CO2

“…Activated carbons are microporous and mesoporus materials widely studied as potential CO 2 adsorbents [9][10][11][12][13][14]. In common opinion, the advantages of activated carbons are their low cost and flexibility in terms of porous texture, regeneration and surface properties [15,16].…”