title: Breakthrough CO₂ adsorption in bio-based activated carbons.
abstract: In this work, the effects of different methods of activation on CO2 adsorption performance of activated carbon were studied. Activated carbons were prepared from biochar, obtained from fast pyrolysis of white wood, using three different activation methods of steam activation, CO2 activation and Potassium hydroxide (KOH) activation. CO2 adsorption behavior of the produced activated carbons was studied in a fixed-bed reactor set-up at atmospheric pressure, temperature range of 25-65°C and inlet CO2 concentration range of 10-30 mol% in He to determine the effects of the surface area, porosity and surface chemistry on adsorption capacity of the samples. Characterization of the micropore and mesopore texture was carried out using N2 and CO2 adsorption at 77 and 273 K, respectively. Central composite design was used to evaluate the combined effects of temperature and concentration of CO2 on the adsorption behavior of the adsorbents. The KOH activated carbon with a total micropore volume of 0.62 cm(3)/g and surface area of 1400 m(2)/g had the highest CO2 adsorption capacity of 1.8 mol/kg due to its microporous structure and high surface area under the optimized experimental conditions of 30 mol% CO2 and 25°C. The performance of the adsorbents in multi-cyclic adsorption process was also assessed and the adsorption capacity of KOH and CO2 activated carbons remained remarkably stable after 50 cycles with low temperature (160°C) regeneration.
authors.affiliation: Department of Chemical and Biological Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, SK S7N 5A9, Canada. Electronic address: ses439@mail.usask.ca.
authors.forename: Sepideh
authors.initials: S
authors.lastname: Shahkarami
authors.affiliation: Department of Chemical and Biological Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, SK S7N 5A9, Canada.
authors.forename: Ramin
authors.initials: R
authors.lastname: Azargohar
authors.affiliation: Department of Chemical and Biological Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, SK S7N 5A9, Canada. Electronic address: ajay.dalai@usask.ca.
authors.forename: Ajay K
authors.initials: AK
authors.lastname: Dalai
authors.affiliation: Department of Chemical and Biological Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, SK S7N 5A9, Canada.
authors.forename: Jafar
authors.initials: J
authors.lastname: Soltan
mesh_terms: D000327:Adsorption; D000393:Air Pollutants / Q000737:chemistry*; D000397:Air Pollution / Q000517:prevention & control*; D002244:Carbon / Q000032:analysis; D002245:Carbon Dioxide / Q000737:chemistry*; D002606:Charcoal / Q000737:chemistry*; D052918:Environmental Restoration and Remediation / Q000379:methods*; D013696:Temperature
chemical_list: D000393:Air Pollutants; C540010:biochar; D002245:Carbon Dioxide; D002606:Charcoal; D002244:Carbon
keywords: Activated carbon; Biochar; Dynamic CO(2) adsorption; Micropore; Surface area