Journal of the Taiwan Institute of Chemical Engineers 89 (2018) 140–150 Contents lists available at ScienceDirect Journal of the Taiwan Institute of Chemical Engineers journal homepage: www.elsevier.com/locate/jtice Synthesis of porous carbon monolith adsorbents for carbon dioxide capture: Breakthrough adsorption study Jasminder Singh a , Haripada Bhunia b,∗ , Soumen Basu a,∗ a School of Chemistry and Biochemistry, Thapar Institute of Engineering and Technology, Patiala 147004, Punjab, India b Chemical Engineering Department, Thapar Institute of Engineering and Technology, Patiala 147004, Punjab, India a r t i c l e i n f o Article history: Received 15 January 2018 Revised 20 April 2018 Accepted 24 April 2018 Keywords: Carbon monoliths Bimodal porosity Carbon dioxide capture Adsorption Breakthrough curve Regeneration a b s t r a c t Carbon monoliths with bimodal porosity were obtained through nanocasting technique from silica mono- liths (hard template) and furfuryl alcohol (precursor). These carbon adsorbents were evaluated as sor- bents for CO 2 capture by using a fixed-bed adsorption set up under dynamic conditions. Carbonization at different temperatures (550 to 950 °C) was carried out that resulted in the generation of different carbon adsorbents containing oxygen functional groups. The textural characterization results reveal the effect of nanocasting technique, which is confirmed from the generation of mesopores (0.41), microp- ores (0.85 cm 3 g −1 ) and high surface area (1225.1 m 2 g −1 ) of adsorbent synthesized at 950 °C, as shows highest CO 2 uptake of 1.0 mmol g −1 at 30 °C and 12.5% CO 2 concentration. The increase in the adsorption capacity with increasing CO 2 concentration and decrease with the increasing adsorption temperature con- firms the physisorption process. Five adsorption–desorption cycles show established materials with excel- lent regeneration stability as an adsorbent. Furthermore, three kinetic models along with three isotherms were used in the present study to analyze the adsorption data and found that fractional order kinetic model and Temkin isotherm fitted best. Thermodynamic studies suggested the exothermic, spontaneous as well as the feasibile nature of the adsorption process. © 2018 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved. 1. Introduction In the Earth’s atmosphere, major greenhouse gases, including methane (CH 4 ), nitrous oxide (N 2 O), carbon dioxide (CO 2 ), and ozone (O 3 ), is considered responsible for rapid climate change and among these gases CO 2 is the second largest contributor to the global warming after water because of its emission has been iden- tified as a main contributor to the atmosphere. The anthropogenic CO 2 emissions are almost entirely caused by combustion of fossil fuels like coal and natural gas to produce energy [1, 2]. The CO 2 concentration increased from 280 ppm to 406.75 ppm at present year (2018) [3] which is expected to increase up to a level of 570 ppm by 2100 [4] which will rise the global surface temper- ature and create problem such as climate change, increase in the acidity of oceans and serious health issues for the living-beings [5, 6]. Currently, carbon capture and storage (CCS) technology are the important technology to reduce the concentration of CO 2 and play a significant role to obtain the required reduction in greenhouse gas (GHG) emissions [7]. CCS includes three basic types: post- ∗ Corresponding authors. E-mail addresses: hbhunia@thapar.edu (H. Bhunia), soumen.basu@thapar.edu (S. Basu). combustion, pre-combustion and oxy-fuel combustion capture. The most widely adopted technology is the post-combustion for CO 2 capture from emission source due to its flexibility and ease of retrofit to existing combustion technologies [8]. It includes chem- ical absorption, cryogenic separation, adsorption, membrane sepa- ration and biological fixation [9, 10]. Among the various methods, the chemical solvent absorption for CO 2 capture is efficient but it requires a large amount of energy for regeneration due to the large emission of flue gases and low CO 2 concentration. Also, it causes equipment corrosion and need for a large absorber volume [11]. CO 2 capture by adsorption method is considered one of the po- tential in terms of cost-effective options because of the cost advan- tage, low energy consumption and ease of applicability over a wide range of temperature and pressure. However, the choice of the ad- sorbents with high CO 2 selectivity and adsorption capacity, high stability, and easy regenerability make it successful [10, 12]. The CO 2 adsorption on solid adsorbents, including porous carbons [13], amine-modified silicas [14], zeolites [15], and metal-organic frame- work compounds [16] have received considerable research interest recently. Carbon-based materials are considered to be one of the outstanding materials for CO 2 adsorption due to their large surface area [17], wide availability [18], low cost [19], adjustable poros- ity [20] and low energy for regeneration [17]. On the other hand, https://doi.org/10.1016/j.jtice.2018.04.031 1876-1070/© 2018 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.