Thermodynamics of CO2 Adsorption on Polyethyleneimine Mesoporous Silica and Activated CarbonAl-Marri MJ1, Al-Saad KA2, Saad MA3, Cortes DJ1and Khader MM1*
- *Corresponding Author:
- Khader MM
Gas Processing Center
College of Engineering, Qatar University
PO Box 2713 Doha, Qatar
E-mail: [email protected]
Received Date: March 08, 2017 Accepted Date: March 13, 2017 Published Date: March 22, 2017
Citation: Al-Marri MJ, Al-Saad KA, Saad MA, Cortes DJ, Khader MM (2017) Thermodynamics of CO2 Adsorption on Polyethyleneimine Mesoporous Silica and Activated Carbon. J Phys Chem Biophys 7: 239. doi: 10.4172/2161-0398.1000239
Copyright: © 2017 Al-Marri MJ, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
A thermodynamic study of the enthalpies of adsorption of CO2 was conducted on polyethyleneimine 10k/ mesoporous silica (PEI-10k/MPS) and activated carbon (AC). These materials were chosen because of their high CO2 sorption capacities at about 85°C for PEI and about 20°C for the AC, therefore can capture CO2 with high efficiency in a wide temperature range. The absolute quantity of adsorbed CO2 as a function of equilibrium pressure at various temperatures was determined experimentally and fitted to isotherms of generalized Langmuir and Toth equations for PEI and AC, respectively. The adsorption of CO2 on PEI was favored with temperature revealing the endothermic nature of the process. On the other hand, CO2 adsorption on the AC was exothermic. The isosteric enthalpy of adsorption on PEI was about constant with CO2 loading at a value of 93 kJ.mol-1, confirming its chemical nature and corroboration with the Langmuir model. The corresponding isosteric enthalpy of the AC was in the range of ~-25 kJ.mol-1 and was continuously decreasing with CO2 loading; confirming the physisorption nature of the process and also that CO2/ CO2 interactions within the adsorption layer was significant.