An Experimental Design Study on CO2 and CH4 Adsorption Equilibria in MWCNT-OH and Optimal Conditions for Maximum CO2 Adsorption against CH4

Equilibrium adsorption property of multi-walled carbon nanotubes functionalized by hydroxyl group (MWCNTOH) was studied using experimental design for adsorption of CH4 and CO2. The effect of temperature, pressure and their interaction on the adsorption capacity was examined by the central composite orthogonal design (CCOD) and the significant effects were determined by analysis of variance. The experiments were carried out at various temperatures (from 288.15 to 308.15 K) and pressures (4.5 to 39.8 bars) to find out the optimal conditions for the maximum adsorption of CO2 versus CH4 on the MWCNT-OH. The statistical analysis of the results showed the significance of linear, interaction and quadratic relation of temperature and pressure to CO2 and CH4 adsorbed capacity. After optimization, the maximum CO2/CH4 selectivity was determined at temperature of 288.15 K and pressure of 21.32 bar which was predicted as 6.35.

کلیدواژه ها:

Design of experiment (DOE) ، Central composite orthogonal design (CCOD) ، MWCNs ، light gas adsorption