چكيده به لاتين
In this research, modeling and simulation of the physical and chemical adsorption of CO2 in a closed system and fixed bed column are discussed. In the adsorbent modeling, the granules are supposed to be spherical and, by writing a mass balance around a radial element, a partial differential equation governing the variation of the intensity of adsorption along the radius and in terms of time is obtained. By applying the boundary condition and the initial condition, considering the physics of each problem, this equation can be solved, but because of the complexity of its analytical solution, the MATLAB pdepe sub-program is used for simulation. For the modeling of the fixed bed, the column is aligned along the height, and by writing the mass balance around it, the partial differential equation is obtained. The method of lines was used to solve in MATLAB. In order to obtain the adsorption rate in the fixed bed, also in the boundary condition of the adsorbent surface, the equilibrium concentration obtained by the model is obtained and thus the amount of adsorbate in the direction of the radius and in terms of time is obtained. To verify the physical and chemical adsorption in a closed system, the available experimental data for adsorbing of CO2 equilibrium by zeolite 13X and sodium hydroxide were used. In order to verify the physical and chemical adsorption in the fixed bed, the experimental data available for adsorbing CO2 by modifying alumina and polyaspartamide were used, and amount of adsorbate of physical and chemical adsorption in the fixed bed versus radius and time and simultaneously concentration of CO2 versus the length of the bed and time was obtained. Respectively the amount in the adsorption of CO2 on the zeolite 13X versus pressure, in the breakthrough curve of CO2 adsorption on polyaspartamide, and in the amount of CO2 adsorbed on the polyaspartamide versus time, are 0.99 and RMSE is approximately 10%. The results of the study of the effect of different parameters such as the effect of feed flow rate, feed concentration and bed height on physical and chemical adsorption. By increasing the flow rate of feed, the slope of breakthrough curve is increased, thus the amount of adsorbed decrease, the slope of Breakthrough curve is increased by increasing feed concentration, by increasing the bed height the slope of Breakthrough curve decreases.
