Experiment and Modeling of Adsorption of CO from Blast Furnace Gas onto CuCl/Boehmite

Adsorption of CO, CO2, and N-2 gas on a CuCl/boehmite is studied in static and dynamic experiments to separate CO from blast furnace gas (BFG). The adsorption isotherms of CO, CO2, and N-2 were measured at 20-60 degrees C. Much more CO than CO2 and N-2 was adsorbed within a given temperature range. The adsorption isotherms of CO display a hysteresis loop and leaping phenomenon. The dual-site Langmuir-Freundlich model was chosen to express the adsorption equilibrium of CO. This isotherm model was successfully achieved to describe the equilibrium data of CO. To express the isotherm of CO2 and N-2, the Langmuir-Freundlich model was applied. Also, breakthrough experiments were performed at 25, 40, and 55 degrees C with 7 bar and 1 L min(-1) (25 degrees C, 1 bar) feed flow rate using simulated BFG (CO/CO2/N-2 = 20:20:60 mol %). Within a given temperature range, the experiment results showed that CO has longer breakthrough time than CO2 and N-2. CO2 and N-2 also showed the roll-up phenomenon within the temperature range tested. To predict the breakthrough curve of the simulated BFG, a one-dimensional, nonisothermal model was formulated. The pseudo-second-order model was selected for CO adsorption kinetics, and the pseudo-first-order model was chosen for CO2 and N-2. This model successfully expressed the experimental data. This study widened the understanding of the static and dynamic adsorption characteristics of simulated BFG on the CuCl/boehmite adsorbent within the considered temperature and pressure range. The results may guide future work, especially to find a feasible pressure swing adsorption process to obtain high-purity CO from BFG.