Theoretical and experimental SO2 adsorption onto pistachio-nut-shell activated carbon for a fixed-bed column

The adsorption and desorption behaviours of SO₂ onto activated carbons, which were prepared from pistachio-nut shells, were studied theoretically and experimentally in a fixed-bed column. A mathematical model considering non-equilibrium, non-isothermal and non-adiabatic effects for a single gas adsorbate on a fixed-bed system was derived and the model was solved by a finite-difference method. A linear driving force (LDF) approximation is used for heat and mass transfer rates. The temperature-dependent Langmuir equilibrium isotherm is used to represent gas–solid equilibrium isotherm. The theoretical study was conducted to compare the present model with the isothermal and adiabatic model. The effects of inlet concentration, flow rate and temperature were studied experimentally. These experimental data showed that the breakthrough time decreased with increasing feed concentration, increasing flow rate and increasing temperature and the trends were correctly predicted by the model calculations.