Fixed-bed adsorption for bulk component system. Non-equilibrium, non-isothermal and non-adiabatic model

Abstract

A mathematical model (non-equilibrium, non-isothermal and non-adiabatic) for bulk single component adsorption on a fixed-bed system is developed. The model takes account of both temperature effects and changes in flow rate due to adsorption of solute, and is therefore more general than previous models. This model is based on the use of linear driving force approximations for heat and mass transfer rates. The temperature-dependent Langmuir equilibrium isotherm is used to represent gas-solid equilibrium isotherm. The model consists of a set of coupled partial differential equations, and the differential equations representing the mass and energy balances are solved by the numerical method of lines. Based on the model simulation, the effects of heats and mass transfer parameters on the concentration profiles through the bed were investigated, and the model predictions were compared with the isothermal and adiabatic model calculations. Also, the adsorption breakthrough curves and temperature profiles of carbon dioxide on activated carbon were measured experimentally for bulk component system. The effects of total pressure, inlet composition and flow rate on breakthrough curves and temperature profiles were studied, and the experimental data were compared with the model calculations. The mathematical model provides a good representation of the experimentally observed behavior of the breakthrough curves and temperature profiles for carbon dioxide on activated carbon, suggesting that the model represents the essential features of the real systems fairly well.