| Summary: | 碩士 === 長庚大學 === 化學工程研究所 === 88 === Abstract
In this research, adsorption breakthrough characteristics of binary VOCs system on activated carbon are investigated. At first the isothermal adsorption curves and adsorption kinetic parameters of acetone, DMF, MEK and toluene in the single component system are determined. Then IAST, POT and RAST model are used to calculate the adsorption capacity of the binary adsorption systems. Nader Vahdat and LDF model are used to calculate the breakthrough curves of the binary adsorption from the single-component isotherm equations.
The result shows that the sum of adsorption capacity of binary systems is lower than the sum of adsorption capacity of VOCs in the single-component system. For breakthrough curve prediction, the weak adsorbate is breakthrough early. According to the competition adsorption effect, weak adsorbate on the activated carbon will be replaced by stronger adsorbate. Weak adsorbate will desorb from the activated carbon and goes into stream. Therefore, outlet concentration of weak adsorbate will increase. To determine the adsorption equilibrium time, the concentration of stronger adsorbate is more important factor than that of weak adsorbate. The more inlet concentration of stronger adsorbate , the faster adsorption equilibrium of the system arrives. The predictions of start time and the maximum concentrations of the breakthrough curves by the model are well for the adsorption binary system. For Nader Vahdat model : The parameters, adsorption capacities and k of stronger adsorbate , in the binary system must be corrected. Nader Vahdat model can predict very well the type II and type III curves of the adsorption BTCs. For LDF model : The parameters, film mass transfer coefficient and surface diffusion coefficient, in binary system must be corrected. LDF model can be used to predict any case adsorption BTCs.
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