Author(s): Camacho, Bárbara Cassiana Rodrigues
Date: 2014
Persistent ID: http://hdl.handle.net/10362/12140
Origin: Repositório Institucional da UNL
Subject(s): Equilibrium adsorption; Adsorption isotherms; Adsorbent materials; Adsorbates; Gravimetric method
Dissertação para obtenção do Grau de Mestre em Engenharia Química e Bioquímica
The objective of this work was the measuring of adsorption equilibrium, by the gravimetric method. Experimental results are presented for the adsorption equilibrium of the series of n-alkanes, ethylene, nitrogen and carbon dioxide in two microporous materials, the metal-organic framework, MIL-53(Al) and zeolite 5A. Both of them have desirable characteristics for adsorption processes, such as the capture and storage of carbon dioxide, natural gas storage, separation of components of biogas, and separation of olefin/paraffin. The determination of the equilibrium of the pure components (ethane, propane, butane, ethylene, carbon dioxide and nitrogen) covers a wide range of thermodynamic conditions; temperatures between 303.15K and 373.15K, as well as pressure values between 0 and 50 bar. The adsorption equilibrium data were analyzed through the global adjustment for each adsorbate/adsorbent system, using the Sips and Toth models. The isosteric heat was also determined. The experimental data of methane, carbon dioxide and nitrogen were correlated successfully by the potential theory of adsorption collapsing into a single characteristic curve, independent of temperature. This analysis allows the extrapolation of adsorption data for other gases, for which no experimental data is still known. The adsorption capacity is generally higher in MIL-53(Al) than in zeolite 5A, and in the two adsorbents, the preferred adsorption capacity for carbon dioxide is a good indication that these materials have a strong potential in the capture and storage of carbon dioxide, in the purification of biogas or purification of methane from natural gas.
