Table of Contents
Research Letters in Physical Chemistry
Volume 2008, Article ID 127328, 4 pages
Research Letter

Determination of Differential Enthalpy and Isotherm by Adsorption Calorimetry

1Research Group on Porous Solid and Calorimetry, Department of Chemistry, Faculty of Sciences, University of the Andes, Carrera 1 No. 18 A 10 Bogotá, Colombia
2Department of Chemistry, Faculty of Sciences, National University of Colombia, Ciudad Universitaria, Transversal 38 No. 40-01 Bogotá, Colombia
3Instituto de Física Aplicada (INFAP), CONICET- Universidad Nacional de San Luis, Ejército de los Andes 950, San Luis D5700HHW, Argentina
4Departamento de Engenharia Química, Universidade Federal do Ceará, Campus do Pici, Fortaleza 60455-760, Brazil

Received 15 May 2008; Accepted 23 June 2008

Academic Editor: Anatoly Rusanov

Copyright © 2008 V. Garcia-Cuello et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


An adsorption microcalorimeter for the simultaneous determination of the differential heat of adsorption and the adsorption isotherm for gas-solid systems are designed, built, and tested. For this purpose, a Calvet heat-conducting microcalorimeter is developed and is connected to a gas volumetric unit built in stainless steel to record adsorption isotherms. The microcalorimeter is electrically calibrated to establish its sensitivity and reproducibility, obtaining 𝐾 = 1 5 4 . 3 4 ± 0 . 2 3 W V 1 . The adsorption microcalorimeter is used to obtain adsorption isotherms and the corresponding differential heats for the adsorption of C O 2 on a reference solid, such as a NaZSM-5 type zeolite. Results for the behavior of this system are compared with those obtained with commercial equipment and with other studies in the literature.