Both thermogravimetry and manometry coupled to calorimetry techniques were used to determine the adsorption equilibrium of ethyl mercaptan in pure and extruded NaX zeolites. Sorption isotherms were investigated from 298 to 373 K, and over a large range of pressure from 10 −4 to 100 hPa. Adsorption heats were measured at 298 K. Reversible adsorption-desorption isotherms are type I shaped and characterize a very high adsorption affinity of NaX zeolites for ethyl mercaptan. The sulfur compound entirely probes NaX zeolite α-cages at micropore saturation. The presence of the mineral binder for the extruded zeolite does not affect the adsorption phenomenon. Adsorption data were well fitted using the Polanyi-Dubinin model. Calorimetric and isosteric heats do not change very much with loading, indicating that NaX zeolite is energetically homogeneous for the adsorption of ethyl mercaptan. Additional information concerning state of adsorbed phase were obtained from isosteric molar entropy curves. Therefore, the NaX faujasite appeared as a powerful potential candidate for industrial desulfurization of natural gas by adsorption process.

In this paper, we present a new experimental procedure which aims at measuring adsorption isotherms and heats of adsorption of volatile organic compounds (VOCs) on porous media in the low relative pressure range for temperatures ranging from 303 to 573 K. The experimental set-up and the experimental dynamic procedure are presented as well as a complete report on the treatment of the rough experimental results to obtain the adsorption isotherms and the adsorption heat curves. Measurement accuracy and repeatability are given. The maximum measurement error is 3% on the adsorbed mass, 9% on the partial pressure of VOC and 15% on the adsorption heat. Results are provided for a toluene/NaY system (isotherm and adsorption heat curve at 423 K in the pressure range 0.4-2000 Pa).

In this paper, we propose a comparative study between a gravimetric apparatus operating under dynamic conditions and a pulse chromatographic device developed for the determination of Henry constants of adsorption for VOC–zeolite systems. In both cases, we provide a description of the experimental set-up and procedure, as well as a complete report on the treatment of the rough experimental data. The experimental errors are also discussed. The comparison work is based on the study of the adsorption of toluene on a NaY zeolite (Si/Al 2.43) for temperatures ranging from 503 to 623 K. The maximal discrepancy found between the experimental Henry constants was 15.0%. The pulse chromatographic method is only dedicated to high-temperature measurements. For low-temperature experiments, the rough data cannot be treated in an efficient way, and it is not possible to obtain reliable Henry constant values. The dynamic gravimetric method is not temperature limited. It is however time-consuming, especially when low-temperature measurements (not presented in this paper) are concerned. Both methods are complementary if the determination of Henry constants is required in a wide temperature range.