Several studies have been reported with the purpose of storing NG in porous media by adsorption. Experimental data and mathematical models that describe the adsorption phenomena of pure methane, the main component of NG (about 90%) already exist, however they do not describe satisfactorily the behavior of NG storage cycles, because of the presence of several other hydrocarbons like ethane, propane, butane and heavier alkanes. This study presents measurements of experimental data for the adsorption equilibrium of binary mixtures of low-molecular-weight alkanes and compares them with mathematical models for multicomponent adsorption prediction based on each pure component adsorption data. Experiments were performed with the binaries methane-ethane, methane-propane and methane-butane. Experimental results were compared with predictions from the Extended Langmuir model and Ideal Adsorbed Solution (IAS) model.

This short communication presents a new technique for evaluation of adsorption equilibrium in the liquid phase using headspace chromatography. The technique may be used in two different modes: single-component equilibrium (the "finite bath" mode) and the multicomponent selectivity mode. Illustrative experimental results are presented for xylenes adsorption on Y zeolite pellets.

Cubic Y zeolite were successfully synthesized using microwave heating for 18 - 25 min, whereas 10 - 50 h are required by hydrothermal heating technique depending upon the lattice Si/Al ratio. To this end, we used a commercial microwave oven modified in order to provide pulsed microwave pumping on the synthesis mixtures. The obtained samples were analyzed by X-ray diffraction, BET surface area and infrared spectroscopy measurements. As a result, we verify that Y zeolite samples obtained from hydrogels containing low aluminum contents, present a good degree of crystallinity and then can be suitable for using in adsorption and catalysis experiments.

Abstract - Selective adsorbents have become frequently used in industrial processes. Recent studies have shown the possibility of using adsorption to separate copper refinery electrolyte contaminants, with better results than those obtained with conventional techniques. During copper electrorefinning, many impurities may be found as dissolved metals present in the anode slime which forms on the electrode surface, accumulated in the electrolyte or incorporated into the refined copper on the cathode by deposition. In this study, synthetic zeolites, chelating resins and activated carbons were tested as adsorbents to select the best adsorbent performance, as well as the best operating temperature for the process. The experimental method applied was the finite bath, which consists in bringing the adsorbent into contact with a finite volume of electrolyte while controlling the temperature. The concentration of metals in the liquid phase was continuously monitored by atomic absorption spectrophotometry (AAS)

The sorption kinetics of some aromatics (toluene, p-xylene, o-xylene and p-diethylbenzene) was studied experimentally with a high sensitivity microbalance (± 1µg) at temperatures between 150 and 210ºC and concentrations in the adsorbed phase of a maximum of 1 mmol/g. In general, the sorption rates decreased in the following order: toluene > p-xylene > o-xylene > p-diethylbenzene. Two diffusion models were tested against the experimental results. One model considers the mass transfer inside the zeolitic micropores as the controlling diffusion step. The other model supposes that resistance to mass transfer in the macropores (formed during pelletization of the crystals with the amorphous ligand) is the limiting step. The results observed for both models are presented and analyzed