The comprehensive comparative study of industrial synthetic granulated zeolites

The article is describing a selection process of the commercial zeolite-based adsorbents, which are optimal for drying of the associated petroleum gas (APG). The series of commercial zeolite adsorbents made in the form of extrudates (А-З) or of a spherical shape (И-О) have been subjected to a number of the lab scale tests, defining such important characteristics of the commercial synthetic granulated zeolites 4A as bulk density, crush and attrition strength, resistance to water, dynamic water vapor capacity. The crush tests have shown that all extrudates have crush strength above consumer requirements. It has been noticed that among the series of the spherical shaped zeolites the zeolite И has best crush strengths, but the attrition of the same zeolite is very high and incompatible with the technology requirements. Based on the defined mechanical characteristics of the zeolites it has been proposed that the zeolite З and all spherical shaped zeolites except И and Л made with the use of a binder that might negatively effect on the dynamic water vapor capacity. In order to be able to recommend tested zeolites for the industrial use the series of continuous tests with repeating water vapors adsorption-zeolite regeneration cycles have been made on the automated lab scale pilot adsorption plant. The adsorbents Е, Ж, З, Н, О appeared to be inappropriate for the industrial use as drying agents for APG. On the contrary, the drying agents А-Д function for a continuous time without a noticeable loss of the dynamic water vapor capacity. The zeolites А and И from the investigated series displayed the largest number of the adsorption-regeneration cycles, more than 20. Taking in account that the adsorbent И has low attrition strength, it might be assumed that this adsorbent was made with faults in its preparation procedure. Nevertheless, for a better selection of commercial adsorbents most suitable for drying ofAPG additional pilot scale tests are required in conditions, which are close to those used in industry in the oil and gas processing plants. Such tests should also be helpful to define not only the deactivation rate of the zeolites but also the degree of the coke formation on the exploited for drying of APG adsorbents. It has been shown that the applied lab scale methods can be used for the selection of the optimal zeolites for drying of APG with purpose to subject the selected adsorbents for further pilot scale tests. Results obtained in the present work can be used in the further studies on the subject.

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