Comparison of commercial 3A zeolites for the ethanol-water separation using pressure swing adsorption.

摘要

Pilot scale fixed bed adsorber was used in the study of adsorption of ethanol and water on commercial zeolites. Breakthrough curves were measured in the fixed bed adsorber containing pellets of 3A zeolite with feed mixtures of water and nitrogen or ethanol and nitrogen. The goal was to investigate the effects of operating conditions such as concentration, temperature and pressure on the breakthrough curves for both water and ethanol. Secondly, two different commercial zeolite samples (zeolite 1 and zeolite 2) were used and their breakthrough curves were recorded and compared to select the best adsorbent for the Pressure Swing Adsorption (PSA) process.;A mathematical model was developed to simulate the experimental data. The adsorption rate model was based on the linear driving force (LDF) approximation. The system of partial differential equations was solved via method of lines using a stiff equation ODE solver with MATLAB. Model parameters were estimated from independent experiment as well as from literature. The agreement between the model predictions and experiments was good.;Based on equilibrium studies, both the zeolites behaved in a similar manner. However, according to the kinetics, zeolite 1 proved to be superior to zeolite 2 because of a higher adsorber capacity and also longer breakthrough times.;Keywords: Pressure Swing Adsorption, fixed bed adsorber, ethanol adsorption, water adsorption, zeolites.