Binary gas dehydration using molecular sieve 4A within the pressure-vacuum swing adsorption

Abstract

This research studied the separation of a binary mixture gas. The separation process was using a pressure vacuum swing adsorption (PVSA) and molecular sieve 4A as adsorbents. The binary mixture gas in this research was nitrogen and water. The research consists of an experiment and numerical model. The laboratory scale experiment was focused on behavior of the water removal and an adsorption capability of adsorbents, The numerical model was used to perform parametric study of the adsorption performance that affected by gas feed velocity, pressure and temperature. The water removal characteristic was employed by the Freundlich isotherm. The experiment shows that the molecular sieve 4A within the PVSA system reached the adsorption efficiency of 94.79% within 6 hours. The absorption decreased along the number of consecutive adsorption cycles. The adsorption modeling shows that gas velocity and working temperature have major effect on the adsorption performance. Increasing pressure improves adsorption performance. However, the results show that the threshold pressure is 3 MPa, which is the point that pressure is not affect the performance any further. The optimize condition in this paper was located at: velocity gas feed of 0.0170 m/s, pressure 3 MPa and temperature 323.15 K.