Experimental investigation of a PSA generator with various sensors to study and improve the performance

• Main Author: Robert, Sherman Louis
• Other Authors: Anutosh Chakraborty
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2021
• Subjects: Engineering::Mechanical engineering
• Online Access: https://hdl.handle.net/10356/150691
• Institution: Nanyang Technological University

The present study seeks to optimise oxygen production experimentally by employing a pressure swing adsorption generator and investigate the parameters of the designed PSA system that affect the quality. It is found that the purity of the oxygen produced is influenced by numerous variables, but in this project, the significant parameters such as pressure, purge flowrate, adsorption and pressurisation time are studied in detail. The molecular sieve namely zeolite JLOX-101 (in major capacity) and zeolite 13X (in minor quantity) are used. The surface characterisation of these two zeolites are also performed by the scanning electron microscopy (SEM) and thermogravimetric analyser. The findings reveal that the estimates for the optimal settings, that are preconceived from the theoretical understanding, turned out to be quite different due to operating conditions and the presence of irreversibility. PSA generators normally produce high purity when operating pressure and purge flow rate is high. However, experiments reveal that there is a point in between low and high operating conditions that produce optimal purity. Setting pressure to about 1.85 bar, around half the maximum operating pressure, achieved the highest purity for the pressure experiments. This discrepancy is in part due to other factors arising when the parameter being studied is varied. For instance, higher pressure tends to increase the flow rate of the feed gas to the adsorption chamber. The system is also found to favour the shorter adsorption and pressurisation time at 2s and 0.1s respectively. This is linked to the small scale of the laboratory setup as compared to larger adsorption beds used in the industry which can have adsorption time of a few minutes. The pressure swing adsorption generator used in the present study is proven to be promising for the possible application in the medical field despite its size. In order to achieve greater purity, relying on a more established and prevalent zeolite 13X as a main adsorbent may yield better results and the removal of argon gas must also be considered.