PDF Publication Title:
Text from PDF Page: 068
5 Validation of the mathematical model 55 factor on the PSA performance indicators is investigated in the range of 30 – 60 %. The results are presented in Tab. 5.2.2-1–2 and Fig. 5.2.2-1. An increased purge flow rate into the system ensures elevated nitrogen productivity values regardless of the investigated purity level. The efficiency of the desorption process is diminished as the operating temperature decreases. As such, an additional reinforcement in the form of the oxygen expulsion from the packed-bed void volume by the nitrogen purge stream is required in order to regenerate the adsorber bed properly. The effect is more pronounced at a low product purity level (1000 ppm O2) than at a high product purity level (10 ppm O2). This is due to the extended oxygen MTZ in the adsorber column caused by the high gas superficial velocity, which leads to intensified axial mass dispersion. Hence, the quantity of oxygen accumulated in the system during the adsorption is higher in the case of low-purity rather than high-purity nitrogen production. For that reason, at 1000 ppm O2, more oxygen is desorbed during the blow-down and shall be purged to enable the adsorbent bed regeneration. Since the air demand remains rather insensitive to the change of the purge flow rate, it is recommended to operate the PSA unit with an increased purge stream flow rate wherever the process conditions are corresponding. Tab. 5.2.2-1 PSA performance at different purge flow rates at product purity of 1000 ppm O2 30 0.0364 94.35 94.81 -0.49 3.19 3.169 0.66 50 0.0606 98.7 100.19 -1.51 3.17 3.129 1.29 Tab. 5.2.2-2 PSA performance at different purge flow rates at product purity of 10 ppm O2 30 0.0364 29.40 25.03 14.87 7.7 8.798 50 0.0606 30.12 27.50 8.69 7.73 8.354 -8.07 Fig. 5.2.2-1 verifies that the model predicts the influence of the purge flow rate in a very precise matter. The trends are correctly identified; however, the model accuracy shows different tendencies at different purities. At the lower product purity level of 1000 ppm O2, the relative error of simulated PSA performance parameters increase with a rising purge flow rate. This outcome can be explained since the elevated purge flow rate results in a reinforcement of the non-uniform distribution of the counter-current gas flow through the column in the experimental set-up, particularly at the Purge proportionality factor [%] Purge flow rate [m3n/h] Productivity [m3n/h N2 / m3 CMS] Air demand [m3n/h air / m3n/h N2] EXP SIM Φ [%] EXP SIM Φ [%] 40 0.0485 97.3 97.60 -0.26 3.18 3.147 1.04 60 0.0727 100.4 102.95 -2.54 3.18 3.112 2.14 Purge proportionality factor [%] Purge flow rate [m3n/h] Productivity [m3n/h N2 / m3 CMS] Air demand [m3n/h air / m3n/h N2] EXP SIM Φ [%] EXP SIM Φ [%] -14.26 40 0.0485 29.64 26.14 11.79 7.78 8.601 -10.55 60 0.0727 30.55 28.58 6.44 7.78 8.208 -5.50PDF Image | Modelling and Simulation of Twin-Bed Pressure Swing Adsorption Plants
PDF Search Title:
Modelling and Simulation of Twin-Bed Pressure Swing Adsorption PlantsOriginal File Name Searched:
dissertation_marcinek.pdfDIY PDF Search: Google It | Yahoo | Bing
CO2 Organic Rankine Cycle Experimenter Platform The supercritical CO2 phase change system is both a heat pump and organic rankine cycle which can be used for those purposes and as a supercritical extractor for advanced subcritical and supercritical extraction technology. Uses include producing nanoparticles, precious metal CO2 extraction, lithium battery recycling, and other applications... More Info
Heat Pumps CO2 ORC Heat Pump System Platform More Info
CONTACT TEL: 608-238-6001 Email: greg@infinityturbine.com (Standard Web Page)