PDF Publication Title:
Text from PDF Page: 141
Chapter 6. Design and Environmental Impact Analysis of a Hybrid PSA-Membrane Separation System the steam-methane reforming process. In their proposed design, the membrane module is placed downstream of the PSA system, with the PSA off-gas acting as membrane feed. The selective surface flow membrane considered for the study had the least affinity for permeation of hydrogen gas as compared to other gas components in the feed. As a result, the low pressure permeate consists mostly of impurities, while the retentate is rich in hydrogen. The high pressure reten- tate is compressed further and mixed with the feed gas before it enters the PSA. This combined process increased the hydrogen recovery from 77.6 % to 84 % while maintaining same hydrogen purity. Their work clearly suggests that there is a definite advantage for combining PSA and membrane to improve hydrogen recovery. Feng et al. [48] investigated two possible membrane-PSA hybrid config- urations. In the first proposed configuration (named as membrane-assisted feed gas pressurization) membrane module is placed upstream of a two bed PSA. The permeate from membrane which is rich in the weakly adsorbing species is sent to a second bed to repressurize it. The retentate side gas becomes the feed of the first bed as usual. The second proposed configuration (named as membrane-assisted co-current depressurization) also uses two bed PSA and comprises of four process steps in one cycle. Here, membrane module is actually placed between the two beds. The permeate side inlet is connected to the bed undergoing depressur- ization, while its permeate side outlet is connected to the other bed undergoing repressurization. As a result of additional separation achieved by the membrane module, gas stream entering the bed getting repressurized is more purer com- pared to standalone PSA. The retentate side stream is used for counter-current purge of depressurized bed. The authors found that for the same feed flow rate, and membrane-assisted co-current depressurization hybrid configuration, hydro- gen product purity increases with a marginal drop in recovery as compared to stand alone PSA. Esteves and Mota [43] used an elaborative simulation-based 141PDF Image | Operation and Control of Pressure Swing Adsorption Systems
PDF Search Title:
Operation and Control of Pressure Swing Adsorption SystemsOriginal File Name Searched:
Khajuria-H-2011-PhD-Thesis.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)