PDF Publication Title:
Text from PDF Page: 097
5.3 Case Studies and Computational Results Therefore, vacuum desorption succeeds the light reflux step. The third key aspect of the cycle is the presence of heavy reflux from CnB to CoB during the entire cycle. From the CO2 concentration profiles of first four steps in Figure 5.3, it is clear that this CO2 reflux helps push the CO2 front towards the light end of the adsorbing bed before we start desorbing and collecting CO2. Thus, we infer that the heavy reflux step is essential for high purity CO2 production. Another aspect of the cycle is the atmospheric desorption step (step 7) after vacuum des- orption (step 6). Since CO2 is not collected as a product during step 7, we observe that the purpose of this step is only to send CO2 reflux to CoB. The step is carried out at the atmo- spheric conditions to ensure a controlled CO2 reflux to CoB such that the CO2 front doesn’t break through CoB’s light end. Final aspect of the cycle is the total reflux step (steps 4 and 8). It is a mutual reflux step in which the CO2 reflux from CnB to CoB helps push hydrogen out of the light end of CoB to the light end of CnB while enhancing adsorbed CO2 concentration in CoB, while the H2 reflux enriches its concentration in CnB and helps CO2 desorb out of the heavy end of CnB. Such a step is important to ensure that both H2 and CO2 are collected at a high purity in subsequent steps, and thus is the longest step in the cycle. The feed stream in the middle of the step provides more hydrogen for the light reflux from CoB to CnB. The optimization results for this case are summarized in Table 5.2. With 10,512 variables and 78 degrees of freedom in the NLP, the optimal solution was obtained in approximately 52 CPU minutes on an Intel Quad core 2.4 GHz machine with 8 GB RAM. At the optimum, the feed flux attained its lower bound of 35 kgmol m−2 hr−1. For this feed flux, and 72% efficiency for compressors and vacuum generator, a power consumption of 536.16 kWh/tonne CO2 captured was obtained after optimization. An optimum CO2 recovery of 98% at a purity of 90% was obtained. Also, a reasonably high hydrogen purity of 98% and a recovery of 91% was obtained simultaneously. In Table 5.2 we also provide a validation of the optimal results obtained using full discretiza- tion approach in AMPL with the method of lines simulations in MATLAB. As discussed in Chapter 5. Superstructure Case Study: Pre-combustion CO2 Capture 83PDF Image | Design and Operation of Pressure Swing Adsorption Processes
PDF Search Title:
Design and Operation of Pressure Swing Adsorption ProcessesOriginal File Name Searched:
anshul_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)