• Clean Technology
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• v.23 no.3
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• pp.237-247
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• 2017

In the dimethyl ether (DME) synthesis and separation process, over 8% by mole of $CO_2$ is fed to the DME synthesis reactor which lowers DME productivity. Therefore, this work focused on the removal of $CO_2$ using three kinds of processes with physical absorbents by comparing the utility consumption through computer simulation of each process. Among the processes selected for comparison are Rectisol$^{(R)}$ process using methanol, Purisol$^{(R)}$ process using n-methyl pyrrolidone (NMP), and SelexolTM process using dimethyl ethers of polyethylene glycol (DEPG) as a solvent. As a result of this study, it was concluded that Purisol$^{(R)}$ process consumes the least energy followed by SelexolTM process. Therefore, it is considered that Purisol$^{(R)}$ process is the most suitable method to absorb $CO_2$ contained in the feed of DME synthesis reactor.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.6
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• pp.88-97
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• 2018

Computer modeling and optimization works have been performed for the separation of the binary mixture of 1-propanol and benzene through a pressure-swing distillation. PRO/II with PRIVISION V10.0 at Schneider Electric company and NRTL liquid activity coefficient model were utilized. The sum of the total reboiler heat duties of the low-high and high-low pressure column configurations were compared. To minimize the utility consumptions, low column, and high column to obtain pure benzene at the top, the number of theoretical stages and optimal feed tray locations for each distillation column were determined and the reflux ratios for each distillation column were also adjusted. As a result of the optimization works, the sum of the total reboiler heat duties for the high-low and low-high pressure configurations were $3.10{\times}10^6kcal/h$ and $2.75{\times}10^6kcal/h$, respectively. In the case where heat integration was applied to low-high pressure configurations, 57.36 % of the total reboiler heat duties could be saved compared to the high-low pressure configurations.

• Clean Technology
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• v.22 no.4
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• pp.241-249
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• 2016

In this study, comparative work has been performed between two-columns and three-columns configurations for an extractive distillation process to produce highly purified ethanol with not less than 99.7 wt% using dimethyl sulfoxide (DMSO) and ethylene glycol (EG) as extracting agents. Optimal ethanol concentration at a concentrator top stream which minimized the total reboiler heat duties was determined for a three-columns configuration for two different solvents. For the thermodynamic model, NRTL liquid activity coefficient model was used and PRO/II with PROVISION 9.4 at Schneider electric company was utilized. DMSO was proved to be a better solvent than EG and three-columns configuration is better than two- columns configuration in the total utility consumptions since some of the liquid water contained in the feed stream was removed at a concentrator bottom liquid stream.