Dynamic modeling and optimization of batch electrodialysis process for hydrochloric acid recovery

Simple item page
dc.contributor.authorRohman, Fakhrony Sholahudin
dc.date.accessioned2014-10-21T03:18:17Z
dc.date.available2014-10-21T03:18:17Z
dc.date.issued2009
dc.descriptionMasteren_US
dc.description.abstractElectrodialysis is a feasible method for acid recovery because it has the capability of separating ionic chemicals from non-ionic chemicals in process or waste streams to achieve product purity or eliminate wastes. At the same time, it can also concentrate the separated chemicals involved. Optimum operating conditions are very important for the electrodialysis process to ensure maximum ED performances. To obtain those optimum operating conditions, an optimization technique using mathematical models was implemented. The Nernst-Planck derived relationship was used to build the dynamic process model which contains set of ordinary differential equations (ODE). A degree of freedom analysis was carried out with 38 unknown parameters were identified. The parameters were determined from the literature and various equations. The developed model was then simulated and the results were compared to Lindheimer et al.’s (1993) experimental work. The high accuracy of the developed model was achieved with 99% degree of confidence. The sensitivity analysis of various ED parameters towards its performances was analyzed. The results showed that process time and energy consumption increased when the higher initial HCl concentration in the dilute and concentrate tanks, higher current density and lower V In order to obtain optimal control trajectory, the dynamic optimization problem was applied using a simultaneous approach i.e. the orthogonal collocation method, where the differential variables were fully discretized. This was implemented within the MATLAB® environment by using the dynopt code package. Five objective functions were used in this study: minimize process time (P1), minimize the dilute concentration (P2), minimize energy consumption (P3), maximize degree separation (P4) and maximize operation profit (P5). From the simulation results, it was found that the control trajectories of P5 was chosen to be the most effective control operation in order to achieve the minimum process time for 99% degree of separation. The control trajectory achieved was reliable and practical. Moreover, the process time achieved for P5 was 51.6% faster than the P2, 60.67% faster than P3 and 7.9% faster than P4. The profit and energy consumption of P5 that were achieved were RM 18.54/batch and 780.202 Wh respectively. The study on the effect of different aspects of optimization towards ED performances was also carried out. Based on the results, it can be concluded that the effective number of interval, number of state collocation and trajectory type for this study was five, three and piecewise continuous linear respectively.conc/Vdil ratio were applied. However, the effect of flowrate towards process time and energy consumption was not significant.en_US
dc.identifier.urihttp://hdl.handle.net/123456789/124
dc.language.isoenen_US
dc.subjectChemical Engineeringen_US
dc.subjectElectrodialysis processen_US
dc.subjectHydrochloric aciden_US
dc.titleDynamic modeling and optimization of batch electrodialysis process for hydrochloric acid recoveryen_US
dc.typeThesisen_US
Files
License bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
license.txt
Size:
1.71 KB
Format:
Item-specific license agreed upon to submission
Description:
Download
Collections
Pusat Pengajian Seni - Tesis