Flow sheet optimization by the concept of sustainable development: alumina industry

Kurucak, Abdurrahman
In this study, effects of changes in various parameters of the Bayer process on the amount of “red mud”, which has many environmental drawbacks, were examined in accordance with the principles of “sustainable development”. The production process of Seydişehir Aluminum Plant is modeled as a case study. First a steady-state mass balance calculation is carried out by incorporating sequential modular approach. Then a model of the Bayer process digester is programmed and several simulations are carried out using this model. Results of the mass balance calculation revealed that changes in the extent of the digestion reaction, which is a function of temperature and caustic concentration, and washing efficiency may have a 2.07% decrease on the amount of red mud produced,which implies nearly 10,000 tons of decline per annum, while amount of hydrate produced is increased by 4.52%. A 7.40 % decrease on the amount of red mud produced on dry basis per kg of hydrate was found to be achievable. Optimum operating temperature for the digester was calculated as 277.3 °C.


Comparison of Fenitrothion and Trifluralin Adsorption on Organo-Zeolites and Activated Carbon. Part II: Thermodynamic Parameters and the Suitability of the Kinetic Models of Pesticide Adsorption
LÜLE ŞENÖZ, Güzide Meltem; Atalay, Mustafa Ümit (Informa UK Limited, 2014-07-04)
The suitability of two kinetic models and the thermodynamic parameters of pesticide adsorption were investigated based on obtained data of previous studies. Kinetic evaluation indicated that the pesticides adsorption on adsorbents followed the pseudo-second-order model. Gibbs free energy (Delta G degrees), enthalpy (Delta H degrees), and entropy (Delta S degrees) were calculated for thermodynamic parameters by using linearized Arrhenius equation. The results indicated that the sorption process of fenitrothi...
Dehydration of alcohol solutions obtained from a solvent recovery process by pervaporation
Büküşoğlu, Emre; Yılmaz, Levent; Department of Chemical Engineering (2010)
Solvent recovery is gaining importance in the chemical production processes to reduce the costs and because of environmental concerns. Therefore separation schemes for recovery and recycle of solvents used in printing and packaging industry were developed. However, a low value by-product, mainly ethyl alcohol and isopropanol, is obtained during the solvent recovery process. If the water concentration of this mixture is decreased below 0.1% by weight, the value of it increases significantly. To dehydrate thi...
Kinetic studies for the production of tertiary ethers used as gasoline additives
Boz, Nezahat; Doğu, Timur; Department of Chemical Engineering (2004)
In the present study, the kinetics studies for etherification reactions were investigated in detail. In the first phase of present study, different acidic resin catalysts were prepared by the heat treatment of Amberlyst-15 catalysts at 220°C at different durations of time and also by the synthesis of sulfonated styrene divinylbenzene cross-linked resins at different conditions. A linear dependence of reaction rate on hydrogen ion-exchange capacity was in 2M2B+ethanol reaction. However, in the case of 2M1B+e...
Chiral seperations by enzyme enhanced ultrafiltration : fractionation ofracemic benzoin
Ölçeroğlu, Ayşe Hande; Yılmaz, Levent; Department of Chemical Engineering (2006)
In this study, a methodology for separation of chiral molecules, by using enhanced ultrafiltration system was developed. Benzoin was the model chiral molecule studied. In the scope of developing this methodology, some parameters were investigated in the preliminary ultrafiltration experiments in order to set the operation conditions for enhanced ultrafiltration experiments. Due to the slight solubility of benzoin in pure water, 15% (v/v) Polyethylene glycol (PEG 400) and 30 % (v/v) Dimethyl sulfoxide (DMSO)...
Dynamic and steady-state analysis of oxidative dehydrogenation of ethane
Karamullaoğlu, Gülsün; Doğu, Timur; Department of Chemical Engineering (2005)
In this research, oxidative dehydrogenation of ethane to ethylene was studied over Cr-O and Cr-V-O mixed oxide catalysts through steady-state and dynamic experiments. The catalysts were prepared by the complexation method. By XRD, presence of Cr2O3 phase in Cr-O; and the small Cr2O3 and V2O4 phases of Cr-V-O were revealed. In H2-TPR, both catalysts showed reduction behaviour. From XPS the likely presence of Cr+6 on fresh Cr-O was found. On Cr-V-O, the possible reduction of V+5 and Cr+6 forms of the fresh sa...
Citation Formats
A. Kurucak, “Flow sheet optimization by the concept of sustainable development: alumina industry,” M.S. - Master of Science, Middle East Technical University, 2010.