Dynamic analysis of adsorption equilibrium and rate parameters of reactants and products in MTBE, ETBE and TAME production

Oktar, N
Murtezaoglu, K
Doğu, Timur
Dogu, G
Adsorption equilibrium constants of ethanol, methanol, isobutylene, isoamylenes (2M2B, 2M1B), MTBE and TAME on Amberlyst 15 catalyst were evaluated from the packed bed moment technique. Adsorption equilibrium constants of alcohols were found to be two orders of magnitude greater than the adsorption equilibrium constants of i-olefins and the corresponding tertiary ethers. However, their apparent heat of adsorption values are quite low (-6,7 kJ/mol and -8.3 kJ/mol for methanol and ethanol, respectively). Among the i-olefins, isobutylene gave the highest adsorption equilibrium constant and the heat of adsorption (-54.2 kJ/mol). The adsorption equilibrium constant of 2M2B on a catalyst, which was pretreated with ethanol, was about three times greater than the corresponding value obtained on fresh catalyst. Second moment analysis indicated that diffusion resistance in both macropores and microspheres of the catalyst are equally significant.


Dynamic analysis of changes in diffusion and sorption parameters in the reaction of SO2with activated soda ash
Doǧu, Gülsen; Keskin, Alne; Doǧu, Timur (Wiley, 1988-8)
Variations in pore structure cause significant changes in diffusion resistance and adsorption characteristics during the reaction of SO2 with activated soda. Breakthrough and moment analysis of the SO2‐activated soda ash reaction showed that the effective diffusion coefficient of SO2 in the solid product (mostly Na2SO3) was about three times smaller than its value in the original activated soda. About 30% of the diffusion flux of SO2 in the solid product was found to be due to surface diffusion. The adsorpt...
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...
Quantum chemical simulation of nitric oxide reduction by ammonia (scr reaction) on v2o5 / tio2 catalyst surface
Soyer, Sezen; Önal, Işıl; Department of Chemical Engineering (2005)
The reaction mechanism for the selective catalytic reduction (SCR) of nitric oxide by ammonia on (010) V2O5 surface represented by a V2O9H8 cluster was simulated by density functional theory (DFT) calculations. The computations indicated that SCR reaction consisted of three main parts. In the first part ammonia activation on Brønsted acidic V-OH site as NH4+ species by a nonactivated process takes place. The second part includes the interaction of NO with pre-adsorbed NH4 + species to eventually form nitros...
Orbey, H.; Orbey, N. (Informa UK Limited, 1989-3)
A data reduction technique is introduced for the evaluation of second virial coefficients of gases at subcritical temperatures. The method makes use of the vapor-liquid equilibrium data, i.e., temperature, saturation pressure, liquid and vapor molar volumes and can be used to obtain second virial coefficients of a wide variety of fluids including polar, associating and quantum gases. The calculated second virial coefficients are in good agreement with their counterparts from literature, which are obtained f...
Dynamic analysis of removal and selective oxidation of H2S to elemental sulfur over Cu-V and Cu-V-Mo mixed oxides in a fixed bed reactor
Yasyerli, S; Dogu, G; Ar, I; Doğu, Timur (Elsevier BV, 2004-10-01)
Selective oxidation of H2S to elemental sulfur was studied using the Cu-V and Cu-V-Mo mixed oxide catalysts with different O-2/H2S ratios between 0 and 3. High activities and high sulfur selectivities reaching 0.98 were obtained with the Cu-V catalyst. The Cu-V-Mo mixed oxide catalyst showed higher activity with a somewhat less selectivity. The Cu-V catalyst, which was originally in the form of alpha-Cu2V2O7, was converted to Cu3VS4, CuS and VOx during the initial stages of reaction. Oxidized form of the ca...
Citation Formats
N. Oktar, K. Murtezaoglu, T. Doğu, and G. Dogu, “Dynamic analysis of adsorption equilibrium and rate parameters of reactants and products in MTBE, ETBE and TAME production,” CANADIAN JOURNAL OF CHEMICAL ENGINEERING, pp. 406–412, 1999, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/62921.