The Experts below are selected from a list of 219 Experts worldwide ranked by ideXlab platform
Ulrich Hoffmann - One of the best experts on this subject based on the ideXlab platform.
-
Kinetics of methyl tertiary butyl ether liquid phase synthesis catalyzed by ion exchange resin—II. Macropore diffusion of methanol as Rate-Controlling Step
Chemical Engineering Science, 1990Co-Authors: Alwin Rehfinger, Ulrich HoffmannAbstract:Abstract The microkinetic model for methyl tertiary butyl ether (MTBE) synthesis presented in an earlier work is extended to the case of macropore diffusion of methanol as the Rate-Controlling Step. Experimental results concerning the activity and selectivity of the sulfonic acid ion exchange resin catalyst were in agreement with a shell-core model, according to which almost none of the methanol-containing core produces the by-product diisobutene while only the outer shell forms the main product MTBE. Experimental effectivenss factors (η) for the isothermal catalyst beads were determined up to η = 5, while the theoretically calculated corresponding η was two-thirds of this value. The limiting effective diffusion coefficient of methanol (in a C 4 mixture of isobutene and 1-butene) in an Amberylst 15 resin was used as an adjustable parameter and found to be 3.5 × 10 −9 m 2 /s at 333 K.
-
Kinetics of methyl tertiary butyl ether liquid phase synthesis catalyzed by ion exchange resin-II. Macropore diffusion of methanol as Rate-Controlling Step
Chemical Engineering Science, 1990Co-Authors: Alwin Rehfinger, Ulrich HoffmannAbstract:The microkinetic model for methyl tertiary butyl ether (MTBE) synthesis presented in an earlier work is extended to the case of macropore diffusion of methanol as the Rate-Controlling Step. Experimental results concerning the activity and selectivity of the sulfonic acid ion exchange resin catalyst were in agreement with a shell-core model, according to which almost none of the methanol-containing core produces the by-product diisobutene while only the outer shell forms the main product MTBE. Experimental effectivenss factors (η) for the isothermal catalyst beads were determined up to η = 5, while the theoretically calculated corresponding η was two-thirds of this value. The limiting effective diffusion coefficient of methanol (in a C4 mixture of isobutene and 1-butene) in an Amberylst 15 resin was used as an adjustable parameter and found to be 3.5 × 10-9 m2/s at 333 K. © 1990.
Alwin Rehfinger - One of the best experts on this subject based on the ideXlab platform.
-
Kinetics of methyl tertiary butyl ether liquid phase synthesis catalyzed by ion exchange resin—II. Macropore diffusion of methanol as Rate-Controlling Step
Chemical Engineering Science, 1990Co-Authors: Alwin Rehfinger, Ulrich HoffmannAbstract:Abstract The microkinetic model for methyl tertiary butyl ether (MTBE) synthesis presented in an earlier work is extended to the case of macropore diffusion of methanol as the Rate-Controlling Step. Experimental results concerning the activity and selectivity of the sulfonic acid ion exchange resin catalyst were in agreement with a shell-core model, according to which almost none of the methanol-containing core produces the by-product diisobutene while only the outer shell forms the main product MTBE. Experimental effectivenss factors (η) for the isothermal catalyst beads were determined up to η = 5, while the theoretically calculated corresponding η was two-thirds of this value. The limiting effective diffusion coefficient of methanol (in a C 4 mixture of isobutene and 1-butene) in an Amberylst 15 resin was used as an adjustable parameter and found to be 3.5 × 10 −9 m 2 /s at 333 K.
-
Kinetics of methyl tertiary butyl ether liquid phase synthesis catalyzed by ion exchange resin-II. Macropore diffusion of methanol as Rate-Controlling Step
Chemical Engineering Science, 1990Co-Authors: Alwin Rehfinger, Ulrich HoffmannAbstract:The microkinetic model for methyl tertiary butyl ether (MTBE) synthesis presented in an earlier work is extended to the case of macropore diffusion of methanol as the Rate-Controlling Step. Experimental results concerning the activity and selectivity of the sulfonic acid ion exchange resin catalyst were in agreement with a shell-core model, according to which almost none of the methanol-containing core produces the by-product diisobutene while only the outer shell forms the main product MTBE. Experimental effectivenss factors (η) for the isothermal catalyst beads were determined up to η = 5, while the theoretically calculated corresponding η was two-thirds of this value. The limiting effective diffusion coefficient of methanol (in a C4 mixture of isobutene and 1-butene) in an Amberylst 15 resin was used as an adjustable parameter and found to be 3.5 × 10-9 m2/s at 333 K. © 1990.
Saeid Azizian - One of the best experts on this subject based on the ideXlab platform.
-
mixed surface reaction and diffusion controlled kinetic model for adsorption at the solid solution interface
Journal of Physical Chemistry C, 2013Co-Authors: Monireh Haerifar, Saeid AzizianAbstract:The effects of diffusion and surface reaction mechanisms have been considered conjointly to investigate the kinetics of adsorption. A new model has been proposed for the modeling of adsorption kinetics at the solid/solution interface in batch systems. Based on generated data points (t, q) by using of the new model, it was found that there is a deviation from linearity as a downward curvature at initial times of adsorption in usual t/q vs time plot, when diffusion contributes to the Rate-Controlling Step of adsorption. Moreover, results of nonlinear fitting to the different experimental data show that the mixed surface reaction and diffusion-controlled model can be useful for kinetics modeling of adsorption in which pure surface reaction or mixed surface reaction and diffusion contribute to the Rate-Controlling Step of adsorption.
-
Mixed Surface Reaction and Diffusion-Controlled Kinetic Model for Adsorption at the Solid/Solution Interface
Journal of Physical Chemistry C, 2013Co-Authors: Monireh Haerifar, Saeid AzizianAbstract:The effects of diffusion and surface reaction mechanisms have been considered conjointly to investigate the kinetics of adsorption. A new model has been proposed for the modeling of adsorption kinetics at the solid/solution interface in batch systems. Based on generated data points (t, q) by using of the new model, it was found that there is a deviation from linearity as a downward curvature at initial times of adsorption in usual t/q vs time plot, when diffusion contributes to the Rate-Controlling Step of adsorption. Moreover, results of nonlinear fitting to the different experimental data show that the mixed surface reaction and diffusion-controlled model can be useful for kinetics modeling of adsorption in which pure surface reaction or mixed surface reaction and diffusion contribute to the Rate-Controlling Step of adsorption.
Monireh Haerifar - One of the best experts on this subject based on the ideXlab platform.
-
mixed surface reaction and diffusion controlled kinetic model for adsorption at the solid solution interface
Journal of Physical Chemistry C, 2013Co-Authors: Monireh Haerifar, Saeid AzizianAbstract:The effects of diffusion and surface reaction mechanisms have been considered conjointly to investigate the kinetics of adsorption. A new model has been proposed for the modeling of adsorption kinetics at the solid/solution interface in batch systems. Based on generated data points (t, q) by using of the new model, it was found that there is a deviation from linearity as a downward curvature at initial times of adsorption in usual t/q vs time plot, when diffusion contributes to the Rate-Controlling Step of adsorption. Moreover, results of nonlinear fitting to the different experimental data show that the mixed surface reaction and diffusion-controlled model can be useful for kinetics modeling of adsorption in which pure surface reaction or mixed surface reaction and diffusion contribute to the Rate-Controlling Step of adsorption.
-
Mixed Surface Reaction and Diffusion-Controlled Kinetic Model for Adsorption at the Solid/Solution Interface
Journal of Physical Chemistry C, 2013Co-Authors: Monireh Haerifar, Saeid AzizianAbstract:The effects of diffusion and surface reaction mechanisms have been considered conjointly to investigate the kinetics of adsorption. A new model has been proposed for the modeling of adsorption kinetics at the solid/solution interface in batch systems. Based on generated data points (t, q) by using of the new model, it was found that there is a deviation from linearity as a downward curvature at initial times of adsorption in usual t/q vs time plot, when diffusion contributes to the Rate-Controlling Step of adsorption. Moreover, results of nonlinear fitting to the different experimental data show that the mixed surface reaction and diffusion-controlled model can be useful for kinetics modeling of adsorption in which pure surface reaction or mixed surface reaction and diffusion contribute to the Rate-Controlling Step of adsorption.
Arthur Garforth - One of the best experts on this subject based on the ideXlab platform.
-
detailed reaction kinetics for the dehydrogenation of methylcyclohexane over pt catalyst
Industrial & Engineering Chemistry Research, 2012Co-Authors: Muhammad Usman, David L Cresswell, Arthur GarforthAbstract:Detailed reaction kinetics of the dehydrogenation of methylcyclohexane were studied over an in-house-prepared 1.0 wt % Pt/γ-Al2O3 catalyst. Experiments were conducted in a fixed-bed reactor for a wide range of operating conditions including reactions without hydrogen in the feed. Kinetic model equations were developed, and the experimental data were analyzed according to the power-law, Langmuir–Hinshelwood–Hougen–Watson (LHHW), and Horiuti–Polanyi kinetic mechanisms. The rate of loss of the first hydrogen molecule in the LHHW single-site surface reaction mechanism was found to be the Rate-Controlling Step. Experiments with 1-methylcyclohexene confirmed that the Rate-Controlling Step does not lie after the loss of the first hydrogen molecule.
