A novel configuration for Pd/Ag/α-Al2O3 catalyst regeneration in the acetylene hydrogenation reactor of a multi feed cracker

2012 ◽  
Vol 198-199 ◽  
pp. 491-502 ◽  
Author(s):  
M.R. Rahimpour ◽  
O. Dehghani ◽  
M.R. Gholipour ◽  
M.S. Shokrollahi Yancheshmeh ◽  
S. Seifzadeh Haghighi ◽  
...  
Keyword(s):  
Catalyst Regeneration ◽  
Acetylene Hydrogenation ◽  
Α Al2o3 ◽  
Hydrogenation Reactor ◽  
Al2o3 Catalyst

scholarly journals An Experimental Approach on Industrial Pd-Ag Supported α-Al2O3 Catalyst Used in Acetylene Hydrogenation Process: Mechanism, Kinetic and Catalyst Decay

Processes ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 136
Author(s):  
Ourmazd Dehghani ◽  
Mohammad Rahimpour ◽  
Alireza Shariati
Keyword(s):  
Kinetic Model ◽  
Experimental Approach ◽  
Catalyst Deactivation ◽  
Catalyst Activity ◽  
Hydrogenation Process ◽  
Support Surface ◽  
Acetylene Hydrogenation ◽  
Wide Range ◽  
Α Al2o3 ◽  
Al2o3 Catalyst

The current research presents an experimental approach on the mechanism, kinetic and decay of industrial Pd-Ag supported α-Al2O3 catalyst used in the acetylene hydrogenation process. In the first step, the fresh and deactivated hydrogenation catalysts are characterized by XRD, BET (Brunauer–Emmett–Teller), SEM, TEM, and DTG analyses. The XRD results show that the dispersed palladium particles on the support surface experience an agglomeration during the reaction run time and mean particle size approaches from 6.2 nm to 11.5 nm. In the second step, the performance of Pd-Ag supported α-Al2O3 catalyst is investigated in a differential reactor in a wide range of hydrogen to acetylene ratio, temperature, gas hourly space velocity and pressure. The full factorial design method is used to determine the experiments. Based on the experimental results ethylene, ethane, butene, and 1,3-butadiene are produced through the acetylene hydrogenation. In the third step, a detailed reaction network is proposed based on the measured compounds in the product and the corresponding kinetic model is developed, based on the Langmuir-Hinshelwood-Hougen-Watson approach. The coefficients of the proposed kinetic model are calculated based on experimental data. Finally, based on the developed kinetic model and plant data, a decay model is proposed to predict catalyst activity and the parameters of the activity model are calculated. The results show that the coke build-up and condensation of heavy compounds on the surface cause catalyst deactivation at low temperature.

CFD Simulation and Optimization of Gas-Solid Phase Temperature of Isothermal Acetylene Hydrogenation Reactor

2018 ◽  
Vol 16 (5) ◽  
Author(s):  
Guihua Hu ◽  
Zhencheng Ye ◽  
Wenli Du ◽  
Feng Qian
Keyword(s):  
Porous Medium ◽  
Solid Phase ◽  
Inlet Temperature ◽  
Acetylene Hydrogenation ◽  
Simulation And Optimization ◽  
Medium Model ◽  
Hydrogenation Reactor ◽  
Porous Medium Model ◽  
Two Temperature ◽  
Hydrogenation Selectivity

Abstract Gas-solid coupled heat transfer in an industrial isothermal acetylene hydrogenation reactor was carried out using computational fluid dynamics (CFD). A two-temperature porous medium model was established by adding source terms to energy equations of the solid and gas phases. The combination of a genetic algorithm with CFD methods is applied to optimization of the kinetic and process parameters of the reaction. The model was validated by comparing the simulated results with those obtained from a one-temperature porous medium model, a two-temperature porous medium model, and industrial data. The optimal hydrogen-to-acetylene ratio and inlet temperature are 1.78 and 326K, respectively. The optimized ethylene yield increase and hydrogenation selectivity are 0.53 % and 0.18 % higher than the values before optimization, respectively. Finally, the effects of the hydrogen-to-acetylene ratio and inlet temperature on the increase in ethylene yield and hydrogenation selectivity are analyzed. Therefore, the hydrogen-to-acetylene ratio and inlet temperature should be reasonably controlled during production.

Kinetic model of K–Ni/α-Al2O3 catalyst for oxidative reforming of methane determined by genetic algorithm

2012 ◽  
Vol 425-426 ◽  
pp. 170-177 ◽  
Author(s):  
Kohji Omata ◽  
Seishiro Kobayashi ◽  
Junpei Horiguchi ◽  
Yasukazu Kobayashi ◽  
Yuichiro Yamazaki ◽  
...  
Keyword(s):  
Genetic Algorithm ◽  
Kinetic Model ◽  
Oxidative Reforming ◽  
Α Al2o3 ◽  
Al2o3 Catalyst

Oxidative CO2 reforming of CH4 over Ni/α-Al2O3 catalyst

2011 ◽  
Vol 17 (3) ◽  
pp. 479-483 ◽  
Author(s):  
A.S.A. Al-Fatesh ◽  
A.A. Ibrahim ◽  
A.H. Fakeeha ◽  
A.E. Abasaeed ◽  
M.R.H. Siddiqui
Keyword(s):  
Co2 Reforming ◽  
Co2 Reforming Of Ch4 ◽  
Α Al2o3 ◽  
Al2o3 Catalyst

scholarly journals Local Structure of Pd1 Single Sites on the Surface of PdIn Intermetallic Nanoparticles: A Combined DFT and CO-DRIFTS Study

Catalysts ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1376
Author(s):  
Nadezhda S. Smirnova ◽  
Igor S. Mashkovsky ◽  
Pavel V. Markov ◽  
Andrey V. Bukhtiyarov ◽  
Galina N. Baeva ◽  
...  
Keyword(s):  
Absorption Band ◽  
Large Distance ◽  
Local Structure ◽  
Co Adsorption ◽  
Surface Plane ◽  
Adsorbed Co ◽  
Α Al2o3 ◽  
Two Peaks ◽  
Al2o3 Catalyst ◽  
Intermetallic Nanoparticles

Local structure of Pd1 single sites on the surface of Pd1In1 intermetallic nanoparticles supported on α-Al2O3 was investigated by the combination of CO-DRIFTS spectroscopy and DFT. CO-DRIFTS spectra of PdIn/Al2O3 catalyst exhibit only one asymmetric absorption band of linearly adsorbed CO comprising two peaks at 2065 and 2055 cm−1 attributable to CO molecules coordinated to Pd1 sites located at (110) and (111) facets of PdIn nanoparticles. The absence of bridged or hollow-bonded CO bands indicates that multipoint adsorption on PdIn nanoparticles is significantly hindered or impossible. DFT results show that on (110) facet multipoint CO adsorption is hindered due to large distance between neighboring Pd atoms (3.35 Å). On (111) facet multipoint CO adsorption on surface palladium atoms is impossible, since adjacent Pd atoms are located below the surface plane.

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