Optical spectroscopic studies of CuCr2O4/γ-Al2O3. Catalyst deactivation under operation in catalytic heat generators

1985 ◽  
Vol 28 (1) ◽  
pp. 195-201 ◽  
Author(s):  
D. A. Arendarskii ◽  
E. A. Paukshtis ◽  
Z. R. Ismagilov ◽  
E. N. Yurchenko
Keyword(s):  
Catalyst Deactivation ◽  
Spectroscopic Studies ◽  
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.

Temperature-programmed propane dehydrogenation over Pt–Sn/Al2O3 catalyst: Application in kinetic and catalyst deactivation studies

2016 ◽  
Vol 30 ◽  
pp. 156-163 ◽  
Author(s):  
Farnaz Tahriri Zangeneh ◽  
Abbas Taeb ◽  
Khodayar Gholivand ◽  
Saeed Sahebdelfar
Keyword(s):  
Catalyst Deactivation ◽  
Propane Dehydrogenation ◽  
Temperature Programmed ◽  
Al2o3 Catalyst

Effect of pretreatment on Pt/Al2O3 and Pt + Re/Al2O3 catalyst deactivation

1985 ◽  
Vol 96 (2) ◽  
pp. 499-506 ◽  
Author(s):  
M PACHECO
Keyword(s):  
Catalyst Deactivation ◽  
Al2o3 Catalyst

Mössbauer spectroscopic studies of the state of Pt−Sn/Al2O3 catalyst for hydrocarbon conversion

1982 ◽  
Vol 21 (3) ◽  
pp. 419-422 ◽  
Author(s):  
V. I. Kuznetsov ◽  
E. N. Yurchenko ◽  
A. S. Belyi ◽  
E. V. Zatolokina ◽  
M. A. Smolikov ◽  
...  
Keyword(s):  
Spectroscopic Studies ◽  
The State ◽  
Hydrocarbon Conversion ◽  
Al2o3 Catalyst

Catalyst Deactivation Simulation Through Carbon Deposition in Carbon Dioxide Reforming over Ni/CaO-Al2O3 Catalyst

2011 ◽  
Vol 6 (2) ◽  
Author(s):  
Istadi Istadi ◽  
Didi D. Anggoro ◽  
Nor Aishah Saidina Amin ◽  
Dorothy Hoo Wei Ling
Keyword(s):  
Carbon Dioxide ◽  
Carbon Deposition ◽  
Catalyst Deactivation ◽  
Carbon Dioxide Reforming ◽  
Al2o3 Catalyst

scholarly journals Selective hydrogenation of benzyl cyanide to 2-phenylethylamine over a Pd/Al2O3 catalyst promoted by synergistic effects of CO2 and water

2015 ◽  
Vol 17 (2) ◽  
pp. 1299-1307 ◽  
Author(s):  
Ashvini Bhosale ◽  
Hiroshi Yoshida ◽  
Shin-ichiro Fujita ◽  
Masahiko Arai
Keyword(s):  
Selective Hydrogenation ◽  
Catalyst Deactivation ◽  
Synergistic Effects ◽  
Benzyl Cyanide ◽  
Al2o3 Catalyst

Synergistic effects of water and CO2 appear for the selective hydrogenation of benzyl cyanide to phenylethylamine in n-hexane over a Pd/Al2O3 catalyst with no catalyst deactivation.

scholarly journals Effect of Oxidants on Syngas Synthesis from Biogas over 3 wt % Ni-Ce-MgO-ZrO2/Al2O3 Catalyst

Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 297 ◽  
Author(s):  
Danbee Han ◽  
Yunji Kim ◽  
Wonjun Cho ◽  
Youngsoon Baek
Keyword(s):  
Renewable Energy ◽  
Catalyst Deactivation ◽  
Global Climate ◽  
Renewable Energy Sources ◽  
Energy Resource ◽  
Value Added ◽  
Boudouard Reaction ◽  
Co2 Conversion ◽  
Conversion Rates ◽  
Al2o3 Catalyst

The utilization of fossil fuels has led to a gradual increase in greenhouse gas emissions, which have accelerated global climate change. Therefore, there is a growing interest in renewable energy sources and technologies. Biogas has gained considerable attention as an abundant renewable energy resource. Common biogases include anaerobic digestion gas and landfill gas, which can be used to synthesize high-value-added syngas through catalytic reforming. Because syngas (CO and H2) is synthesized at high reaction temperature, carbon is generated by the Boudouard reaction from CO and CH4 cracking; thus, C blocks the pores and surface of the catalyst, thereby causing catalyst deactivation. In this study, a simulation was performed to measure the CH4 and CO2 conversion rates and the syngas yield for different ratios of CO2/CH4 (0.5, 1, and 2). The simulation results showed that the optimum CO2/CH4 ratio is 0.5; therefore, biogas reforming over the 3 wt% Ni/Ce-MgO-ZrO2/Al2O3 catalyst was performed under these conditions. CH4 and CO2 conversion rates and the syngas yield were evaluated by varying the R values (R = (CO2 + O2)/CH4) on the effect of CO2 and O2 oxidants of CH4. In addition, steam was added during biogas reforming to elucidate the effect of steam addition on CO2 and CH4 conversion rates. The durability and activity of the catalyst after 200-h biogas reforming were evaluated under the optimal conditions of R = 0.7, 850 °C, and 1 atm.

Analysis of catalyst deactivation during steam reforming of jet fuel on Ni-(PdRh)/γ-Al2O3 catalyst

2011 ◽  
Vol 405 (1-2) ◽  
pp. 149-159 ◽  
Author(s):  
Satish L. Lakhapatri ◽  
Martin A. Abraham
Keyword(s):  
Steam Reforming ◽  
Catalyst Deactivation ◽  
Jet Fuel ◽  
Al2o3 Catalyst

scholarly journals CO2 Self-Poisoning and Its Mitigation in CuO Catalyzed CO Oxidation: Determining and Speeding up the Rate-Determining Step

Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 654
Author(s):  
Kai Cheng ◽  
Songjian Zhao ◽  
Jiazheng Ren ◽  
Haoran Li ◽  
Yongsheng Chen
Keyword(s):  
Co Oxidation ◽  
Catalyst Deactivation ◽  
Co2 Adsorption ◽  
Catalyst Activity ◽  
Major Barrier ◽  
Rate Determining Step ◽  
Co2 Desorption ◽  
Co Conversion ◽  
Speed Up ◽  
Al2o3 Catalyst

Cu-based catalysts are promising for CO oxidation applications with catalyst deactivation being a major barrier. We start with a CuO/Al2O3 catalyst and find that while the CO conversion decreases, CO2 accumulates and the average Cu chemical state stays the same. It suggests CO2 self-poisoning, i.e., CO2 desorption is the rate-determining step. Subsequently, experiments are performed to prove this hypothesis by showing (1) CO2 adsorption inhibits O2 adsorption, (2) complete desorption of CO2 regenerate the catalyst, (3) pre-adsorbed CO2 quenches catalyst activity which recovers during the reaction and (4) the apparent activation energy is consistent with CO2 desorption. It is further evidenced by using a stronger CO2 adsorbing support CeO2 to speed up CO2 desorption from the CuO sites resulting in a superior CuO/CeO2 catalyst. It provides an example for experimentally deciding and speeding up the rate-determining step in a catalytic reaction.

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