Probability of chain growth in coke formation on metals and on supports during catalytic reforming over Pt, Pt-Sn and Pt-Sn-K catalysts mixed physically with Al2O3

2003 ◽  
Vol 20 (6) ◽  
pp. 1017-1022 ◽  
Author(s):  
Sunee Srihiranpullop ◽  
Piyasan Praserthdam
Keyword(s):  
Coke Formation ◽  
Chain Growth ◽  
Catalytic Reforming

scholarly journals Bioalcohol Reforming: An Overview of the Recent Advances for the Enhancement of Catalyst Stability

Catalysts ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 665 ◽  
Author(s):  
Vincenzo Palma ◽  
Concetta Ruocco ◽  
Marta Cortese ◽  
Marco Martino
Keyword(s):  
Fossil Fuels ◽  
Catalyst Deactivation ◽  
Coke Formation ◽  
Catalyst Stability ◽  
Side Reactions ◽  
Catalytic Reforming ◽  
Aqueous Phase Reforming ◽  
Production Of Hydrogen ◽  
Interesting Approach ◽  
Reforming Reactions

The growing demand for energy production highlights the shortage of traditional resources and the related environmental issues. The adoption of bioalcohols (i.e., alcohols produced from biomass or biological routes) is progressively becoming an interesting approach that is used to restrict the consumption of fossil fuels. Bioethanol, biomethanol, bioglycerol, and other bioalcohols (propanol and butanol) represent attractive feedstocks for catalytic reforming and production of hydrogen, which is considered the fuel of the future. Different processes are already available, including steam reforming, oxidative reforming, dry reforming, and aqueous-phase reforming. Achieving the desired hydrogen selectivity is one of the main challenges, due to the occurrence of side reactions that cause coke formation and catalyst deactivation. The aims of this review are related to the critical identification of the formation of carbon roots and the deactivation of catalysts in bioalcohol reforming reactions. Furthermore, attention is focused on the strategies used to improve the durability and stability of the catalysts, with particular attention paid to the innovative formulations developed over the last 5 years.

scholarly journals Mathematical modeling and optimization of semi-regenerative catalytic reforming of naphtha

2021 ◽  
Vol 76 ◽  
pp. 64
Author(s):  
Emilia Ivanchina ◽  
Ekaterina Chernyakova ◽  
Inna Pchelintseva ◽  
Dmitry Poluboyartsev
Keyword(s):  
Octane Number ◽  
Catalyst Deactivation ◽  
Formation Rate ◽  
Coke Formation ◽  
Space Velocity ◽  
Catalyst Stability ◽  
Hydrocarbon Mixture ◽  
Catalytic Reforming ◽  
Modeling And Optimization ◽  
Petroleum Refineries

Catalytic naphtha reforming is extensively applied in petroleum refineries and petrochemical industries to convert low-octane naphtha into high-octane gasoline. Besides, this process is an important source of hydrogen and aromatics obtained as side products. The bifunctional Pt-catalysts for reforming are deactivated by coke formation during an industrial operation. This results to a reduction in the yield and octane number. In this paper modeling and optimization of a semi-egenerative catalytic reforming of naphtha is carried out considering catalyst deactivation and a complex multicomponent composition of a hydrocarbon mixture. The mathematical model of semi-egenerative catalytic reforming considering coke formation process was proposed. The operating parameters (yield, octane number, activity) for different catalysts were predicted and optimized. It was found that a decrease in the pressure range from 1.5 to 1.2 MPa at the temperature 478–481 °C and feedstock space velocity equal to 1.4–1 h induces an increase in the yield for 1–2 wt.% due to an increase in the aromatization reactions rate and a decrease in the hydrocracking reactions rate depending on the feedstock composition and catalyst type. It is shown that the decrease in pressure is limited by the requirements for the catalyst stability due to the increase in the coke formation rate. The criterion of optimality is the yield, expressed in octanes per tons.

Plasma-assisted catalytic reforming of toluene to hydrogen rich syngas

2017 ◽  
Vol 7 (18) ◽  
pp. 4216-4231 ◽  
Author(s):  
Lina Liu ◽  
Qiang Wang ◽  
Jianwei Song ◽  
Shakeel Ahmad ◽  
Xiaoyi Yang ◽  
...  
Keyword(s):  
Coke Formation ◽  
Plasma Catalysis ◽  
Catalytic Reforming ◽  
Toluene Conversion ◽  
By Products

Ni/ZSM-5 in in-plasma catalysis systems has potential for toluene conversion, syngas formation, and inhibition of undesirable by-products and coke formation.

scholarly journals Kinetic study and Modeling of heavy Naphtha Catalytic Reforming process in AL-Daura Refinery

2021 ◽  
Vol 7 (3) ◽  
pp. 1-27
Author(s):  
Mohammad Fadhil Abid ◽  
Haider Majeed Khother
Keyword(s):  
Negative Impact ◽  
Temperature Drop ◽  
Coke Formation ◽  
Reaction Rates ◽  
Reaction Scheme ◽  
Coke Deposition ◽  
Inlet Temperature ◽  
Catalytic Reforming ◽  
Perfect Agreement ◽  
The Third

In the present work, kinetics and modeling of heavy naphtha catalytic reforming process in Al-Daura refinery-Midland refineries Company were studied. A proposed reaction scheme involving (15 pseudo components) connected together by a network of 30 reactions for components in the C6-C8+ range have been modeled. In the present work, kinetics and modeling of heavy naphtha catalytic reforming process in AL-Daura refinery-Midland refineries Company were studied. A proposed reaction scheme involving (15 pseudo components) connected together by a network of 30 reactions for components in the C6-C8+ range have been modeled. The proposed model has been solved numerically using the 4th order Runge–Kutta approach. Alteration of components and temperature, with time and reactor length was evaluated. Results showed that the rate of formation of aromatics is becoming slower as the reactants proceed to the third reactor. The catalytic reaction rates in the reformer are well represented by the Hougen-Watson Langmur-Hinshelwood (HWLH) type form. The deactivation of catalyst causes the reactor behavior to continue changing over a longer period of time. This clearly seems to pay off in the scenario where coke deposition plays such a major role. It was also found that the rate of coke formation increases with the progress from first to the last bed, so keeping a decreasing inlet temperature profile from first to the last bed would lead to more uniform coke content in each bed. The production rate of reformate has a negative impact on the octane number. Temperature drop across the first reactor (~ 45oC) is larger than the temperature drops across the other two reactors (10-12oC). This could be related to the endothermic reaction rate which is faster in the first reactor. The results show that perfect agreement of temperatures, compositions, and fractions molar flow rate at the exit of the third reactor is obtained between predicted values and industrial values.This confirmed the reliability of the present model.  

scholarly journals New Development in Catalytic Reforming Process to Produce High Octane Gasoline

2014 ◽  
Vol 5 (1) ◽  
pp. 223-244
Author(s):  
Khalid A. Sukkar ◽  
Hayam M. Abd Al-Raheem ◽  
Layth S. Sabry ◽  
Lattif A. Resym
Keyword(s):  
Coke Formation ◽  
Space Velocity ◽  
Operating Conditions ◽  
Catalyst Stability ◽  
Internal Diameter ◽  
External Diameter ◽  
Operating Pressure ◽  
Catalytic Reforming ◽  
Weight Percentage ◽  
High Octane

    In this work, improved catalytic reforming reaction was carried out through using reaction promoters Sn, In and Ge. Four types of catalysts were prepared: Pt/HY, Pt-Sn/HY, and Pt-Sn-In/HY, and Pt-Sn-Ge/HY. The weight percentage of metals were 0.5 % for Pt and 0.1% for each of  Sn, In and Ge.    The performances of catalysts (activity, selectivity and catalyst stability) were studied using Iraqi heavy naphtha  of Al-Dura refinery (Baghdad) as feedstock. The catalytic reforming unit consisted of a vertical tubular stainless steel reactor of 20mm internal diameter, 30 mm external diameter and 680 mm height. The operating pressure was atmospheric, and the operating temperatures varied between   425 to 525oC.  For all experimental runs: the weight hourly space velocity WHSV =2, the catalyst amount = 50 g, and H2/HC ratio =3.    The results showed that the best reforming temperature over all four types of prepared catalysts was 475 oC  which gave the highest conversion of heavy naphtha to high octane products (aromatics and branched  isomers). It was concluded that the trimetallic catalyst Pt-Sn-In/HY, and Pt-Sn-Ge/HY show high selectivity to desired reforming products with 91.5% and 85% respectively. On the other hand, the Pt-Sn/HY and Pt/HY, catalysts show slectivities of 79% and 74% respectively.    The results indicated a clear increase in catalyst stability with high resistance to coke formation for catalysts promoted with In and Ge as a third metal. Also, it was noted that the production  of aromatics and isomers  are  increased  for both types of trimetallic catalysts Pt-Sn-In/HY, and Pt-Sn-Ge/HY under the same operating conditions.

An analytical microscopic study of metals in fluidized catalytic cracking catalyst

1986 ◽  
Vol 44 ◽  
pp. 854-855
Author(s):  
Clifford S. Rainey
Keyword(s):  
Electron Microscopy ◽  
Spatial Distribution ◽  
Catalytic Cracking ◽  
Catalyst Deactivation ◽  
Coke Formation ◽  
Acid Sites ◽  
Y Zeolite ◽  
Fcc Catalyst ◽  
Fluidized Catalytic Cracking ◽  
High Regeneration

The spatial distribution of V and Ni deposited within fluidized catalytic cracking (FCC) catalyst is studied because these metals contribute to catalyst deactivation. Y zeolite in FCC microspheres are high SiO2 aluminosilicates with molecular-sized channels that contain a mixture of lanthanoids. They must withstand high regeneration temperatures and retain acid sites needed for cracking of hydrocarbons, a process essential for efficient gasoline production. Zeolite in combination with V to form vanadates, or less diffusion in the channels due to coke formation, may deactivate catalyst. Other factors such as metal "skins", microsphere sintering, and attrition may also be involved. SEM of FCC fracture surfaces, AEM of Y zeolite, and electron microscopy of this work are developed to better understand and minimize catalyst deactivation.

Elemental Distribution in Pt-Re:Al2O3 Naphtha Reforming Catalysts

1980 ◽  
Vol 38 ◽  
pp. 200-201
Author(s):  
R. L. Freed ◽  
M. J. Kelley
Keyword(s):  
Bimetallic Catalyst ◽  
Supported Catalysts ◽  
Coke Formation ◽  
Materials Characterization ◽  
Metal Catalyst ◽  
Elemental Distribution ◽  
Exact Nature ◽  
Naphtha Reforming ◽  
Reforming Catalysts ◽  
Commercial Introduction

The commercial introduction of Pt-Re supported catalysts to replace Pt alone on Al2O3 has brought improvements to naphtha reforming. The bimetallic catalyst can be operated continuously under conditions which lead to deactivation of the single metal catalyst by coke formation. Much disagreement still exists as to the exact nature of the bimetallic catalyst at a microscopic level and how it functions in the process so successfully. The overall purpose of this study was to develop the materials characterization tools necessary to study supported catalysts. Specifically with the Pt-Re:Al2O3 catalyst, we sought to elucidate the elemental distribution on the catalyst.

Coke formation on HFAU and HEMT zeolites. Influence of the reaction temperature and propene pressure

1999 ◽  
Vol 96 (2) ◽  
pp. 303-318 ◽  
Author(s):  
G. A. Doka Nassionou ◽  
P. Magnoux ◽  
M. Guisnet
Keyword(s):  
Reaction Temperature ◽  
Coke Formation
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