Modeling and Simulation Study of an Industrial Radial Moving Bed Reactor for Propane Dehydrogenation Process

2016 ◽  
Vol 14 (1) ◽  
pp. 33-44 ◽  
Author(s):  
Sim Yee Chin ◽  
Anwaruddin Hisyam ◽  
Haniif Prasetiawan
Keyword(s):  
Flow Reactor ◽  
Catalyst Activity ◽  
Coke Formation ◽  
Plug Flow ◽  
Propane Dehydrogenation ◽  
Propane Conversion ◽  
Reactor Model ◽  
Moving Bed ◽  
Coke Content ◽  
Experimental Values

AbstractAn accurate model is required to optimize the propane dehydrogenation reaction carried out in the radial moving bed reactors (RMBR). The present study modeled the RMBR using a plug flow reactor model incorporated with kinetic models expressed in simple power-law model. Catalyst activity and coke formation were also considered. The model was solved numerically by discretizing the RMBR in axial and radial directions. The optimized kinetic parameters were then used to predict the trends of propane conversion, temperature, catalyst activity and coke content in the RMBR along axial and radial directions. It was found that the predicted activation energies of the propane dehydrogenation, propane cracking and ethylene hydrogenation were in reasonable agreement with the experimental values reported in the literature. The model developed has accurately predicted the reaction temperature profile, conversion profile and catalyst coke content. The deviations of these simulated results from the plant data were less than 5%.

scholarly journals Reversible Molten Catalytic Methane Cracking Applied to Commercial Solar-Thermal Receivers

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6229
Author(s):  
Scott C. Rowe ◽  
Taylor A. Ariko ◽  
Kaylin M. Weiler ◽  
Jacob T. E. Spana ◽  
Alan W. Weimer
Keyword(s):  
Flow Reactor ◽  
Plug Flow ◽  
Hydrogen Fuel ◽  
Reactor Model ◽  
Solar Reactor ◽  
Greenhouse Emissions ◽  
Solar Reactors ◽  
And Performance ◽  
Methane Cracking ◽  
Technology Demonstrator

When driven by sunlight, molten catalytic methane cracking can produce clean hydrogen fuel from natural gas without greenhouse emissions. To design solar methane crackers, a canonical plug flow reactor model was developed that spanned industrially relevant temperatures and pressures (1150–1350 Kelvin and 2–200 atmospheres). This model was then validated against published methane cracking data and used to screen power tower and beam-down reactor designs based on “Solar Two,” a renewables technology demonstrator from the 1990s. Overall, catalytic molten methane cracking is likely feasible in commercial beam-down solar reactors, but not power towers. The best beam-down reactor design was 9% efficient in the capture of sunlight as fungible hydrogen fuel, which approaches photovoltaic efficiencies. Conversely, the best discovered tower methane cracker was only 1.7% efficient. Thus, a beam-down reactor is likely tractable for solar methane cracking, whereas power tower configurations appear infeasible. However, the best simulated commercial reactors were heat transfer limited, not reaction limited. Efficiencies could be higher if heat bottlenecks are removed from solar methane cracker designs. This work sets benchmark conditions and performance for future solar reactor improvement via design innovation and multiphysics simulation.

A Kinetic Study of Hydrocarbons Reactivity on Palladium Catalysts through a DFT Approach

2001 ◽  
Vol 677 ◽  
Author(s):  
Valeria Bertani ◽  
Carlo Cavallotti ◽  
Maurizio Masi ◽  
Sergio Carrá
Keyword(s):  
Kinetic Study ◽  
Palladium Catalysts ◽  
Density Functional ◽  
Flow Reactor ◽  
Correlation Energy ◽  
Plug Flow ◽  
Kinetic Scheme ◽  
Atomic Scale ◽  
Basis Set ◽  
Reactor Model

ABSTRACTPalladium clusters have been chosen to represent a typical supported heterogeneous catalyst and their interaction with hydrocarbons has been investigated theoretically. The calculations were performed through density functional theory and the Becke-Lee-Yang-Parr hybrid (B3LYP) functional was adopted to calculate exchange and correlation energy. An effective core potential basis set (ECP on core electrons and Dunning/Huzinaga on outer electrons) was found sufficiently accurate to reproduce experimental data. Clusters containing up to seven Pd atoms were considered and their interaction with hydrogen, methane and ethane and their fragments was analyzed and a kinetic study of the system was performed. Transition states structures and energies were calculated through quantum mechanics and kinetic constants were derived from a statistic thermodynamic approach. On the basis of such information, a kinetic model that accounts for ethane transformations. Finally the kinetic scheme was embedded in a plug flow reactor model and simulations were performed to test the validity of the developed mechanism. In this way information obtained at the atomic scale were adopted to study phenomena occurring on the much higher reactor scale.

scholarly journals Promoters for Improvement of the Catalyst Performance in Methane Valorization Processes

2021 ◽  
Vol 23 (3) ◽  
pp. 147
Author(s):  
I.Z. Ismagilov ◽  
A.V. Vosmerikov ◽  
L.L. Korobitsyna ◽  
E.V. Matus ◽  
M.A. Kerzhentsev ◽  
...  
Keyword(s):  
High Efficiency ◽  
Catalyst Activity ◽  
Operation Mode ◽  
Coke Formation ◽  
Product Yield ◽  
Carbon Accumulation ◽  
Stable Operation ◽  
Coke Content ◽  
Methane Dehydroaromatization ◽  
Long Time

In this work, the introduction of modifying additives in the composition of catalysts is considered as an effective mode of improving functional characteristics of materials for two processes of methane conversion into valuable products – methane dehydroaromatization (DHA of CH4) into benzene and hydrogen and autothermal reforming of methane (ATR of CH4) into synthesis gas. The effect of type and content of promoters on the structural and electronic state of the active component as well as catalyst activity and stability against deactivation is discussed. For DHA of CH4 the operation mode of additives M = Ag, Ni, Fe in the composition of Mo-M/ZSM-5 catalysts was elucidated and correlated with the product yield and coke content. It was shown that when Ag serves as a promoter, the duration of the catalyst stable operation is enhanced due to a decrease in the rate of the coke formation. In the case of Ni and Fe additives, the Ni-Мо and Fe-Mo alloys are formed that retain the catalytic activity for a long time in spite of the carbon accumulation. For ATR of CH4, the influence of M = Pd, Pt, Re, Mo, Sn in the composition of Ni-M catalysts supported on La2O3 or Ce0.5Zr0.5O2/Al2O3 was elucidated. It was demonstrated that for Ni-M/La2O3 catalysts, Pd is a more efficient promoter that improves the reducibility of Ni cations and increases the content of active Nio centers. In the case of Ni-M/Ce0.5Zr0.5O2/Al2O3 samples, Re is considered the best promoter due to the formation of an alloy with anti-coking and anti-sintering properties. The use of catalysts with optimal promoter type and its content provides high efficiency of methane valorization processes.

Hydrogen Production Using Autothermal Reforming of Biodiesel and Other Hydrocarbons for Fuel Cell Applications

Solar Energy ◽  
2006 ◽  
Author(s):  
Jose´ A. Colucci
Keyword(s):  
Gas Chromatography ◽  
Chemical Engineering ◽  
Flow Reactor ◽  
National Laboratory ◽  
Coke Formation ◽  
Plug Flow ◽  
Argonne National Laboratory ◽  
Future Research ◽  
Catalyst Characterization ◽  
Reactor Temperature

The department of Chemical Engineering of the University of Puerto Rico (UPRM) in collaboration with Argonne National Laboratory (ANL) works in the development of a reforming catalyst characterization program. The purpose of this research is to study the viability of using new catalysts to convert Biodiesel, Glycerin and Methanol to a hydrogen rich product gas and compare their production potential, identify the conditions for the accumulation of coke and determine the influence of reactor temperature and water to carbon and oxygen to carbon ratios. A Basket Stirred Tank Reactor (BSTR), Plug Flow Reactor (PFR), Gas Chromatography Mass Spectrophotometer (GCMS) and Gas Chromatography Thermal Conductivity Detector (GCTCD), and Pt and Rh-based catalysts synthesized at ANL were used. During the preliminary ATR experiments, methanol, glycerol and biodiesel showed an increase in H2 production with decreasing O2/C ratio and increases in the reactor temperature. Additionally, Scanning Electron Microscopy (SEM) and EDAX analysis has been performed in some of the catalysts samples. All biodiesel and glycerol experiments performed had shown coke formation. Future research will include, experiments with bio-ethanol and methane as fuel using a Ni-based catalyst synthesized at ANL.

scholarly journals Variables Affecting NOx Formation in Lean-Premixed Combustion

1997 ◽  
Vol 119 (1) ◽  
pp. 102-107 ◽  
Author(s):  
R. C. Steele ◽  
A. C. Jarrett ◽  
P. C. Malte ◽  
J. H. Tonouchi ◽  
D. G. Nicol
Keyword(s):  
Residence Time ◽  
Combustion Temperature ◽  
Flow Reactor ◽  
Plug Flow ◽  
Volume Ratio ◽  
Chemical Reactor ◽  
Inlet Temperature ◽  
Reactor Model ◽  
Reactor Modeling ◽  
Lean Premixed

The formation of NOx in lean-premixed, high-intensity combustion is examined as a function of several of the relevant variables. The variables are the combustion temperature and pressure, fuel type, combustion zone residence time, mixture inlet temperature, reactor surface-to-volume ratio, and inlet jet size. The effects of these variables are examined by using jet-stirred reactors and chemical reactor modeling. The atmospheric pressure experiments have been completed and are fully reported. The results cover the combustion temperature range (measured) of 1500 to 1850 K, and include the following four fuels: methane, ethylene, propane, and carbon monoxide/hydrogen mixtures. The reactor residence time is varied from 1.7 to 7.4 ms, with most of the work done at 3.5 ms. The mixture inlet temperature is taken as 300 and 600 K, and two inlet jet sizes are used. Elevated pressure experiments are reported for pressures up to 7.1 atm for methane combustion at 4.0 ms with a mixture inlet temperature of 300 K. Experimental results are compared to chemical reactor modeling. This is accomplished by using a detailed chemical kinetic mechanism in a chemical reactor model, consisting of a perfectly stirred reactor (PSR) followed by a plug flow reactor (PFR). The methane results are also compared to several laboratory-scale and industrial-scale burners operated at simulated gas turbine engine conditions.

Highly Active and Selective PtSnM1/γ-Al2O3 Catalyst for Direct Propane Dehydrogenation

2021 ◽  
Vol 43 (3) ◽  
pp. 342-342
Author(s):  
Arshid M Ali Arshid M Ali ◽  
Abdulrahim A Zahrani Abdulrahim A Zahrani ◽  
Muhammad A Daous Muhammad A Daous ◽  
Muhammad Umar Seetharamulu Podila and Lachezar A Petrov Muhammad Umar Seetharamulu Podila and Lachezar A Petrov
Keyword(s):  
Catalytic Activity ◽  
Coke Formation ◽  
Protective Layer ◽  
Catalytic Performance ◽  
Active Species ◽  
Propane Dehydrogenation ◽  
Propane Conversion ◽  
Feed Composition ◽  
Highly Active ◽  
Al2o3 Catalyst

This study is aimed to understand the role of alkaline earth elements (AEE) to the catalytic performance of PtSnM1/γ-Al2O3catalystfor the direct propane dehydrogenation (where M1 = Mg, Ca, Sr, Ba). All the catalysts were prepared by using wet impregnation.The overall catalytic performance of all the catalysts was studied at different reaction temperatures, feed composition ratios and GHSV. The best operating reaction conditions were575and#186;C, feed composition ratio of C3H8:H2:N2 = 1.0:0.5:5.5 and GHSV of 3800h-1. An optimal addition of “Ca” to PtSn//γ-Al2O3 catalyst, enhanced the catalytic activity of PtSnM1/γ-Al2O3 catalyst in comparison to other studied AEE. This catalyst had shown the highest propane conversion (~ 55.8 %) with 95.7 % propylene selectivity and least coke formation (7.11 mg.g-1h-1). In general, the increased catalytic activity of PtSnM1/γ-Al2O3 is attributed to the reduced coking extent during the reaction. In addition, the enhanced thermal stability of the PtSnCa/γ-Al2O3catalystis because of the protective layer betweenγ-Al2O3 and active metal, which allows the formation of active species such as PtSn, PtCa2 and Pt2Al phases?

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