scholarly journals Thermodynamic analysis of carbon formation conditions in a steam methane reforming process

2020 ◽  
pp. 136-136
Author(s):  
Dmitry Pashchenko ◽  
Maria Gnutikova
Keyword(s):  
Thermodynamic Analysis ◽  
Chemical Reactions ◽  
Operating Conditions ◽  
Mass Action ◽  
Equilibrium Analysis ◽  
Methane Reforming ◽  
Carbon Formation ◽  
Operational Conditions ◽  
Steam Methane Reforming ◽  
Steam Methane

Thermodynamic equilibrium analysis of the steam methane reforming process to synthesis gas was studied. For this purpose, the system of chemical reactions for carbon production and consumation as well as other side reaction in the steam methane reforming process were analysed. The material balance and the equations of law mass action were obtained for various chemical reactions. The system of those equations were solved by dichotomy method. The investigation was performed for a wide range of operational conditions such as a temperature, pressure, and inlet steam-to-methane ratio. The results obtained, with the help of developed algorithms, were compared with the results obtained via different commercial and open-source programs. All results are in excellent agreement. The operational conditions for the probable formation of carbon were determined. It was established that for the temperature range above 1100K the probability of carbon formation is absent for steam-to-methane ratio above units. The presented algorithm of thermodynamic analysis gives an appearance of the dependence of the product composition and the amount of required heat from operating conditions such as the temperature, pressure and steam-to-methane ratio.

3D CFD Simulations of Local Carbon Formation in Steam Methane Reforming Catalyst Particles

2017 ◽  
Vol 15 (6) ◽  
Author(s):  
Mohsen Behnam ◽  
Anthony G. Dixon
Keyword(s):  
Hot Spots ◽  
Tube Wall ◽  
Particle Diameter ◽  
Catalyst Particle ◽  
Operating Conditions ◽  
Methane Reforming ◽  
Carbon Formation ◽  
Cfd Simulations ◽  
Steam Methane Reforming ◽  
Steam Methane

Abstract The deactivation of catalysts is an important problem in the strongly endothermic steam methane reforming reaction. The local carbon laydown on the catalyst surface may lead to local hot spots, breakage of catalyst particles, and blockage of the reactor tube. Local carbon formation was studied at different operating conditions using particle-scale 3D CFD models of full and hollow cylindrical particles. The results showed that a low steam-to-carbon ratio may cause local carbon formation at high temperature (\gt900K) on the surface of the catalyst particle. The risk of carbon formation was highest at the surface hot spots and inside the catalyst particles where the methane cracking reaction rate exceeded those of the gasification reactions. The internal surface in the 1-hole catalyst particle showed favorable conditions for carbon formation and deposition, similarly to the external surface of the particle. 3D CFD simulations of a 0.76 m length of a full tube of spherical catalyst particles with tube-to-particle diameter ratio 5.96 showed that the rate of carbon formation was much higher next to the heated tube wall and decreased significantly from the tube wall to the tube center.

scholarly journals Carbon Formation and Active Site of Alumina Supported Platinum Catalyst in Steam Methane Reforming Containing Sulfur

2020 ◽  
Vol 63 (2) ◽  
pp. 89-95
Author(s):  
Fumihiro WATANABE ◽  
Ikuko KABURAKI ◽  
Kazumasa OSHIMA ◽  
Naohiro SHIMODA ◽  
Akira IGARASHI ◽  
...  
Keyword(s):  
Active Site ◽  
Platinum Catalyst ◽  
Methane Reforming ◽  
Carbon Formation ◽  
Steam Methane Reforming ◽  
Steam Methane ◽  
Supported Platinum ◽  
Supported Platinum Catalyst

scholarly journals Thermodynamic Analysis of the Effect of Green Hydrogen Addition to a Fuel Mixture on the Steam Methane Reforming Process

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6564
Author(s):  
Robert Kaczmarczyk
Keyword(s):  
Thermodynamic Analysis ◽  
Gaseous Phase ◽  
Equilibrium Concentration ◽  
Equilibrium Composition ◽  
Fuel Mixture ◽  
Methane Reforming ◽  
Hydrogen Addition ◽  
Steam Methane Reforming ◽  
Steam Methane ◽  
Carbon Precipitation

Steam methane (CH4–H2O) reforming in the presence of a catalyst, usually nickel, is the most common technology for generating synthesis gas as a feedstock in chemical synthesis and a source of pure H2 and CO. What is essential from the perspective of further gas use is the parameter describing a ratio of equilibrium concentration of hydrogen to carbon monoxide H/C=xH2/xCO. The parameter is determined by operating temperature and the initial ratio of steam concentration to methane SC= xH2O0/xCH40. In this paper, the author presents a thermodynamic analysis of the effect of green hydrogen addition to a fuel mixture on the steam methane reforming process of gaseous phase (CH4/H2)–H2O. The thermodynamic analysis of conversion of hydrogen-enriched methane (CH4/H2)–H2O has been performed using parametric equation formalism, allowing for determining the equilibrium composition of the process in progress. A thermodynamic condition of carbon precipitation in methane reforming (CH4/H2) with the gaseous phase of H2O has been interpreted. The ranges of substrate concentrations creating carbon deposition for temperature T = 1000 K have been determined, based on the technologies used. The results obtained can serve as a model basis for describing the properties of steam reforming of methane and hydrogen mixture (CH4/H2)–H2O.

Modeling of a Nickel-based Fluidized Bed Membrane Reactor for Steam Methane Reforming Process

2019 ◽  
Vol 41 (2) ◽  
pp. 219-219
Author(s):  
Mustafa Kamal Pasha Mustafa Kamal Pasha ◽  
Iftikhar Ahmad Iftikhar Ahmad ◽  
Jawad Mustafa Jawad Mustafa ◽  
Manabu Kano Manabu Kano
Keyword(s):  
Fluidized Bed ◽  
Membrane Reactor ◽  
Operating Conditions ◽  
Methane Reforming ◽  
Hydrogen Yield ◽  
Reactor Model ◽  
Membrane Area ◽  
Steam Methane Reforming ◽  
Steam Methane ◽  
Process Simulator

Hydrogen being a green fuel is rapidly gaining importance in the energy sector. Steam methane reforming is one of the most industrially important chemical reaction and a key step in the production of high purity hydrogen. Due to inherent deficiencies of conventional reforming reactors, a new concept based on fluidized bed membrane reactor is getting the focus of researchers. In this work, a nickel-based fluidized bed membrane reactor model is developed in the Aspen PLUSand#174; process simulator. A user-defined membrane module is embedded in the Aspen PLUSand#174; through its interface with Microsoftand#174; Excel. Then, a series combination of Gibbs reactors and membrane modules are used to develop a nickel-based fluidized bed membrane reactor. The model developed for nickel-based fluidized bed membrane reactor is compared with palladium-based membrane reactor in terms of methane conversion and hydrogen yield for a given panel of major operating parameters. The simulation results indicated that the model can accurately predict the behavior of a membrane reactor under different operating conditions. In addition, the model can be used to estimate the effective membrane area required for a given rate of hydrogen production.

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