Optimal Design, Modeling and Simulation of an Ethanol Steam Reforming Reactor

Author(s):  
Luis E Arteaga ◽  
Luis M Peralta ◽  
Yannay Casas ◽  
Daikenel Castro

The optimum design, modeling and simulation of a fixed bed multi-tube reformer for the renewable hydrogen production are carried out in the present paper. The analogies between plug flow model and a fixed bed reactor are used as design patterns. The steam reformer is designed to produce enough hydrogen to feed a 200kW fuel cell system (>2.19molH/s) and considering 85% of fuel utilization in the cell electrodes. The reactor prototype is optimized and then analyzed using a multiphysics and axisymmetric model, implemented on FEMLABM(R) where the differential mass balance by convection-diffusion and the energy balance for convection-conduction are solved. The temperature profile is controlled to maximize hydrogen production. The catalyst bed internal profiles and the effect of temperature on ethanol conversion and carbon monoxide production are discussed as well.

Author(s):  
Lida Rahmanzadeh ◽  
Majid Taghizadeh

Abstract Mesoporous MCM-41 containing different amounts of nickel (10, 15 and 20 wt%) and Ce and/or La promoters were prepared by hydrothermal and wet-impregnation methods. The catalysts were characterized by means of temperature-programmed reduction (TPR), X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), N2 adsorption-desorption, Fourier transform infrared (FT-IR) spectroscopy, and thermogravimetric (TGA) analyses. Then, the catalysts were tested for hydrogen production via steam reforming of ethanol in a fixed bed reactor. Hydrogen selectivity and ethanol conversion over Ni/MCM-41 catalyst were 69.6 % and 94 %, respectively. The best catalytic results were obtained with Ce-Ni/MCM-41 catalyst, i. e. 94 % ethanol conversion and 76.5 % hydrogen selectivity. These results remained constant about 90 h time on stream and ethanol conversion decreased to 87 % after 120 h.


Author(s):  
Pablo Giunta ◽  
Norma Amadeo ◽  
Miguel Laborde

The aim of this work is to design an ethanol steam reformer to produce a hydrogen stream capable of feeding a 60 kW PEM fuel cell applying the plug flow model, considering the presence of the catalyst bed (heterogeneous model). The Dusty-Gas Model is employed for the catalyst, since it better predicts the fluxes of a multicomponent mixture. Moreover, this model has shown to be computationally more robust than the Fickian Model. A power law-type kinetics was used. Results showed that it is possible to carry out the ethanol steam reforming in a compact device (1.66 x 10 -5 to 5.27 x 10 -5 m3). It was also observed that this process is determined by heat transfer.


Author(s):  
Shanzhi Xin ◽  
Xu Qingli ◽  
Liao Lifang ◽  
Yan Yongjie

2020 ◽  
Vol 9 (1) ◽  
pp. 107-112 ◽  
Author(s):  
I. Istadi ◽  
Teguh Riyanto ◽  
Luqman Buchori ◽  
Didi Dwi Anggoro ◽  
Roni Ade Saputra ◽  
...  

Plasma-assisted catalytic cracking is an attractive method for producing biofuels from vegetable oil. This paper studied the effect of reactor temperature on the performance of plasma-assisted catalytic cracking of palm oil into biofuels. The cracking process was conducted in a Dielectric Barrier Discharge (DBD)-type plasma reactor with the presence of spent RFCC catalyst. The reactor temperature was varied at 400, 450, and 500 ºC. The liquid fuel product was analyzed using a gas chromatography-mass spectrometry (GC-MS) to determine the compositions. Result showed that the presenceof plasma and catalytic role can enhance the reactor performance so that the selectivity of the short-chain hydrocarbon produced increases. The selectivity of gasoline, kerosene, and diesel range fuels over the plasma-catalytic reactor were 16.43%, 52.74% and 21.25%, respectively, while the selectivity of gasoline, kerosene and diesel range fuels over a conventional fixed bed reactor was 12.07%, 39.07%, and 45.11%, respectively. The increasing reactor temperature led to enhanced catalytic role of cracking reaction,particularly directing the reaction to the shorter hydrocarbon range. The reactor temperature dependence on the liquid product components distribution over the plasma-catalytic reactor was also studied. The aromatic and oxygenated compounds increased with the reactor temperature.©2020. CBIORE-IJRED. All rights reserved


Catalysts ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 497 ◽  
Author(s):  
Abarasi Hart ◽  
Mohamed Adam ◽  
John P. Robinson ◽  
Sean P. Rigby ◽  
Joseph Wood

This paper reports the hydrogenation and dehydrogenation of tetralin and naphthalene as model reactions that mimic polyaromatic compounds found in heavy oil. The focus is to explore complex heavy oil upgrading using NiMo/Al2O3 and CoMo/Al2O3 catalysts heated inductively with 3 mm steel balls. The application is to augment and create uniform temperature in the vicinity of the CAtalytic upgrading PRocess In-situ (CAPRI) combined with the Toe-to-Heel Air Injection (THAI) process. The effect of temperature in the range of 210–380 °C and flowrate of 1–3 mL/min were studied at catalyst/steel balls 70% (v/v), pressure 18 bar, and gas flowrate 200 mL/min (H2 or N2). The fixed bed kinetics data were described with a first-order rate equation and an assumed plug flow model. It was found that Ni metal showed higher hydrogenation/dehydrogenation functionality than Co. As the reaction temperature increased from 210 to 300 °C, naphthalene hydrogenation increased, while further temperature increases to 380 °C caused a decrease. The apparent activation energy achieved for naphthalene hydrogenation was 16.3 kJ/mol. The rate of naphthalene hydrogenation was faster than tetralin with the rate constant in the ratio of 1:2.5 (tetralin/naphthalene). It was demonstrated that an inductively heated mixed catalytic bed had a smaller temperature gradient between the catalyst and the surrounding fluid than the conventional heated one. This favored endothermic tetralin dehydrogenation rather than exothermic naphthalene hydrogenation. It was also found that tetralin dehydrogenation produced six times more coke and caused more catalyst pore plugging than naphthalene hydrogenation. Hence, hydrogen addition enhanced the desorption of products from the catalyst surface and reduced coke formation.


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