scholarly journals Thermochemical Performance Analysis of the Steam Reforming of Methane in a Fixed Bed Membrane Reformer: A Modelling and Simulation Study

Membranes ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 6
Author(s):  
João Paulo Fernando de Medeiros ◽  
Vitória da Fonseca Dias ◽  
José Marcelo da Silva ◽  
Jornandes Dias da Silva

Pd-based membrane reformers have been substantially studied in the past as a promising reformer to produce high-purity H2 from thermochemical conversion of methane (CH4). A variety of research approaches have been taken in the experimental and theoretical fields. The main objective of this work is a theoretical modelling to describe the process variables of the Steam Reforming of Methane (SRM) method on the Pd-based membrane reformer. These process variables describe the specific aims of each equation of the mathematical model characterizing the performance from reformer. The simulated results of the mole fractions of components (MFCs) at the outlet of the Fixed Bed Reformer (FBR) and Packed-Bed Membrane Reformer (PBMR) have been validated. When the H2O/CH4 ratio decreases in PBMR, the Endothermic Reaction Temperature (ERT) is notably increased (998.32 K) at the outlet of the PBMR’s reaction zone. On the other hand, when the H2O/CH4 ratio increases in PBMR, the ERT is remarkably decreased (827.83 K) at the outlet of the PBMR’s reaction zone. An increase of the spatial velocity (Ssp) indicates a reduction in the residence time of reactant molecules inside PBMR and, thus, a decrease of the ERT and conversion of CH4. In contrast, a reduction of the Ssp shows an increase of the residence time of reactant molecules within PBMR and, therefore, a rise of the ERT and conversion of CH4. An increase of the H2O/CH4 ratio raises the conversion rate (CR) of CH4 due to the reduction of the coke content on the catalyst particles. Conversely, a reduction of the H2O/CH4 ratio decreases the CR of CH4 owing to the increase of the coke content on the catalyst particles. Contrary to the CR of CH4, the consumption-based yield (CBY) of H2 sharply decreases with the increase of the H2O/CH4 ratio. An increase of the ERT raises the thermochemical energy storage efficiency (ηtese) from 68.96% (ERT = 1023 K), 63.21% (ERT = 973 K), and 48.12% (ERT = 723 K). The chemical energy, sensible heat, and heat loss reached values of 384.96 W, 151.68 W, and 249.73 W at 973 K. The selectivity of H2 presents higher amounts in the gaseous mixture that varies from 60.98 to 73.18 while CH4 showed lower values ranging from 1.41 to 2.06. Our work is limited to the SRM method. In terms of future uses of this method, new works can be undertaken using novel materials (open-cell foams) and the physical-mathematical model (two-dimensional and three-dimensional) to evaluate the concentration polarization inside membrane reactors.

2021 ◽  
Vol 20 (1) ◽  
pp. 03
Author(s):  
D. R. Dessaune ◽  
V. F. Dias ◽  
J. D. Silva

Thermochemical Packed-Bed (TPB) reformer has been substantially studiedin the past years as a promising equipment to investigate thethermochemical conversion of methane (CH4). This work has as mainobjective a theoretical modelling to describe the process variables of SteamReforming of Methane (SRM) method in the TPB reformer. The TPBreformer is filled with β-SiC open-cell foam where the thermochemicalconversion of CH4 is carried out. The model variables describe the specificaims of work and these objectives can be identified from each equation ofthe developed mathematical model. This work has been proposed to studytwo specific aims as (i) the effective thermal conductivity's effect of thesolid phase (λs,eff.) and (ii) molar flows of chemical components. Theendothermic reaction temperature's profiles are notably increased as thenumeral value of λs,eff. is raised. The Steam Reforming of Methane (SRM)method is suggested to improve the Production Rate (PR) of H2 regardingthe PR of CO. As results, the PR of H2 is of 29.48% while the PR of CO isof 2.76%.


1996 ◽  
Vol 13 (5) ◽  
pp. 367-375 ◽  
Author(s):  
Yehia H. Magdy

The adsorption of mixed dyes, Acid Blue and Basic Red, on to hardwood sawdust has been studied using the fixed bed technique. The influence of various parameters such as bed depth, solution flow rate and dye concentration were studied. The modified bed depth service time (BDST) model has been used to analyze the experimental data. In addition the empty bed residence time (EBRT) technique has been applied to optimize the adsorption process variables for either single or multi-component dyes.


1999 ◽  
Vol 39 (4) ◽  
pp. 85-92 ◽  
Author(s):  
J. Behrendt

A mathematical model for nitrification in an aerated fixed bed reactor has been developed. This model is based on material balances in the bulk liquid, gas phase and in the biofilm area. The fixed bed is divided into a number of cells according to the reduced remixing behaviour. A fixed bed cell consists of 4 compartments: the support, the gas phase, the bulk liquid phase and the stagnant volume containing the biofilm. In the stagnant volume the biological transmutation of the ammonia is located. The transport phenomena are modelled with mass transfer formulations so that the balances could be formulated as an initial value problem. The results of the simulation and experiments are compared.


1992 ◽  
Vol 57 (10) ◽  
pp. 2125-2134 ◽  
Author(s):  
Petr Stehlík ◽  
František Babinec

An application of a fuzzy expert system intended for estimating some parameters of steam reforming can also be one of the examples of an ever increasing utilization of expert systems in practice. The present contribution deals with the method making use of a verified mathematical model for simulating thermal chemical processes in reforming furnace radiation chamber in order to create knowledge base. This base includes linguistic values of selected independent and dependent variable quantities. Examples given illustrate an evaluation of dependent variable quantities (methane conversion into carbon dioxide and monoxide, reaction tube service life) by means of the said expert system based on queries.


2021 ◽  
Vol 95 ◽  
pp. 101-119
Author(s):  
Xianglin Li ◽  
Yiran Wang ◽  
Huailin Fan ◽  
Qianhe Liu ◽  
Shu Zhang ◽  
...  

Author(s):  
Wirya Sarwana ◽  
Akihiko Anzai ◽  
Daichi Takami ◽  
Akira Yamamoto ◽  
Hisao Yoshida

Photocatalytic steam reforming of methane (PSRM) has been studied as an attractive method to produce hydrogen by utilizing photoenergy like solar energy around room temperature with metal-loaded photocatalysts, where methane...


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