scholarly journals Model-Based Quality, Exergy, and Economic Analysis of Fluidized Bed Membrane Reactors

Membranes ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 765
Author(s):  
Tabassam Nafees ◽  
Adnan Ahmed Bhatti ◽  
Usman Khan Jadoon ◽  
Farooq Ahmad ◽  
Iftikhar Ahmad ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Plug Flow ◽  
Aspen Plus ◽  
Fluidized Bed Reactor ◽  
Packed Bed ◽  
Membrane Reactors ◽  
Flow Reactors ◽  
Diffusion Limitations ◽  
Naphtha Reforming ◽  
Petroleum Refineries

In petroleum refineries, naphtha reforming units produce reformate streams and as a by-product, hydrogen (H2). Naphtha reforming units traditionally deployed are designed as packed bed reactors (PBR). However, they are restrained by a high-pressure drop, diffusion limitations in the catalyst, and radial and axial gradients of temperature and concentration. A new design using the fluidized bed reactor (FBR) surpasses the issues of the PBR, whereby the incorporation of the membrane can improve the yield of products by selectively removing hydrogen from the reaction side. In this work, a sequential modular simulation (SMS) approach is adopted to simulate the hydrodynamics of a fluidized bed membrane reactor (FBMR) for catalytic reforming of naphtha in Aspen Plus. The reformer reactor is divided into five sections of plug flow reactors and a continuous stirrer tank reactor with the membrane module to simulate the overall FBMR process. Similarly, a fluidized bed reactor (FBR), without membrane permeation phenomenon, is also modelled in the Aspen Plus environment for a comparative study with FBMR. In FBMR, the continuous elimination of permeated hydrogen enhanced the production of aromatics compound in the reformate stream. Moreover, the exergy and economic analyses were carried out for both FBR and FBMR.

Simulation of biomass gasification in bubbling fluidized bed reactor using aspen plus®

2021 ◽  
Vol 235 ◽  
pp. 113981
Author(s):  
M. Puig-Gamero ◽  
D.T. Pio ◽  
L.A.C. Tarelho ◽  
P. Sánchez ◽  
L. Sanchez-Silva
Keyword(s):  
Fluidized Bed ◽  
Aspen Plus ◽  
Fluidized Bed Reactor ◽  
Biomass Gasification ◽  
Bubbling Fluidized Bed

Membrane-Assisted Reactor Engineering

2001 ◽  
Author(s):  
L. K. Doraiswamy
Keyword(s):  
Plug Flow ◽  
Operating Mode ◽  
Shape Selectivity ◽  
Membrane Reactors ◽  
Inorganic Membrane ◽  
Main Concern ◽  
Inorganic Membranes ◽  
Flow Reactors ◽  
Reactor Material ◽  
Membrane Tube

Like zeolites that combine shape selectivity with catalysis, membranes combine separation with catalysis to enhance reaction rates. The dual functionality of zeolites derives from the nature of the catalytic material, whereas that of membranes derives from the nature of the reactor material. The catalyst in the membrane reactor can be a part of the membrane itself or be external to it (i.e., placed inside the membrane tube). The chief property of a membrane is its ability for selective permeation or permselectivity with respect to certain compounds. Organic membrane reactions are best carried out in reactors made of inorganic membranes, such as from palladium, alumina, or ceramics. Good descriptions of these reactions and the membranes used are available in many reviews, for example, Gryaznov (1986, 1992), Stoukides (1988), Armor (1989), Govind and Ilias (1989), Bhave (1991), Zaspalis and Burggraaf (1991), Hsieh (1989, 1991), Shu et al. (1991), Shieh (1991), Gellings and Bouwmeister (1992), Tsotsis et al. (1993b), Harold et al. (1994), Saracco and Specchia (1994), Sanchez and Tsotsis (1996). A recent trend has been to develop polymeric-inorganic composite type membranes formed by the deposition of a thin dense polymeric film on an inorganic support (Kita et al., 1987; Rezac and Koros, 1994, 1995; Zhu et al., 1996). Another class of membranes under development for organic synthesis is the liquid membrane (Marr and Kopp, 1982; Eyal and Bressler, 1993). The permselective barrier in this type of membrane is a liquid phase, often containing a dissolved “carrier” or “transporter” that selectively reacts with a specific permeate to enhance its transport rate through the membrane. Our main concern in this chapter will be with inorganic membrane reactors. We commence our treatment with an introduction to the exploitable features of membrane reactors (with no attempt to describe membrane synthesis). Then we describe the main variations in design and operating mode of these reactors, develop performance equations for the more important designs, and compare the performances of some important designs with those of the traditional mixed- and plug-flow reactors. Finally, we present a summary of the applications of membrane reactors in enhancing the rates of organic reactions.

Biohydrogen production from soft drink industry wastewater in an anaerobic fluidized bed reactor

2019 ◽  
Vol 14 (3) ◽  
pp. 579-586
Author(s):  
V. S. Menezes ◽  
N. C. S. Amorim ◽  
W. V. Macêdo ◽  
E. L. C. Amorim
Keyword(s):  
Fluidized Bed ◽  
Soft Drink ◽  
Fluidized Bed Reactor ◽  
Packed Bed ◽  
Operating Conditions ◽  
Hydrogen Yield ◽  
Packed Bed Reactors ◽  
Carbonated Soft Drinks ◽  
Anaerobic Fluidized Bed Reactor ◽  
Metabolites Production

Abstract The wastewater from carbonated soft drinks production was used as substrate in an anaerobic fluidized bed reactor (AFBR) to evaluate the production of biohydrogen as a renewable energy. The hydraulic retention time (HRT) ranged from 8 to 0.5 hours (7.92 to 137.09 kg COD m−3 day−1) throughout the experiment and expanded clay was used as support material for biomass adhesion. The average composition of hydrogen in the biogas under the conditions of this experiment was 34%. The maximum hydrogen yield (HY) and the maximum hydrogen production rate (HPR) was 5.87 mol H2/mol substrate and 2.74 L H2 h−1 L−1, respectively, obtained in the HRT of 0.5 hour. Acetic acid was the predominant soluble metabolite detected (88%). Propionic, butyric and caproic acids were quantified with low production (7%, 4% and 1% of soluble metabolites production (SMP)). The anaerobic fluidized bed reactor optimized the average of hydrogen yield by 17% in relation to packed-bed reactors, in a HRT of 0.5 h. The natural fermentation process and operating conditions were favorable to the inhibition of hydrogen-consuming organisms, such as methanogenic archaeas.

scholarly journals Process Simulation of Steam Gasification of Torrefied Woodchips in a Bubbling Fluidized Bed Reactor Using Aspen Plus

2021 ◽  
Vol 11 (6) ◽  
pp. 2877
Author(s):  
Nhut M. Nguyen ◽  
Falah Alobaid ◽  
Bernd Epple
Keyword(s):  
Fluidized Bed ◽  
Conversion Efficiency ◽  
Process Model ◽  
Aspen Plus ◽  
Fluidized Bed Reactor ◽  
Steam Gasification ◽  
Operating Conditions ◽  
Carbon Conversion ◽  
Bubbling Fluidized Bed ◽  
Biomass Ratio

A comprehensive process model is proposed to simulate the steam gasification of biomass in a bubbling fluidized bed reactor using the Aspen Plus simulator. The reactor models are implemented using external FORTRAN codes for hydrodynamic and reaction kinetic calculations. Governing hydrodynamic equations and kinetic reaction rates for char gasification and water-gas shift reactions are obtained from experimental investigations and the literature. Experimental results at different operating conditions from steam gasification of torrefied biomass in a pilot-scale gasifier are used to validate the process model. Gasification temperature and steam-to-biomass ratio promote hydrogen production and improve process efficiencies. The steam-to-biomass ratio is directly proportional to an increase in the content of hydrogen and carbon monoxide, while gas yield and carbon conversion efficiency enhance significantly with increasing temperature. The model predictions are in good agreement with experimental data. The mean error of CO2 shows the highest value of 0.329 for the steam-to-biomass ratio and the lowest deviation is at 0.033 of carbon conversion efficiency, respectively. The validated model is capable of simulating biomass gasification under various operating conditions.

Cluster-Based Modeling of Fluidized Catalytic Oxidation of n-Butane to Maleic Anhydride

2006 ◽  
Vol 4 (1) ◽  
Author(s):  
Hamid Reza Hakimelahi ◽  
Rahmat Sotudeh-Gharebagh ◽  
Navid Mostoufi
Keyword(s):  
Mathematical Model ◽  
Maleic Anhydride ◽  
Fluidized Bed ◽  
Flow Reactor ◽  
Plug Flow ◽  
Fluidized Bed Reactor ◽  
Solid Particles ◽  
Reactor Model ◽  
Two Phase ◽  
Cut Method

A mathematical model is proposed for the partial oxidation on n-butane to maleic anhydride (MAN) in a gas-solid fluidized bed reactor. The reactor consists of two regions, i.e., a lower dense region and an upper dilute region. The dynamic two-phase structure was used for modeling the lower dense bed hydrodynamics. The upper region hydrodynamics was modeled by a cluster based approach. This allows the porosity distribution to be calculated for plug flow reactor model assumed for the gas phase in this region. The basic assumption in the cluster based approach is that the solid particles move only as clusters and the amount of single particles in the upper region is negligible. The mathematical model was obtained from coupling the kinetic sub-model, obtained from the literature, with this hydrodynamics sub-model. Comparing the results of the model with the experimental data available in the literature showed close agreement. Two other methods (i.e., particle based approach and short-cut) were also tested in this work. However, it was found that the cluster based approach modeling is quite suitable for the fluidized bed reactor used in this study. The short-cut method seems reasonably applicable for the prediction of the overall conversion but does not provide any local information (such as concentration profiles, yield, etc.) within the fluidized bed reactor.

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