- Analysis of Catalytic Reactors

2012 ◽  
pp. 454-515
Keyword(s):  
Catalytic Reactors

scholarly journals Recent Developments in Carbon Nanotubes-Reinforced Ceramic Matrix Composites: A Review on Dispersion and Densification Techniques

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 457
Author(s):  
Kar Fei Chan ◽  
Mohd Hafiz Mohd Zaid ◽  
Md Shuhazlly Mamat ◽  
Shahira Liza ◽  
Masaki Tanemura ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Turbine Blades ◽  
Glass Ceramics ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Matrix Composites ◽  
Catalytic Reactors ◽  
Light Emitting ◽  
Commercial Laboratory ◽  
Recent Developments

Ceramic matrix composites (CMCs) are well-established composites applied on commercial, laboratory, and even industrial scales, including pottery for decoration, glass–ceramics-based light-emitting diodes (LEDs), commercial cooking utensils, high-temperature laboratory instruments, industrial catalytic reactors, and engine turbine blades. Despite the extensive applications of CMCs, researchers had to deal with their brittleness, low electrical conductivity, and low thermal properties. The use of carbon nanotubes (CNTs) as reinforcement is an effective and efficient method to tailor the ceramic structure at the nanoscale, which provides considerable practicability in the fabrication of highly functional CMC materials. This article provides a comprehensive review of CNTs-reinforced CMC materials (CNTs-CMCs). We critically examined the notable challenges during the synthesis of CNTs-CMCs. Five CNT dispersion processes were elucidated with a comparative study of the established research for the homogeneity distribution in the CMCs and the enhanced properties. We also discussed the effect of densification techniques on the properties of CNTs-CMCs. Additionally, we synopsized the outstanding microstructural and functional properties of CNTs in the CNTs-CMCs, namely stimulated ceramic crystallization, high thermal conductivity, bandgap reduction, and improved mechanical toughness. We also addressed the fundamental insights for the future technological maturation and advancement of CNTs-CMCs.

Energy-minimization multiscale based mesoscale modeling and applications in gas-fluidized catalytic reactors

2019 ◽  
Vol 35 (8) ◽  
pp. 879-915 ◽  
Author(s):  
Bona Lu ◽  
Yan Niu ◽  
Feiguo Chen ◽  
Nouman Ahmad ◽  
Wei Wang ◽  
...  
Keyword(s):  
Energy Minimization ◽  
Fluid Model ◽  
Scale Up ◽  
Flow Characteristics ◽  
Chemical Kinetic ◽  
Mesoscale Modeling ◽  
Catalytic Reactors ◽  
Chemical Kinetic Model ◽  
Starting Point ◽  
Wide Range

Abstract Gas-solid fluidization is intrinsically dynamic and manifests mesoscale structures spanning a wide range of length and timescales. When involved with reactions, more complex phenomena emerge and thus pose bigger challenges for modeling. As the mesoscale is critical to understand multiphase reactive flows, which the conventional two-fluid model without mesoscale modeling may be inadequate to resolve even using extremely fine grids, this review attempts to demonstrate that the energy-minimization multiscale (EMMS) model could be a starting point to develop such mesoscale modeling. Then, the EMMS-based mesoscale modeling with emphasis on formulation of drag coefficients for different fluidization regimes, modification of mass transfer coefficient, and other extensions are discussed in an attempt to resolve the emerging challenges. Its applications with examples of development of novel fluid catalytic cracking and methanol-to-olefins processes prove that the mesoscale modeling plays a remarkable role in improving the predictions in hydrodynamic behaviors and overall reaction rate. However, the product content primarily depends on the chemical kinetic model itself, suggesting the necessity of an effective coupling between chemical kinetics and flow characteristics. The mesoscale modeling can be believed to accelerate the traditional experimental-based scale-up process with much lower cost in the future.

Influence of the Copper(II) Oxide Dispersion on its Catalytic Properties in Carbon Monoxide Oxidation: A Comparative Study by Using Two Types of Catalytic Reactors

ChemCatChem ◽  
2016 ◽  
Vol 8 (22) ◽  
pp. 3546-3555 ◽  
Author(s):  
Dmitry A. Svintsitskiy ◽  
Ilya Yu. Pakharukov ◽  
Elena M. Slavinskaya ◽  
Tatyana Yu. Kardash ◽  
Valentin N. Parmon ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Comparative Study ◽  
Catalytic Properties ◽  
Carbon Monoxide Oxidation ◽  
Oxide Dispersion ◽  
Catalytic Reactors

Control optimization of tubular catalytic reactors with catalyst decay

1984 ◽  
Vol 23 (1) ◽  
pp. 126-131 ◽  
Author(s):  
Guido Buzzi-Ferraris ◽  
Edoardo Facchi ◽  
Pio Forzatti ◽  
Enrico Tronconi
Keyword(s):  
Catalytic Reactors ◽  
Control Optimization

Transverse concentration and temperature nonuniformities in adiabatic packed-bed catalytic reactors

1999 ◽  
Vol 54 (11) ◽  
pp. 1725-1734 ◽  
Author(s):  
Vemuri Balakotaiah ◽  
Evangelia L. Christoforatou ◽  
David H. West
Keyword(s):  
Packed Bed ◽  
Catalytic Reactors

Membranes and Membrane Processes

MRS Bulletin ◽  
1999 ◽  
Vol 24 (3) ◽  
pp. 19-22 ◽  
Author(s):  
Vasilis N. Burganos
Keyword(s):  
Membrane Separation ◽  
Transport Coefficients ◽  
Electrical Potential ◽  
Artificial Organs ◽  
Energy Storage And Conversion ◽  
Electrical Potential Difference ◽  
Catalytic Reactors ◽  
Membrane Processes ◽  
Separation Science ◽  
Structural And Functional Properties

Membrane separation science has enjoyed tremendous progress since the first synthesis of membranes almost 40 years ago, which was driven by strong technological needs and commercial expectations. As a result, the range of successful applications of membranes and membrane processes is continuously broadening. An additional change lies in the nature of membranes, which is now extended to include liquid and gaseous materials, biological or synthetic. Membranes are understood to be thin barriers between two phases through which transport can take place under the action of a driving force, typically a pressure difference and generally a chemical or electrical potential difference.An attempt at functional classification of membranes would have to include diverse categories such as gas separation, pervaporation, reverse osmosis, micro- and ultrafiltration, and biomedical separations. The dominant application of membranes is certainly the separation of mixed phases or fluids, homogeneous or heterogeneous. Separation of a mixture can be achieved if the difference in the transport coefficients of the components of interest is sufficiently large. Membranes can also be used in applications other than separation targeting: They can be employed in catalytic reactors, energy storage and conversion systems, as key components of artificial organs, as supports for electrodes, or even to control the rate of release of both useful and dangerous species.In order to meet the requirements posed by the aforementioned applications, membranes must combine several structural and functional properties.

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