Journal articles: 'Chemical reactors'

1

Abbas, Sarah A., Adel A. Eidan, and Assaad Al Sahlani. "Solar Reactor Review." International Journal of Heat and Technology 40, no. 3 (June 30, 2022): 671–84. http://dx.doi.org/10.18280/ijht.400303.

Full text

Abstract:

This research paper presents a detailed review of the recent advances concerned with carrying out efficient solar chemical reactions by reviewing the most recent reactors available in the literature that use solid-gas reactions or pyrolysis processes. Major research groups in solar chemistry design and manufacture a wide range of solar reactor configurations, widths, and sizes, including directly radioactive particles. Solar reactors heat up to 1000℃ and can be utilized to store chemical thermal energy in concentrated solar power facilities (CSP). Reactor efficiency is better in bed reactors notably in rotating pyrolysis, fluidized bed reactors with solid gas, and fixed-bed reactor systems. Finally, their description, schematics, and key performance parameters are presented for chemical reactions.

APA, Harvard, Vancouver, ISO, and other styles

2

Slavnic, Danijela, Branko Bugarski, and Nikola Nikacevic. "Oscillatory flow chemical reactors." Chemical Industry 68, no. 3 (2014): 363–79. http://dx.doi.org/10.2298/hemind130419062s.

Full text

Abstract:

Global market competition, increase in energy and other production costs, demands for high quality products and reduction of waste are forcing pharmaceutical, fine chemicals and biochemical industries, to search for radical solutions. One of the most effective ways to improve the overall production (cost reduction and better control of reactions) is a transition from batch to continuous processes. However, the reactions of interests for the mentioned industry sectors are often slow, thus continuous tubular reactors would be impractically long for flow regimes which provide sufficient heat and mass transfer and narrow residence time distribution. The oscillatory flow reactors (OFR) are newer type of tube reactors which can offer solution by providing continuous operation with approximately plug flow pattern, low shear stress rates and enhanced mass and heat transfer. These benefits are the result of very good mixing in OFR achieved by vortex generation. OFR consists of cylindrical tube containing equally spaced orifice baffles. Fluid oscillations are superimposed on a net (laminar) flow. Eddies are generated when oscillating fluid collides with baffles and passes through orifices. Generation and propagation of vortices create uniform mixing in each reactor cavity (between baffles), providing an overall flow pattern which is close to plug flow. Oscillations can be created by direct action of a piston or a diaphragm on fluid (or alternatively on baffles). This article provides an overview of oscillatory flow reactor technology, its operating principles and basic design and scale - up characteristics. Further, the article reviews the key research findings in heat and mass transfer, shear stress, residence time distribution in OFR, presenting their advantages over the conventional reactors. Finally, relevant process intensification examples from pharmaceutical, polymer and biofuels industries are presented.

APA, Harvard, Vancouver, ISO, and other styles

3

Zsembinszki, Gabriel, Aran Solé, Camila Barreneche, Cristina Prieto, A. Fernández, and Luisa Cabeza. "Review of Reactors with Potential Use in Thermochemical Energy Storage in Concentrated Solar Power Plants." Energies 11, no. 9 (September 6, 2018): 2358. http://dx.doi.org/10.3390/en11092358.

Full text

Abstract:

The aim of this study is to perform a review of the state-of-the-art of the reactors available in the literature, which are used for solid–gas reactions or thermal decomposition processes around 1000 °C that could be further implemented for thermochemical energy storage in CSP (concentrated solar power) plants, specifically for SPT (solar power tower) technology. Both direct and indirect systems can be implemented, with direct and closed systems being the most studied ones. Among direct and closed systems, the most used configuration is the stacked bed reactor, with the fixed bed reactor being the most frequent option. Out of all of the reactors studied, almost 70% are used for solid–gas chemical reactions. Few data are available regarding solar efficiency in most of the processes, and the available information indicates relatively low values. Chemical reaction efficiencies show better values, especially in the case of a fluidized bed reactor for solid–gas chemical reactions, and fixed bed and rotary reactors for thermal decompositions.

APA, Harvard, Vancouver, ISO, and other styles

4

Diver, R. B. "Receiver/Reactor Concepts for Thermochemical Transport of Solar Energy." Journal of Solar Energy Engineering 109, no. 3 (August 1, 1987): 199–204. http://dx.doi.org/10.1115/1.3268206.

Full text

Abstract:

Thermochemical transport of solar energy based on reversible chemical reactions may be a way to take advantage of the high-temperature capabilities of parabolic dishes, while minimizing pipe network heat loss, since energy is transported at ambient temperatures in chemical form. Receiver/Reactor design is a key to making thermochemical transport a reality. In this paper the important parameters for solar receiver and chemical reactor design and how they relate to each other are presented. Three basic receiver/reactor types, applicable to thermochemical receiver design, are identified: (1) Tube Receiver/Reactors have tubular reactor elements which are directly heated by solar energy in the receiver. (2) Indirect Receiver/Reactors use an intermediate heat transfer fluid between the receiver and reactor. (3) Direct Absorption Receiver/Reactors absorb sunlight directly on the reactor catalyst. Advantages, limitations, and risks associated with each design are discussed and examples of those that have been built are given. Each type offers its own set of advantages and risks, and warrant further investigation.

APA, Harvard, Vancouver, ISO, and other styles

5

Hoff, Axel A., Hans H. Diebner, and Gerold Baierc. "Reversible Control of Chemical Reaction Systems." Zeitschrift für Naturforschung A 50, no. 12 (December 1, 1995): 1141–46. http://dx.doi.org/10.1515/zna-1995-1214.

Full text

Abstract:

Abstract Starting from an algorithm for continuous chaos control, a reversible control method based on mutual diffusive coupling of chemical reactors is developed. With sufficient coupling strength, the proposed mutual coupling leads to control even if both reactors are of similar size. The controlling and controlled reactor exchange their roles at a certain size ratio. Insufficient coupling can lead to a more complex dynamics than that of the uncoupled reactors. This method for control via reversible coupling of chemical reactors should be implementable on a purely microscopic level.

APA, Harvard, Vancouver, ISO, and other styles

6

Taghizadeh, Majid, and Fatemeh Aghili. "Recent advances in membrane reactors for hydrogen production by steam reforming of ethanol as a renewable resource." Reviews in Chemical Engineering 35, no. 3 (March 26, 2019): 377–92. http://dx.doi.org/10.1515/revce-2017-0083.

Full text

Abstract:

AbstractDuring the last decade, hydrogen has attracted lots of interest due to its potential as an energy carrier. Ethanol is one of the renewable resources that can be considered as a sustainable candidate for hydrogen generation. In this regard, producing hydrogen from ethanol steam reforming (ESR) would be an environmentally friendly process. Commonly, ESR is performed in packed bed reactors; however, this process needs several stages for hydrogen separation with desired purity. Recently, the concept of a membrane reactor, an attractive device integrating catalytic reactions and separation processes in a single unit, has allowed obtaining a smaller reactor volume, higher conversion degrees, and higher hydrogen yield in comparison to conventional reactors. This paper deals with recent advances in ESR in terms of catalyst utilization and the fundamental of membranes. The main part of this paper discusses the performance of different membrane reactor configurations, mainly packed bed membrane reactors, fluidized bed membrane reactors, and micro-membrane reactors. In addition, a short overview is given about the impact of ESR via different catalysts such as noble metal, non-noble metal, and bi-metallic catalysts.

APA, Harvard, Vancouver, ISO, and other styles

7

Thomson, Christopher G., Ai-Lan Lee, and Filipe Vilela. "Heterogeneous photocatalysis in flow chemical reactors." Beilstein Journal of Organic Chemistry 16 (June 26, 2020): 1495–549. http://dx.doi.org/10.3762/bjoc.16.125.

Full text

Abstract:

The synergy between photocatalysis and continuous flow chemical reactors has shifted the paradigms of photochemistry, opening new avenues of research with safer and scalable processes that can be readily implemented in academia and industry. Current state-of-the-art photocatalysts are homogeneous transition metal complexes that have favourable photophysical properties, wide electrochemical redox potentials, and photostability. However, these photocatalysts present serious drawbacks, such as toxicity, limited availability, and the overall cost of rare transition metal elements. This reduces their long-term viability, especially at an industrial scale. Heterogeneous photocatalysts (HPCats) are an attractive alternative, as the requirement for the separation and purification is largely removed, but typically at the cost of efficiency. Flow chemical reactors can, to a large extent, mitigate the loss in efficiency through reactor designs that enhance mass transport and irradiation. Herein, we review some important developments of heterogeneous photocatalytic materials and their application in flow reactors for sustainable organic synthesis. Further, the application of continuous flow heterogeneous photocatalysis in environmental remediation is briefly discussed to present some interesting reactor designs that could be implemented to enhance organic synthesis.

APA, Harvard, Vancouver, ISO, and other styles

8

Chebbi, Rachid. "Chemical reactors sequencing." Computer Applications in Engineering Education 22, no. 2 (April 22, 2011): 195–99. http://dx.doi.org/10.1002/cae.20545.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Caravella, Alessio. "Extended Definition of Conversion and Reaction Extent for a Systematic Development of the Design Equations for Reactor Networks." Processes 12, no. 1 (January 1, 2024): 107. http://dx.doi.org/10.3390/pr12010107.

Full text

Abstract:

The aim of this work is to present in a systematic way a novel general methodology to develop the design equations (heat and mass balances) for networks of ideal reactors, that is, Plug-Flow Reactors (PFRs) and Continuous Stirred Tank Reactors (CSTRs). In particular, after introducing the general definition of conversion to be used for reactor networks, several case studies of interest in chemical engineering are presented as topic-examples of application: (i) adiabatic-stage reactors with recycle, (ii) adiabatic-stage reactors with split, (iii) adiabatic-stage reactors intercooled by reactants and (iv) adiabatic-stage reactors with interstage distributed feed. More generally, the presented methodology can also be applied to develop the design equations for complex networks of interconnected reactors, not restricted to those considered in the present work. The motivation behind the present study lies in the fact that, to the best of our knowledge, a systematic development of the design equations of single reactors in reactor networks is currently missing in the open literature as well as in the reference textbooks of chemical reaction engineering and reactor design.

APA, Harvard, Vancouver, ISO, and other styles

10

Schmidt, Lanny D. "ChemInform Abstract: Millisecond Chemical Reactions and Reactors." ChemInform 31, no. 49 (December 5, 2000): no. http://dx.doi.org/10.1002/chin.200049292.

Full text

APA, Harvard, Vancouver, ISO, and other styles

11

Subbarao, Duvvuri, Reem Hassan Abd Elghafoor Hassan, and Marappagounder Ramasamy. "Heat Transfer with Chemical Reaction in Wall Heated Packed Bed Reactor." Applied Mechanics and Materials 625 (September 2014): 722–25. http://dx.doi.org/10.4028/www.scientific.net/amm.625.722.

Full text

Abstract:

Information on wall heat transfer to packed bed reactors operating with exothermic or endothermic reactions is scarce. Overall wall heat transfer coefficients in a packed bed reactor in presence of an endothermic reaction are measured and observed to be smaller than the expected in the absence of reaction. This observation is in contrast with the reported observations with exothermic reactions in packed beds. A model equation based on energy balance is presented to explain the observations.

APA, Harvard, Vancouver, ISO, and other styles

12

Hogan, R. E., and R. D. Skocypec. "Analysis of Catalytically Enhanced Solar Absorption Chemical Reactors: Part I—Basic Concepts and Numerical Model Description." Journal of Solar Energy Engineering 114, no. 2 (May 1, 1992): 106–11. http://dx.doi.org/10.1115/1.2929987.

Full text

Abstract:

A detailed numerical model is presented for high-temperature, catalytically enhanced, solar absorption chemical reactors. In these reactors, concentrated solar energy is volumetrically absorbed throughout a porous absorber matrix impregnated with a catalyst. The catalyst promotes heterogeneous reactions with fluid-phase reactant species flowing through the absorber. This paper presents a description of a numerical model and the basic concepts of reactor operation. The numerical model of the absorber includes solar and infrared radiation, heterogeneous chemical reactions, conduction in the solid phase, and convection between the fluid and solid phases. The model is nonlinear primarily due to both the radiative transfer and the heterogeneous chemistry occurring in the absorber. The nonlinear two-point boundary value problem is solved using superposition with orthonormalization and an adaptive solution point scheme. This technique preserves accuracy throughout the domain. The model can be modified for other chemical reactions and can be simplified to model volumetric air-heating receivers.

APA, Harvard, Vancouver, ISO, and other styles

13

Lei, Song, Ao Wang, Jian Xue, and Haihui Wang. "Catalytic ceramic oxygen ionic conducting membrane reactors for ethylene production." Reaction Chemistry & Engineering 6, no. 8 (2021): 1327–41. http://dx.doi.org/10.1039/d1re00136a.

Full text

Abstract:

Catalytic ceramic oxygen ionic conducting membrane reactors have great potential in the production of high value-added chemicals as they can couple chemical reactions with separation within a single unit, allowing process intensification.

APA, Harvard, Vancouver, ISO, and other styles

14

Kovacs, Ildiko, Richard V. Jones, Krisztian Niesz, Csaba Csajagi, Bernadett Borcsek, Ferenc Darvas, and Laszlo Urge. "Automated Technology for Performing Flow-Chemistry at Elevated Temperature and Pressure." JALA: Journal of the Association for Laboratory Automation 12, no. 5 (October 2007): 284–90. http://dx.doi.org/10.1016/j.jala.2007.06.009.

Full text

Abstract:

Over the past few years, a series of novel microfluidic-based instruments were developed by ThalesNano, Inc. to carry out dangerous and difficult to perform chemical reactions in a safe and fast manner, resulting in superior performance to what commercial batch reactors could provide. Importance of microfluidic devices is continuously raising, as seen there are more and more publications, applications and devices in this field expanding the borders of chemistry. Furthermore, as one of the main advantages for pharmaceutical applications, these new revolutionary reactors allow the fast, on-the-fly mode optimization of different heterogeneous reactions in a high-throughput fashion. The heart of the reactor systems is the actual reactor bed, called the CatCart system. CatCarts allow easy handling of heterogeneous catalyst or immobilized reagents without further purification of products. In addition, the shoe-box size of these reactors makes them available from laboratories to industrial applications.

APA, Harvard, Vancouver, ISO, and other styles

15

Lu, Ningning, and Donglai Xie. "Novel Membrane Reactor Concepts for Hydrogen Production from Hydrocarbons: A Review." International Journal of Chemical Reactor Engineering 14, no. 1 (February 1, 2016): 1–31. http://dx.doi.org/10.1515/ijcre-2015-0050.

Full text

Abstract:

AbstractMembrane reactors are attracting increasing attention for ultrapure hydrogen production from fossil fuel, integrating catalytic reaction and separation processes into one single unit thus can realize the removal of hydrogen or introduction of reactant in situ, which removes the thermodynamic bottleneck and improves hydrogen yield and selectivity. In this review, the state-of-the-art concepts for hydrogen production through membrane reactors are introduced, mainly including fixed bed membrane reactors, fluidized bed membrane reactors, and micro-channel membrane reactors, referring higher hydrocarbons as feedstock, such as ethanol, propane, or heptane; novel heating methods, like solar energy realized through molten salt; new modular designs, including panel and tubular configurations; ultra-compact micro-channel designs; carbon dioxide capture with chemical looping; multifuel processors for liquid and/or solid hydrocarbons; etc. Recent developments and commercialization hurdles for each type of membrane reactor are summarized. Modeling the reactor is fundamental to explore complex hydrodynamics in reactor systems, meaningful to investigate the effects of some important operating factors on reactor performances. Researches for reactor modeling are also discussed. Reaction kinetics for hydrocarbons reforming and reactor hydrodynamics are summarized respectively. Cold model is introduced to investigate physical phenomena in reactors.

APA, Harvard, Vancouver, ISO, and other styles

16

BORCKMANS, P., G. DEWEL, A. DE WIT, E. DULOS, J. BOISSONADE, F. GAUFFRE, and P. DE KEPPER. "DIFFUSIVE INSTABILITIES AND CHEMICAL REACTIONS." International Journal of Bifurcation and Chaos 12, no. 11 (November 2002): 2307–32. http://dx.doi.org/10.1142/s0218127402005881.

Full text

Abstract:

Diffusive instabilities provide the engine for an ever increasing number of dissipative structures. In this class autocatalytic chemical systems are prone to generate temporal and spatial self-organization phenomena. The development of open spatial reactors and the subsequent discovery in 1989 of the stationary reaction–diffusion patterns predicted by Turing [1952] have triggered a large amount of research. This review aims at a comparison between theoretical predictions and experimental results obtained with various type of reactors in use. The differences arising from the use of reactions exhibiting either bistability of homogeneous steady states or a single one in a CSTR are emphasized.

APA, Harvard, Vancouver, ISO, and other styles

17

Šilhan, Martin, Petr Polívka, and Petra Dvořáková Ruskayová. "Production of Energy and Hydrogen within Chemical Plants Using Small Nuclear Reactors." Chemické listy 118, no. 2 (February 15, 2024): 118–22. http://dx.doi.org/10.54779/chl20240118.

Full text

Abstract:

The article outlines the possibility of synergistic use of small nuclear reactors and low- and high-temperature electrolysis. The small modular nuclear reactor is compared to common types of renewables. Furthermore, possible small nuclear reactors application in chemical enterprises is shown.

APA, Harvard, Vancouver, ISO, and other styles

18

Saeidi, Samrand, Masoud Talebi Amiri, Nor Aishah Saidina Amin, and Mohammad Reza Rahimpour. "Progress in Reactors for High-Temperature Fischer–Tropsch Process: Determination Place of Intensifier Reactor Perspective." International Journal of Chemical Reactor Engineering 12, no. 1 (January 1, 2014): 639–64. http://dx.doi.org/10.1515/ijcre-2014-0045.

Full text

Abstract:

Abstract High-temperature Fischer–Tropsch (HTFT) process aims to produce lighter cuts such as gasoline and diesel. For many years there have been studies and improvements on HTFT process to make the existing reactors more efficient. Recent studies proposed new configurations such as dual-type membrane reactor and coupling configurations reactor, which improved the performances of this process. This achievement persuades us to update the existing knowledge about the available reactors for HTFT process. In this article, features and performances overview of two classes of reactors are reviewed. The first class consists of the reactors which are based on older studies, and the second one includes recent studies which are called product intensifier reactors. Finally, it is shown that the product intensifier reactors have higher CO conversions and lower selectivity of undesired by-products which results in higher production yield of gasoline. Furthermore, the place of product intensifier reactor among common reactors with regard to the influence of the process parameters on the product distribution has been estimated.

APA, Harvard, Vancouver, ISO, and other styles

19

Zhang, Qun, Han Hai, Chengyu Li, Yuming Wang, Peng Zhang, and Xin Wang. "Predictions of NOx and CO emissions from a low-emission concentric staged combustor for civil aeroengines." Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering 234, no. 5 (December 21, 2019): 1075–91. http://dx.doi.org/10.1177/0954410019895881.

Full text

Abstract:

This study is aimed to establish a detailed chemical reactor network model based on the analysis of complex reaction flowfield structures in aeroengine combustors, so that the emissions of nitrogen oxides and carbon monoxide from advanced civil aeroengines can be predicted quickly and accurately. In this study, a low-emission concentric staged combustor with three axial swirlers is designed for civil aeroengines, and numerical simulations of the three-dimensional reaction flowfields of the combustor during four load phases of takeoff, climb, approach, and idle, are conducted. Based on the numerical results, a simple chemical reactor network model with seven perfectly stirred reactors and a detailed chemical reactor network model using up to 15 perfectly stirred reactors are established. Using the developed chemical reactor network models and the detailed JP10 chemical reaction mechanism—composed of 374 step elementary reactions and 82 species, the emission variations of nitrogen oxides and carbon monoxide are predicted and compared with those estimated using an empirical formula and with the numerical results as a function of the combustion load. Using a combined chemical reactor network–computational fluid dynamics analysis method, the variations of the formation path, the mechanism, and the amounts of nitrogen oxides in the combustor and in the perfectly stirred reactors, are analyzed as a function of the combustion load. In addition, the effects of fuel and air pilot-to-total ratio on nitrogen oxides emissions for the 100% load condition are also analyzed. It is found that at high loads, the production rate of the thermal NO is the highest, while at low loads, the production rate of the prompt NO is the highest. The nitrogen oxide is mainly produced in the pilot zone and the recirculation zone, while its production in the outer main stage zone is low. The results show that the NOx emissions predicted by the complex chemical reactor network model are most consistent with those elicited using the empirical formula.

APA, Harvard, Vancouver, ISO, and other styles

20

Terreni, Jasmin, Andreas Borgschulte, Magne Hillestad, and Bruce D. Patterson. "Understanding Catalysis—A Simplified Simulation of Catalytic Reactors for CO2 Reduction." ChemEngineering 4, no. 4 (November 20, 2020): 62. http://dx.doi.org/10.3390/chemengineering4040062.

Full text

Abstract:

The realistic numerical simulation of chemical processes, such as those occurring in catalytic reactors, is a complex undertaking, requiring knowledge of chemical thermodynamics, multi-component activated rate equations, coupled flows of material and heat, etc. A standard approach is to make use of a process simulation program package. However for a basic understanding, it may be advantageous to sacrifice some realism and to independently reproduce, in essence, the package computations. Here, we set up and numerically solve the basic equations governing the functioning of plug-flow reactors (PFR) and continuously stirred tank reactors (CSTR), and we demonstrate the procedure with simplified cases of the catalytic hydrogenation of carbon dioxide to form the synthetic fuels methanol and methane, each of which involves five chemical species undergoing three coupled chemical reactions. We show how to predict final product concentrations as a function of the catalyst system, reactor parameters, initial reactant concentrations, temperature, and pressure. Further, we use the numerical solutions to verify the “thermodynamic limit” of a PFR and a CSTR, and, for a PFR, to demonstrate the enhanced efficiency obtainable by “looping” and “sorption-enhancement”.

APA, Harvard, Vancouver, ISO, and other styles

21

Ni, Xiong-Wei. "Another Critical Look at Three-Phase Catalysis." Pharmaceutical Fronts 02, no. 03 (September 2020): e117-e127. http://dx.doi.org/10.1055/s-0040-1722219.

Full text

Abstract:

AbstractThree-phase catalysis, for example, hydrogenation, is a special branch of chemical reactions involving a hydrogen reactant (gas) and a solvent (liquid) in the presence of a metal porous catalyst (solid) to produce a liquid product. Currently, many reactors are being used for three-phase catalysis from packed bed to slurry vessel; the uniqueness for this type of reaction in countless processes is the requirement of transferring gas into liquid, as yet there is not a unified system of quantifying and comparing reactor performances. This article reviews current methodologies in carrying out such heterogeneous catalysis in different reactors and focuses on how to enhance reactor performance from gas transfer perspectives. This article also suggests that the mass transfer rate over energy dissipation may represent a fairer method for comparison of reactor performance accounting for different types/designs of reactors and catalyst structures as well as operating conditions.

APA, Harvard, Vancouver, ISO, and other styles

22

Cabet, C., J. Jang, J. Konys, and P. F. Tortorelli. "Environmental Degradation of Materials in Advanced Reactors." MRS Bulletin 34, no. 1 (January 2009): 35–39. http://dx.doi.org/10.1557/mrs2009.10.

Full text

Abstract:

AbstractAdvanced fission-based reactors challenge our ability to fully understand environment–materials reactions in terms of fundamental stability and kinetics, including the influences of composition, microstructure, and system design, and to predict associated long-term performance. This article briefly describes corrosion reactions and the processes by which such are managed for several elevated-temperature environments associated with advanced reactor concepts: helium, molten Pb–Bi, fluorides, and supercritical water. For most of the subject environments, corrosion resistance critically depends on the ability to form and maintain protective surface layers. Effects of corrosion on mechanical behavior can be from thermally and chemically induced changes in microstructures or from environmental effects on cracking susceptibility. In most cases, the simultaneous effects of chemical reactivity and radiation have not been fully addressed, nor has much attention been paid to newly emerging alloy compositions or the effects of substantially increased operating temperatures.

APA, Harvard, Vancouver, ISO, and other styles

23

Guay, M. "Linearizability of Chemical Reactors." IFAC Proceedings Volumes 31, no. 17 (July 1998): 489–94. http://dx.doi.org/10.1016/s1474-6670(17)40384-3.

Full text

APA, Harvard, Vancouver, ISO, and other styles

24

Zeyer, K. P., G. Dechert, W. Hohmann, R. Blittersdorf, and F. W. Schneider. "Coupled Bistable Chemical Systems - Experimental Realization of Boolean Functions Using a Simple Feedforward Net." Zeitschrift für Naturforschung A 49, no. 10 (October 1, 1994): 953–63. http://dx.doi.org/10.1515/zna-1994-1010.

Full text

Abstract:

AbstractWe use the BZ-reaction and the MBO-reaction to implement the Boolean functions AND, OR, NAND , and NOR by the coupling of three chemical reactors. The experimental setup is analogous to a simple neural feedforward network with two reactors serving as the input layer and one reactor as the output layer. Coupling between the input and output reactors is carried out through the flow rate (BZ- and MBO-reaction) and through the electrical current by the use of Pt working electrodes (BZ-reaction). The XOR- and XN OR functions may be realized with 5 reactors using combinations of the AND, NOR, NOR - and the AND, NOR, Or-chemical gates, respectively.

APA, Harvard, Vancouver, ISO, and other styles

25

Jiang, Junan, Ning Yang, Hanyang Liu, Jianxin Tang, Chenfeng Wang, Rijie Wang, and Xiaoxia Yang. "Modification of Meso-Micromixing Interaction Reaction Model in Continuous Reactors." Processes 11, no. 5 (May 22, 2023): 1576. http://dx.doi.org/10.3390/pr11051576.

Full text

Abstract:

The yields of chemical reactions are highly dependent on the mixing pattern between reactants. Herein, we report the modification of a meso-micromixing interaction reaction model which is applied in batch reactors by leveraging the flow characteristics in the continuous reactors. Both experimental and model-predicted yields were compared using the classical Villermaux–Dushman method in a self-designed split and recombination reactor. This modified model significantly reduced the error in predicted product yields from approximately 15% to within 3%, compared to a model containing the micromixing term only. The effects of flow rates and reactor structure parameters on mixing performance were analyzed. We found that increasing flow rates and the degree of twist in the mixing element’s grooves, as well as decreasing the cross-sectional area of grooves, improved mixing performance. The optimization of reactor flow rates and structural parameters was achieved by combining Gaussian process regression and Bayesian optimization with the modified model. This approach provided higher target product yields for consecutive reactions, while simultaneously achieving a lower pressure drop in the reactor. Corresponding combinations of reactor parameters were also identified during this process. Our modified model-based optimization methodology can be applied to a diversity of reactors, serving as a reference for the selection of their structure and operational parameters.

APA, Harvard, Vancouver, ISO, and other styles

26

Mularski, Jakub, and Norbert Modliński. "Impact of Chemistry–Turbulence Interaction Modeling Approach on the CFD Simulations of Entrained Flow Coal Gasification." Energies 13, no. 23 (December 7, 2020): 6467. http://dx.doi.org/10.3390/en13236467.

Full text

Abstract:

This paper examines the impact of different chemistry–turbulence interaction approaches on the accuracy of simulations of coal gasification in entrained flow reactors. Infinitely fast chemistry is compared with the eddy dissipation concept considering the influence of turbulence on chemical reactions. Additionally, ideal plug flow reactor study and perfectly stirred reactor study are carried out to estimate the accuracy of chosen simplified chemical kinetic schemes in comparison with two detailed mechanisms. The most accurate global approach and the detailed one are further implemented in the computational fluid dynamics (CFD) code. Special attention is paid to the water–gas shift reaction, which is found to have the key impact on the final gas composition. Three different reactors are examined: a pilot-scale Mitsubishi Heavy Industries reactor, a laboratory-scale reactor at Brigham Young University and a Conoco-Philips E-gas reactor. The aim of this research was to assess the impact of gas phase reaction model accuracy on simulations of the entrained flow gasification process. The investigation covers the following issues: impact of the choice of gas phase kinetic reactions mechanism as well as influence of the turbulence–chemistry interaction model. The advanced turbulence–chemistry models with the complex kinetic mechanisms showed the best agreement with the experimental data.

APA, Harvard, Vancouver, ISO, and other styles

27

Han, Suyong, Marjan Alsadat Kashfipour, Mahdi Ramezani, and Milad Abolhasani. "Accelerating gas–liquid chemical reactions in flow." Chemical Communications 56, no. 73 (2020): 10593–606. http://dx.doi.org/10.1039/d0cc03511d.

Full text

APA, Harvard, Vancouver, ISO, and other styles

28

Лабутин, Александр, Aleksandr Labutin, Владимир Невиницын, Vladimir Nevinitsyn, Галина Волкова, Galina Volkova, Владислав Сальков, and Vladislav Sal'kov. "THE CONTROL ALGORITHM FOR CONCENTRATION OF THE TARGET PRODUCT IN THE CHEMICAL REACTOR." Automation and modeling in design and management of 2018, no. 2 (February 20, 2019): 34–40. http://dx.doi.org/10.30987/article_5c387d62698a75.92047422.

Full text

Abstract:

A chemicalreactor is one of the common apparatuses in chemical industry. Despite a large number of theworks related to automation and control of chemical reactors, the problem of synthesizing controlsystems that provide the maintenance of optimal modes of their operation remains practically unsolved.This is related to the principal feature of chemical reactors as controlled objects, namely,manifold, non-linearity, and multi-coupling. An outcome from this situation is to develop a physicaltheory of control, in particular synergetic control theory. The problem of analytical synthesis of nonlinear control law for the concentration of the target component in a chemical reactor has been solved.We use the methods of synergetic control theory, simulation methodsand methods of computational experiment. The paper deals with continuous stirred tank reactor equipped with a mechanicalstirrer and cooling jacket. The reactor operates in the polytropic mode. The multistep series-parallelexothermic process is carried out in the reactor. The objective of chemical reactor operationis to obtain the key product of specified concentration.

APA, Harvard, Vancouver, ISO, and other styles

29

Mattisson, Tobias. "Materials for Chemical-Looping with Oxygen Uncoupling." ISRN Chemical Engineering 2013 (May 8, 2013): 1–19. http://dx.doi.org/10.1155/2013/526375.

Full text

Abstract:

Chemical-looping with oxygen uncoupling (CLOU) is a novel combustion technology with inherent separation of carbon dioxide. The process is a three-step process which utilizes a circulating oxygen carrier to transfer oxygen from the combustion air to the fuel. The process utilizes two interconnected fluidized bed reactors, an air reactor and a fuel reactor. In the fuel reactor, the metal oxide decomposes with the release of gas phase oxygen (step 1), which reacts directly with the fuel through normal combustion (step 2). The reduced oxygen carrier is then transported to the air reactor where it reacts with the oxygen in the air (step 3). The outlet from the fuel reactor consists of only CO2 and H2O, and pure carbon dioxide can be obtained by simple condensation of the steam. This paper gives an overview of the research conducted around the CLOU process, including (i) a thermodynamic evaluation, (ii) a complete review of tested oxygen carriers, (iii) review of kinetic data of reduction and oxidation, and (iv) evaluation of design criteria. From the tests of various fuels in continuous chemical-looping units utilizing CLOU materials, it can be established that almost full conversion of the fuel can be obtained for gaseous, liquid, and solid fuels.

APA, Harvard, Vancouver, ISO, and other styles

30

Lu, Wang, Pietro Bartocci, Alberto Abad, Aldo Bischi, Haiping Yang, Arturo Cabello, Margarita de Las Obras Loscertales, Mauro Zampilli, and Francesco Fantozzi. "Dimensioning Air Reactor and Fuel Reactor of a Pressurized CLC Plant to Be Coupled to a Gas Turbine: Part 2, the Fuel Reactor." Energies 16, no. 9 (April 30, 2023): 3850. http://dx.doi.org/10.3390/en16093850.

Full text

Abstract:

Bioenergy with Carbon Capture and Storage (BECCS) technologies are fundamental to reach negative CO2 emissions by removing it from the atmosphere and storing it underground. A promising solution to implement BECCS is pressurized Chemical Looping Combustion (CLC), which involves coupling a pressurized CLC reactor system to a turboexpander. The typical configuration chosen is to have an air reactor and a fuel reactor based on coupled circulating fluidized beds. The fluidization regime in both reactors is preferred to be fast fluidization to enhance gas particle contact and solids circulation among reactors. To design the two reactors, Aspen Plus software was used, given that the new version has a module for fluidized bed modeling. At first, the oxygen carrier was designed ex novo, but given that it is a composite compound mainly made by nickel oxide freeze-granulated on alumina (Ni40Al-FG), the molecular structure has been inserted in Aspen Plus. Then, based on the power of the gas turbine, the power output per kg of evolving fluid (in this case, depleted air) is calculated using Aspen Plus. Once the nitrogen content in the depleted air is known, the total air at the inlet of the air reactor is calculated. The fuel reactor is modeled by inserting the reduction reactions for nickel-based oxygen carriers. The paper presents a useful methodology for developing pressurized Chemical Looping Combustors to be coupled to gas turbines for power generation. The provided data will be cross-validated with 0D-models and experimental results.

APA, Harvard, Vancouver, ISO, and other styles

31

Невиницын, Владимир, Vladimir Nevinitsyn, Александр Лабутин, Aleksandr Labutin, Галина Волкова, and Galina Volkova. "TEMPERATURE MODE MANAGEMENT OF CHEMICAL REACTOR." Automation and modeling in design and management of 2018, no. 2 (February 20, 2019): 41–48. http://dx.doi.org/10.30987/article_5c387d62f2a733.72337613.

Full text

Abstract:

A chemical reactor is one of the common apparatuses in chemical industry. Despite a large number of the works related to automation and control of chemical reactors, the problem of synthesizing control systems that provide the maintenance of optimal modes of their operation remains practically unsolved. This is related to the principal feature of chemical reactors as controlled objects, namely, manifold, non-linearity, and multi-coupling. An outcome from this situation is to develop a physical theory of control, in particular synergetic control theory. The problem of analytical synthesis of nonlinear control law of the chemical reactor temperature regime has been solved. We use the methods of synergetic control theory, simulation methods and methods of computational experiment. The paper deals with continuous stirred tank reactor equipped with a mechanical stirrer and cooling jacket. The reactor operates in the polytropic mode. The multistep series-parallel exothermic process is carried out in the reactor. The objective of chemical reactor operation is to obtain the key product of specified concentration. Using the analytical design method of aggregated regulators, a non-linear control algorithm was synthesized, which solves the problem of stabilization of reaction mixture temperature in the apparatus under the action of disturbances on the object. Computer simulation of the object–regulator isolated system showed such properties of synthesized control system as the disturbance invariance, covariance to the given actions, and asymptotic stability.

APA, Harvard, Vancouver, ISO, and other styles

32

Gill, Kirandeep K., Rachel Gibson, Kam Ho Chester Yiu, Patrick Hester, and Nuno M. Reis. "Microcapillary film reactor outperforms single-bore mesocapillary reactors in continuous flow chemical reactions." Chemical Engineering Journal 408 (March 2021): 127860. http://dx.doi.org/10.1016/j.cej.2020.127860.

Full text

APA, Harvard, Vancouver, ISO, and other styles

33

Shi, Li. "Integration of Optimization and Model Predictive Control of an Intensified Continuous Three-Phase Catalytic Reactor." International Journal of Chemical Reactor Engineering 13, no. 1 (March 1, 2015): 51–62. http://dx.doi.org/10.1515/ijcre-2014-0101.

Full text

Abstract:

Abstract Intensified continuous three-phase catalytic reactors working in high-pressure and -temperature conditions are particularly effective at coping with mass transfer limitations during three-phase catalytic reactions. They are highly nonlinear, multivariable systems and behave differently from conventional batch, fed-batch or continuous non-intensified reactors. This paper deals with an integration of real-time optimization and model predictive control (RTO–MPC) of an intensified continuous three-phase catalytic reactor. A steady-state model developed by regression method is used in optimization layer and gives the reference trajectory for control layer. At control layer, a linear MPC is proposed based on identified state space model. The performance of RTO–MPC is illustrated by simulation

APA, Harvard, Vancouver, ISO, and other styles

34

Duran, J. E., F. Taghipour, and M. Mohseni. "Evaluation of model parameters for simulating TiO2 coated UV reactors." Water Science and Technology 63, no. 7 (April 1, 2011): 1366–72. http://dx.doi.org/10.2166/wst.2011.191.

Full text

Abstract:

A CFD-based model for simulating TiO2 coated photocatalytic reactors used in drinking water treatment applications was preliminarily evaluated. The model includes aspects of hydrodynamics, mass transfer, UV-radiation field, and surface chemical reactions. Appropriate models for each of the associated physicochemical phenomena were experimentally or analytically examined. Once defined and evaluated, the individual models were integrated into a CFD-based model for simulating photocatalytic reactor performance, which was experimentally evaluated.

APA, Harvard, Vancouver, ISO, and other styles

35

Ribeiro, João Peres, Margarida S. C. A. Brito, Ricardo Jorge Santos, and Maria Isabel Nunes. "Reactive PLIF Method for Characterisation of Micromixing in Continuous High-Throughput Chemical Reactors." Processes 10, no. 10 (September 22, 2022): 1916. http://dx.doi.org/10.3390/pr10101916.

Full text

Abstract:

This work aimed to test and optimise reactive Planar Laser-Induced Fluorescence (PLIF) methods for the visualisation of the micromixing regions in chemical reactors using standard PLIF and Particle Image Velocimetry (PIV) equipment with the laser source 512 nm. Two methods were tested: (i) an acid–base reaction with fluorescein as the reaction-sensitive tracer and (ii) Fenton’s reaction, with Rhodamine B as the reaction tracer. Both test-reactions were studied in stopped-flow equipment to define suitable operational conditions, namely the chemical composition of the inflow streams, the concentration of reagents and fluorophore, and suitable excitation light wavelength. The visualisation of the micromixing regions was tested in a continuous flow reactor with a T-jet geometry. A laser light sheet emitted from an Nd:YAG laser illuminated the axial section of the demonstration reactor. The mixing dynamics and the reaction course were visualised with the acid–base reactive PLIF images. Fenton’s reactive PLIF method showed the overall distribution of mixing and reaction regions. The main contribution of this work is benchmarking two methods with costs that enable the visualisation of micromixing regions in continuous high-throughput reactors.

APA, Harvard, Vancouver, ISO, and other styles

36

Jasińska, Magdalena. "Test Reactions to Study Efficiency of." Chemical and Process Engineering 36, no. 2 (June 1, 2015): 171–208. http://dx.doi.org/10.1515/cpe-2015-0013.

Full text

Abstract:

Abstract Effects of mixing on the course of fast chemical reactions are relatively well understood, especially in homogeneous systems. This enables to design and operate chemical reactors with the goal to achieve a high yield of a desired product and use systems of complex reactions as a chemical probe (chemical test reactions) to identify progress of mixing and quality of mixture. Recently, a number of studies have focused on the application of chemical test reactions to identify energy efficiency of mixing, being a convenient way of comparing mixers and reactors in terms of their mixing efficiency. This review offers a presentation of chemical test reactions available in the literature and methods of applications of test reactions to identify the energy efficiency of mixing. Also methods to assess the extent of micromixing by measuring product distribution or segregation index, and to determine the time constant for mixing are presented for single phase homogeneous systems and two-phase liquid-liquid systems.

APA, Harvard, Vancouver, ISO, and other styles

37

Lindeque, Rowan, and John Woodley. "Reactor Selection for Effective Continuous Biocatalytic Production of Pharmaceuticals." Catalysts 9, no. 3 (March 14, 2019): 262. http://dx.doi.org/10.3390/catal9030262.

Full text

Abstract:

Enzyme catalyzed reactions are rapidly becoming an invaluable tool for the synthesis of many active pharmaceutical ingredients. These reactions are commonly performed in batch, but continuous biocatalysis is gaining interest in industry because it would allow seamless integration of chemical and enzymatic reaction steps. However, because this is an emerging field, little attention has been paid towards the suitability of different reactor types for continuous biocatalytic reactions. Two types of continuous flow reactor are possible: continuous stirred tank and continuous plug-flow. These reactor types differ in a number of ways, but in this contribution, we focus on residence time distribution and how enzyme kinetics are affected by the unique mass balance of each reactor. For the first time, we present a tool to facilitate reactor selection for continuous biocatalytic production of pharmaceuticals. From this analysis, it was found that plug-flow reactors should generally be the system of choice. However, there are particular cases where they may need to be coupled with a continuous stirred tank reactor or replaced entirely by a series of continuous stirred tank reactors, which can approximate plug-flow behavior. This systematic approach should accelerate the implementation of biocatalysis for continuous pharmaceutical production.

APA, Harvard, Vancouver, ISO, and other styles

38

Assadi, Aymen Amine, Bouzaza Abdelkrim, and Wolbert Dominique. "Kinetic Modeling of VOC Photocatalytic Degradation Using a Process at Different Reactor Configurations and Scales." International Journal of Chemical Reactor Engineering 14, no. 1 (February 1, 2016): 395–405. http://dx.doi.org/10.1515/ijcre-2015-0003.

Full text

Abstract:

AbstractThis work investigated the performance of isovaleraldehyde (3-methylbutanal) removal from gas streams in photocatalytic reactors at room temperature. The feasibility of pollutant removal using the up-scaled reactor was systematically assessed by monitoring the removal efficiency at different operational parameters, such as geometries of reactor, air flow rate and inlet concentration. A proposal modeling for scaling up the photocatalytic reactors is described and detailed in this present study. In this context, the photocatalytic degradation of isovaleraldehyde (Isoval) in gas phase is studied. In fact, the removal rate has been compared at different continuous ﬂow reactors: a photocatalytic tangential reactor (PTR), planar reactor and P5000 pilot. The effects of the inlet concentration, ﬂow rate, geometries and size of reactors on the removal efficiency are also studied. A kinetic model taking into account the mass transfer step is developed. The modeling is done by introducing an equivalent intermediate (EI) formed by the photo-oxidation of Isoval. This new approach has substantially improved the agreement between modeling and experiments with a satisfactory overall description of the mineralization from lab to pilot scales.

APA, Harvard, Vancouver, ISO, and other styles

39

Nacheva, P. M., B. Peña-Loera, and F. Moralez-Guzmán. "Treatment of chemical-pharmaceutical wastewater in packed bed anaerobic reactors." Water Science and Technology 54, no. 2 (July 1, 2006): 157–63. http://dx.doi.org/10.2166/wst.2006.499.

Full text

Abstract:

Biological degradation in packed bed anaerobic mesophilic reactors with five different support materials was studied for the treatment of chemical-pharmaceutical wastewater with high COD (23–31 g/L), which contains toxic organic compounds. Experimental up-flow bio-filters were operated at different organic loads for a two-year period. Removals of 80–98% were obtained in the reactors with sand, anthracite and black tezontle, but at relatively low organic loads, less than 3.6 kg m−3 d−1. The reactor with granular activated carbon (GAC) had a better performance; efficiencies higher than 95% were obtained at loads up to 17 kg m−3 d−1 and higher than 80% with loads up to 26 kg m−3 d−1. Second in performance was the reactor with red tezontle which allows COD removals higher than 80% with loads up to 6 kg m−3 d−1. The use of GAC as support material allows greater biodegradation rates than the rest of the materials and it makes the process more resistant to organic load increases, inhibition effects and toxicity. Methanogenic activity was inhibited at loads higher than 21.9 kg m−3 d−1 in the GAC-reactor and at loads higher than 3.6 kg m−3 d−1 in the rest of the reactors. At loads lower than the previously mentioned, high methane production yield was obtained, 0.32–0.35 m3CH4/kg CODremoved.

APA, Harvard, Vancouver, ISO, and other styles

40

Liu, Guangdong, Cody Landry, and Khashayar Ghandi. "Prediction of rate constants of important chemical reactions in water radiation chemistry in sub and supercritical water – non-equilibrium reactions." Canadian Journal of Chemistry 96, no. 2 (February 2018): 267–79. http://dx.doi.org/10.1139/cjc-2017-0315.

Full text

Abstract:

The rate constants for reactions involved in the radiolysis of water under relevant thermodynamic conditions in supercritical water-cooled reactors are estimated for inputs in simulations of the radiation chemistry in Generation IV nuclear reactors. We have discussed the mechanism of each chemical reaction with a focus on non-equilibrium reactions. We found most of the reactions are activation controlled above the critical point and that the rate constants are not significantly pressure dependent below 300 °C. This work will aid industry with developing chemical control strategies to suppress the concentration of eroding species.

APA, Harvard, Vancouver, ISO, and other styles

41

Chaedir, Benitta A., Jundika C. Kurnia, Lianjun Chen, Lishuai Jiang, and Agus P. Sasmito. "Numerical Investigation of Ventilation Air Methane Catalytic Combustion in Circular Straight and Helical Coil Channels with Twisted Tape Insert in Catalytic-Monolith Reactors." Catalysts 10, no. 7 (July 17, 2020): 797. http://dx.doi.org/10.3390/catal10070797.

Full text

Abstract:

In a catalytic combustion of ventilation air methane, one of the key factors determining the reactor performance is the geometry of the reactor. It should be designed to provide maximum energy conversion at minimum catalyst usage and operating cost. This numerical study is conducted to investigate the catalytic combustion of ventilation air methane from a gassy underground mine in a circular straight and helical reactor channel with twisted tape insert. A three-dimensional computational fluid dynamics model which considers conservation of mass, momentum, energy, and species together with chemical reactions, and constitutive relations for species properties and reactions kinetics was developed and validated against the previously published data. The effect of several key factors affecting the catalytic combustion performance such as inlet Reynolds number, twisted tape ratio, and reactor length are evaluated to obtain the optimum reactor parameters. For evaluation purpose, the reaction performance of the studied reactors will be compared to the straight reactor without twisted tape which is set as a baseline. The results give a firm confirmation on the superior performance of the reactors with twisted tape insert as compared to those without. In addition, it is found that helical reactors generate higher net power as compared to their respective straight reactor counterpart despite having lower FoM due to larger catalyst area. Interestingly, the higher twisting ratio offers better performance in terms of net power as well as FoM. Overall, the results highlight the potential of twisted tape insert application in catalytic combustion.

APA, Harvard, Vancouver, ISO, and other styles

42

He, Li, Han, Cabassud, and Dahhou. "Development of a Numerical Model for a Compact Intensified Heat-Exchanger/Reactor." Processes 7, no. 7 (July 15, 2019): 454. http://dx.doi.org/10.3390/pr7070454.

Full text

Abstract:

A heat-exchanger/reactor (HEX reactor) is a kind of plug-flow chemical reactor which combines high heat transfer ability and chemical performance. It is a compact reactor designed under the popular trend of process intensification in chemical engineering. Previous studies have investigated its characteristics experimentally. This paper aimed to develop a general numerical model of the HEX reactor for further control and diagnostic use. To achieve this, physical structure and hydrodynamic and thermal performance were studied. A typical exothermic reaction, which was used in experiments, is modeled in detail. Some of the experimental data without reaction were used for estimating the heat transfer coefficient by genetic algorithm. Finally, a non-linear numerical model of 255 calculating modules was developed on the Matlab/Simulink platform. Simulations of this model were done under conditions with and without chemical reactions. Results were compared with reserved experimental data to show its validity and accuracy. Thus, further research such as fault diagnosis and fault-tolerant control of this HEX reactor could be carried out based on this model. The modeling methodology specified in this paper is not restricted, and could also be used for other reactions and other sizes of HEX reactors.

APA, Harvard, Vancouver, ISO, and other styles

43

Andreev, Aleksandr S., and Konstantin V. Aksenchik. "MATHEMATICAL MODELING AND EVALUATION OF THERMODYNAMIC PERFECTION OF A CHEMICAL REACTOR." ChemChemTech 67, no. 5 (April 4, 2024): 114–20. http://dx.doi.org/10.6060/ivkkt.20246705.6964.

Full text

Abstract:

The development of a formalized mathematical model for quantitative and qualitative assessment of the thermodynamic perfection of a gas chemical reactor is described in the article. The reactor was considered as an energy technology system, that is, in the unity of the transformation of matter and energy. Mathematical modeling and evaluation of the thermodynamic perfection of a chemical reactor is generalized to a class of known chemically active gas systems characteristic of ammonia synthesis, sulfur dioxide oxidation, methanol synthesis, nitric oxide oxidation, etc. The equilibrium degree of transformation of a substance and exergy are taken as the determining parameters for modeling and evaluating the thermodynamic perfection of a chemical reactor. These parameters are functions of temperature and reflect the opposing tendencies of the process when it changes, the evaluation of which allows us to quantify the finding of the maximum exergy in the coordinates (E-T) when justifying the optimal temperatures of the process. The model was tested on a specific example of a sulfur dioxide oxidation reactor in the production of sulfuric acid. The public Octave programming environment was used for computer modeling. The developed mathematical model is recommended to be used in the operational preparation and optimization of the initial data for the design of gas reactors. The mathematical model can be supplemented with a mathematical model developed by the authors earlier for quantifying the current profile of the degrees of transformation of the target component of a chemically active reactive gas mixture in the course of its movement in a polytropic tubular reactor of the "pipe in a pipe" type. After testing and setting up the model in practice, it can be used in an automated control system for chemical reactors, including when creating adaptive control systems. For citation: Andreev A.S., Aksenchik K.V. Mathematical modeling and evaluation of thermodynamic perfection of a chemical reactor. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2024. V. 67. N 5. P. 114-120. DOI: 10.6060/ivkkt.20246705.6964.

APA, Harvard, Vancouver, ISO, and other styles

44

Ao, Rui, Ruihua Lu, Guanghui Leng, Youran Zhu, Fuwu Yan, and Qinghua Yu. "A Review on Numerical Simulation of Hydrogen Production from Ammonia Decomposition." Energies 16, no. 2 (January 13, 2023): 921. http://dx.doi.org/10.3390/en16020921.

Full text

Abstract:

Ammonia (NH3) is regarded as a promising medium of hydrogen storage, due to its large hydrogen storage density, decent performance on safety and moderate storage conditions. On the user side, NH3 is generally required to decompose into hydrogen for utilization in fuel cells, and therefore it is vital for the NH3-based hydrogen storage technology development to study NH3 decomposition processes and improve the decomposition efficiency. Numerical simulation has become a powerful tool for analyzing the NH3 decomposition processes since it can provide a revealing insight into the heat and mass transfer phenomena and substantial guidance on further improving the decomposition efficiency. This paper reviews the numerical simulations of NH3 decomposition in various application scenarios, including NH3 decomposition in microreactors, coupled combustion chemical reactors, solid oxide fuel cells, and membrane reactors. The models of NH3 decomposition reactions in various scenarios and the heat and mass transport in the reactor are elaborated. The effects of reactor structure and operating conditions on the performance of NH3 decomposition reactor are analyzed. It can be found that NH3 decomposition in microchannel reactors is not limited by heat and mass transfer, and NH3 conversion can be improved by using membrane reactors under the same conditions. Finally, research prospects and opportunities are proposed in terms of model development and reactor performance improvement for NH3 decomposition.

APA, Harvard, Vancouver, ISO, and other styles

45

Rashmi Pradhan, Swaraj, Ramón Fernando Colmenares-Quintero, and Juan Carlos Colmenares Quintero. "Designing Microflowreactors for Photocatalysis Using Sonochemistry: A Systematic Review Article." Molecules 24, no. 18 (September 12, 2019): 3315. http://dx.doi.org/10.3390/molecules24183315.

Full text

Abstract:

Use of sonication for designing and fabricating reactors, especially the deposition of catalysts inside a microreactor, is a modern approach. There are many reports that prove that a microreactor is a better setup compared with batch reactors for carrying out catalytic reactions. Microreactors have better energy efficiency, reaction rate, safety, a much finer degree of process control, better molecular diffusion, and heat-transfer properties compared with the conventional batch reactor. The use of microreactors for photocatalytic reactions is also being considered to be the appropriate reactor configuration because of its improved irradiation profile, better light penetration through the entire reactor depth, and higher spatial illumination homogeneity. Ultrasound has been used efficiently for the synthesis of materials, degradation of organic compounds, and fuel production, among other applications. The recent increase in energy demands, as well as the stringent environmental stress due to pollution, have resulted in the need to develop green chemistry-based processes to generate and remove contaminants in a more environmentally friendly and cost-effective manner. It is possible to carry out the synthesis and deposition of catalysts inside the reactor using the ultrasound-promoted method in the microfluidic system. In addition, the synergistic effect generated by photocatalysis and sonochemistry in a microreactor can be used for the production of different chemicals, which have high value in the pharmaceutical and chemical industries. The current review highlights the use of both photocatalysis and sonochemistry for developing microreactors and their applications.

APA, Harvard, Vancouver, ISO, and other styles

46

TACHIKAWA, Enzo, Takeshi SUWA, and Nobuhide KURIBAYASHI. "Chemical decontamination of water reactors." Journal of the Atomic Energy Society of Japan / Atomic Energy Society of Japan 28, no. 5 (1986): 390–97. http://dx.doi.org/10.3327/jaesj.28.390.

Full text

APA, Harvard, Vancouver, ISO, and other styles

47

Donati, Gianni, and Renato Paludetto. "Scale up of chemical reactors." Catalysis Today 34, no. 3-4 (February 1997): 483–533. http://dx.doi.org/10.1016/s0920-5861(96)00069-7.

Full text

APA, Harvard, Vancouver, ISO, and other styles

48

DeWitt, Sheila H. "Micro reactors for chemical synthesis." Current Opinion in Chemical Biology 3, no. 3 (June 1999): 350–56. http://dx.doi.org/10.1016/s1367-5931(99)80052-0.

Full text

APA, Harvard, Vancouver, ISO, and other styles

49

Balakotaiah, V., and D. Kodra. "Stability Criteria for Chemical Reactors." IFAC Proceedings Volumes 25, no. 5 (April 1992): 1–10. http://dx.doi.org/10.1016/s1474-6670(17)50965-9.

Full text

APA, Harvard, Vancouver, ISO, and other styles

50

Helbig, A., W. Marquardt, and F. Allgöwer. "Nonlinearity Measures for Chemical Reactors." IFAC Proceedings Volumes 31, no. 11 (June 1998): 143–52. http://dx.doi.org/10.1016/s1474-6670(17)44920-2.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Chemical reactors'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles