Design considerations for tubular reactors with highly exothermic reactions

Shinnar, Reuel; Doyle, Francis J.; Budman, Hector; Morari, Manfred

doi:10.1002/aic.690381106

Cited by 29 publications

(21 citation statements)

References 21 publications

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“…3), where the inlet air temperature was 200 °C and the highest temperature rise was limited to 50 °C. The multitubular reactor is one of the typical reactors for highly exothermic reactions 40. The monolith reactor is widely applied to exothermic heterogeneous gas‐phase reactions like ammonia oxidation and catalytic partial oxidation of methane to synthesis gas by adiabatic operation 41, 42.…”

Section: Resultsmentioning

confidence: 99%

Integrated Reactor‐Combustor Recycling System for Safe Operation by Catalytic Removal of Excess O₂

Zeng

Zhou

et al. 2021

Chem Eng & Technol

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A reactor‐combustor recycling system is proposed for safe operation of a hydrocarbon‐ and O2‐rich reactor by catalytically combusting excess O2 and recycling generated CO2 for dilution. The Pt/Al2O3 catalysts are determined as active and stable, and the Mars van Krevelen mechanism is applied for the combustion kinetics. Modeling and simulation of the system involving reactor, heater, combustor, valve, and cooler are performed, where multitubular, monolith, and microstructured reactors are compared for addressing the strong exothermic combustion. The system is highly promising because 99.9 % O2 can be consumed and explosion risk be eliminated via CO2 dilution. The microstructured combustor exhibits the highest potential by considering heat management, pressure drop, and compactness.

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Section: Resultsmentioning

confidence: 99%

Integrated Reactor‐Combustor Recycling System for Safe Operation by Catalytic Removal of Excess O₂

Zeng

Zhou

et al. 2021

Chem Eng & Technol

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“…This phenomenon may increase in severity when multi-tubular reactors are used, as slight differences in packing may lead to maldistribution of the flow between the different tubes (Afandizadeh and Foumeny, 2001). The use of a multi-tubular configuration is, however, often required as radial heat transfer in a packed bed is low and causes hot spots to arise in larger diameter vessels (Shinnar et al, 1992;Vervloet et al, 2013).…”

Section: Granulesmentioning

confidence: 99%

“…Conventionally, these tubes are randomly packed with particles. A complication that is often encountered is packing inconsistencies amongst the different tubes that manifest themselves in a maldistribution of the flow caused by differences in pressure drop (Shinnar et al, 1992). One notable benefit that a 3D-printed catalyst may offer is consistency; as the printed structures are identical, the pressure drop over the different tubes is exactly the same and thus the even distribution of reactants is facilitated.…”

Section: The Reactor Scalementioning

confidence: 99%

Review on Additive Manufacturing of Catalysts and Sorbents and the Potential for Process Intensification

Rosseau

Willemsen²,

Roghair

et al. 2022

Front. Chem. Eng.

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Additive manufacturing of catalyst and sorbent materials promises to unlock large design freedom in the structuring of these materials, and could be used to locally tune porosity, shape and resulting parameters throughout the reactor along both the axial and transverse coordinates. This contrasts catalyst structuring by conventional methods, which yields either very dense randomly packed beds or very open cellular structures. Different 3D-printing processes for catalytic and sorbent materials exist, and the selection of an appropriate process, taking into account compatible materials, porosity and resolution, may indeed enable unbounded options for geometries. In this review, recent efforts in the field of 3D-printing of catalyst and sorbent materials are discussed. It will be argued that these efforts, whilst promising, do not yet exploit the full potential of the technology, since most studies considered small structures that are very similar to structures that can be produced through conventional methods. In addition, these studies are mostly motivated by chemical and material considerations within the printing process, without explicitly striving for process intensification. To enable value-added application of 3D-printing in the chemical process industries, three crucial requirements for increased process intensification potential will be set out: i) the production of mechanically stable structures without binders; ii) the introduction of local variations throughout the structure; and iii) the use of multiple materials within one printed structure.

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“…Since one cannot control the temperature dynamically in thousands of reactor tubes with varying flow rates, one would design a tubular reactor with a large heat-transfer area and a small temperature drop such that the effective temperature is that of the cooling medium, which is dynamically controlled to be practically constant (see Shinnar et al, 1992). Contrary to the laboratory, however, the control of all dominant variables may not be possible in real operation for a variety of technological reasons.…”

Section: Aiche Journal December 2000mentioning

confidence: 99%

On defining the partial control problem: concepts and examples

Kothare

Shinnar

Rinard

et al. 1998

Proceedings of the 1998 American Control Conference. ACC (IEEE Cat. No.98CH36207)

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Many complex chemical processes having a large number of process variables and poorly understood models can be controlled reasonably well by controlling only a small subset of process variables using an equally small number of manipulated uariables. This is the central premise of this article and is referred to as partial control. Knowing4 or unknowingly, this idea has been and continues to be applied to successfully control numerous complex industrial processes. Despite its widespread use, partial control has never been explicitly formulated. The partial control problem is defined. A number of terms is introduced such as process variable dominance, modelable responses, practicaldegrees of freedom, and sufficiency of partial control. The new framework allows incorporation of both engineering-based decisions and more rigorous theoretical tools to achieve the goals of partial control. A number of practical examples illustrate the applicability of these concepts. IntroductionThe chemical and petrochemical industry is characterized by processes which can be classified as highly complex. This complexity arises from several sources:Process model uncertainty: The development of detailed and accurate models for chemical processes is rarely possible or prohibitively expensive. For example, the kinetics and mechanisms of many chemical reactions are often far too complex to allow an exact mathematical description. As a consequence, the model of the chemical process, which is based on this imperfect understanding of the kinetics, is inherently imperfect and has a large uncertainty associated with it. Inherent process nonlinearity:The steady state and dynamic behavior of chemical processes is generally highly nonlinear, implying the potential existence of complex behavior such as multiple steady states, instabilities, and limit cycles. Linear models are rarely suitable for describing these processes except in an unrealistically narrow operating regime.Correspondence concerning this article should be addressed to M. V. Kotharr. 2456December 2000 ProceAs constraints: The manipulated variables are limited in magnitude due to equipment limitations such as pump and compressor throughput limits and actuator limits. On the other hand, the process states and outputs are constrained to lie between prespecified limits of their reference values; these limits are arising due to stringent product specifications dictated by market demands, safety limits, or environmental regulations on effluent concentrations. The need for minimizing material and energy costs has led to the use of multiple material recycle loops and complex energy management networks. As a result, chemical processes have evolved into highly integrated, and, at times, unmanageable, monolithic systems. Large-scale qstem aspects:The total number of controlled and manipulated process variables is generally large and typically, the former is significantly larger than the latter. It is important to have a methodology to decide which of the large number of process and state varia...

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Design considerations for tubular reactors with highly exothermic reactions

Cited by 29 publications

References 21 publications

Integrated Reactor‐Combustor Recycling System for Safe Operation by Catalytic Removal of Excess O₂

Integrated Reactor‐Combustor Recycling System for Safe Operation by Catalytic Removal of Excess O₂

Review on Additive Manufacturing of Catalysts and Sorbents and the Potential for Process Intensification

On defining the partial control problem: concepts and examples

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Design considerations for tubular reactors with highly exothermic reactions

Cited by 29 publications

References 21 publications

Integrated Reactor‐Combustor Recycling System for Safe Operation by Catalytic Removal of Excess O2

Integrated Reactor‐Combustor Recycling System for Safe Operation by Catalytic Removal of Excess O2

Review on Additive Manufacturing of Catalysts and Sorbents and the Potential for Process Intensification

On defining the partial control problem: concepts and examples

Contact Info

Product

Resources

About

Integrated Reactor‐Combustor Recycling System for Safe Operation by Catalytic Removal of Excess O₂

Integrated Reactor‐Combustor Recycling System for Safe Operation by Catalytic Removal of Excess O₂