Characterization of reaction enthalpy and kinetics in a microscale flow platform

Ladosz, Agnieszka; Kuhnle, Christina; Jensen, Klavs F.

doi:10.1039/d0re00304b

Cited by 29 publications

(52 citation statements)

References 50 publications

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“…Importantly, the reaction rate can be easily adjusted by varying the catalyst concentration. As the reaction has been studied as a model reaction by several research groups, [16][17][18][19][20][21][22], the results can be well compared.…”

Section: Hydrolysis Of Acetic Anhydridementioning

confidence: 99%

“…In a batch calorimeter, the conversion can be determined over time and known kinetics [16] or inline measurements [17]. Ładosz et al [18] have shown Highlights • Simultaneous determination of enthalpy of mixing and heat of reaction using a flow calorimeter.…”

Section: Introductionmentioning

confidence: 99%

“…In this work we aim to simultaneously investigate the heat of reaction and the enthalpy of mixing for the hydrolysis of acetic anhydride in a scalable continuous flow calorimeter. This model reaction has served for several continuous [18] and batch [16,17,[19][20][21] calorimetric studies and is particularly suitable because the reaction rate can simply be tuned by the help of the acid concentration, which catalyses the reaction. A milli-scale continuous flow calorimeter, scalable to production scale, as used by us [12] is applied.…”

Section: Introductionmentioning

confidence: 99%

“…A milli-scale continuous flow calorimeter, scalable to production scale, as used by us [12] is applied. Compared to other reactor setups to determine the enthalpy of reaction, for example Ładosz et al [18], who used three temperature sensors, this calorimeter measures the temperature profile using ten temperature sensors. Even though the temperature profile is not indicated gapless, we report that a continuous indication is not necessary since the resolution of the temperature profile can be increased with different flow rates and the obtained data are highly reliable.…”

Section: Introductionmentioning

confidence: 99%

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Simultaneous determination of enthalpy of mixing and reaction using milli-scale continuous flow calorimetry

Steinemann

Rütti

Moser³

et al. 2022

J Flow Chem

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A simultaneous determination of the enthalpy of mixing and reaction in a scalable continuous milli-scale flow calorimeter is investigated. As obtained calorimetric data is pivotal for the safety assessment of chemical reactions and processes. The acid-catalysed selective, homogeneous hydrolysis of acetic anhydride with half-lives from a few seconds to a few minutes is investigated as a model reaction. For the enthalpy of mixing 7.2 ± 2.8 kJ/mol and for the enthalpy of reaction −60.8 ± 2.5 kJ/mol were determined. For reactions that show complete conversion in the continuous reactor, a technique is introduced to further improve the accuracy of the reaction enthalpy determination. Thereby, the resolution of the observed temperature profile is increased by measuring the profile at different flow rates. Applying this procedure, the reaction enthalpy of −62.5 kJ/mol was determined which is in good agreement with literature values for this model reaction. Graphical abstract

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Section: Hydrolysis Of Acetic Anhydridementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Simultaneous determination of enthalpy of mixing and reaction using milli-scale continuous flow calorimetry

Steinemann

Rütti

Moser³

et al. 2022

J Flow Chem

View full text Add to dashboard Cite

show abstract

“…For the development of accurate kinetic models that assist chemical reactor development, design and optimization, extensive knowledge of interaction between reaction kinetics and hydrodynamics is essential [4]. Thus, the interest in the development of continuous flow calorimeter increases constantly [5][6][7][8]. Moreover, the miniaturization of calorimetry enables the investigation of fast and highly exothermic reactions under safe conditions due to the superior temperature control when compared to standard batch equipment [9].…”

Section: Introductionmentioning

confidence: 99%

Software-guided microscale flow calorimeter for efficient acquisition of thermokinetic data

2021

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Fast chemical process development is inevitably linked to an optimized determination of thermokinetic data of chemical reactions. A miniaturized flow calorimeter enables increased sensitivity when examining small amounts of reactants in a short time compared to traditional batch equipment. Therefore, a methodology to determine optimal reaction conditions for calorimetric measurement experiments was developed and is presented in this contribution. Within the methodology, short-cut calculations are supplemented by computational fluid dynamics (CFD) simulations for a better representation of the hydrodynamics within the microreactor. This approach leads to the effective design of experiments. Unfavourable experimental conditions for kinetics experiments are determined in advance and therefore, need not to be considered during design of experiments. The methodology is tested for an instantaneous acid-base reaction. Good agreement of simulations was obtained with experimental data. Thus, the prediction of the hydrodynamics is enabled and the first steps towards a digital twin of the calorimeter are performed. The flow rates proposed by the methodology are tested for the determination of reaction enthalpy and showed that reasonable experimental settings resulted. Graphical abstract A methodology is suggested to evaluate optimal reaction conditions for efficientacquisition of kinetic data. The experimental design space is limited by thestepwise determination of important time scales based on specified input data.

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Kinetic study in an automatic continuous‐flow photochemical platform with machine learning

et al. 2023

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In this work, we first solved the partial differential equation of the one‐dimensional axial diffusion model in an open‐source platform, that is, FEniCS, to explore the influence of the axial dispersion on the reaction yield‐to‐time profile. Then, we built an automatic platform, which included a photomicroreactor, a continuously controlled pump, a high‐power UV‐LED light source, an in‐line visible‐light absorbance analytical unit, and a Raspberry Pi based controlling unit. Moreover, steady‐state feeding and sampling functions could be realized in this continuous‐flow photochemical platform. The homogeneous photolysis of methylene blue and the photo‐Favorskii rearrangement synthesis of ibuprofen as the model reactions were used to validate the robustness of this automatic platform with unsteady‐state and steady‐state operations, through which kinetic study was carried out using genetic algorithm based symbolic regression, leading to deep understanding on reaction mechanisms and benefits for process optimization.

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Characterization of reaction enthalpy and kinetics in a microscale flow platform

Abstract: We report an isothermal flow calorimeter for characterization of reaction enthalpy and kinetics. The platform consists of a thermoelectric element and a glass-silicon microreactor to measure heat flux and an...

Cited by 29 publications

References 50 publications

Simultaneous determination of enthalpy of mixing and reaction using milli-scale continuous flow calorimetry

Simultaneous determination of enthalpy of mixing and reaction using milli-scale continuous flow calorimetry

Software-guided microscale flow calorimeter for efficient acquisition of thermokinetic data

Kinetic study in an automatic continuous‐flow photochemical platform with machine learning

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