Experimental and simulation study of the temperature distribution in a <scp>bench‐scale</scp> fixed bed <scp>Fischer–Tropsch</scp> reactor

Shen, Jianqi; Li, Yun‐Chao; Ho, Wei Hua; Liu, Xinying; Hildebrandt, Diane

doi:10.1002/aic.17145

Cited by 10 publications

(4 citation statements)

References 40 publications

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“…Therefore, we advise considering anisotropy in regard to local hot spots since homogeneous temperature distributions within materials play a decisive role in many applications. High yields in syntheses can also only be guaranteed if the temperature distribution within the reaction volume is constant and homogeneously distributed. − Especially in fixed-bed reactors, the homogeneity of temperature in granular mixtures comes into play …”

Section: Resultsmentioning

confidence: 99%

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Evaluation of Effective Heat Transport and Temperature Gradients in Thermally Anisotropic Particulate Arrangements

Lebeda,

Retsch

2023

ACS Appl. Eng. Mater.

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New materials are often designed to possess anisotropic properties to meet the specific demands of challenging applications. Thermally anisotropic materials are particularly important in the thermal management of electronics. Using anisotropic fillers is a common strategy to tailor the thermal transport properties of macroscopic materials. Various studies have demonstrated the role of filler concentration on the effective material properties. Strikingly, little is known about the contribution of the filler microstructure. Here, we study anisotropic filler particles in a 2D composite material. We determined the two main effects caused by the anisotropy. First, we show that the thermal percolation behavior changes drastically depending on the particle orientation. This enables the design of granular composites with widely adjustable effective thermal conductivities governed by composition and orientation. Second, we observe strong differences in local temperature distributions between isotropic and anisotropic mixtures. The admixture of anisotropic constituents leads to strong internal temperature gradients. These are unfavorable for many thermal management applications. Consequently, anisotropy can control the effective heat transport in composite materials, but adverse temperature gradients need to be considered.

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Section: Resultsmentioning

confidence: 99%

“…61−63 Especially in fixed-bed reactors, the homogeneity of temperature in granular mixtures comes into play. 64 Figure 5. (a) Percolation paths for optimum orientation of α = 30°of the anisotropic components.…”

Section: Implications For Applications Of Anisotropic Mixturesmentioning

confidence: 99%

Evaluation of Effective Heat Transport and Temperature Gradients in Thermally Anisotropic Particulate Arrangements

Lebeda,

Retsch

2023

ACS Appl. Eng. Mater.

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“…Most of the measurement setups involve the installation of fixed thermocouples at defined radial and axial positions in the fixed-bed reactor. Instead or in addition to this, thermocouple guide tubes are also inserted into the fixed-bed mostly in axial but also in radial direction, along with temperature measurements carried out at arbitrary points using movable thermocouples [1][2][3]. Such invasive methods lead to a falsification of the measurement results compared to a 'real' undisturbed fixed-bed due to a strong manipulation of the bed properties (e.g.…”

Section: Introductionmentioning

confidence: 99%

Non-invasive temperature monitoring in fixed-bed reactors by electrical capacitance tomography

Weiss,

Fischerauer,

Jess

et al. 2024

Meas. Sci. Technol.

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Knowledge of the temperature distribution in fixed-bed reactors is of great importance for process control and optimization in many processes of the chemical industry. The state of the art is defined by invasive measuring methods for temperature measurement in such reactors. However, all invasive methods influence both the structure of the fixed-bed and the flow conditions and thus falsify the measurement results compared to real undisturbed conditions in a fixed-bed, above all with regard to the radial temperature profile. In addition, the temperature distribution in the entire reactor is usually derived from a few discrete measuring points based on a model, which sometimes results in large deviations from reality. In this article, electrical capacitance tomography (ECT) is explored as an alternative, non-invasive measurement method to monitor the temperature distribution inside fixed-bed reactors. The method exploits the temperature dependence of the effective bulk permittivity of the reactor filling. By way of an example, this dependence has been investigated in this work for two different hydrogenation catalysts. A temperature-resistant ECT sensor has been designed to perform measurements under the influence of temperature. The investigations show that, with the aid of ECT, it is possible to detect relative temperature changes in the region of interest with the materials examined.

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“…By the state of the art, this is measured with temperature probes in a localized and invasive way. Mathematical models are then used to derive the conditions in the entire reactor based on these measurements [1]. The results obtained are uncertain and the method produces measurement errors due to the influences of the packed bed structure and the heat transport.…”

Section: Introductionmentioning

confidence: 99%

E5.3 - Suitability of ECT for Non-invasive Temperature Monitoring in Fixed-bed Reactors

Weiß¹,

Fischerauer²,

Jess³

2023

Lectures

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We characterize the temperature-dependent effective permittivities of two-phase materials (glass beads, hydrogenation catalyst) by means of electrical impedance measurements in a temperature range from about 25 °C to 240 °C. Measurements with the same materials using a commercial electrical capacitance tomography (ECT) system are carried out while the temperature of the fixed bed is changed. The images show that the measurement method is able to detect temperature gradients in a fixed bed, even though further efforts are needed to improve the quality of the results.

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Experimental and simulation study of the temperature distribution in a bench‐scale fixed bed Fischer–Tropsch reactor

Cited by 10 publications

References 40 publications

Evaluation of Effective Heat Transport and Temperature Gradients in Thermally Anisotropic Particulate Arrangements

Evaluation of Effective Heat Transport and Temperature Gradients in Thermally Anisotropic Particulate Arrangements

Non-invasive temperature monitoring in fixed-bed reactors by electrical capacitance tomography

E5.3 - Suitability of ECT for Non-invasive Temperature Monitoring in Fixed-bed Reactors

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