Nonlocal modeling of continuously stirred tank reactors with residence time distribution
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J. Alberto Ochoa-Tapia
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Jose Alvarez-Ramirez
Abstract
The residence time distribution (RTD) has an important impact in the performance of chemical reacting systems. The segregated fluid assumption is commonly used to assess the analysis and design of chemical reactors. Models derived from the segregated fluid assumption for continuously stirred tank reactors (CSTR) rely on batch reactor models. A drawback of such assumption is that the CSTR model structure is not recovered in the limit when the RTD becomes very narrow (e.g., a Dirac delta). The aim of the present work is to propose a nonlocal modeling approach that is consistent with the CSTR model structure. The main idea is to represent the reactor as a continuum of tiny differential CSTRs determined by the RTD. The resulting nonlocal model is expressed as integrodifferential equations representing the interaction of reactive molecules of a given residence time with molecules of all residence times. By doing this, the nonlocal model is reduced to the usual CSTR model in the limit when the RTD is very narrow. The methodology was illustrated with three worked cases of dimerization, autocatalytic and series reaction schemes, and the results were compared with that obtained with the segregated fluid assumption. It was found that nonlocal models predict lower conversions than the segregated fluid models.
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Research ethics: Not applicable.
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Informed consent: Not applicable.
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Author contributions: J.A. Ochoa-Tapia: Conceptualization; research; original draft writing. J. Alvarez-Ramirez: Research. The authors have accepted responsibility for the entire content of this manuscript and approved its submission.
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Use of Large Language Models, AI and Machine Learning Tools: None declared.
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Conflict of interest: The authors state no conflict of interest.
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Research funding: None declared.
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Data availability: The raw data can be obtained on request from the corresponding author.
Symbols
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Concentration
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Residence time distribution
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Reaction rate constant
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Reaction rate
Greek
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Residence time
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Mean residence time
Acronyms
- CSTR
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Continuously stirred tank reactor
- LM
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Local model
- NLM
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Nonlocal model
- RTD
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Residence time distribution
- SFM
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Segregated fluid model
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Artikel in diesem Heft
- Frontmatter
- Articles
- Toxicological assessment of reactive blue 19 dye aqueous solutions under UV-LED light
- Enhanced degradation of malachite green through heterogeneous processes using an iron oxide catalyst
- Optimization design of a two-step microreactor with spiral structure for high-performance catalytic reactions
- Kinetics of manganese removal from groundwater via biological activated carbon fiber
- Study of temperature dynamics and influencing factors during composting process
- Nonlocal modeling of continuously stirred tank reactors with residence time distribution
- Enhanced tribological performance of transesterified corn oil biodiesel blends with CuO and TiO2 nanoparticles: experimental analysis on wear and friction reduction using environment friendly lubricants
- Maximum sensitivity constrained modified Smith predictor for delayed integrating type stirred tank reactors model
- Effect of ion exchange resin membranes and activated carbon electrodes in water desalination using capacitive deionization technique with saline streams
- Kinetic and thermodynamic study of maize stalk biomass using thermogravimetric analysis
