A one-parameter model for describing the residence time distribution of closed continuous flow systems characterized by nonlinear reaction kinetics: Rod and ball mills

A new residence-time distribution (RTD) function has been developed and applied to quantitative dye studies as an alternative to the traditional advection-dispersion equation (AdDE). The new method is based on a jointly combined four-parameter gamma probability density function (PDF). The gamma residence-time distribution (RTD) function and its first and second moments are derived from the individual two-parameter gamma distributions of randomly distributed variables, tracer travel distance, and linear velocity, which are based on their relationship with time. The gamma RTD function was used on a steady-state, nonideal system modeled as a plug-flow reactor (PFR) in the laboratory to validate the effectiveness of the model. The normalized forms of the gamma RTD and the advection-dispersion equation RTD were compared with the normalized tracer RTD. The normalized gamma RTD had a lower mean-absolute deviation (MAD) (0.16) than the normalized form of the advection-dispersion equation (0.26) when compared to the normalized tracer RTD. The gamma RTD function is tied back to the actual physical site due to its randomly distributed variables. The results validate using the gamma RTD as a suitable alternative to the advection-dispersion equation for quantitative tracer studies of non-ideal flow systems.

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Residence time distribution in continuous flow stirred tank reactors

The Canadian Journal of Chemical Engineering ◽

10.1002/cjce.5450470603 ◽

1969 ◽

Vol 47 (6) ◽

pp. 514-514 ◽

Cited By ~ 3

Author(s):

T. C. Hsiang ◽

Park M. Reilly

Keyword(s):

Residence Time ◽

Continuous Flow ◽

Time Distribution ◽

Residence Time Distribution ◽

Stirred Tank ◽

Stirred Tank Reactors

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The Influence of Residence Time Distribution on Continuous Flow Polymerization

10.26434/chemrxiv.7726166.v1 ◽

2019 ◽

Author(s):

Marcus Reis ◽

Travis Varner ◽

Frank Leibfarth

Keyword(s):

Residence Time ◽

Continuous Flow ◽

Time Distribution ◽

Residence Time Distribution ◽

Flow Reactor ◽

Continuous Production ◽

Flow Chemistry ◽

Statistical Correlations ◽

Tubular Reactors ◽

Vis Spectroscopy

<p>Continuous-flow chemistry is emerging as an enabling technology for the synthesis of precise polymers. Despite recent advances in this rapidly growing field, there remains a need for a fundamental understanding of how fluid dynamics in tubular reactors influence polymerizations. Herein, we report a comprehensive study of how laminar flow influences polymer structure and composition. Tracer experiments coupled with in-line UV-vis spectroscopy demonstrate how viscosity, tubing diameter, and reaction time affect the residence time distribution (RTD) of fluid in reactor geometries relevant for continuous-flow polymerizations. We found that the breadth of the RTD has strong, statistical correlations with reaction conversion, polymer molar mass, and dispersity for polymerizations conducted in continuous flow. These correlations were demonstrated to be general to a variety of different reaction conditions, monomers, and polymerization mechanisms. Additionally, these findings inspired the design of a droplet flow reactor that minimizes the RTD in continuous-flow polymerizations and enables the continuous production of well-defined polymer at a rate of 1.4 kg/day. </p>

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