Assessment of the plug flow and dead volume ratios in a sub-surface horizontal-flow packed-bed reactor as a representative model of a sub-surface horizontal constructed wetland

This paper proposes the use of a preliminary, phenol removal step to reduce peak loads arriving at a conventional effluent plant. A packed bed reactor (PBR) using polyurethane foam, porous glass and also cocoa fibres as the inert support material was used. Experiments have been carried out where the flow-rates, plus inlet and outlet phenol concentrations were measured. A simple, plug-flow model is proposed to represent the results. Zero, first order, Monod and inhibited kinetics rate equations were evaluated. It was found that the Monod model gave the best fit to the experimental data and allowed linear graphs to be plotted. The Monod saturation constant, K, is approximately 50 g m-3, and ka is around 900 s-1.

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Esterification of oleic acid and ethanol in plug flow (packed bed) reactor under supercritical conditions

The Journal of Supercritical Fluids ◽

10.1016/s0896-8446(00)00055-3 ◽

2000 ◽

Vol 18 (2) ◽

pp. 121-130 ◽

Cited By ~ 36

Author(s):

R Goddard ◽

J Bosley ◽

B Al-Duri

Keyword(s):

Oleic Acid ◽

Plug Flow ◽

Packed Bed ◽

Packed Bed Reactor ◽

Supercritical Conditions

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Reactor engineering calculations with a detailed reaction mechanism for the oxidative coupling of methane

International Journal of Chemical Reactor Engineering ◽

10.1515/ijcre-2020-0138 ◽

2020 ◽

Vol 18 (12) ◽

Author(s):

Sonya Rivera ◽

Andrin Molla ◽

Phillip Pera ◽

Michael Landaverde ◽

Robert Barat

Keyword(s):

Synthesis Gas ◽

Oxidative Coupling ◽

Plug Flow ◽

Packed Bed ◽

Oxidative Coupling Of Methane ◽

Packed Bed Reactor ◽

Feed Ratio ◽

Continuous Stirred Tank Reactor ◽

Perfect Mixing ◽

Feed Temperature

AbstractThe oxidative coupling of methane (OCM) is a potential option for conversion of excess natural gas to higher value products or useful feedstocks. The preferred or ideal OCM stoichiometry is: 2CH4 + O2 → C2H4 + 2H2O, but real OCM produces a variety of species. Using a detailed mechanism from the literature for OCM over a La2O3/CeO2 catalyst that combines coupled elementary gas phase and surface reactions, a reactor engineering study has been done. Adiabatic packed bed reactor (PBR, modeled as plug flow) and continuous stirred tank reactor (CSTR, perfect mixing) simulations using this mechanism are presented. Each reactor simulation used the same total number of catalyst sites. Process variables included CH4/O2 feed ratio (7, 11), feed temperature (843–1243 K), and feed rate. All runs were conducted at 1.01E5 Pa pressure. The results show the CSTR produces high conversions at much lower feed temperatures than those required by the PBR. Once full PBR “light off” occurs, however, its CH4 conversions exceed CSTR. The simulations reveal OCM over this catalyst at these conditions gives a mixture of synthesis gas (CO, H2) and C2Hx (primarily C2H4 plus small quantities of C2H6 and C2H2). The CSTR favors the production of synthesis gas, while the PBR favors C2Hx. Within the suite of CSTR cases, C2Hx is favored at the lowest feed temperature and highest CH4/O2 feed ratio.

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An experimental study of gas phase back mixing under the counter-current gas-liquid flow on a vertical expanded metal sheet packing by static tracer technique

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19800214 ◽

1980 ◽

Vol 45 (1) ◽

pp. 214-221

Author(s):

Jan Červenka ◽

Mirko Endršt ◽

Václav Kolář

Keyword(s):

Gas Phase ◽

Flow Model ◽

Plug Flow ◽

Packed Bed ◽

Metal Sheet ◽

Concentration Profiles ◽

Expanded Metal ◽

Gas Liquid Flow ◽

Counter Current ◽

Back Mixing

Gas phase back mixing has been measured in a column packed with vertical expanded metal sheet under the counter-current flow of gas and liquid by the static method using a tracer. The observed experimental concentration profiles has not confirmed our earlier proposed model of back mixing, based on the concentration profiles in absorption runs. These profiles do not even conform with the axially dispersed plug flow model currently used to describe axial mixing in packed bed columns. The concentration profiles may be described by a combination of the axially dispersed plug flow model with back flow.

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Analysis of observability of model parameters for physical absorption of poorly soluble gases in packed beds

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19822639 ◽

1982 ◽

Vol 47 (10) ◽

pp. 2639-2653 ◽

Cited By ~ 2

Author(s):

Pavel Moravec ◽

Vladimír Staněk

Keyword(s):

Transfer Functions ◽

Plug Flow ◽

Packed Bed ◽

Model Parameters ◽

Packed Bed Column ◽

Interfacial Transport ◽

Complex Arithmetic ◽

Physical Absorption ◽

Poorly Soluble ◽

Phase Lags

Expressions have been derived for four possible transfer functions of a model of physical absorption of a poorly soluble gas in a packed bed column. The model has been based on axially dispersed flow of gas, plug flow of liquid through stagnant and dynamic regions and interfacial transport of the absorbed component. The obtained transfer functions have been transformed into the frequency domain and their amplitude ratios and phase lags have been evaluated using the complex arithmetic feature of the EC-1033 computer. Two of the derived transfer functions have been found directly applicable for processing of experimental data. Of the remaining two one is useable with the limitations to absorption on a shallow layer of packing, the other is entirely worthless for the case of poorly soluble gases.

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