MODELING OF A TRICKLE-BED REACTOR: THE …



MODELING OF A TRICKLE-BED REACTOR: THE HYDROGENATION OF 2-BUTANONE ON A

RUTHENIUM CATALYST.

Author(s): Germain, A.; Crine, M.; Marchot, P.; L'Homme, G. A.

Author Affiliation: Univ de Liege, Belg

Source: ACS Symp Ser Int Symp on Chem React Eng, 5th Mar 13-15 1978 n 65 1978 Houston, TX, USA Am

Chem Soc Washington, DC p 411-424

Publication Year: 1978

Abstract: The prediction of the performances of a trickle-bed reactor is possible knowing only the intrinsic rate

equation, if a good description of the topological liquid distribution is available. This one can be obtained using the

percolation theory and resolving the local forces balances at the gas-liquid and liquid-solid interfaces. For the

hydrogenation of 2-butanone, the authors could obtain calculated values of the conversion in satisfactory agreement

with the experiments, provide that they take into account all the possible mass transfer processes between all the

different types of bed areas. So for the first time the description of the liquid distribution in a trickle-bed catalytic

reactor is sufficiently detailed to allow the quantitative prediction of the performances of such a reactor using a

volatile liquid reactant. 21 Refs. EI Order Number: 79070000877

Subjects: CHEMICAL EQUIPMENT; CHEMICAL REACTION - Hydrogenation; CATALYSTS;

RUTHENIUM AND ALLOYS ;TRICKLE-BED REACTOR

Identifiers: TRICKLE-BED REACTOR

Classification Codes: 547

Effectiveness Factor of Partially Wetted Catalyst Particles: Evaluation and Application to the Modeling

of Trickle Bed Reactors

Author(s): Lemcoff, N.O. Cukierman, A.L.; Martinez, O.M.

Author Affiliation: Ciudad Univ, Buenos Aires, Argent

Source: Catal Rev Sci Eng v 30 n 3 1988 p 393-456 ISSN: 0360-2451 CODEN: CRSEC9

Publication Year: 1988

Abstract: The literature has been reviewed on the subject of evaluation and application of the effectiveness factor of

catalyst particles in trickle bed reactor design. Numerical solutions have been presented for different catalyst particle

geometries and, in most cases, for simple reaction kinetics. Also, several approximate equations have been derived

that make the evaluation of the effectiveness factor much easier. Ramachandran and Smith's approximation for gas

limiting reactant systems and Dudukovic's definition of Thiele modulus for a liquid reactant system have been proven

to be important contributions. Although significant progress has been found in this area, there are still several aspects

which remain to be thoroughly analyzed. The applications covered include catalyses of oxidation of ethyl alcohol ad

sulfur dioxide, hydrogenation of methylstyrene, and hydrodesulfurization of heavy oils. EI Order Number:

Catalysts--Applications; Chemical Equipment--Reactors; Ethanol--Oxidation; Styrene--Hydrogenation; Sulfur

Dioxide--Oxidation; Petroleum Refining ;Effectiveness Factor; Trickle Bed Reactor; Methylstyrene; Ethyl Alcohol;

Heavy Oils; Mass Transfer

Identifiers: Effectiveness Factor; Trickle Bed Reactor; Methylstyrene; Ethyl Alcohol; Heavy Oils; Mass Transfer

Classification Codes: 803

Document Type: JA

Treatment: AT

2

ISCRE 9: NINTH INTERNATIONAL SYMPOSIUM ON CHEMICAL REACTION ENGINEERING.

VOLUME 1 - CONTRIBUTED PAPERS.

Source: Chemical Engineering Science ISCRE 9: Ninth International Symposium on Chemical Reaction Engineering.

Volume 1 - Contributed Papers. v 41 n 4 1986 Philadelphia, PA, USA p 607-1135 ISSN: 0009-2509 CODEN:

CESCAC

Publication Year: 1986

Abstract: This conference contains 65 papers reporting recent advances in chemical reaction engineering. The

papers are grouped as follows: applications to biological and solid state processes, mass transport in reactors, fixed

bed reactors, fluidized bed reactors, gas-solid-liquid reaction systems, transients in reactor and reaction systems,

industrial reaction modeling, polymerization and deploymerization, and parametric sensitivity and multiplicity. EI

Order Number: 87040064701

CHEMICAL EQUIPMENT--Reactions; CATALYSTS; MASS TRANSFER; POLYMERIZATION;

MATHEMATICAL MODELS; CHEMICAL REACTIONS ;FLUIDIZED BED REACTORS; REACTOR

MODELING; POLYMERIZATION REACTORS; TRICKLE-BED REACTORS; EIREV

Identifiers: FLUIDIZED BED REACTORS; REACTOR MODELING; POLYMERIZATION REACTORS;

TRICKLE-BED REACTORS; EIREV

Classification Codes: 802

Document Type: CP

3

MODELING OF TRICKLE BED REACTORS AT HIGH TEMPERATURES AND PRESSURES

WITH VOLATILE FEEDS.

Author(s): Collins, George M. Hess, Richard K.; Hook, Bruce D.; Akgerman, Aydin

Author Affiliation: Texas A&M Univ, Kinetics, Catalysis & Reaction Engineering Lab, College Station, TX, USA

Source: Annu Meet Am Inst Chem Eng 1984 Annual Meeting - American Institute of Chemical Engineers. 1984

San Francisco, CA, USA Sponsored by: AIChE, New York, NY, USA AIChE New York, NY, USA 31p Paper:

108B ISSN: 0196-7282 CODEN: AMAEDX

Publication Year: 1984

Abstract: The purpose of this study was to develop a model to predict the behavior of trickle beds when the liquid

feed is volatile. The model developed is compared with a non-volatile liquid phase model employing the same

kinetics. In the model it is assumed that the reactor is operating in plug flow and that there is no significant wall flow,

the catalyst bed is completely wetted, the mass transfer effects are negligible, the feed is volatile, and that the reaction

takes place on the wetted catalyst in the liquid phase. It is intended to apply this model to hydrotreating processes

which take place at high temperatures and pressures with partial vaporization of the feed. 40 Refs. EI Order

Number: 85040053530

CHEMICAL EQUIPMENT--Reactors; CATALYSTS; CHEMICAL REACTIONS - Hydrogenation;

CHEMICAL ENGINEERING - Mathematical Models; FLOW OF FLUIDS - Packed Beds; LIQUIDS -

Chemical Reactions ;TRICKLE BEDS; PLUG FLOW; WALL FLOW; HYDROTREATING; VOLATILE

LIQUID FEEDS

Identifiers: TRICKLE BEDS; PLUG FLOW; WALL FLOW; HYDROTREATING; VOLATILE LIQUID

FEEDS

Classification Codes: 802

Document Type: CA

4

ADVANCES IN TRICKLE-BED REACTOR MODELING.

Author(s): Crine, Michel L'Homme, Guy A.

Author Affiliation: Univ de Liege, Groupe de Chimie Appliquee et de Genie Chimique, Liege, Belg

Source: Recent Adv in the Eng Anal of Chem React Syst 1984 John Wiley & Sons New York, NY, USA p

430-461

Publication Year: 1984

Abstract: Various attempts in modeling heat and mass transport processes are reviewed in this paper. These models

are characterized by a homogeneous representation of the fluid flows wherein the gas and liquid flow rates are

assumed to be independent of the position in the packing. The paper shows how the main concepts of percolation

theory may lead to a phenomenological description of the fluid flow hydrodynamics and, in turn, to the modeling of

various transport processes such as the dynamic liquid holdup, the catalyst irrigation rate, the axial dispersion and the

radial flow spreading in the liquid phase. These models are compared with experimental results and empirical

correlations reported in the literature. (Edited author abstract) 54 Refs. EI Order Number: 85120175747

CHEMICAL EQUIPMENT--Reactors; CHEMICAL REACTIONS - Mathematical Models; FLOW OF

FLUIDS; HEAT TRANSFER - Mathematical Models; MASS TRANSFER - Mathematical Models

;TRICKLE-BED REACTOR; RESIDENCE TIME DISTRIBUTION; PERCOLATION PROCESS

Identifiers: TRICKLE-BED REACTOR; RESIDENCE TIME DISTRIBUTION; PERCOLATION PROCESS

Classification Codes: 802

Document Type: MC

Treatment: NT

5

IMMOBILIZED CELL REACTOR-SEPARATOR: EFFECTS OF PRESSURE AND GAS FLOW ON

REACTOR PERFORMANCE.

Author(s): Dale, M. C. Okos, M. R.; Wankat, P. C.

Author Affiliation: Purdue Univ, West Lafayette, Indiana, USA

Source: Amer Inst Chem Eng Natl Eng Natl Meet American Institute of Chemical Engineers 1983 Summer National

Meeting (Preprints). 1983 Denver, CO, USA Sponsored by: AIChE, New York, NY, USA AIChE New York,

NY, USA 26p Paper: N 77D CODEN: ACENC9

Publication Year: 1983

Subjects: BIOCHEMICAL ENGINEERING; ;WHEY LACTOSE FERMENTATION; BUBBLE COLUMN;

TRICKLE COLUMN; REACTOR MODELING; COLUMN PERFORMANCE; SPONGE PACKED

COLUMN

Identifiers: WHEY LACTOSE FERMENTATION; BUBBLE COLUMN; TRICKLE COLUMN; REACTOR

MODELING; COLUMN PERFORMANCE; SPONGE PACKED COLUMN

Classification Codes: 461

Document Type: CA

Record 1

Mathematical modeling of the process of oxidation of SO$-2$/ in a fixed trickle bed of catalyst

Author(s): Stegasov, A.N.; Kirillov, V.A.

Corporate Source: Inst Kataliza SO RAN, Novosibirsk, Russia

Source: Teoreticheskie Osnovy Khimicheskoi Tekhnologii v 27 n 4 Jul-Aug 1993 p 393-397 CODEN: TOKTA8

Publication Year: 1993

Abstract: The mathematical model is proposed for calculation of the process of oxidation of sulfur dioxide in a fixed

catalyst bed under continuous and pulsed feeds of the liquid phase. The model is verified using the results of

experimental-data processing. In Russian 13 Refs EI Order Number: 94011170299

Subjects: Mass transfer; Differential equations; Hydrodynamics; Mathematical models; Oxidation; Chemical

reactors

Identifiers: Trickle-bed reactors; Balance equations; Liquid phase; Gaseous phase; Numerical experiments

Classification Codes: 631.2

Document Type: JA

Treatment: TX

1

Effectiveness Factor of Partially Wetted Catalyst Particles: Evaluation and Application to the Modeling

of Trickle Bed Reactors

Author(s): Lemcoff, N.O. Cukierman, A.L.; Martinez, O.M.

Author Affiliation: Ciudad Univ, Buenos Aires, Argent

Source: Catal Rev Sci Eng v 30 n 3 1988 p 393-456 ISSN: 0360-2451 CODEN: CRSEC9

Publication Year: 1988

Abstract: The literature has been reviewed on the subject of evaluation and application of the effectiveness factor of

catalyst particles in trickle bed reactor design. Numerical solutions have been presented for different catalyst particle

geometries and, in most cases, for simple reaction kinetics. Also, several approximate equations have been derived

that make the evaluation of the effectiveness factor much easier. Ramachandran and Smith's approximation for gas

limiting reactant systems and Dudukovic's definition of Thiele modulus for a liquid reactant system have been proven

to be important contributions. Although significant progress has been found in this area, there are still several aspects

which remain to be thoroughly analyzed. The applications covered include catalyses of oxidation of ethyl alcohol ad

sulfur dioxide, hydrogenation of methylstyrene, and hydrodesulfurization of heavy oils. EI Order Number:

Catalysts--Applications; Chemical Equipment--Reactors; Ethanol--Oxidation; Styrene--Hydrogenation; Sulfur

Dioxide--Oxidation; Petroleum Refining ;Effectiveness Factor; Trickle Bed Reactor; Methylstyrene; Ethyl Alcohol;

Heavy Oils; Mass Transfer

Identifiers: Effectiveness Factor; Trickle Bed Reactor; Methylstyrene; Ethyl Alcohol; Heavy Oils; Mass Transfer

Classification Codes: 803

Document Type: JA

Treatment: AT

2

RECENT ADVANCES IN THE ANALYSIS AND DESIGN OF TRICKLE-BED REACTORS.

Author(s): Ramachandran, P. A. Dudukovic, M. P.; Mills, P. L.

Author Affiliation: Washington Univ, St. Louis, MO, USA

Source: Sadhana v 10 n pt 1-2 Apr 1987 p 269-298 ISSN: 0256-2499 CODEN: SAPSER

Publication Year: 1987

Abstract: This paper summarizes some progress in our understanding of trickle-bed reactors. The particular topics

discussed in this review are the basic hydrodynamics, flow regime transition, pressure drop and holdup calculations,

use of tracers, modelling of partial wetting effects, reactor design of and catalyst testing in trickle beds. The rapid

advances made in these areas are critically examined and some problems which need further investigation are

outlined. (Author abstract) 72 Refs. EI Order Number: 88010000352

Subjects: CHEMICAL EQUIPMENT; HYDRODYNAMICS; CATALYSTS ;TRICKLE-BED REACTORS;

MULTIPHASE REACTORS

Identifiers: TRICKLE-BED REACTORS; MULTIPHASE REACTORS

Classification Codes: 802

Document Type: JA

Treatment: X

3

LIQUID DISPERSION IN TRICKLE-BED REACTORS WITH GAS-LIQUID COCURRENT

DOWNFLOW.

Author(s): Chu, C. F. Ng, K. M.

Author Affiliation: Univ of Massachusetts, Amherst, MA, USA

Source: Amer Inst Chem Eng Natl Eng Natl Meet American Institute of Chemical Engineers 1986 Annual Meeting.

1986 Miami Beach, FL, USA Sponsored by: AIChE, New York, NY, USA AIChE New York, NY, USA 10p

Paper: 33E CODEN: ACENC9

Publication Year: 1986

Abstract: The flow pattern can deviate form ideal plug flow in both trickling and pulsing flows. The liquid dispersion

in those flow regimes are investigated separately, as the mechanisms causing the deviation of flow pattern from plug

flow are different. In trickling flow, the dispersion of the liquid phase occurs in the flow path which is determined with

computer-generated packed column. Dispersion in pulsing flow is studied with a combination of the method of

characteristics and analysis of liquid dispersion in the liquid slug and gas pulse. The axial dispersion coefficients are

then determined based on Monte Carlo simulation. Finally, liquid dispersion in trickle beds containing porous

packings is also discussed. (Author abstract) 16 Refs. EI Order Number: 87060096922

FLUID DYNAMICS--Mathematical Models; CHEMICAL EQUIPMENT - Reactors; FLOW OF FLUIDS -

Pulsatile Flow; MATHEMATICAL STATISTICS - Monte Carlo Methods ;LIQUID DISPERSION;

TRICKLE-BED REACTORS; TRICKLING FLOW; AXIAL DISPERSION COEFFICIENTS; POROUS

PACKINGS

Identifiers: LIQUID DISPERSION; TRICKLE-BED REACTORS; TRICKLING FLOW; AXIAL

DISPERSION COEFFICIENTS; POROUS PACKINGS

Classification Codes: 631

Document Type: CA

4

MODELING THE HYDROTREATING REACTIONS OF A HEAVY RESIDUAL OIL IN A PILOT

TRICKLE-BED REACTOR.

Author(s): Iannibello, Antonio Marengo, Sergio; Burgio, Gerlando; Baldi, Giancarlo; Sicardi, Silvio; Specchia, Vito

Author Affiliation: Stazione Sperimentale per i Combustibili, Milan, Italy

Source: Ind Eng Chem Process Des Dev v 24 n 3 Jul 1985 p 531-537 ISSN: 0019-7882 CODEN: IEPDAW

Publication Year: 1985

Abstract: The removal of sulfur and metals from a heavy residual oil by hydrotreating in a pilot trickle-bed reactor

was examined. Catalysts with different active components on two different supports (bauxite and alumina) were

tested. The results were interpreted via several models that took into account the physical and chemical complexity of

the three-phase system. A first-order kinetics approach proved valid for the bauxite-based catalysts, having a wide

pore size distribution, provided that the hydrodynamic effects in the reactor had been suitably accounted for by either

external liquid holdup or apparent intraparticle diffusivity. In contrast, the results from the alumina catalyst required

interpretation with a different model, probably because of the different pore size distribution. 31 Refs. EI Order

Number: 85080106901

HYDROCARBONS--Processing; CHEMICAL EQUIPMENT - Reactors; HYDRODYNAMICS; CATALYSTS

- Alumina ;HYDROTREATING REACTIONS; HEAVY RESIDUAL OIL; PILOT TRICKLE-BED REACTOR

Identifiers: HYDROTREATING REACTIONS; HEAVY RESIDUAL OIL; PILOT TRICKLE-BED

REACTOR

Classification Codes: 803

Document Type: JA

Treatment: X

5

KINETIC MODELING OF THE OXIDATION OF GLUCOSE INTO GLUCONIC ACID USING A

TRICKLE BED REACTOR.

Author(s): Long, Nguyen Qui Germain, A.

Author Affiliation: Univ de Liege, Inst de Chimie, Liege, Belg

Source: Amer Inst Chem Eng Natl Eng Natl Meet 1985 Spring National Meeting and Petro Expo '85 - American

Institute of Chemical Engineers. 1985 Houston, TX, USA Sponsored by: AIChE, New York, NY, USA AIChE

New York, NY, USA 26p Paper: 70D CODEN: ACENC9

Publication Year: 1985

Abstract: A new continuous process was studied for the synthesis of gluconic acid by oxidation of glucose on a

palladium catalyst. In order to optimize the productivity and the selectivity of the process, a kinetic model was

developed based on data obtained in a continuous micro trickle bed reactor. This model correlates accurately the

formation of gluconic acid as well as side products with the operating variables. It enables one to show that the very

high catalyst loading of trickle bed reactors can considerably improve the selectivity of reactions normally realized in

slurry reactors. 9 Refs. EI Order Number: 85080111069

SUGAR--Oxidation; CHEMICAL REACTIONS - Reaction Kinetics; CHEMICAL EQUIPMENT - Reactors;

CATALYSTS; ACIDS - Manufacture; PALLADIUM AND ALLOYS ;GLUCONIC ACID; CONTINUOUS

MICRO TRICKLE BED REACTOR; GLUCONOBACTER; ASPERGILLUS NIGER

Identifiers: GLUCONIC ACID; CONTINUOUS MICRO TRICKLE BED REACTOR;

GLUCONOBACTER; ASPERGILLUS NIGER

Classification Codes: 822

Document Type: CA

6

MODELLING OF A TRICKLE-BED REACTOR - THE HYDROGENATION OF XYLOSE TO

XYLITOL.

Author(s): Herskowitz, M.

Author Affiliation: Ben Gurion Univ of the Negev, Dep of Chemical Engineering, Beer Sheva, Isr

Source: Chem Eng Sci v 40 n 7 1985 p 1309-1311 ISSN: 0009-2509 CODEN: CESCAC

Publication Year: 1985

Abstract: The purpose of this paper is to develop a model for predicting the conversion of xylose to xylitol in a

trickle-bed reactor. The hydrogen and xylose concentrations in the liquid are calculated as a function of the liquid and

gas superficial velocities, the pressure and temperature in the reactor. Since the hydrogen concentration in the liquid is

at least two orders of magnitude smaller than the xylose concentration while the diffusivity of hydrogen in the liquid is

only five times larger than the diffusivity of xylose, the assumption that the concentration of xylose is uniform in the

catalyst pores is justified. 24 Refs. EI Order Number: 85100138998

CHEMICAL EQUIPMENT--Reactors; CHEMICAL REACTIONS - Hydrogenation ;TRICKLE-BED

REACTOR; XYLOSE; XYLITOL

Identifiers: TRICKLE-BED REACTOR; XYLOSE; XYLITOL

Classification Codes: 802

Document Type: JA

Treatment: X

7

MODELING OF TRICKLE BED REACTORS AT HIGH TEMPERATURES AND PRESSURES

WITH VOLATILE FEEDS.

Author(s): Collins, George M. Hess, Richard K.; Hook, Bruce D.; Akgerman, Aydin

Author Affiliation: Texas A&M Univ, Kinetics, Catalysis & Reaction Engineering Lab, College Station, TX, USA

Source: Annu Meet Am Inst Chem Eng 1984 Annual Meeting - American Institute of Chemical Engineers. 1984

San Francisco, CA, USA Sponsored by: AIChE, New York, NY, USA AIChE New York, NY, USA 31p Paper:

108B ISSN: 0196-7282 CODEN: AMAEDX

Publication Year: 1984

Abstract: The purpose of this study was to develop a model to predict the behavior of trickle beds when the liquid

feed is volatile. The model developed is compared with a non-volatile liquid phase model employing the same

kinetics. In the model it is assumed that the reactor is operating in plug flow and that there is no significant wall flow,

the catalyst bed is completely wetted, the mass transfer effects are negligible, the feed is volatile, and that the reaction

takes place on the wetted catalyst in the liquid phase. It is intended to apply this model to hydrotreating processes

which take place at high temperatures and pressures with partial vaporization of the feed. 40 Refs. EI Order

Number: 85040053530

CHEMICAL EQUIPMENT--Reactors; CATALYSTS; CHEMICAL REACTIONS - Hydrogenation;

CHEMICAL ENGINEERING - Mathematical Models; FLOW OF FLUIDS - Packed Beds; LIQUIDS -

Chemical Reactions ;TRICKLE BEDS; PLUG FLOW; WALL FLOW; HYDROTREATING; VOLATILE

LIQUID FEEDS

Identifiers: TRICKLE BEDS; PLUG FLOW; WALL FLOW; HYDROTREATING; VOLATILE LIQUID

FEEDS

Classification Codes: 802

Document Type: CA

8

MODELLING AND DESIGN OF A TRICKLE BED REACTOR.

Author(s): Sicardi, S.

Author Affiliation: Politecnico di Torino, Dipartimento di Scienza dei Materiali ed Ingegneria Chimica, Turin, Italy

Source: Institution of Chemical Engineers Symposium Series ISCRE 8, The Eighth International Symposium on

Chemical Reaction Engineering. n 87 1984 Edinburgh, Scotl Sponsored by: Inst of Chemical Engineers, Rugby, Engl

Inst of Chemical Engineers (EFCE Event n 299) Rugby, Engl p 169-176 ISSN: 0307-0492 CODEN: ICESDB

ISBN: 0-85295-176-0

Publication Year: 1984

Abstract: In a trickle bed reactor, when a volatile key reactant is controlling, the experimental conversion rate is

generally higher than that determined with the model of totally wetted particles. The models proposed to interpret this

phenomenon are based on very different approaches and, at the present, are not completely reliable for the design of

the trickle bed reactor. An empirical correlation for the evaluation of the conversion rate is proposed: it is obtained

from the experimental data taken from the literature and is valid for three different reactions. It is useful information

for reactor design. 11 Refs. EI Order Number: 85060080026

CHEMICAL REACTIONS--Reaction Kinetics; CHEMICAL EQUIPMENT - Reactors; CATALYSIS -

Performance; CATALYSIS - Mathematical Models ;TRICKLE BED REACTOR; VOLATILE KEY

REACTANT; CONVERSION RATES; TOTALLY WETTED PARTICLES; MICROKINETICS

Identifiers: TRICKLE BED REACTOR; VOLATILE KEY REACTANT; CONVERSION RATES;

TOTALLY WETTED PARTICLES; MICROKINETICS

Classification Codes: 802

Document Type: CA

9

MODELLING OF A GAS-SOLID TRICKLE FLOW REACTOR FOR THE CATALYTIC OXIDATION

OF HYDROGEN SULPHIDE TO ELEMENTAL SULPHUR.

Author(s): Verver, A. B. Swaay, W. P. M.

Author Affiliation: Akzo Engineering BV, Arnhem, Neth

Source: Institution of Chemical Engineers Symposium Series ISCRE 8, The Eighth International Symposium on

Chemical Reaction Engineering. n 87 1984 Edinburgh, Scotl Sponsored by: Inst of Chemical Engineers, Rugby, Engl

Inst of Chemical Engineers (EFCE Event n 299) Rugby, Engl p 177-184 ISSN: 0307-0492 CODEN: ICESDB

ISBN: 0-85295-176-0

Publication Year: 1984

Abstract: The gas-solid trickle flow contactor is studied as a reactor for desulfurization of gases with small amounts

of H//2S producing elemental sulfur. Experiments on the conversion of H//2S and O//2 and on mass transfer

performance have been carried out in a bench-scale pilot plant at 150 to 300 degree C. The performance is

described by two reactor models. The first model considers only mass transfer between gas and solid particles in

series with reaction, and the other takes account of diffusion phenomena in the gas-solids emulsion (trickles) in

parallel with reaction. At increasing temperature, mass transfer phenomena show an increasingly important limitation

for the conversion rate. Results show the influence of trickle formation. 7 Refs. EI Order Number: 85060080028

SULFUR COMPOUNDS--Oxidation; CHEMICAL EQUIPMENT - Reactors; AIR POLLUTION - Control;

CATALYSTS - Zeolites; CATALYSIS - Mathematical Models ;DRY DESULFURIZATION; HYDROGEN

SULFIDE; GAS-SOLID TRICKLE FLOW REACTOR; BENCH-SCALE TESTING

Identifiers: DRY DESULFURIZATION; HYDROGEN SULFIDE; GAS-SOLID TRICKLE FLOW

REACTOR; BENCH-SCALE TESTING

Classification Codes: 804

Document Type: CA

10

OXIDATION OF SULFUR DIOXIDE IN A TRICKLE-BED REACTOR: A STUDY OF REACTOR

MODELLING.

Author(s): Berruti, F. Hudgins, R. R.; Rhodes, E.; Sicardi, S.

Author Affiliation: Univ of Waterloo, Dep of Chemical Engineering, Waterloo, Ont, Can

Source: Can J Chem Eng v 62 n 5 Oct 1984 p 644-650 ISSN: 0008-4034 CODEN: CJCEA7

Publication Year: 1984

Abstract: In the reported experiments, the catalytic oxidation of sulfur dioxide on activated carbon by oxygen in the

presence of water was carried out to study a laboratory-scale trickle-bed reactor. The particular aim of this study

was to develop empirical models describing the reactor behavior for reactions in which the controlling reactant is in

the gas phase. Water and various gaseous SO//2-air-O//2 mixtures were fed co-currently downward through a fixed

bed of small carbon particles wetted to various degrees. The liquid distribution nozzle was designed to minimize

entrance disturbances. Sulfuric acid product was analyzed by conventional titration methods. The experimental data

are satisfactorily interpreted by either of two different models: one considers that the external area of the catalyst is

divided into two zones (wetted and dry) both active with respect to mass transfer; the other assumes that only one

zone of the external area involves mass transfer and that the mass transfer coefficient must be calculated according to

film theory. 15 Refs. EI Order Number: 84120221396

Subjects: SULFUR DIOXIDE; CHEMICAL EQUIPMENT - Reactors; MATHEMATICAL MODELS;

CATALYSTS - Activated Carbon; OXYGEN; WATER ;TRICKLE-BED REACTORS

Identifiers: TRICKLE-BED REACTORS

11

PERFORMANCE OF A PILOT TRICKLE-BED REACTOR FOR HYDROTREATING OF

PETROLEUM FRACTIONS: DYNAMIC ANALYSIS.

Author(s): Iannibello, Antonio Marengo, Sergio; Guerci, Alessandro; Baidi, Giancarlo; Sicardi, Silvio

Author Affiliation: Stazione Sperimentale per i Combustibili, Milan, Italy

Source: Ind Eng Chem Process Des Dev v 22 n 4 Oct 1983 p 594-598 ISSN: 0019-7882 CODEN: IEPDAW

Publication Year: 1983

Abstract: The total liquid holdup and the intraparticle apparent diffusivity have been measured in a pilot trickle-bed

reactor by a dynamic method. Different liquids and catalyst particles were tested. The total holdup show that pore

filling of the catalyst may be considered as total even at very low liquid flow rate and at a relatively high temperature.

The apparent intraparticle diffusivity is in line with that measured in bench scale reactors and with other liquid phases.

22 Refs. EI Order Number: 84020018842

Subjects: CHEMICAL EQUIPMENT; HYDROCARBONS - Processing

Classification Codes: 802

12

TRICKLE-BED REACTORS: A REVIEW.

Author(s): Herskowitz, Mordechay Smith, J. M.

Author Affiliation: Ben Gurion Univ of the Negev, Beer Sheva, Isr

Source: AIChE J v 29 n 1 Jan 1983 p 1-18 ISSN: 0001-1541 CODEN: AICEAC

Publication Year: 1983

Abstract: In the last few years experimental and theoretical studies that contribute to improved design and scaleup

of trickle-bed reactors have been published. The scope of this study is to review critically these improvements.

Progress in understanding local rates of reaction is considered first. Then recent developments in reactor design are

analyzed. 110 Refs. EI Order Number: 83050061600

Subjects: CHEMICAL EQUIPMENT; CATALYSTS ;TRICKLE BED REACTORS

Identifiers: TRICKLE BED REACTORS

Classification Codes: 802

13

COMPARISON OF CURRENT MODELS FOR TRICKLE-BED REACTORS WITH APPLICATION

TO A MODEL REACTION SYSTEM.

Author(s): Mills, P. L. Dudukovic, M. P.

Author Affiliation: Monsanto Co, St. Louis, Mo, USA

Source: Preprints -Division of Petroleum Chemistry American Chemical Society Preprints - Division of Petroleum

Chemistry, American Chemical Society, Volume 28, Number 2: Symposia. v 28 n 2 Feb 1983 Seattle, WA, USA

Sponsored by: ACS Div of Petroleum Chemistry, Washington, DC, USA ACS Washington, DC, USA p 525

ISSN: 0569-3799 CODEN: ACPCAT

Publication Year: 1983

Subjects: CHEMICAL EQUIPMENT; ;COCURRENT DOWNFLOW OF GAS ON LIQUID REACTANTS;

LIQUID-PHASE HYDROGENATION AND OXIDATION; HYDRODESULFURIZATION OF

PETROLEUM FEEDSTOCKS; HYDRODENITROGENATION OF COAL LIQUIDS; TRICKLE-BED

REACTOR PERFORMANCE PREDICTION; ABSTRACT ONLY

Identifiers: COCURRENT DOWNFLOW OF GAS ON LIQUID REACTANTS; LIQUID-PHASE

HYDROGENATION AND OXIDATION; HYDRODESULFURIZATION OF PETROLEUM FEEDSTOCKS;

HYDRODENITROGENATION OF COAL LIQUIDS; TRICKLE-BED REACTOR PERFORMANCE

PREDICTION; ABSTRACT ONLY

Classification Codes: 802

Document Type: CA

14

TRICKLE-BED REACTORS: DYNAMICS TRACER TESTS, REACTION STUDIES AND

MODELING OF REACTOR PERFORMANCE.

Author(s): El-Hisnawi, A. A. Dudukovic, M. P.; Mills, P. L.

Author Affiliation: Washington Univ, St. Louis, Mo, USA

Source: ACS Symp Ser Chemical Reaction Engineering - Boston Develped in Advance of the 7th International

Symposium on Chemical Reaction Engineering. 1982 Boston, Mass, USA Sponsored by: ACS, Washington, DC,

USA ACS Washington, DC, USA p 421-440 CODEN: ACSMC8 ISBN: 0-8412-0732-1

Publication Year: 1982

Subjects: CHEMICAL EQUIPMENT; ;GAS-PHASE, RATE LIMITING REACTANT; LIQUID-SOLID

CONTRACTING EFFICIENCY; GAS-LIQUID-SOLID MASS TRANSFER COEFFICIENTS; REACTOR

PERFORMANCE PREDICTION; RATE LIMITING CHARACTERISTICS; NON-INTERACTING

GAS-LIQUID REGIME

Identifiers: GAS-PHASE, RATE LIMITING REACTANT; LIQUID-SOLID CONTRACTING EFFICIENCY;

GAS-LIQUID-SOLID MASS TRANSFER COEFFICIENTS; REACTOR PERFORMANCE PREDICTION;

RATE LIMITING CHARACTERISTICS; NON-INTERACTING GAS-LIQUID REGIME

Classification Codes: 802

Document Type: CA

15

DESIGN AND SCALE-UP OF TRICKLE BED REACTORS. SOLID-LIQUID CONTACTING

EFFECTIVENESS.

Author(s): Baldi, Giancarlo

Author Affiliation: Politecnico of Torino, Istituto di Chimica Industriale, Turin, Italy

Source: NATO Advanced Study Institutes Series, Series E, Applied Sciences Multiphase Chemical Reactors.

Volume II - Design Methods n 52 1981 Vimeiro, Port Sponsored by: NATO Advanced Study Inst Sijthoff &

Noordhoff, Alphen aan den Rijn, Neth and Rockville, Md, USA p 323-341 ISSN: 0304-9930 CODEN: NASEDC

ISBN: 90-286-2821-5

Publication Year: 1981

Subjects: CHEMICAL EQUIPMENT; ;DESIGN AND SCALE-UP OF TRICKLE BED REACTORS;

SOLID-LIQUID CONTACTING EFFECTIVENESS; MICROKINETICS; HYDRODYNAMICS;

SOLID-LIQUID EFFECTIVENESS FACTOR; CATALYST WETTING

Identifiers: DESIGN AND SCALE-UP OF TRICKLE BED REACTORS; SOLID-LIQUID CONTACTING

EFFECTIVENESS; MICROKINETICS; HYDRODYNAMICS; SOLID-LIQUID EFFECTIVENESS

FACTOR; CATALYST WETTING

Classification Codes: 802

Document Type: CA

16

DYNAMICS OF A TRICKLE-BED HYDROCRACKER WITH A QUENCHING SYSTEM.

Author(s): Yan, T. Y.

Author Affiliation: Mobil Res & Dev Corp, Princeton, NJ

Source: Can J Chem Eng v 58 n 2 Apr 1980 p 259-266 ISSN: 0008-4034 CODEN: CJCEA7

Publication Year: 1980

Abstract: A mathematical model has been developed to simulate the dynamic behavior of a trickle-bed

hydrocracker without and with one quench. The model was used to study the effects of parameters on transient

temperature and hydrocarbon feed profiles. The system was found to be very sensitive to inlet temperatures and the

states of catalyst activity. The model can be used to guide design and operation of a quenching system, i. e. , proper

location, starting time, and quantity of quench stream, to prevent excess temperature rise that would otherwise lead

to left double quote run-away right double quote condition and poor product yields. 18 Refs. EI Order Number:

80110002035

Subjects: CHEMICAL EQUIPMENT; CHEMICAL REACTIONS - Hydrocracking; MATHEMATICAL

MODELS; DYNAMICS ;TRICKLED-BED REACTORS

Identifiers: TRICKLED-BED REACTORS

Classification Codes: 802

17

AXIAL DISPERSION OF GAS AND SOLID PHASES IN A GAS-SOLID PACKED COLUMN AT

TRICKLE FLOW.

Author(s): Roes, A. W. M. van Swaaij, W. P. M.

Author Affiliation: Twente Univ of Technol, Enschede, Neth

Source: Chem Eng J (Lausanne) v 18 n 1 Aug 1979 p 13-28 ISSN: 0300-9467 CODEN: CMEJAJ

Publication Year: 1979

Abstract: Axial dispersion of gas and solid phases in a gas-solid packed column at trickle flow, a promising new

countercurrent operation, was evaluated using residence time distribution (RTD) experiments. The column was

packed with dumped Pall rings, the gas phase was air at ambient conditions and the solid was a porous catalyst

carrier. At a given solid flow rate axial dispersion of the gas phase decreases with increasing gas velocity and is

strongly dependent upon solid mass flux. Axial dispersion of the solid phase is approximately independent of the gas

velocity and it is reduced if the solid mass flux is increased. For conditions of practical importance, 2-5 and 5-15 Pall

ring layers correspond to the height of a mixing unit in the gas and solid phase, respectively. 23 Refs. EI Order

Number: 80010000366

Subjects: FLOW OF FLUIDS; HEAT TRANSFER; MASS TRANSFER ;COUNTERCURRENT

OPERATION

Identifiers: COUNTERCURRENT OPERATION

Classification Codes: 631

TRICKLE-BED REACTORS.

Author(s): Ng, K. M. Chu, C. F.

Author Affiliation: Univ of Massachusetts, Amherst, MA, USA

Source: Chem Eng Prog v 83 n 11 Nov 1987 p 55-63 ISSN: 0009-2495 CODEN: CEPRA8

Publication Year: 1987

Abstract: Trickle-bed reactors can be defined as a fixed bed of catalyst particles, contacted by a gas-liquid,

two-phase flow. The flow may be cocurrent (downflow or upflow) or countercurrent. In this article, cocurrent

downflow is considered, which, because of its relatively lower pressure drop and the absence of flooding, is by far

the most common mode of operation in industrial practice. Trickle-bed reactors are used primarily in the petroleum

industry for hydrocracking, hydrodesulfurization, and hydrodenitrogenation. Many basic aspects of trickle-bed

reactors are not yet fully understood, making design from fundamentals very difficult. The axial Peclet number in the

trickling regime, which is in agreement with the experimental data, is relatively independent of the liquid flow rate. 10

Refs. EI Order Number: 88030036194

CHEMICAL EQUIPMENT--Reactors; FLOW OF FLUIDS - Two Phase; PETROLEUM REFINERIES -

Equipment; PETROLEUM REFINING - Nitrogen Removal; HYDROCARBONS - Hydrocracking

;TRICKLE-BED REACTORS DESIGN; GAS-LIQUID SYSTEM; COCURRENT DOWNFLOW;

CATALYST PARTICLES; CATALYST FIXED BED

Identifiers: TRICKLE-BED REACTORS DESIGN; GAS-LIQUID SYSTEM; COCURRENT DOWNFLOW;

CATALYST PARTICLES; CATALYST FIXED BED

Classification Codes: 802

Document Type: JA

Treatment: GX

2

SIMPLE MULTICOMPONENT DESCRIPTION OF THE INFLUENCE OF THE PARTICLE AND

PORE SIZE OF COMMERCIAL CATALYSTS ON THE HYDRODESULFURIZATION OF HEAVY

GAS OIL IN (SMALL) TRICKLE-FLOW REACTORS.

Author(s): Gosselink, J. W. Stork, W. H. J.

Author Affiliation: Shell Research BV, Amsterdam, Neth

Source: Chem Eng Process v 22 n 3 Nov 1987 p 157-162 ISSN: 0255-2701 CODEN: CENPEU

Publication Year: 1987

Abstract: Catalysts for the catalytic hydrodesulfurization (HDS) process are still being improved, for instance by

optimization of particle size and shape and pore structure. They are generally tested in small-scale trickle-flow

equipment. A simple multicomponent model has been developed to describe the influence of the particle and pore

sizes on the heavy gas oil HDS performance in such equipment. The model is based on both the diffusion through the

catalyst pores and the chemical HDS reaction on the catalyst inner surface of the individual sulfur components. It

makes use of a broad distribution function for the HDS reaction rate constants k, and assumes that all the

components have the same effective diffusion coefficient less than D greater than . This model, which has the mean

value of k, this is less than k greater than , and less than D greater than as the only two parameters, gives an excellent

description of the HDS performance of Co/Mo/A1//2O//3 catalysts over broad ranges of space velocities and

catalyst particle sizes. (Author abstract) 23 Refs. EI Order Number: 88020020604

GAS OIL--Desulfurization; CATALYSTS - Porosity; PARTICLE SIZE ANALYSIS - Mathematical Models;

DIFFUSION - Optimization; POROUS MATERIALS - Mass Transfer; CHEMICAL EQUIPMENT - Reactors

;HEAVY GAS OIL HYDRODESULFURIZATION; TRICKLE FLOW REACTORS; CATALYST PARTICLE

SIZE EFFECT; CATALYST PORE SIZE EFFECT; PARTICLE SIZE OPTIMIZATION

Identifiers: HEAVY GAS OIL HYDRODESULFURIZATION; TRICKLE FLOW REACTORS; CATALYST

PARTICLE SIZE EFFECT; CATALYST PORE SIZE EFFECT; PARTICLE SIZE OPTIMIZATION

Classification Codes: 523

Document Type: JA

Treatment: NTX

3

TRICKLE-BED REACTORS: LIQUID DIFFUSIONAL EFFECTS IN A GAS-LIMITED REACTION.

Author(s): Beaudry, E. G. Dudukovic, M. P.; Mills, P. L.

Author Affiliation: Washington Univ, St. Louis, MO, USA

Source: AIChE J v 33 n 9 Sep 1987 p 1435-1447 ISSN: 0001-1541 CODEN: AICEAC

Publication Year: 1987

Abstract: A model is developed for predicting the performance of a partially wetted trickle-bed reactor for a

gas-limiting reaction of order less than or equal to one. The model indicates that under certain conditions the liquid

reactant may affect the reaction rate due to its inability to rapidly diffuse to catalyst areas that are in direct contact

with the gas. This model is the first to explain and predict on a rational basis the experimental results for the

hydrogenation of diluted alpha -methylstyrene and aqueous maleic acid reported in the literature. A criterion that

determines when liquid reactant effects can be expected is developed and reported. (Author abstract) 31 Refs. EI

Order Number: 87120192853

CHEMICAL EQUIPMENT--Reactors; ORGANIC COMPOUNDS - Hydrogenation; CATALYSTS - Wetting;

ACIDS - Hydrogenation; MASS TRANSFER; GASES ;TRICKLE-BED REACTORS; LIQUID

DIFFUSIONAL EFFECTS; GAS-LIMITED REACTION; MALEIC ACID

Identifiers: TRICKLE-BED REACTORS; LIQUID DIFFUSIONAL EFFECTS; GAS-LIMITED REACTION;

MALEIC ACID

Classification Codes: 802

Document Type: JA

Treatment: TX

4

GAS-SOLID TRICKLE-FLOW REACTOR FOR THE CATALYTIC OXIDATION OF HYDROGEN

SULPHIDE: A TRICKLE-PHASE MODEL.

Author(s): Verver, A. B. Van Swaaij, W. P. M.

Author Affiliation: Twente Univ of Technology, Enschede, Neth

Source: Chem Eng Sci v 42 n 3 1987 p 435-445 ISSN: 0009-2509 CODEN: CESCAC

Publication Year: 1987

Abstract: The oxidation of H//2S by O//2 producing elemental sulfur has been studied at temperatures of 100-300

degree C and at atmospheric pressure in a laboratory-scale gas-solid trickle-flow reactor. In order to describe mass

transfer in the trickle-flow reactor, a reactor model has been developed in which a particle-free, upflowing gas phase

and a dense, downflowing gas-solids suspension, the so-called trickle phase, are distinguished. From the experiments

and from the reactor model calculations it appears that for the H//2S-O//2 reaction no mass transfer limitations occur

at temperatures up to about 200 degree C, whereas at 300 degree C gas-phase mass transfer and diffusion within

the dense solids suspensions offer resistance to reaction. (Edited author abstract) 16 Refs. EI Order Number:

87070105627

HYDROGEN SULFIDE--Oxidation; CHEMICAL EQUIPMENT - Reactors; SOLIDS - Suspensions; MASS

TRANSFER; ZEOLITES ;GAS-SOLID TRICKLE-FLOW REACTOR; TRICKLE-PHASE MODEL;

TRICKLE PHASE

Identifiers: GAS-SOLID TRICKLE-FLOW REACTOR; TRICKLE-PHASE MODEL; TRICKLE PHASE

Classification Codes: 931

Document Type: JA

Treatment: TX

5

CATALYTIC HYDROTREATING OF BITUMEN DERIVED COKER GAS OIL: A MODIFIED

KINETIC MODEL FOR PILOT AND COMMERCIAL PLANTS.

Author(s): Yui, S. M. Sanford, E. C.

Author Affiliation: Syncrude Canada Ltd, Edmonton, Alberta, Can

Source: Preprints - Tenth Canadian Symposium on Catalysis. 1986 Kingston, Ont, Can Sponsored by: Chemical

Inst of Canada, Catalysis Div, Ottawa, Ont, Can Chemical Inst of Canada Ottawa, Ont, Can p 30-39

Publication Year: 1986

Abstract: A new kinetic model for hydrotreating of coker gas oil has been developed. First and 1. 5th order kinetics

are applied to nitrogen (HDN) and sulfur removal (HDS), respectively. The model incorporates terms for hydrogen

partial pressure (H//2PP) and catalyst wetting efficiency. By analyzing the pilot plant data, the power terms of 1. 3

(HDN) and 0. 8 (HDS) for H//2PP were obtained. The wetting efficiency of a commercial unit is assumed to be

unity. The pilot scale trickle-bed, on the other hand, is only partially wetted; therefore, the plug flow assumption

cannot be applied. The validity of the model was confirmed by commercial data. (Edited author abstract) 11 Refs. EI

Order Number: 88030044950

GAS OIL--Processing; CHEMICAL REACTIONS - Reaction Kinetics; CATALYSTS - Wetting; CHEMICAL

EQUIPMENT - Reactors; HYDROGEN - Pressure Effects ;COKER GAS OIL; CATALYTIC

HYDROTREATING; CATALYST WETTING EFFICIENCY; PLUG FLOW; TRICKLE-BED REACTOR

Identifiers: COKER GAS OIL; CATALYTIC HYDROTREATING; CATALYST WETTING EFFICIENCY;

PLUG FLOW; TRICKLE-BED REACTOR

Classification Codes: 523

Modelling of catalytic SO$-2$/ oxidation for continuous and periodic liquid flow through a trickle bed

Author(s): Stegasov, A.N.; Kirillov, V.A.; Silveston, P.L.

Corporate Source: Siberian Branch of the Russian Acad of Science, Novosibirsk, Russia

Source: Chemical Engineering Science v 49 n 22 Nov 1994 Pergamon Press Inc Tarrytown NY USA p

3699-3710 ISSN: 0009-2509 CODEN: CESCAC

Publication Year: 1994

Abstract: SO$-2$/ oxidation over an activated carbon catalyst in a dynamically operated, adiabatic trickle bed can

be described by a system of partial differential equations representing mass balances on four components in two

phases, a fifth component only in the gas phase, two heat balances (one in the mixed fluid phase and the other for the

stationary catalyst particles) and a total mass balance on the liquid phase. A stable, efficient algorithm has been

developed to integrate the system of equations so as to predict the temperature profile in the bed and the acid

concentration leaving the trickle bed. The adjustable parameter used to obtain the prediction, the wetting fraction,

agrees well with experimental correlations of wetting vs liquid flow. The model is thus accurate. The effect of different

kinetic models for SO$-2$/ oxidation on the simulations is examined. In English (Author abstract) 29 Refs. EI

Order Number: 95012528892

Subjects: Oxidation; Reaction kinetics; Sulfur dioxide; Sulfuric acid; Activated carbon; Catalysts; Mathematical

models; Differential equations; Algorithms; Integration; Wetting; Flow of fluids; Particles (particulate matter)

Identifiers: Trickle bed; Intermittent liquid flow

Classification Codes: 802.2

Document Type: JA

Treatment: TX

Record 2

Liquid-phase methanol synthesis: modelling of a monolithic reactor

Author(s): Cybulski, Andrzej; Edvinsson, Rolf; Irandoust, Said; Andersson, Bengt

Corporate Source: Delft Univ of Technology, Delft, Neth

Source: Chemical Engineering Science v 48 n 20 Oct 1993 p 3463-3478 ISSN: 0009-2509 CODEN: CESCAC

Publication Year: 1993

Abstract: A mathematical model of a monolithic reactor for liquid-phase methanol synthesis is developed. The

performance of a commercial-scale monolithic reactor is simulated. The influence of various design parameters for

different solvents and process conditions is studied. Over the range of process conditions considered, it was found

that the mass transfer is sufficiently fast to allow the process to be operated essentially in the kinetic regime. The

numerical results are compared with literature data on slurry columns, autoclaves and trickle-bed reactors. The

performance of the monolithic reactor was found to be commensurable with these reactors. In view of some of the

unique advantages of the monolithic reactor it can be a viable alternative to the conventional methanol reactors. In

English (Author abstract) refs EI Order Number: 93111127433

Subjects: Chemical reactors; Mathematical models; Methanol; Synthesis (chemical); Performance; Mass transfer;

Reaction kinetics; Solvents

Identifiers: Monolithic reactor; Liquid phase methanol synthesis; Design parameters; Kinetic regime; Process

conditions

Classification Codes: 802.1

Document Type: JA

Treatment: AT

Record 3

Simulation of hydrodewaxing reactor by stochastic method

Author(s): Yang, Jianli; Li, Jianlong

Corporate Source: Qingdao Inst of Chemical Technology, Qingdao, China

Source: Journal of Chemical Engineering of Chinese Universities v 6 n 3 Sep 1992 p 264-270 ISSN: 1003-9015

CODEN: GHGXEG

Publication Year: 1992

Abstract: An industrial reactor is divided into MXN reaction zones which are in series and parallel. A model for the

conversion rate of the hydrodewaxing reaction in a given zone was derived from a pure death process and

Sylvester-Pitayagulsarn model. The gas and liquid flow distributions in each zone were predicted by a Markov

process with discrete state and discrete time is in agreement with the industrial operational data. The effects of the

feed temperature and the feeding rate on the performances of the industrial hydrodewaxing reactor were also

discussed in the paper. In Chinese (Edited author abstract) 8 Refs EI Order Number: 93050994396

Subjects: Chemical reactors; Dewaxing; Flow of fluids; Computer simulation

Identifiers: Trickle bed; Hydrodewaxing

Classification Codes: 802.1

Document Type: JA

Treatment: X

Record 4

Modelling of non-catalytic reactions in a gas-solid trickle flow reactor. Dry, regenerative flue gas

desulphurisation using a silica-supported copper oxide sorbent

Author(s): Kiel, J.H.A.; Prins, W.; Van Swaaij, W.P.M.

Corporate Source: Univ of Twente, Enschede, Neth

Source: Chemical Engineering Science v 47 n 17-18 Dec 1992 p 4271-4286 ISSN: 0009-2509 CODEN:

CESCAC

Publication Year: 1992

Abstract: A one-dimensional, two-phase axially dispersed plug flow model has been developed to describe the

steady-state performance of a relatively new type of reactor, the gas-solid trickle flow reactor (GSTFR). In this

reactor, an upward-flowing gas phase is contacted with a downward-flowing dilute solids phase over an inert

packing. The model is derived from the separate mass and heat balances for both the gas and (porous) solids phases

for the case of a non-catalytic gas-solid reaction, which is first-order in the gaseous reactant. The reaction rate may

also depend on the solid reactant concentration, but this concentration is assumed to be low and uniform throughout

the solids volume. From the model, axial profiles can be calculated numerically for the four independent variables, viz,

the gas-phase and solids-phase temperatures and the concentrations of the gaseous and solid reactant. Under

isothermal conditions, the model equations can be solved analytically; the resulting expressions for the axial profiles of

the gaseous and solid reactant are presented. The model is applied to predict the flue gas desulphurisation

performance of a full-scale GSTF absorber in a dry, regenerative process for the simultaneous removal of SO$-x$/

and NO$-x$/ from flue gases. In this process, to be operated at 350-400$DGR@C, the sorbent material consists of

a porous silica support (spherical particles, 1.5 mm diameter) with 7.5 wt% CuO deposited on this support by an

ion-exchange technique. The model calculations are based on experimental findings from previous studies regarding

reaction kinetics, hydrodynamics of the two-phase flow, gas-solids mass transfer and testing of the integrated

process in a bench-scale plant. It appears that SO$-2$/ removal efficiencies over 95% can be achieved in a GSTF

absorber with a length of 15 m. In English (Edited author abstract) EI Order Number: 93010682094

Subjects: Chemical reactors; Flue gases; Desulfurization; Flow of fluids; Performance; Mathematical models;

Adsorbents; Reaction kinetics; Silica; Copper oxides; Two phase flow; Temperature distribution; Hydrodynamics

Identifiers: Trickle flow reactor; Gas phase axial profiles

Classification Codes: 802

Document Type: JA

Treatment: TX

Record 5

Trickle-bed reactors. State of art and perspectives

Author(s): Gianetto, A.; Specchia, V.

Corporate Source: Politecnico di Torino, Italy

Source: Chemical Engineering Science First International Conference on Gas-Liquid and Gas-Liquid-Solid Reactor

Engineering Sep 13-16 1992 v 47 n 13-14 Sep-Oct 1992 Columbus, OH, USA p 3197-3218 ISSN: 0009-2509

CODEN: CESCAC

Publication Year: 1992

Abstract: Theoretical and phenomenological aspects of trickle-bed reactors as reported in a wide number of

papers of the last 35 years have been reviewed. The following engineering topics have been focused by trying a

critical interpretation of the attained results: hydrodynamics, fluid-solid contacting, theoretical and semiempirical

models, mass transfer phenomena, heat and pressure effects. The more recent themes considered in the literature and

some important future trends of scientific and applied research have been enlightened. In English (Author abstract)

111 Refs EI Order Number: 92110624673

Subjects: Chemical reactors; Mathematical models; Hydrodynamics; Mass transfer; Heat transfer

Identifiers: Trickle bed reactors; Catalyst wetting; Fluid solid contacting; Wetting efficiency

Classification Codes: 802.1

Document Type: JA

Treatment: LTG

Record 6

Multiphase reactors. Models and experimental verification

Author(s): Dudukovic, M.P.; Devanathan, N.; Holub, R.

Corporate Source: Washington Univ, St. Louis, MO, USA

Source: Revue de l'Institut Francais du Petrole v 46 n 4 Jul-Aug 1991 p 439-465 ISSN: 0020-2274 CODEN:

RFPTBH

Publication Year: 1991

Abstract: This paper addresses the issue of improving our understanding of the hydrodynamics in two commonly

used reactor types: bubble columns and trickle beds. We use two different approaches. For the bubble column we

develop and present a technique for measurement of liquid velocities and turbulence parameters in order to provide

much needed data. We then suggest that this, coupled with another experimental technique for evaluation of voidage

profiles, would yield all the necessary measurements for critical evaluation of the existing two phase flow models. In

trickle-beds we develop a simple phenomenological model for liquid flow and confront it with the available data for

pressure drop, holdup and flow regime transition. Based on this we develop a model for liquid distribution and

suggest that quantification of any such model requires the use of noninvasive imaging technology of which we give an

example. In English 50 Refs EI Order Number: 91100313157

Subjects: Chemical Reactors; Chemical Equipment--Bubble Columns; Hydrodynamics--Mathematical Models;

Computer Aided Analysis; Flow of Fluids--Multiphase

Identifiers: Trickle Beds; Computer Aided Radioactive Particle Tracking; Multiphase Reactors;

Backmixing Parameters; Flow Regime Transition; Ergun Coefficients

Classification Codes: 802

Document Type: JA

Treatment: TXL

Record 1

Modelling of non-catalytic reactions in a gas-solid trickle flow reactor. Dry, regenerative flue gas

desulphurisation using a silica-supported copper oxide sorbent

Author(s): Kiel, J.H.A.; Prins, W.; Van Swaaij, W.P.M.

Corporate Source: Univ of Twente, Enschede, Neth

Source: Chemical Engineering Science v 47 n 17-18 Dec 1992 p 4271-4286 ISSN: 0009-2509 CODEN:

CESCAC

Publication Year: 1992

Abstract: A one-dimensional, two-phase axially dispersed plug flow model has been developed to describe the

steady-state performance of a relatively new type of reactor, the gas-solid trickle flow reactor (GSTFR). In this

reactor, an upward-flowing gas phase is contacted with a downward-flowing dilute solids phase over an inert

packing. The model is derived from the separate mass and heat balances for both the gas and (porous) solids phases

for the case of a non-catalytic gas-solid reaction, which is first-order in the gaseous reactant. The reaction rate may

also depend on the solid reactant concentration, but this concentration is assumed to be low and uniform throughout

the solids volume. From the model, axial profiles can be calculated numerically for the four independent variables, viz,

the gas-phase and solids-phase temperatures and the concentrations of the gaseous and solid reactant. Under

isothermal conditions, the model equations can be solved analytically; the resulting expressions for the axial profiles of

the gaseous and solid reactant are presented. The model is applied to predict the flue gas desulphurisation

performance of a full-scale GSTF absorber in a dry, regenerative process for the simultaneous removal of SO$-x$/

and NO$-x$/ from flue gases. In this process, to be operated at 350-400$DGR@C, the sorbent material consists of

a porous silica support (spherical particles, 1.5 mm diameter) with 7.5 wt% CuO deposited on this support by an

ion-exchange technique. The model calculations are based on experimental findings from previous studies regarding

reaction kinetics, hydrodynamics of the two-phase flow, gas-solids mass transfer and testing of the integrated

process in a bench-scale plant. It appears that SO$-2$/ removal efficiencies over 95% can be achieved in a GSTF

absorber with a length of 15 m. In English (Edited author abstract) EI Order Number: 93010682094

Subjects: Chemical reactors; Flue gases; Desulfurization; Flow of fluids; Performance; Mathematical models;

Adsorbents; Reaction kinetics; Silica; Copper oxides; Two phase flow; Temperature distribution; Hydrodynamics

Identifiers: Trickle flow reactor; Gas phase axial profiles

Classification Codes: 802

Document Type: JA

Treatment: TX

Record 2

Trickle-bed reactors. State of art and perspectives

Author(s): Gianetto, A.; Specchia, V.

Corporate Source: Politecnico di Torino, Italy

Source: Chemical Engineering Science First International Conference on Gas-Liquid and Gas-Liquid-Solid Reactor

Engineering Sep 13-16 1992 v 47 n 13-14 Sep-Oct 1992 Columbus, OH, USA p 3197-3218 ISSN: 0009-2509

CODEN: CESCAC

Publication Year: 1992

Abstract: Theoretical and phenomenological aspects of trickle-bed reactors as reported in a wide number of

papers of the last 35 years have been reviewed. The following engineering topics have been focused by trying a

critical interpretation of the attained results: hydrodynamics, fluid-solid contacting, theoretical and semiempirical

models, mass transfer phenomena, heat and pressure effects. The more recent themes considered in the literature and

some important future trends of scientific and applied research have been enlightened. In English (Author abstract)

111 Refs EI Order Number: 92110624673

Subjects: Chemical reactors; Mathematical models; Hydrodynamics; Mass transfer; Heat transfer

Identifiers: Trickle bed reactors; Catalyst wetting; Fluid solid contacting; Wetting efficiency

Classification Codes: 802.1

Document Type: JA

Treatment: LTG

Record 3

Multiphase reactors. Models and experimental verification

Author(s): Dudukovic, M.P.; Devanathan, N.; Holub, R.

Corporate Source: Washington Univ, St. Louis, MO, USA

Source: Revue de l'Institut Francais du Petrole v 46 n 4 Jul-Aug 1991 p 439-465 ISSN: 0020-2274 CODEN:

RFPTBH

Publication Year: 1991

Abstract: This paper addresses the issue of improving our understanding of the hydrodynamics in two commonly

used reactor types: bubble columns and trickle beds. We use two different approaches. For the bubble column we

develop and present a technique for measurement of liquid velocities and turbulence parameters in order to provide

much needed data. We then suggest that this, coupled with another experimental technique for evaluation of voidage

profiles, would yield all the necessary measurements for critical evaluation of the existing two phase flow models. In

trickle-beds we develop a simple phenomenological model for liquid flow and confront it with the available data for

pressure drop, holdup and flow regime transition. Based on this we develop a model for liquid distribution and

suggest that quantification of any such model requires the use of noninvasive imaging technology of which we give an

example. In English 50 Refs EI Order Number: 91100313157

Subjects: Chemical Reactors; Chemical Equipment--Bubble Columns; Hydrodynamics--Mathematical Models;

Computer Aided Analysis; Flow of Fluids--Multiphase

Identifiers: Trickle Beds; Computer Aided Radioactive Particle Tracking; Multiphase Reactors;

Backmixing Parameters; Flow Regime Transition; Ergun Coefficients

Classification Codes: 802

Document Type: JA

Treatment: TXL

Record 4

Thermal waves in the periodic operation of a trickle-bed reactor

Author(s): Haure, Patricia M.; Bogdashev, S.M.; Bunimovich, M.; Stegasov, A.N.; Hudgins, R.R.; Silveston, P.L.

Corporate Source: Univ Nacional de Mar del Plata, Mar del Plata, Argent

Source: Chemical Engineering Science Eleventh International Symposium on Chemical Reaction Engineering -

ISCRE 11: New Horizons for Reaction Engineering Jul 8-11 1990 v 45 n 8 1990 Toronto, Ont, Can p 2255-2261

ISSN: 0009-2509 CODEN: CESCAC

Publication Year: 1990

Abstract: Periodic operation of a trickle-bed reactor with on-off liquid flow using SO$-2$/ oxidation over

activated carbon at 26$DGR@C as a test reaction yields a large increase in the oxidation rate. A portion of this

increase is due to a higher bed temperature. The on-off liquid flow causes a rising temperature front which is followed

by a falling front in the direction of the liquid flow. These moving waves have been observed and are predicted by a

dynamic trickle-bed reactor model which allows for gas-liquid mass transfer, product inhibition of reaction and

evaporation. This model was used without fitted constants, but gave nevertheless a satisfactory representation of the

experimental data. In English (Author abstract) 12 Refs EI Order Number: 90110059040

Subjects: Chemical Reactors; Sulfur Dioxide--Oxidation; Carbon--Activated; Mass Transfer

Identifiers: Trickle-Flow Reactor; Thermal Waves; Periodic Operation; On-Off Liquid Flow-Cycling

Classification Codes: 802

Document Type: JA

Treatment: X

Record 5

Novel model for reaction in trickle beds with flow maldistribution

Author(s): Funk, Gregory A.; Harold, Michael P.; Ng, Ka M.

Corporate Source: Univ of Massachusetts, Amherst, MA, USA

Source: Industrial & Engineering Chemistry Research v 29 n 5 May 1990 p 738-748 ISSN: 0888-5885 CODEN:

IECRED

Publication Year: 1990

Abstract: The effect of liquid maldistribution on reaction in a trickle-bed reactor is examined by using a discrete

model. It is based on a computer-generated, two-dimensional bed packed with equal-sized spherical catalyst pellets.

The configuration of the liquid inlet distributor is included in the model. The flow on and intraparticle diffusion and

reaction in each and every catalyst pellet are sequentially analyzed, leading to predictions of the overall reactor

behavior. The interplay between flow patterns, wetting on individual pellets, and effectiveness enhancement is

demonstrated. The present model offers advantages over other conventional models in terms of overall reaction rate

predictions, the ability in the description of irregular morphological features, the absence of the artificial backmixing of

materials, and others. In English (Author abstract) 44 Refs

Subjects: Chemical Reactions; Chemical Reactors; Catalysts; Flow of Fluids--Computer Simulation; Computer

Programming--Algorithms; Catalysis

Identifiers: Trickle Beds; Flow Maldistribution; Trickle Bed Reactors

Classification Codes: 802

Document Type: JA

Treatment: TX

Record 6

Steady-state models for SO$-2$/ oxidation in a trickle-bed reactor

Author(s): Haure, Patricia M.; Hudgins, R.R.; Silveston, P.L.

Corporate Source: Univ of Waterloo, Waterloo, Ont, Can

Source: Chemical Engineering Journal and the Biochemical Engineering Journal v 43 n 3 May 1990 p 121-125

ISSN: 0300-9467 CODEN: CMEJAJ

Publication Year: 1990

Abstract: Published mathematical models for the steady-state operation of integral trickle-bed reactors are not all

capable of predicting experimental results obtained for the catalytic oxidation of sulfur dioxide over activated carbon.

Only the model of A.R. Mata and J.M. Smith, which considers variable gas composition within the reactor as well as

the variability of the wetting efficiency with the liquid flow rate was successful. An empirical relationship between the

wetting and the liquid flow rate was derived from steady-state data and found to coincide with that of M.

Herskowitz. In English (Edited author abstract) 20 Refs

Subjects: Sulfur Dioxide; Chemical Equipment--Reactors; Mathematical Models--Testing; Carbon--Activated

Identifiers: Trickle-Bed Reactor; Steady State Models; Catalytic Oxidation; Model Predictions

Classification Codes: 804

Document Type: JA

Treatment: TX

Record 7

Model for trickle bed reactors in view of changing gas velocity

Author(s): Lekshmi-Narayanan, H.; Pan, Chin-Min; Haure, Patricia M.; Hudgins, R.R.

Corporate Source: Univ of Waterloo, Waterloo, Ont, Can

Source: Canadian Journal of Chemical Engineering v 68 n 2 Apr 1990 p 327-329 ISSN: 0008-4034 CODEN:

CJCEA7

Publication Year: 1990

Abstract: The trickle-bed reactor model of S. Goto and J.M. Smith is modified to account for changes in the gas

velocity as a result of the solubility of the active gaseous species in the liquid phase, its rate of uptake by the liquid,

and the extent of its participation in the reaction. There appear to be practical cases for which changes in the velocity

of the gas phase should not be ignored. In this note, we examine the conditions under which the constant gas velocity

assumption can lead to significant errors. In English (Edited author abstract) 2 Refs

Subjects: Chemical Equipment; Chemical Engineering - Mathematical Models; Flow of Fluids

Identifiers: Trickle Bed Reactors; Material Balances; Reversible Reactions

Classification Codes: 802

Document Type: JA

Treatment: T

Record 8

Mathematical modeling of a gas-liquid reaction in an irrigated catalyst bed reactor

Author(s): Klinger, A.V.; Novikov, A.V.; Fedoseeva, T.V.; Popov, O.S.

Corporate Source: Kalininsk Polytechnical Inst, USSR

Source: Theoretical Foundations of Chemical Engineering (English Translation of Teoreticheskie Osnovy

Khimicheskoi Tekhnologii) v 22 n 6 Jul 1989 p 520-525 ISSN: 0040-5795 CODEN: TFCEAU

Publication Year: 1989

Abstract: A mathematical model was proposed to describe the process macrokinetics in a gas-liquid column-type

reactors with an irrigated catalyst bed and the results of modeling compared with the experimental data. The model is

based on mass transfer in liquid films. The process macrokinetics in the reactor, known as a trickle bed reactor,

were experimentally studied for the case of glucose hydrogenation on a stationary nickel catalyst. In English (Edited

author abstract) 30 Refs

Subjects: Catalysis; Chemical Equipment - Reactors; Glucose - Hydrogenation; Flow of Fluids - Films; Catalysts -

Nickel; Mass Transfer - Mathematical Models

Identifiers: Column Reactors; Differential Equations; Gas-Liquid Reactions; Irrigated Packed Bed

Reactors; Liquid Film Mass Transfer; Trickle Bed Reactors

Classification Codes: 802

Document Type: JA

Treatment: TX

Periodic operation of trickle bed reactor for hydrogenolysis in gas-liquid-liquid-solid four phases

Author(s): Yamada, Hiroshi; Goto, Shigeo

Corporate Source: Nagoya Univ, Nagoya, Jpn

Source: Journal of Chemical Engineering of Japan v 30 n 3 Jun 1997 Soc of Chemical Engineers, Jpn Tokyo Japan

p 478-483 ISSN: 0021-9592 CODEN: JCEJAQ

Publication Year: 1997

Abstract: Trickle bed reactors are the most common gas-liquid-solid three-phase reactors involving a solid

catalyst, and gaseous and liquid reactants. If solvents in the liquid phase are indissoluble in each other,

gas-liquid-liquid-solid four phases exist in the reactor. Deprotection of amino acid was studied in a trickle bed

reactor as a typical example of a four-phase system. A reactant (carbobenzoxy phenylalanine) could be dissolved in

an organic phase and hydrogenated to a product (phenylalanine) using a Pd/C solid catalyst. Phenylalanine had

hydrophilic properties and transferred from the organic phase to the aqueous phase. When two liquids were

continuously introduced into the four-phase reactor, the product (phenylalanine) was deposited on the surface of the

catalyst and the catalytic activity gradually decreased. Periodic operation was adopted to solve this problem. Only

distilled water was periodically introduced into the reactor to wash the catalyst, which could be completely

regenerated after this washing period. The optimal reaction period was determined by simulation to obtain a high

concentration of the product. In English (Author abstract) 5 Refs. EI Order Number: 97093813539

Subjects: Chemical reactors; Hydrogenation; Solvents; Amino acids; Catalyst activity; Aromatic compounds; Phase

transitions; Dissolution

Identifiers: Trickle bed reactors; Multiphase reactors

Classification Codes: 802.3

Document Type: JA

Treatment: G

Record 2

Modelling of hydrotreating process in a trickle-bed reactor

Author(s): Kumar, V. Ramesh; Balaraman, K.S.; Rao, V.S. Ramachandra; Ananth, M.S.

Corporate Source: Indian Inst of Technology, Madras, India

Source: Petroleum Science and Technology v 15 n 3-4 Apr-May 1997 Marcel Dekker Inc New York NY USA p

283-295 ISSN: 1091-6466 CODEN: PSTEFV

Publication Year: 1997

Abstract: Pilot scale hydrotreating experiments have been conducted on straight run high speed diesel oil (SR

HSDO) using commercially available Co-Mo on Al$-2$/O$-3$/ catalyst. Kinetics of hydrodesulphurization and

hydrodenitrogenation are studied using the models that took into account the physical and chemical complexities of

the three phase system. Correlations are developed to predict the product properties based on operating conditions.

The results show a good agreement with the experimental data. In English (Author abstract) 5 Refs.

Subjects: Diesel fuels; Gas oils; Catalysts; Alumina; Chemical reactors; Reaction kinetics; Desulfurization;

Correlation methods; Cobalt

Identifiers: Hydrodenitrogenation; Hydrodesulphurization; Trickle bed reactors

Classification Codes: 523

Document Type: JA

Treatment: X

Record 3

Analysis of rate enhancement in a periodically operated trickle-bed reactor

Author(s): Gabarain, L.; Castellari, A.T.; Cechini, J.; Tobolski, A.; Haure, P.

Corporate Source: Universidad Nacional de Mar del Plata

Source: AIChE Journal v 43 n 1 Jan 1997 AIChE New York NY USA p 166-172 ISSN: 0001-1541 CODEN:

AICEAC

Publication Year: 1997

Abstract: When a trickle-bed reactor (TBR) is operated periodically, the bed is fed with liquid on and off, while

the gas phase passes continuously. Rates and conversions could be higher than those corresponding to the

steady-state operation. In the `dry cycles' the heat generated by the reaction can drive the vaporization of the liquid

phase, and a much more rapid `gas phase' reaction may occur. There is a trade-off between the potential for

hot-spot formation and the fact that overall rates are higher during cycling. A qualitative understanding of the phase

transition in TBRs is obtained by a simple phenomenological model that takes into account different transport and

reaction mechanisms occurring in a catalytic particle under different cycling conditions. A mathematical model is used

to predict results. In English (Author abstract) 16 Refs.

Subjects: Chemical reactors; Reaction kinetics; Vaporization; Thermal cycling; Phase transitions; Catalysts; Particles

(particulate matter); Mathematical models; Mass transfer

Identifiers: Trickle bed reactors; Hot spot formation; Dry cycles

Classification Codes: 802.1

Document Type: JA

Treatment: TX

Record 4

Continuous lumping model for simulation of hydrocracking

Author(s): Laxminarasimhan, C.S.; Verma, R.P.; Ramachandran, P.A.

Corporate Source: Indian Oil Corp, Faridabad, India

Source: AIChE Journal v 42 n 9 Sep 1996 AIChE New York NY USA p 2645-2653 ISSN: 0001-1541

CODEN: AICEAC

Publication Year: 1996

Abstract: Hydrocracking of vacuum gas oil is an important chemical process involving complex reaction mixtures.

The reaction is carried out in a trickle-bed reactor, considering reaction kinetics along with such hydrodynamic

effects as mass transfer, intraparticle diffusion, and partial wetting. Since reaction kinetics is critical to modeling and

simulation of a hydrocracking reactor, a modeling approach needs to capture the complex chemistry of the process,

along with the elegance of the solution method. The complex chemistry of hydrocarbon is represented by an elegant

continuous lumping approach to modeling. The true boiling point of the mixture is used as the characterization

parameter. Since the rate constant of hydrocracking is assumed to be a monotonic function of the true boiling point, it

is possible to reformulate mass-balance equations in terms of rate constant as a continuous variable. A novel

distribution function p(k,K), which determines the fractional yield distribution of species, was formulated based on

data from the cracking patterns of various model compounds. Resulting integrodifferential equations are solved

numerically to obtain yields of various fractions as a function of reactor residence time. Model predictions are

compared with limited published data to show the utility of the model. In English (Author abstract) Refs. EI Order

Number: 96103358237

Subjects: Hydrocracking; Computer simulation; Mathematical models; Gas oils; Reaction kinetics; Hydrodynamics;

Chemical reactors; Integrodifferential equations; Probability; Computational fluid dynamics

Identifiers: Continuous lumping model; Vacuum gas oil; Complex reaction mixtures; Trickle bed reactor;

Hydrodynamic effects; Mass balance equation; Fractional yield distribution

Classification Codes: 802.2

Document Type: JA

Treatment: T

Record 5

Interfacial mass transfer in trickle-bed reactor modelling

Author(s): Toppinen, S.; Aittamaa, J.; Salmi, T.

Corporate Source: Abo Akademi, Abo, Finl

Source: Chemical Engineering Science v 51 n 18 Sep 1996 Pergamon Press Inc Tarrytown NY USA p 4335-4345

ISSN: 0009-2509 CODEN: CESCAC

Publication Year: 1996

Abstract: A rigorous steady-state model was written for trickle-bed reactors. The mass and heat transfer

resistances both between the gas phase and the liquid phase and between the liquid phase and the catalyst surface

are included in the reactor model. The mass transfer is modelled using both the Maxwell-Stefan equations and the

effective diffusivity method. The numerical solution of the model is discussed. The reactor model was attached to a

flowsheet simulator that provided all the required physical property and phase-behaviour calculations. Finally, an

industrial hydrogenation reactor was simulated as an example. The simulation results were used to examine the

importance of local mass and heat transfer resistances in the reactor. In English (Author abstract) 24 Refs. EI

Order Number: 96093332245

Subjects: Chemical reactors; Mass transfer; Heat transfer; Maxwell equations; Diffusion in gases; Diffusion in

liquids; Computer simulation; Physical properties; Thermodynamic properties; Reaction kinetics; Mathematical

models; Flowcharting

Identifiers: Trickle bed reactors; Rigorous steady state model; Effective diffusivity method

Classification Codes: 802.1

Document Type: JA

Treatment: GT

Record 6

Three-phase reactor model for hydrotreating in pilot trickle-bed reactors

Author(s): Korsten, Hans; Hoffmann, Ulrich

Corporate Source: TU Clausthal, Clausthal-Zellerfeld, Ger

Source: AIChE Journal v 42 n 5 May 1996 AIChE New York NY USA p 1350-1360 ISSN: 0001-1541

CODEN: AICEAC

Publication Year: 1996

Abstract: A three-phase reactor model for describing the hydrotreating reactions in a trickle-bed reactor was

developed. It includes correlations for determining mass-transfer coefficients, solubility data, and properties of the

compounds under process conditions. The model, based on the two-film theory, was tested with regard to the

hydrodesulfurization of vacuum gas oil in a new high-pressure pilot plant operated under isothermal conditions. The

sulfur content of the product oil was found to depend strongly on the gas/oil flow ratio within the reactor. This is due

to the inhibiting effect of hydrogen sulfide on the chemical reaction rates described by Langmuir-Hinshelwood

kinetics. The poor conversion which, in contrast to industrial plants, is often observed in pilot plant reactors can be

explained by incomplete catalyst wetting produced by low liquid velocities. The simulation shows a good agreement

with the experiments carried out in a wide range of temperature, pressure, space velocity and gas/oil ratio. In

English (Author abstract) Refs. EI Order Number: 96063207522

Subjects: Chemical reactors; Computer simulation; Chemical reactions; Correlation methods; Mass transfer;

Solubility; Physical properties; Sulfur; Hydrogen sulfide; Reaction kinetics; Wetting

Identifiers: Three phase reactor model; Hydrotreating reaction; Pilot trickle bed reactors; Mass transfer

coefficient; Hydrodesulfurization; Vacuum gas oil; Two film theory; Langmuir-Hinshelwood kinetics

Classification Codes: 802.1

Document Type: JA

Treatment: G

Record 7

Modelling of a trickle-bed reactor: II. The hydrogenation of 3-hydroxypropanal to 1,3-propanediol

Author(s): Valerius, G.; Zhu, X.; Hofmann, H.; Arntz, D.; Haas, T.

Corporate Source: Universitaet Erlangen-Nuernberg, Erlangen, Ger

Source: Chemical Engineering and Processing v 35 n 1 Jan 1996 p 11-19 CODEN: CENPEU

Publication Year: 1996

Abstract: 1,3-Propanediol can be synthesized by the hydrogenation of 3-hydroxypropanal over a nickel catalyst.

The aim of the investigation was to obtain information about the mass transfer and degree of wetting in a trickle-bed

reactor. The model for the concentration and temperature profiles in a pilot reactor employed was based on kinetic

measurements in an autoclave. Two different approximations of the overall catalyst effectiveness factor were used:

(1) the effectiveness factors of dry, half wetted and totally wetted slabs were weighted as proposed by Beaudry,

Mills and Dudukovic: (2) a new cylinder shell model was used, leading to one-dimensional mass balance equations

inside the porous catalyst particle for all possible values of the external wetting efficiency on the particle scale. In

English (Author abstract) 14 Refs. EI Order Number: 96033109343

Subjects: Chemical reactors; Mathematical models; Hydrogenation; Organic compounds; Mass transfer; Wetting;

Reaction kinetics; Catalysts; Nickel; Temperature measurement; Composition

Identifiers: Trickle bed reactor; Hydroxypropanal; Propanediol; Effectiveness factor; Cylinder shell model; Mass

balance equations; Acrolein; Spinning basket reactors

Classification Codes: 802.1

Document Type: JA

Treatment: T

Record 8

Modelling of a trickle-bed reactor: I. Extended definitions and new approximations

Author(s): Valerius, G.; Zhu, X.; Hofmann, H.

Corporate Source: Universitaet Erlangen-Nuernberg, Erlangen, Ger

Source: Chemical Engineering and Processing v 35 n 1 Jan 1996 p 1-9 CODEN: CENPEU

Publication Year: 1996

Abstract: Important ideas in the modelling of trickle-bed reactors given in the literature are summarized, partly

extended and placed into context which, in future, will hopefully lead to a more satisfactory theory about the

important physical and chemical processes in this type of reactor. Based on the common behaviour of different

reaction systems and results of previous investigations, general model equations are formulated, which seem to be

applicable to many reactions in a trickle-bed reactor. A new approximation for the overall catalyst effectiveness

factor - the so-called cylinder shell model - is presented, which leads to one-dimensional mass balance equations

inside the catalyst for all possible values of the external wetting efficiency on a particle scale. In English (Author

abstract) 16 Refs. EI Order Number: 96033109342

Subjects: Chemical reactors; Mathematical models; Reaction kinetics; Approximation theory; Catalysts; Wetting;

Mass transfer; Solubility; Gases; Catalyst deactivation

Identifiers: Trickle bed reactor; Cylinder shell model; Mass balance equations; Effectiveness factor; Gaseous

reactant; Mass transfer resistance

Classification Codes: 802.1

Document Type: JA

Treatment: T

Record 9

Dynamic modelling of catalytic three phase reactors

Author(s): Warna, J.; Salmi, T.

Corporate Source: Abo Akademi, Abo, Finl

Source: Computers & Chemical Engineering v 20 n 1 Jan 1996 Pergamon Press Inc Tarrytown NY USA p 39-47

ISSN: 0098-1354 CODEN: CCENDW

Publication Year: 1996

Abstract: Dynamic models were developed for three phase slurry and trickle bed reactors operating in

non-isothermal conditions. The model equations for the gas, liquid and catalyst phases consisted of parabolic partial

differential equations (PDE) and ordinary differential equations (ODE), which were converted to ODEs using finite

difference approximations for the spatial derivatives. The ODEs were solved by a stiff ODE solver (LSODE) using

the backward difference method. The numerical strategy proved to be reliable. The reactor simulation programs

were included in a flowsheet simulator. The use of the programs was illustrated with two case studies: oxidation of

SO$-2$/ and hydrogenation of toluene. The example simulations showed that the dynamic approach provides a

meaningful path to the steady state of the reactor and gives valuable information of the reaction dynamics. In English

(Author abstract) Refs. EI Order Number: 95112929965

Subjects: Chemical reactors; Computer simulation; Mathematical models; Partial differential equations; Finite

difference method; Approximation theory; Numerical methods; Hydrogenation; Toluene; Oxidation; Sulfur dioxide;

Convergence of numerical methods; Catalysis

Identifiers: Catalytic three phase reactors; Trickle bed reactors; Ordinary differential equations; Backward

difference method; Flowsheet simulator

Classification Codes: 802.1

Document Type: JA

Treatment: TX

Record 10

Simulation of non-ideal flow in a trickle bed hydrotreater by the cross-flow model

Author(s): Tsamatsoulis, Dimitris; Papayannakos, Nikos

Corporate Source: Univ of Athens, Athens, Greece

Source: Chemical Engineering Science v 50 n 23 Dec 1995 Pergamon Press Inc Tarrytown NY USA p 3685-3691

ISSN: 0009-2509 CODEN: CESCAC

Publication Year: 1995

Abstract: The cross-flow model is used for the description of non-ideal behaviour of the liquid flow in a bench scale

hydrotreater. Experimental data were received at reaction conditions using non-porous particles of various sizes.

Total and static holdup and film thickness are correlated with liquid velocity and particle size. Mass transfer

characteristic parameters are also correlated with liquid flow, particle size and bed porosity. System response

simulation to stepwise feed tracer concentration change and best fit to experimental data yield the values of model

parameters. In English (Author abstract) 17 Refs. EI Order Number: 96012991042

Subjects: Flow of fluids; Mathematical models; Computer simulation; Chemical reactors; Particles (particulate

matter); Mass transfer; Particle size analysis; Fluidized beds; Porosity; Films

Identifiers: Non-ideal flow; Trickle bed hydrotreater; Cross-flow model; Non-porous particles; Mass transfer

characteristic parameters; Bed porosity; System response simulation; Feed tracer concentration change; Model

parameters; Liquid velocity

Classification Codes: 631.1

Document Type: JA

Treatment: ATX

Record 11

Multicomponent mass and energy transport on different length scales in a packed reactive distillation

column for heterogeneously catalysed fuel ether production

Author(s): Sundmacher, Kai; Hoffmann, Ulrich

Corporate Source: Technische Universitaet Clausthal, Clausthal-Zellerfeld, Ger

Source: Chemical Engineering Science Chemical Reaction Engineering: Science & Technology Proceedings of the

13th International Symposium on Chemical Reaction Engineering. Part A Sep 25-28 1994 v 49 n 24A Dec 1994

Baltimore, MD, USA 2 Pergamon Press Inc Tarrytown NY USA p 4443-4464 ISSN: 0009-2509 CODEN:

CESCAC

Publication Year: 1994

Abstract: A reactive distillation column was operated which was packed with acid ion exchange rings catalysing the

production of the octane enhancer methyl-tert.-butylether (MTBE) from methanol (MeOH) and isobutene (IB). Two

types of catalytic rings were used: a block polymer (BP) with a capacity of 4.54 meq(H$+$PLU$/)/g and a glass

supported precipitated polymer (GPP) with a capacity of 0.9 meq(H$+$PLU$/)/g. Fluid dynamic experiments with

pure MeOH and pure MTBE show that the catalytic packings, which are located in the upper column section, work

under trickle flow conditions. Nonreactive distillation experiments reveal sustained macroscale oscillations of fluxes,

pressure and temperature that are caused by the distillation behaviour of the binary mixture MeOH/IB. These

oscillations were also detected in the reactive distillation process with the highly stable, but less active GPP catalyst.

The local compositions and temperatures from the nonoscillatory reactive distillation experiments with the BP catalyst

are subjected to a detailed analysis of microscale solid-liquid and vapour-liquid transport resistances based on the

Generalised Maxwell-Stefan approach. It turns out that the mass transport resistances inside the catalyst can vary

significantly along the packing. The main mass transport resistance at the vapour-liquid interface is located on the

liquid side. In English (Author abstract) 18 Refs. EI Order Number: 95042664673

Subjects: Ethers; Energy transfer; Mass transfer; Distillation columns; Catalysis; Methanol; Block copolymers; Fluid

dynamics; Packing; Distillation; Composition; Catalysts

Identifiers: Fuel ether; Catalytic ring; Packed reactive distillation column; Glass supported precipitated polymer;

Acid ion exchange ring; Octane enhancer methyl tertiary butyl ether; Isobutene

Classification Codes: 804.1

Document Type: JA

Treatment: X

Record 12

Modelling of biodegradation processes in trickle-bed bioreactors

Author(s): Hekmat, D.; Vortmeyer, D.

Corporate Source: Technical Univ of Munich, Munich, Ger

Source: Chemical Engineering Science Chemical Reaction Engineering: Science & Technology Proceedings of the

13th International Symposium on Chemical Reaction Engineering. Part A Sep 25-28 1994 v 49 n 24A Dec 1994

Baltimore, MD, USA 2 Pergamon Press Inc Tarrytown NY USA p 4327-4345 ISSN: 0009-2509 CODEN:

CESCAC

Publication Year: 1994

Abstract: This paper deals with the mathematical modelling of a biological process to remove organic compounds

from industrial waste gas. Modelling results will be compared with experimental data from measurements utilizing a

laboratory-scale trickle-bed bioreactor. In such an apparatus, the biodegradation of the organic pollutants takes

place via aerobic oxidation in biofilm, which is immobolized on a packing material. Two organic compounds were

chosen as model pollutants, i.e. ethanol and polyakylated benzenes. In addition, data from the literature of a third

compound, dichloromethane, will be analysed. The mathematical model used in this work is based on the stationary

differential mass balances along the reactor height together with the corresponding reaction terms. The experiments

with ethanol reveal that over a large range of gas inlet concentrations, the rate limiting factor of the degradation

process is oxygen limitation. The reason for this is the small partition coefficient of ethanol resulting in large liquid

concentrations. Thus, the pollutant is mineralized at a relatively high rate until dissolved oxygen inside the biofilm is

depleted. In these cases, model calculations with a zeroth-order reaction term describe the experimental data well.

The experiments with polyalkylated benzenes reveal that substrate limitation occurs within the relevant range of gas

inlet concentrations. The reason for this is the large partition coefficient resulting in small liquid concentrations. Thus,

first-order reaction applies. Again, a rather good agreement of model and experiment is achieved. The analysis of the

data of dichloromethane yields kinetic data within the transition regime of first-order and zeroth-order reaction rates.

Thus, no significant difference is observed with the model calculations using either reaction order. The mathematical

model presented can serve as a basis or proper design, up-scaling, and control strategies of trickle-bed bioreactors.

In English (Author abstract) 21 Refs. EI Order Number: 95042664666

Subjects: Biodegradation; Mathematical models; Industrial waste treatment; Bioreactors; Oxidation; Biofilms;

Ethanol; Benzene; Oxygen; Reaction kinetics; Chlorine compounds

Identifiers: Polyalkylated benzene; Dichloromethane; Mass balance; Trickle bed bioreactor; Mineralization

Classification Codes: 802.2

Document Type: JA

Treatment: TX

Record 13

Experimental and modeling study of kinetics and selectivity in the oxidation of a poly($alpha@-olefin)

lubricant

Author(s): Koh, Choon-Seok; Butt, John B.

Corporate Source: Northwestern Univ, Evanston, IL, USA

Source: Industrial & Engineering Chemistry Research v 34 n 2 Feb 1995 ACS Washington DC USA p 524-535

ISSN: 0888-5885 CODEN: IECRED

Publication Year: 1995

Abstract: A major means of lubricant oil degradation is by oxidation in the presence of metal surfaces that can have

catalytic activity. In this work an experimental and modeling study has been carried out on the oxidation kinetics and

selectivity of a typical poly($alpha@-olefin) (PAO) lubricant in the presence of both inert (glass) and active (brass,

steel) surfaces in the temperature range 170-240 $DGR@C. Inhibition of the reaction by zinc dialkyl

dithiophosphate (ZDP) has been investigated. A batch recycling trickle-bed reactor system has been developed

which provides reliable data on intrinsic chemical kinetics. Reaction rates are a strong function of temperature, with

products appearing in the order of water, carbon dioxide, aldehydes, ketones, acids, and alcohols in both gas and

liquid phases. Significant changes in viscosity and molecular weight were observed for T $GRT 200 $DGR@C. A

four-lump (PAO, carbonyl-containing compounds in the liquid phase, gaseous products, and deposits) kinetic model

has been developed that gives good agreement with experimental results, including oxidation rate promotion by

metals and inhibition by ZDP. In English (Author abstract) 48 Refs. EI Order Number: 95032625608

Subjects: Lubricants; Reaction kinetics; Catalyst selectivity; Oxidation; Degradation; Surfaces; Catalyst activity;

Chemical reactors; Viscosity; Molecular weight; Mathematical models; Composition

Identifiers: Poly(alpha olefin) lubricant; Catalytic metal surfaces; Zinc dialkyl dithiophosphate; Batch recycling

trickle bed reactor; Chemical kinetics; Reaction rates

Classification Codes: 607.1

Document Type: JA

Treatment: TX

Record 14

Partial wetting and forced reaction mixture transition in a model trickle-bed reactor

Author(s): Ruzicka, Jiri; Hanika, Jiri

Corporate Source: Czech Acad of Sciences, Czech

Source: Catalysis Today Proceedings of the International Symposium on the Dynamics of Catalytic Systems Aug

29-Sep 3 1993 v 20 n 3 Aug 19 1994 Prague, Czech Repub Elsevier Science Publishers B.V. Amsterdam Neth p

467-484 ISSN: 0920-5861 CODEN: CATTEA

Publication Year: 1994

Abstract: The model trickle-bed reactor had a trickle bed simulated as a vertical string of commercial catalyst

cylindrical pellets. This paved the way for the separation and control of hydrodynamic regime effects to focus on the

effects of mass and heat transfer and the influence or the model system used. The novel fixation of the catalyst pellets

was to avoid their intrusion into the pellets which was the drawback of previous experimental arrangements. In

English 12 Refs. EI Order Number: 94112441235

Subjects: Chemical reactors; Wetting; Catalysts; Mass transfer; Heat transfer; Packed beds; Mathematical models;

Combustion; Hydrodynamics

Identifiers: Trickle bed reactor; Light off

Classification Codes: 802.1

Document Type: JA

Treatment: X

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