- Type of paper
: Paper in book
Title: Effect of the Internal Mass Transfer Resistance on the
Ni/Al2O3 Deactivation by Thiophene
- Authors:
- Zrnčević, Stanka (55196)
- Tomašić, Vesna
- Editors
- Guczi, L
- Solymosi, F
- Tetenyi, P
Publisher: Elsevier
Year: 1993
Pages: from 2547 to 2550
Number of references: 5
Language: engleski
Summary: Influence of mass transfer resistance on the rate of
Ni/Al2O3 deactivation by thiophene in the reaction of benzene hydrogenation
was investigated. The process was studied using the gas-flow differential
fixed bed reactor at atmospheric total pressure on catalyst pellet 5*5 mm
in the temperature range from 373 to 473 K. Excellent agreement was found
with a power law equation da/dt=kd * ad. The results indicate that the
deactivation rate constant decreases with increasing temperature
with simultaneous increase in deactivation order.
Keywords: catalyst deactivation, poisoning by thiophene, kinetic model, influence of mass transfer
- Type of paper
: Paper in book
Title: Impurity poisoning of Ni-catalyst pellet
- Authors:
- Rušić, Davor
- Zrnčević, Stanka (55196)
- Editors
- Delmon, D.
- Froment, G.F.
Publisher: Elsevier
Year: 1994
Pages: from 623 to 627
Number of references: 9
Language: engleski
Summary: The problem of decrease in catalyst activity due an
irreversible adsorption of poison was solved numerically using a single
point collocation approximation. The numerical results are compared with
experimental data obtained by measuring concentration changes due to
thiophene poisoning of Ni/Al2O3 in benzene hydrogenation.
The kinetic experiments, activity tests, and poisonning experiments were
measured in a series of differential reactor experiments at atmospheric
total pressure at temperature 403, 427 and 448 K.
It was found that the impurity poisoning concentration of benzene and
thiophene decreases from a maximum value at the surface to the centre. This
is reflected in the residual activity profile which has a maximum at the
centre of the pellet. It also was found that there is satisfactory degree
of correlation between calculated effectivenes factor and obtained with
experimental obsertvation.
Keywords: impurity poisoning, concentration profile, matematical model of deactivation, effectivenes factor
- Type of paper
: Paper in journal
Title: Effect of Mass Transfer Resistance on Kinetic Parameters
of Ni/Al2O3 Deactivation by Thiophene
- Authors:
- Tomašić, Vesna
- Meider, H
- Plavšić, D
- Gomzi, Zoran (13886)
- Zrnčević, Stanka (55196)
Journal: Kem.Ind.
Number: 9
ISSN: 0022-9830
Volume: 40
Year: 1991
Pages: from 345 to 348
Number of references: 22
Language: hrvatski
Summary: The majority of catalyst used in industry today are in
theform of highly porous particles. As most of active sites arelocated in
the framework of pores, reactant must be transportedto and within particles
before they can be converted. Transferresistances strongly affect the
kinetic parameters of thereaction rate, and it is possible to assume that
the kineticparameters of catalyst deactivation will also depend on
theextent of mass transfer limitation.
Influence of mass transfer resistance on the rate of
Ni/Al2O3deactivation by thiophene in the reaction of benzenehydrogenation
was investigated. The process was studied using theisothermal differential
fixed-bed reactor in the temperaturerange 373-473 K, on powdered catalyst
and catalyst pellet 5x5 mm.
Experimental data have been correlated with the power lowkinetic
equation. The nonlinear regression analysis was appliedto estimate the
kinetic parameters (Nelder-Mead optimizationmethod).
The results indicate that the rate constant decreases withincreasing
temperature and catalyst particle size, with asimultaneous increase in
deactivation order. This finding isconfirmed by the experimentally
determined activation energy forcatalyst deactivation, which is 3.59 kJ/mol
and 12.51 kJ/mol indiffusion region and kinetic region, respectively.
Keywords: Catalyst Poisoning Kinetics, Mass Transfer Limitation
- Type of paper
: Paper in journal
Title: Catalytic Reforming and Catalysts affect the Quality of
Reformate
- Authors:
- Sertić-Bionda, Katica
- Vrbanović, Željko
- Zrnčević, Stanka (55196)
- Rukavina, V
Journal: Erdol und Kohle-Erdgas-Petrochemie
Number: 4
ISSN: 0014-0058
Volume: 45
Year: 1992
Pages: from 167 to 172
Number of references: 21
Language: engleski
Summary: The effect of process variables and physical and
chemical properties of catalysts on the rates of reactions in catalytic
reforming was studied. The experiments were carried out on apilot plant
scale under the following process canditions:temperature range 490-525 C,
Weight Hourly Space Velocity (WHSV)range 2.7-5.4 1/h, H/CH ratio 7 and 5-6,
operating pressure 27and 12 bar.
High pressure catalyst R-16G and low pressure catalyst R-62were
studied.
It was found that temperature increase favourably effects theRON
increase and improves the gasoline quality, regardless of thecatalyst type.
The experiments indicated that R-62 is more active than R-16Gin
promoting aromatization reactions, because it enablesoperating at lower
pressure. This statement is correlated withthe knowledge of "structure
insensitivity" of naphthenesdehydrogenation reactions.
Physical properties of spent catalysty and coke deposit onthem showed
that there was no deactivation of the catalystsbecause the catalysts
exposure time in the reactor was too short(approx. 23 hours).
Keywords: Catalytic Reforming, Process Variables, Physical and Chemical Properties of Catalyst
- Type of paper
: Paper in journal
Title: Effect of Process Parameters in Catalytic Reforming on the
Reduction of Aromatic Hydrocarbons in Motor Gasoline
- Authors:
- Sertić-Bionda, Katica
- Vrbanović, Željko
- Rukavina, V
- Zrnčević, Stanka (55196)
Journal: Kem.Ind.
Number: 8
ISSN: 0022-9830
Volume: 41
Year: 1992
Pages: from 297 to 302
Number of references: 25
Language: hrvatski
Summary: One of the new requirements of catalytic reforming
is thereduction of gasoline vapour pressure in order to lower
thehydrocarbon emission. Another requirement is the elimination ofhighly
toxic aromatic hydrocarbons, pacticularly benzene. Sincethe reformate is
major highoctane-blending component, it isimportant to choose such process
parameters that will ensure thelowest possible content of aromatics.
Therefore, the activity of two commercial catalysts, thehight pressure
R-16 G and low pressure R-62, was tested in apilot plant fixed-bed reactor
at various temperatures, 490-525 C,and various space times, 0.18-0.37 h.
It was found that the low pressure catalyst R-62 is moreactive for the
aromatization reactions than the hight pressurecatalyst R-16 G. This can be
attributed to the favourablereaction conditions (low pressure). The results
also proved thatthe naphthenes of six carbon atoms in a molecule are the
majorsource of aromatic hydrocarbons while the reactions of
naphthenedehydroisomerization and paraffin dehydrocyclization contributeto
a smaller extent.
Keywords: Catalyst Reforming, Reduction of Aromatic Hydrocarbons, Pt-Re/Al2O3 Catalyst, Process Parameters
- Type of paper
: Paper in journal
Title: Effect of Operating Parameters on the Hydrocracking and
Isomerization Reactions in the Naphtha Reforming
- Authors:
- Sertić-Bionda, Katica
- Vrbanović, Željko
- Rukavina, V
- Zrnčević, Stanka (55196)
Journal: Chem.Biochem.Eng.Q.
Number: 3
ISSN: 0352-9568
Volume: 6
Year: 1992
Pages: from 133 to 138
Number of references: 20
Language: engleski
Summary: The influence of the operating parameters on the
activity oftwo commercial Pt-Re/Al2O3 catalyst (R-62 and R-16G),
onhydrocracking and isomerization reactions in naphtha reformingwas
investigated. The reactions were performed in a fixed-bedreactor of 26 mm
i.d. at space velocity from 2.7 to 5.4 1/h andat temperatures of 505 and
525 C.
It has been found that the yield of liquid product at bothtemperatures
increases with increasing space velosity but R-62catalyst is more active
than the R-16G. This means that R-16Gactivity is higher for hydrocracking
reactions when the gaseousproducts are formed. It should also be noted that
higher activityof R-16G for hydrocracking is not only influenced by the
acidsites of alumina but also by the higher operating pressure (27bar).
Catalyst R-62 has shown higher activity in dehydroisomerizationreactions of
CyC5 naphthenes into aromatic hydrocarbons than theR-16G. This directly
influences the quality of the products.
Keywords: Naphtha Reforming, Hydrocracking and Isomerization reactions, Pt-Re/Al2O3 Catalyst, Reaction Parameters
- Type of paper
: Paper in journal
Title: Effect of Catalyst Preparation on Ni-Al2O3 Poisoning by
Thiophene
- Authors:
- Zrnčević, Stanka (55196)
- Meider, H
- Plavšić, D
Journal: Chem.Eng.J.
ISSN: 0300-9467
Volume: 49
Year: 1992
Pages: from 45 to 48
Number of references: 29
Language: engleski
Summary: The influence of experimental conditions such as
thetemperature of calcination and pelleting pressure on
Ni-Al2O3deactivation by thiophene in benzene hydrogenation is outlinedand
discussed.
It was found that benzene hydrogenation over unpoisonednickel catalyst
is a structure-insensitive reaction. However, itsinhibition by thiophene
produced structure sensitivity: thereaction rate was less sensitive to
thiophene for large nickelcrystallites (formed during catalyst calcination
at hightemperatures followed by reduction), than for small
crystallites.Thus the structure sensitivity of poison adsorption imparted
anapparent structure sensitivity to the main reaction in thepresence of a
poison in the feedstream (secondary structuresensitivity).
The pore structure of the catalyst pellet directly influencesthe degree
of diffusion resistance of both the main and thepoisoning reactions. It was
found that higher mass transferresistances increase the life-time of the
pellets while a lowermass transfer resistance increases the overall
effectivenesfactor.
Keywords: Catalyst Preparation, Thioresistance, Temperature of Calcination, Pelleting Pressure
- Type of paper
: Paper in journal
Title: Modelling of Catalyst Pellet Poisoning for Benzene
Hydrogenation
- Authors:
- Rušić, Davor
- Zrnčević, Stanka (55196)
Journal: J.Chem.Tech.Biotechnol.
ISSN: 0268-2575
Volume: 57
Year: 1993
Pages: from 217 to 220
Number of references: 17
Language: engleski
Summary: Based on the kinetic of benzene hydrogenation, pore
diffusionand catalyst deactivation, time-dependent effectiveness behaviorof
a single Ni-SiO2-Al2O3 catalyst pellet where the chemicalreaction rate is
determined by pore diffusion was simulated fordifferent conditions of
operation.
Poisoning kinetics were measured in a series of differentialreactor
experiments at atmospheric total pressure at temperaturesranging from 403
to 473 K.
A computed effectiveness factor has been compared withexperimental
values for a catalyst pellet of industrial size. Agood degree of
correlation between theoretical prediction and theexperimental results was
found.
Keywords: Catalysis, Catalyst Poisoning, Diffusion, Pellet Modelling
- Type of paper
: Paper in journal
Title: Role of Chemical Reaction Engineering in Catalyst Design
- Authors:
- Zrnčević, Stanka (55196)
Journal: Kem.Ind.
Number: 6
ISSN: 0022-9830
Volume: 42
Year: 1993
Pages: from 187 to 193
Number of references: 68
Language: hrvatski
Summary: Solid catalyst are an integral part of most industrial
reactors. Catalyst development is, thus, a fundamental part of chemical
reaction engineering. In this article, we try to show how the chemical
reaction engineering via mathematical models can identify the key catalyst
design variables and quantify their optimum values.
Keywords: Chemical Reaction Engineering, Catalyst Design
- Type of paper
: Paper in journal
Title: Preparation of Ni/Al2O3 Catalyst by Impregnation
- Authors:
- Zrnčević, Stanka (55196)
- Gomzi, Zoran (13886)
Journal: Kem.Ind.
Number: 3
ISSN: 0022-9830
Volume: 44
Year: 1995
Pages: from 115 to 120
Number of references: 22
Language: hrvatski
Summary: The performance of supported catalyst depends
critically on its active ingredient within support. For those catalyst
prepared by impregnation of support with solution containing the
appropriate metal precursor, the internal distribution of the catalytically
active components within support can be depend upon the duration of the
impregnation and concentration of impregnant solution.
The work investigates the effect of time and concentration od NiCl2 in
impregnant solution on the internal distribution of nickel in -Al2O3. A
model of impregnation is developed that includes a mathematical description
of all processes.
From the simulation results it was concluded that the concentration
profile of precursor of catalytically active ingredient inside support
depends on the initial concentration of impregnant solution. The results
indicate that the distribution of nickel chloride inside the -Al2O3 pellet
is uniform as long as the initial concentration of NiCl2 in impregnant
solution is small. However, by higher concentrations the active ingredient
is absorbed near the outer surface of support.
The activity of prepared Ni/Al2O3 calcined and noncalcined was tested
using benzene hydrogenation as a model reaction. The obtained results
reveal that the catalyst activity increases with the increase of nickel
concentration, especially in the case of catalyst calcination. However, the
influence of calcination on catalyst activity is more significant with
higher nickel loading on support. This fact can be explained by low
concentration of nickel aluminate which is produced in reaction between
nickel oxide and alumina, and which cannot be easily reduced to
catalytically active form of nickel.
Keywords: Catalyst preparation by impregnation, Mathematical model of impregnation
- Type of paper
: Paper in proceedings
Title: Hydrogenation of 1-Methoxy-2-(4-Nitrophenil)-Ethane in
Batch Slurry Reactor
- Authors:
- Glavanović, Tatjana
- Đurinski, M.
- Gržeta, B.
- Zrnčević, Stanka (55196)
- Editors
- nisu navedeni,
Proceedings title: Catalysis in Multiphase Reactors
Language: engleski
Place: Lyon, Francuska
Year: 1994
Pages: from P81 to P87
Meeting: European Symposium-549th Event of the EFChE
Held: from 12/07/94 to 12/09/94
- Type of paper
: Summary in proceedings
Title: Effect of Catalyst Particle Size on the Rate of Ni/Al2O3
Deactivation
- Authors:
- Tomašić, Vesna
- Gomzi, Zoran (13886)
- Zrnčević, Stanka (55196)
Language: hrvatski
Place: Novi Sad
Year: 1991
Pages: from 201 to 201
Meeting: III jugoslovenski simpozijum o hemijskom inženjerstvu
Held: from 01/16/91 to 01/18/91
- Type of paper
: Summary in proceedings
Title: Poisoning of Ni/Al2O3 by Thiophene / Modelling of
deactivation Kinetics
- Authors:
- Tomašić, Vesna
- Gomzi, Zoran (13886)
- Zrnčević, Stanka (55196)
- Editors
- nisu navedeni,
Proceedings title: Knjiga sažetaka XI Sastanka kemičara Hrvatske
Language: hrvatski
Place: Zagreb
Year: 1991
Pages: from 277 to 277
Meeting: XII Sastanak kemičara Hrvatske
Held: from 02/11/91 to 02/13/91
- Type of paper
: Summary in proceedings
Title: Modelling of the Fixed Bed Reactor
- Authors:
- Tomašić, Vesna
- Gomzi, Zoran (13886)
- Zrnčević, Stanka (55196)
- Editors
- nisu navedeni,
Proceedings title: Knjiga sažetaka XIII Sastanka kemičara Hrvatske
Language: hrvatski
Place: Zagreb
Year: 1993
Pages: from 332 to 332
Meeting: XIII Sastanak kemičara Hrvatske
Held: from 02/08/93 to 02/10/93
- Type of paper
: Summary in proceedings
Title: Deactivation Kinetics of Ni-Al2O3 Catalyst
- Authors:
- Tomašić, Vesna
- Zrnčević, Stanka (55196)
Proceedings title: New Achievements in Chromatography
Language: engleski
Place: Opatija
Year: 1992
Pages: from 15 to 15
Meeting: New Achievements in Chromatography
Held: from 10/13/92 to 10/15/92
- Type of paper
: Summary in proceedings
Title: Preparation of Ni/Al2O3 Catalyst by Impregnation
- Authors:
- Holjevac, Tamara
- Jagnić, Anita
- Trajkovski, Danijela
- Gomzi, Zoran (13886)
- Zrnčević, Stanka (55196)
- Editors
- nisu navedeni,
Language: hrvatski
Place: Zagreb
Year: 1995
Pages: from 348F to 348F
Meeting: XIV Skup hrvatskih kemičara
Held: from 02/06/95 to 02/08/95
- Type of paper
: Summary in proceedings
Title: Effect of Thermal Treatments on Thioresistance of Ni/Al2O3
Catalyst during Benzene Hydrogenation
- Authors:
- Tomašić, Vesna
- Gomzi, Zoran (13886)
- Zrnčević, Stanka (55196)
Proceedings title: CHISA '93
Language: engleski
Place: Praha, Czech Republic
Year: 1993
Pages: from 3061 to 3061
Meeting: The 11th International Congress of Chemical Engineering, Chemical Equipment Design and Automation
Held: from 08/29/93 to 09/03/93
- Type of paper
: Summary in proceedings
Title: Estimation of Kinetic Parameters for Benzene Hydrogenation
- Authors:
- Gomzi, Zoran (13886)
- Zrnčević, Stanka (55196)
- Tomašić, Vesna
- Editors
- nisu navedeni,
Proceedings title: CHISA '93
Language: engleski
Place: Praha, Czech Republic
Year: 1993
Pages: from 3062 to 3062
Meeting: The 11th International Congress of Chemical Engineering, Chemical Equipment Design and Automation
Held: from 08/29/93 to 09/03/93
- Type of paper
: Summary in proceedings
Title: Effect of Catalyst Particle Size on Deactivation in
Benzene Hydrogenation
- Authors:
- Zrnčević, Stanka (55196)
- Gomzi, Zoran (13886)
- Meider, H
- Plavšić, D
- Editors
- nisu navedeni,
Proceedings title: Strategies 2000 (Preprints II)
Language: engleski
Place: Karlsruhe, Deutschland
Year: 1991
Pages: from 18 to 18
Meeting: Fourth World Congress of Chemical Engineering
Held: from 06/16/91 to 06/21/91
- Type of paper
: Summary in proceedings
Title: Liquid Phase Oxidation of Toluene in Acetic Acid Solution
- Authors:
- Gomzi, Zoran (13886)
- Smolčić, Silvana
- Zrnčević, Stanka (55196)
- Editors
- nisu navedeni,
Proceedings title: Strategies 2000 (Preprints II)
Language: engleski
Place: Karlsruhe, Deutschland
Year: 1991
Pages: from 53 to 53
Meeting: Fourth World Congress of Chemical Engineering
Held: from 06/16/91 to 06/21/91
- Type of paper
: Summary in proceedings
Title: Ferrite Powders Prepared through the Supercritical Drying
Method: Magnesium Ferrite Aerogels
- Authors:
- Willey, R.J.
- Kotur, Elke
- Oliver, S.A.
- Busca, G.
Proceedings title: Preprints of the lst Italian Conference on Chemical and Process Engineering
Language: engleski
Place: Firenca
Year: 1993
Pages: from 0 to 0
Meeting: Ist Con. Chem. Proc. Eng.
- Type of paper
: Summary in proceedings
Title: Mixed Iron Oxide-Magnesia Aerogels: Relationship of
Catalyst Activity to Surface Characterization
- Authors:
- Kotur, Elke
- Willey, R.J.
- Busca, G.
Language: engleski
Place: Pittsburg
Year: 1993
Pages: from 0 to 0
Meeting: 13th North Am. Meet. Soc.
- Type of paper
: Summary in proceedings
Title: Mixed Iron Oxide-Magnesia Aerogels for the Selective
Catalytic Reduction of Nitric Oxide by Ammonia
- Authors:
- Kotur, Elke
- Kehoe, J
- Willey, R.J.
Language: engleski
Year: 1993
Pages: from 0 to 0
Meeting: The Bernett Ins. Chem. Anal. Mat. Sci., Science Day
- Type of paper
: Summary in proceedings
Title: Effect of Catalyst Pore Size on Deactivation in Benzene
Hydrogenation
- Authors:
- Zrnčević, Stanka (55196)
- Gomzi, Zoran (13886)
- Meider, H
- Plavšić, D
Proceedings title: Strategies 2000 (Preprints II)
Language: engleski
Place: Karlsruhe, Deutschland
Year: 1991
Pages: from 18 to 18
Meeting: Fourth World Congress of Chemical Engineering
Held: from 06/16/91 to 06/21/91
- Type of paper
: Summary in proceedings
Title: Influence of Thermal Treatments on the Properties of
Ni/Al2O3 Catalysts.
- Authors:
- Tomašić, Vesna
- Gomzi, Zoran (13886)
- Zrnčević, Stanka (55196)
- Editors
- nisu navedeni,
Language: hrvatski
Place: Zagreb
Year: 1995
Pages: from 337 to 337
Meeting: XIV Skup hrvatskih kemičara
Held: from 02/06/95 to 02/08/95
- Type of paper
: Summary in proceedings
Title: Catalytic Properties of Cu/ZSM-5 Catalyst for
Decomposition of NOx
- Authors:
- Tomašić, Vesna
- Gomzi, Zoran (13886)
- Zrnčević, Stanka (55196)
Language: engleski
Place: Istanbul, Turska
Year: 1995
Pages: from 643 to 643
Meeting: 35th IUPAC Congress
Held: from 08/14/95 to 08/19/95
- Type of paper
: Summary in proceedings
Title: Effects of Reaction Parameters in
1-Methoxy-2-(4-Nitrophenil)-Ethane Hydrogenation
- Authors:
- Glavanović, Tatjana
- Zrnčević, Stanka (55196)
Language: engleski
Place: Istanbul, Turska
Year: 1995
Pages: from 542 to 542
Meeting: 35th IUPAC Congress
Held: from 08/14/95 to 08/19/95
- Type of paper
: Ph.D.
Title:
- Type of paper
: M.A.
Title: The Experimental and Theoretical Investigation of
Ni-Catalyst Deactivation
Faculty: Fakultet kemijskog inženjerstva i tehnologije Zagreb
Author: TOMAŠIĆ VESNA
Date of defense: 11/18/93
Language: hrvatski
Number of pages: 107
- Type of paper
: Mentorship
Title: The experimental and theoretical investigation of
Ni-catalyst deactivation
Faculty: Fakultet kemijskog inženjerstva i tehnologije Zagreb
Mentor: ZRNČEVIĆ STANKA
Date of defense: 11/18/93
Number of pages: 107
Author: Tomašić mr Vesna
Degree level: M.A.
- Type of paper
: Mentorship
Title: Mathematical Model Development for Catalyst Deactivation
Faculty: Fakultet kemijskog inženjerstva i tehnologije Zagreb
Mentor: ZRNČEVIĆ STANKA
Date of defense: 04/24/92
Number of pages: 129
Author: Rušić Dr. Davor
Degree level: Ph.D.
- Type of paper
: Mentorship
Title: Chlorosulphonation of m-chloraniline with
dimethylformamide as catalyst
Faculty: Fakultet kemijskog inženjerstva i tehnologije Zagreb
Mentor: ZRNČEVIĆ STANKA
Date of defense: 02/18/94
Number of pages: 85
Author: Kotarac Mr Branko
Degree level: M.A.
- Type of paper
: Invited lecture
Title: Role of Chemical Reaction Engineering in Catalyst Design
Institution: XIII Skup hrvatskih kemičara
Year: 1993
- Type of paper
: Invited lecture
Title: Mass Transfer and Reaction in Slurry Reactor
Institution: Pliva
Year: 1995
- Type of paper
: Other
Title: Effect of Catalyst Preparation Method on the Rate of
Deactivation
- Authors:
- Zrnčević, Stanka (55196)
Type of work: javno predavanje
Language: hrvatski
