Deactivation of a catalyst pellet with nonuniform activity distribution

1988 ◽  
Vol 12 (2-3) ◽  
pp. 153-157
Author(s):  
A. Brunovská
Keyword(s):  
Activity Distribution ◽  
Catalyst Pellet

Role of catalyst pellet activity distribution in catalyst poisoning

1994 ◽  
Vol 108 (2) ◽  
pp. 141-156
Author(s):  
Alena Brunovská ◽  
Bibiána Remiarová ◽  
Pavol Pranda
Keyword(s):  
Catalyst Poisoning ◽  
Activity Distribution ◽  
Catalyst Pellet

Estimation of the catalyst pellet activity distribution from zero order kinetic data

1987 ◽  
Vol 52 (10) ◽  
pp. 2426-2437 ◽  
Author(s):  
Alena Brunovská ◽  
Josef Horák
Keyword(s):  
Diffusion Coefficient ◽  
Rate Constant ◽  
Kinetic Data ◽  
Reaction Rate ◽  
Reaction Rate Constant ◽  
Zero Order ◽  
Simultaneous Estimation ◽  
Activity Distribution ◽  
Catalyst Pellet ◽  
The Mean

In this paper a method of simultaneous estimation of the catalyst pellet activity distribution, the mean reaction rate constant, and the diffusion coefficient from kinetic data is described. As kinetic data measurements of outlet concentration from laboratory continuous stirred tank reactor vs feed rate for zero order reaction is used. The estimation technique is verified on simulated data. The mean reaction rate constant is estimated from the region of investigated dependence in which reactant penetrates into the whole catalyst pellet. The value of the effective diffusion coefficient and the activity distribution are estimated from the regime in which the reactant penetrates into the part of the pellet only.

Estimation of the catalyst pellet activity distribution from experimental kinetic data

1989 ◽  
Vol 54 (2) ◽  
pp. 388-399 ◽  
Author(s):  
Alena Brunovská ◽  
Bibiana Remiarová ◽  
Carlo Lebrun
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Gradient Method ◽  
Kinetic Data ◽  
Adjoint Equation ◽  
Ethylene Hydrogenation ◽  
Activity Distribution ◽  
Catalyst Pellet ◽  
Single Pellet ◽  
Scanning Electron

In this paper a method of catalyst pellet activity distribution estimation from experimental kinetic data is described. Measurements of outlet concentration from a laboratory continuous stirred single-pellet reactor vs feed rate for ethylene hydrogenation on Pt/alumina pellet are used as kinetic data. To find the best estimate the gradient method is employed and the gradient is computed with the help of the adjoint equation. The estimated activity distribution is compared with the Pt distribution obtained by the scanning electron microscope.

Optimum activity distribution in a catalyst pellet for a complex reaction

1983 ◽  
Vol 38 (12) ◽  
pp. 1977-1982 ◽  
Author(s):  
A.L. Cukierman ◽  
M.A. Laborde ◽  
N.O. Lemcoff
Keyword(s):  
Complex Reaction ◽  
Optimum Activity ◽  
Activity Distribution ◽  
Catalyst Pellet

Estimation of the catalyst pellet activity distribution from kinetic data

1987 ◽  
Vol 52 (10) ◽  
pp. 2412-2425 ◽  
Author(s):  
Alena Brunovská ◽  
Josef Horák
Keyword(s):  
Kinetic Data ◽  
Reaction Rate ◽  
Noisy Data ◽  
Volumetric Flow Rate ◽  
Reaction Rate Constant ◽  
Test Reaction ◽  
Activity Distribution ◽  
Catalyst Pellet ◽  
Kinetic Region ◽  
Outlet Stream

The possibility of estimating the activity distribution inside an industrial catalyst pellet from measurements of the composition of the outlet stream of a laboratory stirred tank reactor vs volumetric flow rate is discussed. It is assumed that the form of the reaction rate expression for the chosen testing reaction is known and the value of the corresponding reaction rate constant can be evaluated from the measurements in the kinetic region on the crushed pellet. A procedure is proposed which allows to determine whether the activity distribution estimation is feasible, and demands on the model test reaction are discussed. The estimation technique is applied to simulated (both precise and noisy) data.

Superselective Radioembolization of Hepatocellular Carcinoma: 5-Year Results of a Prospective Study

1994 ◽  
Vol 33 (05) ◽  
pp. 206-214 ◽  
Author(s):  
J. Triller ◽  
H. U. Baer ◽  
Livia Geiger ◽  
H. F. Beer ◽  
C. Becker ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Survival Rates ◽  
Absorbed Dose ◽  
Pulmonary Complications ◽  
Pulmonary Shunt ◽  
Recurrent Tumour ◽  
Activity Distribution ◽  
A Prospective Study ◽  
Overall Survival Rates

SummaryTwenty patients with unresectable hepatocellular carcinoma (HCC) were followed up to 5 years after transarterial radiotherapy with 90Y-resin particles. Diagnostic radioembolizations of 99mTc-macroaggregates facilitated scintigraphic assessment of activity distribution, dose evaluation and final procedural verification. The overall survival rates were 56, 38 and 14% (after 1, 2 and 3 years, resp.). Patients with unifocal HCC and a single feeding artery (n = 7) even presented 83, 67 and 40% (2 alive after 2.75 and 4 years). With multiple arteries (n = 7), the longest survival was 26 months. Patients with multifocal HCC survived up to 33 months after selective radioembolization. Quality of life was improved in all. Survival was positively correlated with absorbed dose but residual/recurrent tumour occurred even after ≥300 Gy. Post-treatment symptoms were minimal (35 applications), pulmonary shunt rates were correctly predicted and pulmonary complications avoided.

Modelling of catalyst pellet deactivation

1985 ◽  
Vol 50 (11) ◽  
pp. 2381-2395
Author(s):  
Alena Brunovská ◽  
Ján Buriánek ◽  
Ján Ilavský ◽  
Ján Valtýni
Keyword(s):  
Experimental Data ◽  
Numerical Results ◽  
Benzene Hydrogenation ◽  
Alumina Catalyst ◽  
Temperature Changes ◽  
Catalyst Pellet ◽  
Model Equations ◽  
Catalytic Poison

The diffusion and the shell progressive models of deactivation caused by irreversible chemisorption of a catalytic poison are presented for a single catalyst pellet. The method for solution of the model equations is proposed. The numerical results are compared with experimental data obtained by measuring concentration and temperature changes due to thiophene poisoning in benzene hydrogenation over a nickel-alumina catalyst.

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