References of "Heyen, Georges"
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See detailSupervised learning for a Kraft recovery boiler: a data mining approach with Random Forests.
Sainlez, Matthieu ULg; Heyen, Georges ULg; Lafourcade, Sébastien

in Favrat, Daniel; Maréchal, François (Eds.) ECOS 2010 Volume IV (Power plants and Industrial processes) (2011, January 01)

A data mining methodology, the random forests, is applied to predict high pressure steam production from the recovery boiler of a Kraft pulping process. Starting from a large database of raw process data ... [more ▼]

A data mining methodology, the random forests, is applied to predict high pressure steam production from the recovery boiler of a Kraft pulping process. Starting from a large database of raw process data, the goal is to identify the input variables that explain the most significant output variations and to predict the high pressure steam flow. [less ▲]

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See detailModeling post-combustion CO2 capture with amine solvents
Léonard, Grégoire ULg; Heyen, Georges ULg

in Computer Aided Chemical Engineering (2011), 29

Carbon capture and storage is a technology that can contribute to face the challenge of rising energy demand combined with a growing environmental awareness. In the present work, the CO2 capture process ... [more ▼]

Carbon capture and storage is a technology that can contribute to face the challenge of rising energy demand combined with a growing environmental awareness. In the present work, the CO2 capture process with monoethanolamine (MEA) is modeled using the simulation tool Aspen Plus. Two different modeling approaches are studied and compared: the equilibrium and the rate-based approaches. An optimization of key process parameters is performed and process modifications are studied with the objective of improving the global process energy efficiency. [less ▲]

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See detailExperimental procedure and statistical data treatment for the kinetic study of selective hydrodechlorination of 1,2-dichloroethane into ethylene over a Pd-Ag sol–gel catalyst
Pirard, Sophie ULg; Pirard, Jean-Paul ULg; Heyen, Georges ULg et al

in Chemical Engineering Journal (2011), 173(3), 801-812

The kinetics of selective hydrodechlorination of 1,2-dichloroethane into ethylene over a Pd- Ag/SiO2 catalyst was studied using an a priori experimental design with five independent variables—temperature ... [more ▼]

The kinetics of selective hydrodechlorination of 1,2-dichloroethane into ethylene over a Pd- Ag/SiO2 catalyst was studied using an a priori experimental design with five independent variables—temperature and partial pressures of 1,2-dichloroethane, hydrogen, ethylene and hydrogen chloride. A Langmuir–Hinshelwood model including two types of active site and the 1,2-dichloroethane adsorption as the rate-determining step was found to fit correctly with experimental data, according to the analysis of variance and the analysis of pondered residuals. The study allowed for catalytic deactivation. The rigorous experimental and statistical approach followed to carry out such a kinetic study is explained in detail. [less ▲]

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See detailOptimisation du procédé de captage de CO2 dans des solvants aminés
Léonard, Grégoire ULg; Heyen, Georges ULg

in Récents Progrès en Génie des Procédés (2011), 101

Post-combustion carbon capture in amine solvents is currently one of the most promising technologies to prevent large quantities of CO2 from being emitted into the atmosphere. Two models (equilibrium and ... [more ▼]

Post-combustion carbon capture in amine solvents is currently one of the most promising technologies to prevent large quantities of CO2 from being emitted into the atmosphere. Two models (equilibrium and kinetics) have been built using the Aspen Plus software in order to optimise the capture process. A sensitivity study at constant CO2 capture rate has shown that the solvent concentration, its flow rate and its regenerating pressure have the largest influence on the process energy requirement. Different process flowsheet modifications such as the lean vapor compression, an absorber inter-cooling and the split-flow configuration have been simulated as well, decreasing the energy cost of the process. Tests on a pilot installation will be made that will help to validate this model. [less ▲]

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See detailRecurrent neural network prediction of steam production in a Kraft recovery boiler
Sainlez, Matthieu ULg; Heyen, Georges ULg

in Pistikopoulos, E. N.; Georgiadis, M. C.; Kokossis, A. C. (Eds.) 21st European Symposium on Computer Aided Process Engineering (Part B) (2011)

In this paper, neural networks approaches are compared for predicting the high pressure (HP) steam flow rate from a Kraft recovery boiler. We apply two types of neural networks: a static multilayer ... [more ▼]

In this paper, neural networks approaches are compared for predicting the high pressure (HP) steam flow rate from a Kraft recovery boiler. We apply two types of neural networks: a static multilayer perceptron and a dynamic Elman’s recurrent neural network. Starting from a one-day database of raw process data related to the boiler, the goal is to model and predict the next 12-hours of HP steam flow production from the boiler to the steam turbine. The results illustrate the potential of the dynamic approach in this task. [less ▲]

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See detailSupervised learning for a Kraft recovery boiler: a data mining approach with Random Forests.
Sainlez, Matthieu ULg; Heyen, Georges ULg; Lafourcade, Sébastien

Conference (2010, June)

A data mining methodology, the random forests, is applied to predict high pressure steam production from the recovery boiler of a Kraft pulping process. Starting from a large database of raw process data ... [more ▼]

A data mining methodology, the random forests, is applied to predict high pressure steam production from the recovery boiler of a Kraft pulping process. Starting from a large database of raw process data, the goal is to identify the input variables that explain the most significant output variations and to predict the high pressure steam flow. [less ▲]

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See detailModeling post-combustion CO2 capture with amine solvents
Léonard, Grégoire ULg; Heyen, Georges ULg

Conference (2010)

Oral communication at the Cape-forum, Aachen, 2010. Modeling CO2 capture process and optimization of some process parameters with an equilibrium-based model.

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See detailModeling post-combustion CO2 capture with amine solvents
Léonard, Grégoire ULg; Heyen, Georges ULg

Poster (2010)

In order to avoid the emission of large amounts of greenhouse gas, CO2 capture in fossil fuel power plants and subsequent underground CO2 sequestration is studied. The capture occurs by reactive CO2 ... [more ▼]

In order to avoid the emission of large amounts of greenhouse gas, CO2 capture in fossil fuel power plants and subsequent underground CO2 sequestration is studied. The capture occurs by reactive CO2 absorption into chemical solvent systems at moderate temperature (~50°C) followed by solvent regeneration at higher temperature (~120°C). So far, the most employed solvent for acid gas capture is monoethanolamine (MEA). One main drawback of this technology is the high energy consumption necessary to regenerate the solvent. In the present work, the CO2 capture process with MEA is modeled using the simulation tool Aspen Plus®. The base case process is optimized and some process improvements are studied that imply a significant decrease of the process exergy consumption. [less ▲]

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See detailQuantitative study of catalytic activity and catalytic deactivation of Fe–Co/Al2O3 catalysts for multi-walled carbon nanotube synthesis by the CCVD process
Pirard, Sophie ULg; Heyen, Georges ULg; Pirard, Jean-Paul ULg

in Applied Catalysis A : General (2010), 382

The catalytic deactivation during multi-walled carbon nanotube (MWNT) synthesis by the CCVD process and the influence of hydrogen on it were quantified. Initial specific reaction rate, relative specific ... [more ▼]

The catalytic deactivation during multi-walled carbon nanotube (MWNT) synthesis by the CCVD process and the influence of hydrogen on it were quantified. Initial specific reaction rate, relative specific productivity and catalytic deactivation were studied. Carbon source was ethylene, and a bimetallic iron–cobalt catalyst supported on alumina was used. The catalytic deactivation was modeled by a decreasing hyperbolic law, reflecting the progressive accumulation of amorphous carbon on active sites. While the initial specific reaction rate was found not to be influenced by hydrogen, catalytic deactivation was found to be modified in the presence of hydrogen, which delayed and slowed down the deactivation by avoiding amorphous carbon deposition, thus leading to a greater relative specific productivity of carbon nanotubes. [less ▲]

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See detailPerformance monitoring of an industrial boiler: classification of relevant variables with Random Forests
Sainlez, Matthieu ULg; Heyen, Georges ULg

in Pierucci, Sauro; Ferraris, Guido Buzzi (Eds.) 20th European Symposium on Computer Aided Process Engineering – ESCAPE20 (2010)

A data mining methodology, the random forests, is applied to analyze pollutant emission from the recovery boiler of a Kraft pulping process. Starting from a large database of raw process data, the goal is ... [more ▼]

A data mining methodology, the random forests, is applied to analyze pollutant emission from the recovery boiler of a Kraft pulping process. Starting from a large database of raw process data, the goal is to identify the input variables that explain the most output variations. [less ▲]

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See detailAdaptation and testing of data reconciliation software for CAPE-OPEN compliance
Radermecker, Eric; Dumont, Marie-Noëlle ULg; Heyen, Georges ULg

in Computer Aided Chemical Engineering (2009), 26

The experience gained in the development of a CAPE-OPEN 1.0 thermo socket for the BELSIM-VALI software is presented. A material object has been developed and interfaced with the modelling code. The user ... [more ▼]

The experience gained in the development of a CAPE-OPEN 1.0 thermo socket for the BELSIM-VALI software is presented. A material object has been developed and interfaced with the modelling code. The user interface has been adapted. Several case studies were analysed, with performance comparison between the native thermodynamic model, and properties obtained from several CAPE-OPEN thermo plugs. [less ▲]

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See detailPropulsion vehicle integration for reusable launcher using in-flight oxygen collection
Bizzarri, D.; Hendrick, Patrick ULg; Heyen, Georges ULg et al

in Aerospace Science and Technology (2008), 12(6), 429-435

The use of in-flight oxygen collection has shown to significantly improve space launcher performance. The conceptual approach followed by Belgian teams working on oxygen collection has been to try to ... [more ▼]

The use of in-flight oxygen collection has shown to significantly improve space launcher performance. The conceptual approach followed by Belgian teams working on oxygen collection has been to try to widening the available design margins in order to reduce the required technological leap and limit the economical risk associated with such a development. The aim of the ESA-funded theoretical and experimental study on an air separation device is to demonstrate the possibility of performing efficient air distillation in a compact rotating column. An integration of the vehicle, propulsion system and separation unit designs is presented. The objective is to optimise the overall vehicle performance while keeping technological difficulty and system complexity at a reasonable level. Reference vehicles are presented within their specific mission profiles with an emphasis on TSTO's. Different layouts of the internal energy and mass flowsheets have been studied and were compared in order to make best use of the refrigeration capacity of the hydrogen fuel running through the propulsion system during the first phase of the flight. In those flowsheets, the separator is considered as a classical distillation tray column. That analysis provides the requirements in terms of heat exchange capacity, compression ratios and number of so-called transfer units needed in the separator. The system is intentionally kept simple to limit complexity, but the analysis is thorough and accurate, including, for example, the effect of the presence of argon. Results for a supersonic carrier are presented. A compact separation unit has been designed in order to reach those requirements. That includes internals, practical building with estimates of pressure drops, separation performance and flow limitation. Main results are given, sizing of the separator bed is provided for a carrier plane showing that such on-board separator is indeed practical. (C) 2007 Elsevier Masson SAS. All rights reserved. [less ▲]

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See detailOptimization of experimental procedure and statistical data treatment for kinetics of ethylene hydrogenation on a copper-magnesia catalyst
Pirard, Sophie ULg; Heinrichs, Benoît ULg; Heyen, Georges ULg et al

in Chemical Engineering Journal (2008), 138(1-3), 367-378

This study is an example of practical application of kinetic data treatment for simultaneous model discrimination and parameter estimation. The study is applied to the hydrogenation of ethylene on a ... [more ▼]

This study is an example of practical application of kinetic data treatment for simultaneous model discrimination and parameter estimation. The study is applied to the hydrogenation of ethylene on a copper-magnesia catalyst and brings a deepened analysis about the experimental strategy by comparing several alternative strategies using a priori and sequential experimental designs. The best model corresponds to a Langmuir-Hinshelwood mechanism with non-competing adsorption of hydrogen and ethylene and where the rate-determining step is either the addition of molecularly adsorbed hydrogen or the addition of the second atom of hydrogen adsorbed dissociatively. Furthermore, the important question of knowing in practice how many designs and how many measurements per design are actually necessary to determine accurate kinetic and physico-chemical parameters, is addressed. A data correction procedure is also presented that takes catalyst deactivation into account. (C) 2007 Elsevier B.V. All rights reserved. [less ▲]

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See detailRow by row simulation of heat recovery steam generators : comparing different types of initialization as well as the LMTD and ε-NTU simulation method
Dumont, Marie-Noëlle ULg; Heyen, Georges ULg

Conference (2007, May)

We developed a model which makes it possible to simulate a boiler rows by row. This model as well uses the European approach of log mean temperature difference as the American approach of effectiveness ... [more ▼]

We developed a model which makes it possible to simulate a boiler rows by row. This model as well uses the European approach of log mean temperature difference as the American approach of effectiveness-number of transfer unit. These approaches are compared in term of results and speed of calculation. We also present the difficulties encountered and some means of circumventing them. Some cases of superheater are treated in order to illustrate our matter. [less ▲]

Detailed reference viewed: 25 (11 ULg)