CHIM0695-2

Duration

20h Th, 45h Pr

Number of credits

	Master in chemical and materials engineering (120 ECTS)	4 crédits

Lecturer

Grégoire Léonard

Language(s) of instruction

English language

Organisation and examination

Teaching in the first semester, review in January

Units courses prerequisite and corequisite

Prerequisite or corequisite units are presented within each program

Learning unit contents

The course proposes an introduction to the general principles of modeling and applies these principles to the field of process engineering.
First, the objectives, usefulness and limitations of modeling and simulation are presente. The methodology for building a model is exposed, proceeding via the identification of a conceptual model and its implementation into a simulation model. The key elements of the conceptual model are discussed: balance equations, fundamental laws, constraints and specifications, degrees of freedom. It is then discussed how this general modeling procedure applies to solving process flowsheets.
In the next chapters, the selection of an appropriate method for predicting the thermodynamic properties of mixtures observed in chemical engineering processes is recalled. Then, the modeling of typical unit operations in process engineering is presented: reactors, heat exchangers, distillation units, flash tanks... Different approaches are also compared for solving process flowsheets, relying either on the simultaneous solving of all equations (equations oriented) or on the use of a physical stream sequence in the process (sequential modular). The principle of process tearing to facilitate iterative flowsheet solving is described and methods are proposed to identify optimal tear streams. Numerical methods typically used in chemical engineering to solve equations are also described (Newton, Wegstein, Broyden...). Moreover, the course also introduces the analysis of the energy supply and demand in a chemical process and their representation under the form of composite curves. Finally, the modeling applied to chemical engineering is illustrated by studying CO2 capture, re-use and storage technologies.
Besides theoretical classes, the use of process models is trained in commercial software packages (Aspen Tech), leading to solve typical problems observed in the industry.

Learning outcomes of the learning unit

In this course, students will gain theoretical and practical knowledge in order to be able to develop, calibrate and efficiently use mathematical models in general, and for chemical engineering processes in particular.
They will first learn the different steps in the construction of a general model, and apply this methodology for chemical engineering processes. They will be able to select a relevant thermodynamic model to predict the properties of a chemical system. They will learn how to build a conceptual model for single physical unit operations, identifying specifications, characteristic variables, and the resulting degrees of freedom. They will be able to include these bloc models into a flowsheet model and to propose a solving architecture based on the sequential modular approach, including the identification of tear streams. They will be able to select adapted numerical methods to solve industrial processes models.
The heat integration part of this course aims at gaining skills in the analysis of the performances of a heat exchanger network as well as in the synthesis and design of such system. Students will be able to represent the thermal energy requirement of a process under the form of composite curves. On that basis, they must be able to identify the potential of energy-saving technologies like: combustion air pre-heating, oxygen-enriched combustion, limitation of the excess air, pressure change in boilers and condensers, use of heat pumps or refrigeration cycles, integration of thermodynamic cycles (cogeneration). Based on the composite curves, students must be able to design efficient heat exchanger networks (selection of heat transfer fluids and decision about the amount of heat to be transferred) that maximize the energy re-use.
From the practical works, the students will learn to use the simulation tool Aspen Plus and they will get an introduction to Aspen Hysys. They will test the limits of modeling and train their understanding of chemical engineering processes thanks to the use of simulation models.

Prerequisite knowledge and skills

Pre-requisite :
Thermodynamique chimique appliquée, CHIM0009
Introduction au génie chimique et aux procédés industriels, CHIM9306
Introduction to numerical analysis MATH0006
Basics of heat exchangers, fuels use, thermodynamic cycles, refrigeration.

Co-requisite :
Physical unit operations I, CHIM9299

Planned learning activities and teaching methods

Theoretical classes will give students an insight in the basics of modeling with particular application to the modeling of chemical engineering processes. During the heat integration part of the lectures, the theoretical basics of energy integration are presented and illustrated through simple examples. Students must perform an individual work: design of a heat exchanger network to maximize the energy recovery for a process with known energy demand and supply.
In parallel to the lectures, practical classes will be held with the objectives of training the use of simulation software. Students will work in groups of 2, using commercial simulation tools.

Mode of delivery (face-to-face ; distance-learning)

Course held in the first semester. Lectures (2h/week) and practical classes (4h/week).

Assessment methods and criteria

Practical classes reports (by groups of 2, 40% of the final note).
Written examination (60% of the final note).
It is necessary to achieve a note of minimum 8/20 for each part (practical classes and theory) to pass the class. The note of the practical classes can be kept for the second session. No second session is organised for the practical classes.

Work placement(s)

Organizational remarks

Contacts

1) Grégoire Léonard (G.Leonard@ulg.ac.be)
2) Marie-Noëlle Dumont (mn.dumont@ulg.ac.be)

Introduction to the modelling of chemical processes