Chemical Engineering

PART I - Fundamentals of risk analysis 1 Nomenclature and definitions. The concept of risk. Risk in the chemical process industry. Its measure and representation. (2h) 2 Risk sources. Accident scenarios. Techniques for hazard identification: check-list, HazOp, FMECA, Fault Tree Analysis (FTA) and Event tree Analysis (ETA). Criteria for selection and areas of application. Examples of application. (12h) 3 Consequence analysis and effects models. Release models. Generalities for two-phase flows. Dispersion models for toxic chemicals: Gaussian models and dense gas models. Fires models: pool-fire, jet-fire, flash fires and fireball. Explosion models: physical explosions, BLEVEs, Vapour Cloud Explosions, confined explosions. Threshold values and probit equations. (20h) 4 Frequency and probability estimation. Historical analisys. Alternative techniques: costruction, qualitative and quantitative analyses of FTA and ETA. Examples of application. (9h) 5 Risk measures and their representation. Criteria for selection and presentation methods of the risk estimations. Tolerability criteria and risk assessment. (8h) 6 Generalities on domino effects. (1h) PART II - Prevention and protection systems 7 Safety systems. Emergency procedures, active and passive systems. Basic concepts on inherent safety. (4h) 8 Typical accidental scenarios for the main equipment of the process industry. Corresponding safety systems. (6h) 9 Typology, characteristics, selection and placement of relief devices. Relief valves, rupture disks and their combinations. Relief systems, depressuring systems, and their sizing. (12h) 10 Containment and handling systems: atmospheric discharge, headers, phase separators, quenching, absorbption, flares. (10h) 11 Basic concepts on fire systems and firefighting techniques (2h) PARTE III – Analysis of historical cases (4h) Note: the indicated hours include practical exercises

Mandatory pre-requisites for a fruitful comprehension of the topics taught during the lectures are a good knowledge of the fundamentals of thermodynamics (chemical, physical and thermodynamic properties of materials, concept of fluid phase equilibrium, thermodynamic processes, etc.). A general knowledge of design and operating principles of the main chemical process equipment items can be very useful and it is strongly suggested

1. Lecture notes 2. Daniel A. Crowl ; Joseph F. Louvar, "Chemical process safety : Fundamentals with applications" /. ‐ 2. ed. ‐ Upper Saddle River : Prentice Hall 3. Center for Chemical Process Safety: "Guidelines for chemical process quantitative risk analysis" /. ‐ 2. ed. ‐ New York. AIChE 4. CCPS (Center for Chemical Process Safety), 2008a, Guidelines for hazard evaluation procedures, 3rd Edition, Wiley Interscience, New York

The course will entirely consists of face-to-face lectures, both theoretical and hands-on practical applications. Theory classes will provide students with the basic knowledge about the main techniques adopted for the risk assessment of chemical process plants. The various alternative techniques will be illustrated, the main selection criteria will be discussed and finally the methods of application will be shown. The theory lessons will be followed by practical examples of application where both simple and more complex practical problems will be solved by the students, either individually and collectively, based on the knowledge gained during the theory classes. This will provide students with the necessary ability of properly analysing and solving a practical case study, as well as introducing, if required, the necessary modifications in the different methodologies presented, to adapt them to the specific case under examination. At the same time, the adopted teaching methodology is expected to allow students to get a better collaborative skill and the capability of presenting the obtained results.

Attending the course is not mandatory and students can get a basic knowledge of the topics covered by their own, by studying the suggested textbooks and similar reading. Nonetheless, also based on past experience, it is believed that attending the lectures, and expecially the practical classes, will allow students to get the required skill in selecting and applying the theoretical background to a practical case. This is also an important self-check of their ability and, under this respect, attending the course is highly suggested.

The written exam aims at assessing the student's capability in applying the theoretical methodologies presented during the lectures to a specific study-case. The test will last approximately 1.5 h and will consist in the numerical solution, possibly with the help of graphical-logical models (e.g. logic trees), of a problem with given data. The problem will be solved by students individually, possibly using any kind of documentation deemed useful by the student (textbooks, notes, etc.), excluding external communication devices such smarthpone etc. The oral exam (optional) will focus on specific aspects of the learnt methodologies and aims at assessing their comprehension level, also including their reliability, their limits of application, their possible underlying simplifying hypotheses and available alternatives. Foreign students can take the exam in English, upon request.

1. American Petroleum Institute: Recommended Practice RP 520 e 521 2. F.P. Lees, Loss prevention in the process industry, 3rd Ed., Vol. 3 3. CCPS (Center for Chemical Process Safety) 2000. Guidelines for pressure relief and effluent handling systems (2nd Ed.). American Institution of Chemical Engineers, New York. ISBN: 978-0-470-76773-3

The course will entirely consist of face-to-face lectures, both theoretical and hands-on practical applications. Theory classes will provide students with the basic knowledge about the main techniques adopted for the risk assessment of chemical process plants. The various alternative techniques will be illustrated, the main selection criteria will be discussed and finally the methods of application will be shown. The theory lessons will be followed by practical examples of application where both simple and more complex practical problems will be solved by the students, either individually and collectively, based on the knowledge gained during the theory classes. This will provide students with the necessary ability of properly analysing and solving a practical case study, as well as introducing, if required, the necessary modifications in the different methodologies presented, to adapt them to the specific case under examination. At the same time, the adopted teaching methodology is expected to allow students to get a better collaborative skill and the capability of presenting the obtained results.