Contents
Seveso Accidental Release Case History
Sponsor: Ronald J. Willey (Northeastern University)
This presentation describes a widely discussed case history that illustrates how minor engineering errors can cause significant problems; problems that should not be repeated. The accident was in Seveso, Italy in 1976. It was a small release of a dioxin that caused many serious injuries.
The package can be used in an undergraduate classroom or an industrial training session. The package can be modified to fit different contexts including: reaction engineering (runaway reactions), heat transfer (heat transport from the reactor walls to the liquid), mass transfer (the resultant dispersion of material from a release), and reaction stoichiometry. The entire module can be presented in about 50 minutes.
The Seveso case history is an especially good teaching module, showing how a minor problem and a minor release can cause very serious injuries. The root cause of this release included a poor engineering design, operator negligence, and poor supervision. The intent of this teaching module is to motivate engineers and supervisors to pay attention to the details.
This product includes five excellent problems and solutions that illustrate the lessons to be learned from this case history. The problems can be used in the following courses: a) Stoichiometry, b) Thermodynamics, c) Kinetics, d) Heat Transfer, and e) Ethics. Or they can be used in industrial training sessions in the areas of process design and engineering management.
Seminar on Fire
Sponsor: Reed Welker and Charles Springer (University of Arkansas)
This Powerpoint presentation (with notes) covers fundamentals of fires and explosions and is recommended as an introduction to the subject including such topics as:
- technical definition of fires and explosions,
- physical characteristics of various fires,
- necessary conditions for fires and explosions, and
- elementary properties, such as flammability limits (LFL and UFL), minimum oxygen concentration (MOC), minimum ignition energy (MIE), flame speeds, burning rates, etc.
The limiting factor in burning most liquids and solids is the rate of evaporation (liquid) and pyrolysis (solid), and so the burning rates of liquids and solids are dependent on the heat transfer back to the fuel and are functions of the radiant properties of the flame, the energy absorbing properties of the fuel, and the flame temperature. The burning rate of gas is dependent on the fuel release rate. Gases are easy to ignite and solids are relatively difficult to ignite, but dusts are a special class of solids that are easily ignited. Pictures are included of pool fires, BLEVEs, and extinguishing pool fires.
This product helps prepare engineers to design systems that reduce the probability of fires and explosions. Some coverage also discusses the design methods used to mitigate fires (venting, fire proofing, fire suppression, etc.), and provides references for safe designs (NFPA, CCPS. etc.).
Runaway Reactions - Experimental Characterization and Vent Sizing
Sponsor: Ron Darby (Texas A&M University)
This module is an updated and revised version of the module entitled “A Unit Operations Laboratory Experiment for Runaway Reactions”, published by SACHE in 2001. The title has been changed to reflect the more general utility of the module for education, training and instruction of personnel in industrial, governmental or other laboratories who are concerned with the characterization and sizing of relief vents for runaway reactions, in addition to universities who would like to include this subject matter in lecture and/or laboratory courses concerned with process safety.
The Advanced Reactive Screening Tool (ARSST) is an easy to use and cost effective calorimeter that can be used to quickly and safely identify potential chemical reactivity hazards. It can also yield critical experimental data on the kinetic characteristics of runaway reactions that can be scaled up to full scale process conditions and can be used directly to estimate the size of a relief device that would be required to protect the reactor against the over-pressure that would result from a runaway reaction.
This instruction module describes the ARSST and its operation, and illustrates how this instrument can easily be used to experimentally determine the transient characteristics of runaway reactions, and how the resulting data can be analyzed and utilized to size the relief vent for such systems. It can also be easily incorporated into a Chemical Engineering Unit Operations Laboratory as an effective educational laboratory experiment utilizing a practical and physically realistic example reactive system.
Reactive and Explosive Materials
Sponsors:
R. Willey (Northeastern University)
J. F. Louvar (Wayne State University)
This module is an updated and revised version of the module entitled “A Unit Operations Laboratory Experiment for Runaway Reactions”, published by SACHE in 2001. The title has been changed to reflect the more general utility of the module for education, training and instruction of personnel in industrial, governmental or other laboratories who are concerned with the characterization and sizing of relief vents for runaway reactions, in addition to universities who would like to include this subject matter in lecture and/or laboratory courses concerned with process safety.
The Advanced Reactive Screening Tool (ARSST) is an easy to use and cost effective calorimeter that can be used to quickly and safely identify potential chemical reactivity hazards. It can also yield critical experimental data on the kinetic characteristics of runaway reactions that can be scaled up to full scale process conditions and can be used directly to estimate the size of a relief device that would be required to protect the reactor against the over-pressure that would result from a runaway reaction.
This instruction module describes the ARSST and its operation, and illustrates how this instrument can easily be used to experimentally determine the transient characteristics of runaway reactions, and how the resulting data can be analyzed and utilized to size the relief vent for such systems. It can also be easily incorporated into a Chemical Engineering Unit Operations Laboratory as an effective educational laboratory experiment utilizing a practical and physically realistic example reactive system.
Explosions
Sponsor: Reed Welker (University of Arkansas)
This SACHE product covers the fundamentals of explosions and some practices necessary for preventing explosions. The 35 minute video includes:
- Pictures showing the consequences of explosions.
- Discussion of definitions, such as auto-ignition temperature (AIT), lower and upper flammability limits (LFL/UFL), minimum ignition energy (MIE), limiting oxygen concentration (LOC), flash point (FP), etc.
- The distinction between physical and chemical explosions.
- Detailed discussions covering boiling liquid expanding vapor explosions (BLEVES), dust explosions, deflagrations, and detonations.
The video can be used as an introduction to a lecture on explosions, or given to students for self study prior to a more detailed discussion in a classroom setting. This product can be used in universities or industrial training sessions. In the university, it can be used in various courses such as design, thermodynamics, kinetics, or a safety course. In industry, it can be used for new engineers as an introduction to chemical process safety.
The recommended practices and related references include:
- Explosion prevention technology, such as reliefs, venting devices, etc.
- Codes and Standards – NFPA, ASME, and API.
- Textbooks, CCPS Guidelines, Periodicals, Short Courses, and SACHE materials.
Properties of Materials
Sponsor: Ronald J. Willey (Northeastern University)
This SACHE product provides an elementary explanation of several important properties of materials and their relationship to chemical process safety. It is intended for chemical engineering students in their second or third year of undergraduate training. It is assumed that the students have had limited industrial experience. This product can also be used for training (or retraining) of young engineers and/or plant operators.
This product includes explanations concerning:
- Material Safety Data Sheet (MSDS)
- Flammability, Explosive and Toxicity Properties
- Flammability Classifications
- NFPA Stability Ratings, and
- Detailed references for more advanced information
Safety, Health, and Environmental Text for Textbooks
Sponsors:
S. Horsch (Wayne State University)
M. Horsch (University of Michigan) J. Louvar (Wayne State University)
SACHE's objectives are to:
- assist professors to add safety, health, and environmental (SHE) concepts to the core courses of all chemical engineering departments
- assist professionals to appreciate the importance of SHE concepts in university and company environments
- help companies to improve their safety and environmental performance
The genesis of this product was at a Faculty Workshop where a group professors made the following remark: 'The best way for professors to add SHE concepts to their courses is to have these materials in their textbooks.' This product, consequently, was developed to help authors to add safety, health, and environmental concepts to their textbooks. The subjects addressed include:
- Kinetics
- Thermodynamics
- Stoichiometry
- Mass Transport
- Heat Transport
- Design
This product has three major sections:
- Text with Examples to embed into the chapters of textbooks
- Problems and Solutions for the end of the chapters
- SHE related Figures that can be added anywhere within textbooks and/or for enhancing lectures
The materials were primarily adapted from existing SACHE products.
Chemical Reactivity Hazards
Sponsor: Robert Johnson (Unwin Co.)
This web-based instructional module contains about 100 web pages with extensive links, graphics, videos, and supplemental slides. It can be used either for classroom presentation or as a self-paced tutorial. The module is designed to supplement a junior or senior chemical engineering course by showing how uncontrolled chemical reactions in industry can lead to serious harm, and by introducing key concepts for avoiding unintended reactions and controlling intended reactions. The five main sections in the module cover (1) three major incidents that show the potential consequences of uncontrolled reactions; (2) how chemical reactions get out of control, including consideration of reaction path, heat generation and removal, and people/property/environmental response; (3) data and lab testing resources used to identify reactivity hazards, (4) four approaches to making a facility inherently safer with respect to chemical reactivity hazards; and (5) strategies for designing facilities both to prevent and to mitigate uncontrolled chemical reactions. The module concludes with a ten-question informative quiz. An extensive Glossary and Bibliography are directly accessible from any page.
Mini-Case Histories
Joe Louvar and Durai Dakshinamoorthy (Wayne State University)
This product emphasizes learning from history or being doomed to repeat it. It includes three sections:
- Mini-Case Histories
- Process Safety Beacon
- Safety Concepts
as described below:
Mini-Case Histories: There are eight PowerPoint presentations, with notes, that cover the accidents at Bhopal, Monsanto, Phillips, Flixborough, Morton, Tosco, Hickson, and Sonat. The root causes of each accident are included, such as, poor designs, lack of training, and poor management. The information summarized in these case histories was taken from SACHE products, and reports by the Chemical Safety Board.
Process Safety Beacon: The Center for Chemical Process Safety is publishing monthly, one-page case histories or lessons learned. They are available on the Internet via CCPS Beacon. A few of the Beacons are included in this product to remind readers that these lessons are available.
Safety Concepts: This product includes six PowerPoint presentations: Relief Valves; Prevent Runaway Reactions; Manage Design, Construction, and Operations; BLEVEs; Explosions; and Prevent Explosions. The concepts covered are those that are especially relevant to chemical plant accidents.
The Mini-Case Histories and Safety Concepts were developed in a PowerPoint format to give users the opportunity to add slides or lessons as desired.
Rupture of a Nitroaniline Reactor
Sponsor: Ronald J. Willey (Northeastern University)
This case study of the rupture of a nitroaniline reactor demonstrates safety concepts that are especially important to both new and experienced engineers including:
- Runaway reactions need to be understood and appropriately controlled to prevent major losses.
- A Safety review is an important process for identifying potential problems and developing approaches to solve the problems.
- Redundant controls are needed in critical applications.
- Relief systems consisting of a rupture disk followed by a spring operated relief valve must be properly installed and maintained.
- Training operators and engineers to recognize the consequences of operating errors is important.
- Management decisions to override safety systems must be thoroughly thought through before implementation of such action.
The lessons of this product are very important, and they will be true and relevant forever. The PowerPoint presentation in this product includes problems (with solutions for the instructor). A pdf document provides background for the presentation.
Consequence Modeling Source Models I: Liquids & Gases
Sponsor: Jan Wagner (Oklahoma State University)
This module was developed to help introduce issues of safety and loss prevention in undergraduate engineering courses. Each of the five major sections can be used independently, depending on the student's backgrounds.
- Section 1 is an introduction to the role of source models in the risk assessment process.
- Section 2 introduces the basic information required to select or develop an appropriate source model for a given release scenario.
- The fundamental concepts of the 1st Law of Thermodynamics, the mechanical energy balance, and friction losses in pipes and fittings are reviewed briefly in Section 3.
- Section 4 deals with flow of liquids in pipes and orifices. The example problems are intended to introduce loss prevention issues, and they can be used in any fluid mechanics class.
- Section 5 presents the flow of ideal gas in orifices and pipes. This material may be appropriate in fluid mechanics or thermodynamics classes. The derivations of equations for compressible flow are intended to show the relationships between physical phenomena and the mathematical model; the fundamental concepts apply to ideal and real gases.
The module resources include text, accompanying PowerPoint presentations, student homework problems, and an instructor's solution manual.
Solutions to Student Problem Set Volume 1
Sponsors: J. R. Welker and C. Springer (University of Arkansas)
"Safety, Health, and Loss Prevention in Chemical Processes - Problems for Undergraduate Engineering Curricula" Volume 1 was originally published by CCPS in 1990. Copies were given to universities and sold to industry. This was a very popular and valued product that is currently out of print. J. Wagner (Oklahoma State University) recently put this product in electronic format for distribution here. The problems are available via the Links menu on this site and to students logged into the site.
The 90 problems involve issues of safety, health, and loss prevention and provide students and new engineers with important insights to industrial processes. This material can also be used as a reference for industrial courses for new engineering employees. These safety problems and solutions further demonstrate that safety and health issues are handled with basic engineering principles and logic. Finally, through the use of this material, we hope to instill in students and engineers an increased recognition of the importance of chemical process safety and the recognition that they have the professional and ethical responsibility to provide safe chemical plants, processes and products.
The problems were designed to use in existing engineering courses, such as: stoichiometry, material balance, mass transfer, heat transfer, thermodynamics, process control, and design courses. The authors believe that it is important that students work on these problems while attending there undergraduate courses and throughout their education. This process should develop a safety culture within engineers that will help them throughout their careers.
Solutions to Student Problem Set Volume 2
Sponsors:
R. Willey (Northeastern University)
D. Crowl (Michigan Tech University)
R. Welker (University of Arkansas)
R. Darby (Texas A&M University)
"Safety, Health, and Loss Prevention in Chemical Processes - Volume 2" was originally published by CCPS in 2002 and distributed to SACHE University Members. This was a very popular and valued product that is now out of print. R. Willey recently put this volume in electronic form for distribution here.
Like the Volume 1 problems, the 218 problems teach safety, health, and loss prevention. This solution set represents problems and solutions produced by SACHE in the period 1990 to 2000.
The problems were designed for use in existing engineering courses, such as: Stoichiometry, Thermodynamics, Fluid Mechanics, Kinetics, Heat Transfer, Process Dynamics and Control, Computer Solutions, and Mass Transfer. The authors believe that including these problems in a required undergraduate course helps engineering students develop a safety culture and mind set that will benefit them throughout their careers.
Student AIChE 2002 Design Problem Solution
Sponsors:
S. Horsch and J. Louvar (Wayne State University)
J. Wehman (BASF Corporation, retired)
This product includes a solution to the 2002 AIChE Design Problem that was developed by a student (S. Horsch) with significant assistance from very knowledgeable design professionals; these are the professionals who developed this design problem, and they have worked on this design in an industrial environment.
This product includes concepts, calculations, and drawings that can be used in future AIChE design solutions, for example:
- Relief valve calculations for gases, liquids, and two phase flows;
- Safety review including hazards and resulting safety measures to prevent accidents and inherent safety concepts and features;
- The process flow diagram (PFD) and process and instrument diagram (P&ID); and
- MathCad programs for making the design calculations.
All of the MathCad programs and Visio drawings can be copied for using in future design problem solutions. Additionally, the safety review and inherent safety discussions will be an excellent aid in the development of safety and inherent design concepts for all future AIChE design problems. The AIChE Student Chapters Committee that administers the annual AIChE Design competition approved posting of this example problem.