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.
Case History: A Batch Polystyrene Reactor Runaway
Sponsor: Ron Willey (Northeastern University)
This case history describes a runaway reaction that occurred in a batch reactor manufacturing polystyrene. Companies now use semi-batch reactors (or stepwise addition of reactants) for such highly exothermic reactions. This case history emphasizes the importance of carefully analyzing and controlling exothermic reactions. When control is lost, the consequences can be catastrophic – for this case, a large fire due to an uncontrolled release of a flammable material, or to large reactor explosions (a nitroaniline reactor explosion case history in another SACHE product).
In this case study, lessons learned include:
- use of redundant process control equipment with audible alarms,
- use of semi-automated discharge systems,
- maintenance of critical process control equipment,
- develop, manage, and test emergency procedures,
- understand the hazardous characteristics of exothermic reactions,
- understand that semi-batch reactors should be used for highly exothermic reactions, and
- use of the Dow Fire and Explosion Index to identify and eliminate potential design and operating problems.
This case history is in a PowerPoint format that includes notes. The presentation can be used in reactor kinetics or design courses.
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.
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.
Conservation of Life: Application of Process Safety Management
Sponsor: J. Klein (DuPont)
This SACHE product introduces “conservation of life” (COL) as a fundamental principle of chemical engineering design and practice, equivalent in importance to conservation of energy and mass. This presentation provides a good introduction to application of process safety and provides an overall structure for consideration of process safety by students.
COL principles that are discussed include:
- Assess material/process hazards
- Evaluate hazardous events
- Manage process risks
- Consider real-world operations
- Ensure product sustainability.
Most of the presentation is spent on the first three principles, which are most important to chemical engineering design and education, but all principles are introduced. Important factors for assessment of toxicity, flammability, reactivity, and dust hazards are provided. Use of PHAs, layers of protection, inherently safer methodologies, and human factors for managing process risk are highlighted. The “Swiss Cheese Model” is also introduced to consider how layers of protection can fail, potentially leading to catastrophic incidents such as the Deepwater Horizon oil spill in 2010.
This product can be used in the university (introductory engineering, design, or kinetics courses) or for the introduction of process safety for new industrial employees. COL can be used by universities as a concept and unifying theme for increasing awareness, application, and integration of process and product safety throughout the chemical engineering curriculum and for meeting the revised ABET accreditation criteria.
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.