Contents
T2 Runaway Reaction and Explosion
Sponsor: Ronald J. Willey (Northeastern University)
The main reason for the explosion at T2 Laboratories, Inc. was the lack of understanding of the hazards involved in dealing with a potential runaway reaction. This product emphasizes the following:
- A runaway reaction is a reaction that can no longer be controlled in the existing equipment, and exothermic reactions can run away, especially when (potentially unknown) secondary exothermic reactions can occur at higher than expected temperatures (sometime termed temperatures of no return).
- All major processes should have a complete hazard identification study completed beforehand and revisited regularly after the process is built.
The main source of information for this product is the T2 CSB report cited in the references. This product includes a PowerPoint presentation including lecture notes. An example problem based on this accident is available in the textbook by Scott Fogler entitled “Essentials of Chemical Reaction Engineering” (Prentice-Hall, 2011).
Dow Fire and Explosion Index (F&EI) and Chemical Exposure Index (CEI) Software
Sponsors:
S. Mannan (Mary Kay O’Connor Process Safety Center)
W. Smades (Dow Chemical Company)
This SACHE product covers The Dow Fire and Explosion Index Hazards Classification Guide 7th edition and Chemical Exposure Index Guide developed by The Dow Chemical Company and published by AIChE. The program was developed as a collaborative effort between the Mary Kay O'Connor Process Safety Center, The Dow Chemical Company and the American Institute of Chemical Engineers (AIChE).
F&EI is a quantitative hazard index. It is based on historical data as well as the energy potential of the materials under evaluation and the extent to which loss prevention practices are applied. F&EI helps engineers to be aware of the hazards in each process unit and facilitates decisions to reduce the severity and/or the probability of the potential incident.
The Chemical Exposure Index (CEI) provides a simple method of rating the acute health hazard to people in neighboring plants or communities due to chemical release incidents. The CEI system provides a method of ranking one hazard relative to another. The CEI is used:
- For conducting an initial Process Hazard Analysis (PHA),
- To identify recommendations to mitigate risks, and
- In Emergency Response Planning.
This product includes the programmed calculations for the Fire and Explosion Index and Dow Chemical Exposure Index. User input determines the penalties and credits used to calculate the Fire and Explosion Index. Dow CEI lets the user simulate six different and independent release scenarios (gas, liquid overfill, etc) simultaneously. The results include the airborne quantity, Chemical Exposure Index, and Hazard Distance.
Instructions for installing the software are included in the startup file.
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.
Safe Handling Practices: Methacrylic Acid
Sponsor: Ronald J. Willey (Northeastern University)
This SACHE product introduces students to the hazards of handling acrylic monomers along with safe handling practices that are relevant for handling any monomer. Acrylic monomers have some unique challenges including being corrosive and combustible with the potential for unanticipated, uncontrolled exothermic runaway reactions. The product includes five files that give an excellent introduction for handling monomers:
- SACHE Product Introduction 2009: This describes the Rohm & Haas accident including a time line.
- Tank Car Video: This is a TV news report and and Rohm and Haas description of the tank car accident with methyacrylic acid that happened on July 22, 1988. (7 minutes)
- R&H Article: This is a description of an accident investigation method as applied to the Rohm & Haas accident.
- Acrylic Monomer Handling: This is a Rohm & Haas training presentation for safely handling acrylic monomers. Although the presentation is for acrylic monomers, the seven principles described are generally applicable for handling any monomer. European Bulletin: A Safe Handling Manual for methacrylic acid developed in Europe.
Note that a MSDS (Material Safety Data Sheet) and International Safety Card (containing NIOSH safety information) are included for methacrylic acid; since this information can become stale, updated information (available on the web) should be obtained when this instructional material is used.
The Bhopal disaster: A Case History
Sponsor: Ronald J. Willey (Northeastern University)
This SACHE product summarizes the events that led to one of the most significant toxic releases that has occurred to date in the chemical process industry. This product focuses on the chemical processes involved and can best be used in a course devoted to process safety as well as in courses dealing with chemical kinetics (as an example of a runaway reaction) or related to mass transfer and atmospheric dispersion.
This product includes three resources:
- Bhopal SACHE (Adobe pdf file) includes many details of the accident scenario including descriptions of the plant (and its equipment and piping), background chemistry, and potential hazards along with detailed references.
- Bhopal SACHE Presentation (PowerPoint) includes speaker notes and includes much of the material in the word document.
- The video, “Unraveling Bhopal,” describes Bhopal with many scenes of the city, plant, and accident scenario. This 16 minute video was produced by the Union Carbide Corporation and includes details of the accident and the subsequent Union Carbide investigation illustrating the details and complexities of an accident investigation. The video is available through streaming video in BhopalDescription.pdf.
Safety in the Chemical Process Industries
Sponsor: D.A. Crowl (Michigan Tech University)
This video series entitled "Safety in the Chemical Process Industries" presents a strong introduction to the application of chemical process safety technology in an actual chemical facility. All video material was taped at the Chemical Engineering Research Department at BASF Corporation in Wyandotte, Michigan. Most of the demonstrations are given using actual process equipment in the BASF Process Development (PD) facility.
This series is designed as instructional material for undergraduate students in chemical or mechanical engineering as well as industrial engineers or chemists who are being introduced to industrial safety for the first time. This series provides significant supplementary material for an existing undergraduate chemical engineering course on chemical process safety. This series was funded by the National Science Foundation and by BASF Corporation.
Hyperlinks to streaming video sources are included in a word processing file (updated 31 January 2007). A Study Guide and Instructor's Guide were written to accompany the video, and both guides are included with this product.
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.
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.
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.
Fire Protection Concepts
Sponsor: Reed Welker (University of Arkansas)
This SACHE product introduces the fundamental concepts of fires including their extinguishment and control. This streaming video presentation consists of two parts:
Section 1: “Fundamentals of Fire Behavior” describes some of the fundamental characteristics of fires including basic definitions, the fire triangle, and reaction mechanisms. Examples of burning gases, liquids, and solids are discussed and demonstrated in addition to the difference between a premixed flame and a diffusion flame. The importance of turbulence and buoyancy is discussed along with their effects on the behavior and size of large fires. (30 minutes)
Section 2: “Fire Extinguishment and Control” describes the major aspects of fire protection systems. National Fire Protection Association fire classification is discussed. Passive and Active methods of fire control are discussed. Passive methods include inventory reduction, replacement of flammable materials, separation of process areas from storage, diking and impoundment, and fireproofing of structures. Active methods include water for extinguishment and control, regular and high expansion foams, dry chemicals, vaporizing liquids, and inerting agents. Field tests demonstrating these methods are shown. (41 minutes)
Hyperlinks to streaming video sources are included in a word processing file to view the videos.
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.
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.
Design for Overpressure and Underpressure Protection
Sponsors:
S. S. Grossel (Process Safety and Design, Inc.)
J. F. Louvar (Wayne State University)
This product will help faculty, students, and professionals incorporate proper overpressure and underpressure protection in their process designs. This package helps students:
- Understand the technology, special engineering devices, and methods that are used for protection against overpressure and underpressure (vacuum) incidents,
- Understand the root causes of overpressure and underpressure incidents, and
- Design plants with the appropriate features to protect against overpressure and underpressure incidents.
This SACHE product contains two PowerPoint presentations that can be copied and modified to fit specific teaching/learning objectives. It includes detailed instructions covering a) reliefs, b) runaway reactions, and c) safeguards to prevent accidents. This product can be used in design, fluid flow, or control courses. Some background information is included in this package (see Abstract - References) to assist the student in understanding these general concepts. The package is deliberately designed to be only an introduction to these topics. Using this introductory approach, the package can be used for three half-hour lectures or two hours of self-study exercises.
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.
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.
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
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.