bluuebunny/crossref_metadata_2025 huggingface dataset:
Simulating flammability under process conditions
Authors: O'Shaughnessey Dan , Powers Bruce
Published: June 2004

Establishing safe operating parameters requires the determination of flammability characteristics under a myriad of process conditions. In order to meet these needs, a combined approach of literature search, calculational modeling, and experimental simulation is often utilized. A few specific projects will be reviewed as example methods for evaluating flammability properties under challenging environments. Flammability diagrams and system configuration figures are presented for further review while the interesting discoveries of each project are covered for interpretation and application to process conditions.
The oxygen balance criterion for thermal hazards assessment
Authors: Shanley E. S. , Melhem G. A.
Published: June 2004

It is a matter of considerable practical importance to recognize metastable, potentially hazardous chemical compositions so that suitable thermal hazard management means can be provided as a part of process safety management. This communication is a report on our evaluation of the oxygen balance criterion as a screening technique for thermal hazard assessment.
Hazard evaluation of polymerizable compounds
Authors: Frurip D. J. , Chakrabarti A. , Hofelich T. C. , Martinez S. J. , Whiting L. F.
Published: June 2004

Reactive monomers are a special class of materials used widely in the chemical industry in the production of polymers. Many of these materials are thermally unstable and may polymerize during handling and storage with a release of significant amounts of energy. If this energy is not controlled properly, it can lead to a runaway reaction. Compounding the concern for the stability of monomers is the fact that these materials are typically transported and stored in large volume. The undesired initiation of the polymerization reaction may be caused by a number of factors, including contamination, exposure to extreme environmental conditions, or inhibitor loss. For example, an “unintended” polymerization can result from a seemingly benign procedure such as spill control with common absorbents. These and other factors mean that the reactive chemicals evaluation of monomers presents special problems and concerns which require more detailed experimental design for reliable hazard testing. This paper discusses the practical aspects of reactive chemicals testing strategies for monomers and rules‐of‐thumb for monomer inhibition, compatibility, spill control, and so‐called quenching (also called short‐stopping) agents. The techniques discussed range from simple “age and observe” type tests to more sophisticated heat flux calorimetry evaluations. We also discuss the more routine application of Differential Scanning Calorimetry and Accelerating Rate Calorimetry to monomers. Vent sizing applications with the VSP device are also presented with emphasis on total containment during a runaway.
Detonation flame arrester qualifying application parameter for explosion prevention in vapor handling systems
Authors: Lapp Ken , Werneburg Hal
Published: June 2004

Compliance with air quality initiatives often involves the installation of a vapor collection system (VCS). The purpose of a VCS is to collect and direct vapors to a flare, incinerator or recovery unit. This practice creates a hazardous situation wherein an explosive vapor is tied into an ignition source.

This paper examines nine factors in creating the most severe flame front possible in a practical, full sized piping system. They are: gas types, gas mixtures, pre‐ignition pressure, temperature of the ignition energy, temperature of the mixture, ignition location, pipe configuration, protected side restrictions and endurance to stabilized flame. The paper also examines which of these factors are in the jurisdiction of the plant process and those factors for which proof of capability have been demonstrated by commercially manufactured detonation flame arresters in actual tests.

Many certification standards define the acceptance testing of DFA's. They have been evolving and improving over the past two decades. A summary is made of which flame propagation parameters are addressed by various standards.

When reviewed in this context, and applied to practical operating conditions, new levels of confidence and safety are created. The critical variables within the control of the industry are outlined. This information can be applied to reduce the current high frequency of vapor transportation explosions.
Dow's chemical exposure index guide
Authors: Marshall John T. , Mundt Art
Published: June 2004

A number of events in the 1970's and 1980's impacted the course of process safety. Incidents such as Flixborough, Seveso, Three‐Mile Island, and Bhopal are well known throughout industry and are recognized as examples of major disasters. Even though events leading up to these disasters were completely different they had one common element between them: a substance was released from a manufacturing unit, became airborne and presented a hazard of such magnitude as to place the safety of both employees and the surrounding public in jeopardy. As a result, industry became increasingly concerned regarding potential loss, in human and economic terms, as plants and equipment grew in size [1]. The Flixborough incident raised the level of concern for process safety, particularly in terms of the hazards presented by fire and explosion. Seveso and Three‐Mile Island emphasized the need to consider far‐field exposure. The Bhopal incident created an urgent need to recognize and understand the expected downwind impact of potential releases of acutely toxic substances to the air. In order to meet this need, the Dow Chemical Company, a recognized leader in the area of safety and loss prevention, presented a Chemical Exposure Index in 1986. AIChE has recently published an updated version entitled Dow's Chemical Exposure Index Guide (first edition).

The above publication appears as an AIChE Technical Manual entitled Dow's Chemical Exposure Index Guide [ISBN 0‐8169‐0647‐5] and is available through the AIChE Customer Service Department, 345 East 47th St., New York, N.Y. 10017. Telephone: 1‐800‐242‐4363.
Protection of storage tanks from two‐phase flow due to fire exposure
Authors: Fisher Harold G. , Forrest Harry S.
Published: June 2004

Various approaches are presented to protect storage tanks from fire exposure. Design techniques for emergency relief devices flowing vapor or two‐phase vapor‐liquid flow are discussed. The effects of maximum design pressure versus emergency relief device set pressure, fire exposure insulation and water spray protection, fire exposure duration, relief device flow characterization and inlet pipe pressure drop and discharge pipe back pressure must all be considered when designing to protect storage tanks.

This paper discusses some aspects of pressure relief design for low pressure storage tanks. The concepts and techniques discussed here can be modified to include design guidance/recommended design parameters from specific standards. Even if not used for pressure relief design, the concepts/calculations presented should be useful for Process Hazard Analysis studies to determine the relative ranking of credible scenarios.

The reader is cautioned that no attempt was made to cover every design situation or conform to any design standard/recommended practice. There are too many specific scenarios and too many (unnecessary) conflicts between standards/recommended practices. Instead, the reader is cautioned to ensure that all prescribed federal, state and local as well as company design standards are followed when mandated.
The anticipated impact of the EPA's RMP regulation on the ammonia industry
Authors: Auger John E.
Published: June 2004

Over three years ago the Occupational Safety and Health Act (OSHA) process safety management regulation became effective in the United States. Most of us have dealt with the initial shock of that regulation and what it entailed and, hopefully, we have things pretty much under control.

Although, one hates to be the bearer of bad news, it is not yet time to relax. The Environmental Protection Agency (EPA) has another process safety regulation in store for the ammonia industry. In fact, in some areas, the EPA's upcoming risk management programs regulation makes the OSHA regulation look like child's play.

It is much better to be proactive than reactive when responding to new regulations. A proactive approach allows one to make the correct long‐term decisions without the pressure of a compliance deadline.
Choosing the level of detail for hazard identification
Authors: Deshotels Robert , Dejmek Mark
Published: June 2004

To be cost‐effective, a process hazards analysis effort should concentrate on those areas where there is the greatest potential for risk reduction. The level of detail of the analysis is a factor which affects the magnitude of effort and the completeness of the results. Often, there is an opportunity to combine components together to be analyzed as a single entity, in order to increase the efficiency of the hazard identification process. Issues arise concerning how to combine components, and what should be the appropriate level of detail for consideration. For instance, a level of detail shown on piping and instrumentation diagrams which has proven convenient for process design may not be sufficient or optimal for hazard identification. To resolve such issues, some guidelines are proposed for determining the appropriate level of detail. These guidelines have been deduced from the intent of the analysis and the basic assumptions of the methodology.
Quantitative risk assessment in Europe
Authors: Pasman Hans J.
Published: June 2004

Quantitative risk assessment is comprised of the following steps: identification, consequence analysis, probability estimation, consideration of mitigation measures, as well as judging the outcome against certain criteria of tolerability. The first two steps are showing an increase in acceptability; the rest remain the center of controversy.
PSM's most common struggle: Implementing mechanical integrity
Authors: Remson Andrew C. , Farmer Jill H. , King C. Stephen
Published: June 2004

Most companies have found that of the 14 OSHA PSM elements, Mechanical Integrity (MI) presents the greatest implementation challenge. Although maintenance departments have successfully installed, repaired, and replaced plant equipment for decades, many of these same maintenance departments have struggled with OSHA's PSM requirements. One major challenge is prioritizing resources. Opportunities to improve will always exist; however, it is often difficult to effectively allocate money and manpower. Another challenge is simply getting organized. The MI program should be supported by appropriate, useful procedures; but given the multifaceted and ever‐changing nature of maintenance, what procedures should be written? How detailed should the procedures be? With nearly 3 years of PSM enforcement complete, an analysis of OSHA's MI citations helps to provide insight to these challenges. This paper presents ideas for implementing MI in a manner that meets OSHA's expectations while contributing to safe, effective maintenance in PSM‐covered processes. In particular, the paper presents ideas for developing MI programs that effectively prioritize company resources, with appropriate inspection/test/preventive maintenance and quality assurance (QA) activities. This paper also presents ideas for developing a list of mechanical integrity procedures to address OSHA's requirements as well as the type of information to include in those procedures.
Utility and energy cost containment
Authors: Newhouse Roland
Published: June 2004

One of the most lucrative areas for improving bottom line profitability is related to an organization's costs for utilities and energy. Such thing as gas, electric, water, and telephones are treasure chests of cost reduction opportunities. In the past, these items have been viewed as a fixed expense or basic mundane commodity. In recent years, these items have become a large portion of product cost now must be examined on a contiual basis. A formal income improvement program to capture and report on the savings is a requirement for remaining competitive in a global economy.
Critical elements in the design of piping systems for toxic fluids
Authors: Getz R. C.
Published: June 2004

While releases of hazardous/toxic fluids from pressurized pipelines are infrequent, the potential for a catastrophic event resulting from such a release warrants extraordinary care of the hazardous/toxic piping systems containing these fluids, during the entire plant life cycle.

System identification, segregation, material and component selection, construction techniques, and preventative maintenance programs all contribute to improved system reliability, and are discussed herein. Methods to mitigate damages in the event of a failure are also discussed.
A comparative examination of the fire performance of pipe insulation
Authors: Babrauskas Vytenis
Published: June 2004

A standard method for evaluating the fire performance of pipe insulation is not available in North America. In Europe, however, the regional standards organization NORDTEST has had available for several years now a method specifically designed for this purpose. The NORDTEST NT FIRE 036 test is a full‐scale room fire test where the pipe insulation is installed along the ceiling and subjected to a gas burner fire. Four classes of performance (Class I through III, plus unrated) are used to evaluate the products. In the present work, 4, different pipe insulation products, representing the most common materials used for this purpose, have been examined according to this test. The results showed that rock wool insulation gave the best fire performance, with phenolic foam being in the least safe rated category. Synthetic foam rubber and polyethylene insulation products gave intermediate performance.
Flame propagation in pipes of pneumatic conveying systems and exhaust equipment
Authors: Vogl Albrecht
Published: June 2004

The dust explosion course in pipes of pneumatic conveying systems is discussed. A high number of large scale tests was carried out and the influence of pipe diameter, dust concentration, conveying velocity, location of the ignition source and powder specific parameters was taken into account. The concentration of the ignited dust/air mixture is measured and controlled by an opto‐electronic measuring system. The flame propagation time, the flame front velocity and the explosion pressure depending on the distance of the flame front from the ignition source are shown as well as the explosion pressure as a function of the flame front velocity. The experimental results give important hints concerning the explosion course in pipes, the strength of pipes and location of disengagement systems under practical operating conditions.
Explosion protection of pipe systems conveying combustible dusts or flammable gases
Authors: Senecal Joseph A. , Garzia Henry W.
Published: June 2004

A complete solution to explosion protection in facilities processing combustible dusts or flammable gases often involves consideration of dust and gas conveying systems as well as primary process volumes. The pipes or ducts of the conveying system can serve as efficient means of propagating deflagrations from point to point in a plant. Subsequent to the implementation of the requirements of the Clean Air Act Amendments of 1990 the need for explosion protection systems on pipes and ducts has increased. VOCs and vapors of hazardous chemicals are commonly incinerated. Such systems are subject to flash back failure and ignition of flammable gases in the feed pipe. Feed bins and product collectors up and down stream are at risk of ignition from sparks generated at grinding stations. Systems feeding dusty solids to furnaces are subject to flash back. This paper summarizes present day methods of detecting pipeline deflagration events and intercepting same using either fast closing valves or chemical barrier systems. Modes of deflagration detection, type and placement of barriers are discussed. The impact of the phase out of the production of halons in this area is also discussed. Examples of combustible dust and flammable gas protection systems are described.
Pressure relief with highly viscous fluids
Authors: Fründt Jens , Steiff Artur , Weinspach Paul‐Michael
Published: June 2004

The required vent area for pressure relief equipment is affected by the gas/vapor‐liquid disengagement. The main objective of this work is the experimental verification of disengagement models for highly viscous fluids. The dynamic two‐phase flow in the vessel is modeled with a one dimensional finite volume approach, the phase slip is taken into account with a drift flux model recommended by DIERS. The simulation shows good agreement with the experiment if the drift velocity is considered as a function of the fluid phase viscosity.
Viscosity correction factor for safety relief valves
Authors: Darby Ron , Molavi Kamyar
Published: June 2004

A commercial computation fluid dynamics (CFD) code was used to compute the discharge coefficient for a representative relief valve configuration and various nozzle sizes, for Newtonian liquids with various viscosities. The results are compared with values of the viscosity correction factor, Kv, from the API Recommended Practice 520, and equations are proposed to represent both the Kv curve and the computational results in a correspondings form, which also includes the effect of the dimensionless nozzle diameter on the valve Kv.
Advancing inherent safety into methodology
Authors: Lutz William K.
Published: June 2004

Competition in commodity centered chemicals, in the Chemical Process Industry (CPI), has led many chemical companies to consider cost reduction in every facet of their businesses. Once the obvious fixed cost control measures are achieved, the invention, development, and commercialization of new and existing products is questioned for cost reduction opportunities. The challenge is to bring the product line to market with sufficient volume and quality at a lower cost than any competitors. Short term and long term profitability, per capita of the corporation, must continue upward or at least break‐even in the low end of the chemical business cycle. Consideration of the principles of chemistry and physics early in the development and throughout the life of a chemical product can eliminate the need for instrumentation or administrative controls that add significant cost to the product over its lifetime. This paper examines opportunities to use inherent safety principles to improve lifetime cost, while reducing or eliminating hazards.
Successful use of stainless steels in nitrogen‐based fertilizer plants
Authors: Tersmeden Knut
Published: June 2004

In ammonia plants duplex stainless steels have been successfully used in many heat exchangers operating up to 600°C in cooling water polluted by chlorides. The duplex stainless steels offer a safe and cost‐effiecient alternative to carbon steel and stainless steels in the 300 series. In urea plants operating with stripper technology the material for the stripper, condenser, H.P. piping and reactor is reviewed. The good performance of 2RE69 has lead to a wider usage especially when 316L Urea Grade has been replaced for the Snamprogetti stripper. The new bimetallic tubing using a 2RE69 tubing with an inner lining of zirconium is now an accepted solution. Welding consumables are also presented.
A quantitative approach to determination of NFPA reactivity hazard rating parameters
Authors: Hofelich T. C. , Prine B. A. , Scheffler N. E.
Published: June 2004

The National Fire Protection Association (NFPA) has developed a system for labeling short‐term acute hazards of materials in fire, or emergency situations [1]. The procedures for obtaining the hazard rating for health and flammability are based upon measured quantities [2], but the basis for assigning reactivity ratings are largely qualitative [1]. This paper proposes a quantitative approach for assigning reactivity hazard ratings.
No good deed goes unpunished: Case studies of incidents and potential incidents caused by protective systems
Authors: Dowell A. M. , Hendershot D. C.
Published: June 2004

In the course of chemical process and plant design, engineers identify potential hazardous incidents. These potential incidents may be identified through special hazard analysis reviews and procedures, or by the design team in the course of design activities. To manage and control those hazards, the team will modify the initial design, often by adding on additional protective devices and systems—alarms, interlocks or active protective systems. However, any change in a system, even a change intended to prevent or mitigate a potential hazardous incident, also has the potential to introduce new hazards, or new mechanisms by which existing hazards can result in an incident. A number of case studies illustrating this point are reviewed. The examples illustrate the importance of a management of change program, which must consider all changes including the addition of safety devices and systems, and which must throughly consider all potential effects on the system.
Utilize plant data from emergency relief events to test design methods: A proposal to the AIChE DIERS users group
Authors: Edwards Victor H. , Howard Walter B.
Published: June 2004

Advanced methods for the design of emergency relief systems were developed under the auspices of the AIChE Design Institute for Emergency Relief Systems (DIERS). Rapid progress has continued, but most testing has been done at laboratory or small pilot plant scale. Full scale tests of design methods for emergency relief systems are much needed, but would be prohibitively expensive.

Proposed here is a practical alternative: Use existing production data from operating plants to test design methods for emergency relief systems. Fortunately, although most emergency pressure relief events represent plant upsets and lost production, the relief system prevents a catastrophe in most process upsets. However, the qualitatively successful operation of an emergency relief system in a given upset does not represent proof of the design method employed. More importantly, it does not guarantee that the existing relief system will perform successfully in every credible upset that the process might experience in the future.

Advocated here is an industry‐wide program to use data from selected process upsets to systematically evaluate the effectiveness of current emergency relief system design methods to quantitatively predict the performance of existing emergency relief systems. Products of this effort would include confirmation of a significant number of existing design methods, identification of deficiencies in current methods, and a published compendium of documented and evaluated case histories of full‐scale relief system performance. In addition to its instructive value to workers in emergency relief, the compendium could be used to test new design methods.

This proposal is offered to the AIChE DIERS Users' Group. The DIERS Users' Group, which is comprised of over one hundred member companies, has representatives qualified to define, organize, sponsor, and execute a multi‐company research program of this type. (NOTE: At the semiannual meeting of the AIChE DIERS Users' Group in Calgary, Alberta, Canada on September 9, 1996, this proposal was presented to and adopted by the DIERS Users' Group and assigned to the Case Histories Committee.)
Carbon disulfide incidents during viscose rayon processing
Authors: Hall Danal S. , Losee Lyman A.
Published: June 2004

Two incidents occurred in a viscose rayon manufacturing process about a month apart during the same step of a semi‐monthly cleaning operation in a carbon disulfide recovery box. The operation removes sulfides that accumulate on equipment surfaces during the week. In both incidents, carbon disulfide was released from the recovery box into the vapor exhaust system and the area surounding the recovery box. Ignition occurred and the resulting vapor flash propagated throughout the vapor exhaust system and the operating bay. Both incidents caused extensive equipment and building damage and minor injuries to personnel.

Investigation and recommendations after the first incident, although appropriate, did not eliminate the root cause of the problem. Additional information obtained during the investigation of the second incident showed that a combination of several modifications and subtle changes in that particular process line, in conjunction with the colder temperatures of fall and winter, resulted in the incidents. The changing of the critical balance of temperature, pressure in the closed system, and sudden volatilization of accumulated carbon disulfide in an unlikely location were triggered by startup of the cleaning operation. Once the carbon disulfide vapor pressure vented from the closed system numerous ignition sources were available.

The discussion will focus on the importance of management of change for seemingly small, logical changes, and on the importance of attention to small details in an accident investigation.
Batch runaway reaction relief: Re‐evaluation of “Credible” scenario
Authors: Singh Jasbir
Published: June 2004

Many chemical reactions in the fine chemical and related industries are performed in a semi‐batch manner under isothermal conditions. Relief system design evaluation for runaway reactions, using DIERS methodology for example, is frequently studied adiabatically using data derived from batch mode testing. In many cases, however, evaluation of the process isothermally under the realistic semi‐batch mode can be extremely useful, often helping to greatly reduce the vent size as a result of a better understanding of the process. In some cases, it is even possible to eliminate runaway reaction as a viable case for relief sizing. Such evaluations of venting are fully consistent with DIERS methodology.

This paper presents the arguments for sizing vents for scenarios other than the very worst case, by objective evaluation of trips and interlocks, so that the level of risk is reduced to an acceptable level without the need for extremely large vents.
Fully quantitative predictive maintenance/inspection planning optimization for chemical process plant components
Authors: Mauney David A. , Schmidt Michael E. G.
Published: June 2004

Predictive maintenance/inspection planning and fitness‐for‐service analyses are being applied more frequently to address the effect of component aging affecting plant reliabibility. Component aging is one of the critical issues in an increasingly competitive environment, especially in plant components built and installed during the 50s and 60s. Maintenance optimization is also a critical issue for components, such as those that operate in the creep regime, and therefore age quickly. Maximizing the value received for each predictive maintenance/inspection dollar is the key. This article introduces the use of decision analysis to unite engineering analysis and economic evaluation for decision making. To illustrate this idea, examples of this approach applied to chemical facility components will be presented. In addition, the concept of priority‐ranking multiple component maintenance/inspectio projects having maintenance budget and safety constraints in a way that maximizes Net Present Value, will be presented.
KG: New data and analysis
Authors: Senecal Joseph A. , Beaulieu Patricia A.
Published: June 2004

The design and deflagration pressure relief vents is based on correlations developed for various types of combustible materials and for enclosures of different strengths. The primary guideline for deflagration vent design in the US is NFPA 68 Guide for Venting of Deflagrations [5]. That document gives guidance for the design of vents for enclosures containing flammable gases, specifically hydrogen, coke oven gas, propane, and methane. Application of the guide to other gases is achieved using the KG value. Values of KG are published for a relatively small number of gases, as seen in Table D‐1 of NFPA 68. This work present KG data on several additional gases obtained in a laboratory scale test vessel along with analysis of the results with respect to published values of fundamental burning velocity.
Risk based prioritization of maintenance repair work
Authors: Harnly John A.
Published: June 2004

This paper describes the development of a risk ranked Inspection Recommendation procedure that is used by one of Exxon's chemical plants to prioritize repairs that have been identified during equipment inspection.

As part of the Company's Safety Management Practices initiative in the late 1980's a procedure was put into place to ensure that an Inspector's repair recommendations were properly addressed by the organization. The initial procedures were successful at “systematizing” the documentation and stewardship‐to‐completion of the Inspector's recommendation, however, there were complications with the original process:

The Inspector made a simple High, Medium or Low assessment of the priority/criticality of the recommendation. Frequently, this resulted in disagreements with Operations about the true priority of the recommendation.

If there was agreement on the priority of the recommendation, there was still disagreement on the relative rank within the priority‐which high priority was the highest priority?

With limited funds to spend on repairs, it was (and is) important to make sure that the money was being spent on the highest risk items that had the greatest risk reduction/cost benefit ratio.

To address these concerns, the procedure was modified to incorporate a risk assessment of the recommendation by both the Inspector and Operations. In the new procedure, the Inspector describes the deficiency that he/she finds and assesses the probability of failure within a certain time‐frame. Operations must assess the consequences, from an environmental, safety and economics standpoint, were the failure to occur. These assessments are combined in the typical risk equation (risk = probability × consequences) to arrive at a severity index which serves to rank the recommendation relative to the other recommendations. Because Operations participates in the assessment there is very little disagreement about the priority of the recommendation. The severity index puts the recommendations in order so it is quite clear which are the highest priority recommendations. This process has helped to focus the entire organization on those deficiencies that represent the greatest risk with the result that less time and money is spent correcting items that have a low risk/cost benefit ratio, allowing these savings to be used to reduce the higher risks in the plant.
Pressure relief system documentation: Equipment based relational database is key to OSHA 1910.119 compliance
Authors: Berwanger P. C. (Pat) , Kreder R. A. (Rob)
Published: June 2004

Under OSHA 1910.119, all Process Safety Management (PSM) facilities are required to keep their pressure relief system design information current. This article demonstrates why a pressure relief system design verification effort must be based on an equipment list, rather than a relief device list, in order to ensure that every piece of equipment is adequately protected. The formerly common practice of simply checking the design bases of all existing relief devices is deficient is deficient since this technique does not systematically ensure that every piece of equipment is protected.

The “Berwanger Method” is a step by step process for designing or analyzing a pressure relief system to meet OSHA 1910.119 Process Safety Information (PSI) and Process Hazard Analysis (PHA) mandates. The method uses a relational database which tracks the relationships between protected equipment, potential overpressure scenarios, and protective devices.

The challenge facing an operating company does not end once the design basis has been “verified”—the design basis information must also be maintained and be readily accessible to avoid costly reinvention of the wheel down the road. The “Berwanger Method” also addresses these maintenance issues.
Team situation awareness for process control safety and performance
Authors: Kaber David B. , Endsley Mica R.
Published: June 2004

This paper defines situation awareness (SA) and discusses its importance to operator‐machine system safety and functioning in the context of process control activities. Specifically, identified are relationships of human detection of critical process cues converying the status of automated control systems and operator interpretation of the meaning and relevance of such information to the potential for negative incidents in chemical processing. Beyond individual operator SA in interacting with control systems, intra‐ and inter‐ work team SA are discussed for supporting individual attainment of process control responsibilities. Factors critical to team SA are discussed. “Road blocks” to team SA are also analytically examined. Lastly, methods for assessing individual and team SA are reviewed and vehicles for relating outcomes of these methods to changes in process control operator and team behavior to improve human‐machine system safety and performance are relayed.
A detailed reaction study of phosphorus trichloride and water
Authors: Melhem G. A. , Reid D.
Published: June 2004

This paper reports on a comprehensive literature search and small scale experimental work on the reaction characteristics of phosphorous trichloride and water. More than 30 tests were conducted, including both closed and open test cells. The water to phosphorus trichloride molar ratio was varied from 1 to 25. When in contact, water and phosphorus trichloride will form two liquid layers with a reaction starting at the interface. The impact of variables on reaction rates including the interface surface area, layer depth, and stirring were investigated experimentally. A reaction rate model that fits all the measured data is presented. Case studies illustrating the use of this data for emergency relief systems and vent containment design are presented in reference. [1].
Dust explosion mitigation using Q‐Rohr and exkop
Authors: Stevenson William J.
Published: June 2004

Dust explosions have been with us for a long time. The first record of a dust explosion occurred in Turin, Italy, on December 14, 1785 [1]. The detailed record of this event is left to us by Count Morozzo. The event took place in Mr. Giacomelli's bakery. We know from his account that the weather was unseasonably dry, that a boy who worked in the bakery was using a shovel to stir and transfer the flour to a chute from a store room to the bakery and he had a lighted lamp to work by. The rest, as the saying goes, is history. No one was killed, and the building was saved by the sagacious fact of having plenty of windows. Since that first record, of course, there have been many explosions with much loss of life and significant economic consequences.
Making safety second nature
Authors: Kletz Trevor A.
Published: June 2004

From the 1960s onwards, the chemical and oil industries developed and used a number of new safety techniques which, in time, became second nature to those who applied them. They included the use of QRA for deciding priorities, Hazop and audits for identifying problems, inherently safer design for avoiding hazards, and more thorough investigation of incidents for identifying underlying causes. However, it has not yet become second nature to remember the accidents of the past and the actions needed to prevent them happening again.

I joined industry in 1944 and moved to production in 1952. Then, and for at least 15 years afterwards, safety was a non‐technical subject that could be left to arts graduates and elderly foremen. There was concern that people should not be hurt—great attention was paid to the lost‐time accident rate—but there was no realization, that it was a subject worthy of systematic study by experienced technologists.

This view changed at the end of the 1960s. A new generation of plants had been built, operating at higher temperatures and pressures and containing larger inventories of hazardous chemicals; the result was a series of fires and explosions and a worsening fatal accident rate. Figure 1 shows the situation in ICI, at the time the UK, s largest chemical company. Other companies experienced a similar state of affairs.

As a result in 1968, I was appointed one of the company's first technical safety advisers, an unusual appointment at the time for someone with my experience, and if the reason for my appointment had not been so obvious I would have wondered what I had done wrong. I and my colleagues tried to apply the same sort of systematic thinking to safety that we applied in our other professional work. We developed some new concepts and techniques and adopted others. A common feature of our ides, realized only in restrospect, was that they consisted of more than mere problem‐solving techniques. Once people had got used to these new concepts and used them a few times, they began to look at a whole range of problems in a different way.
Analysis of hydrogen fluoride release at Texas city
Authors: Woodward John L. , Woodward Hillary Z.
Published: June 2004

On October 31, 1987 a crane lifting a heat exchanger convection section failed and severed a 4″ loading line and a 2″ pressure relief line to an HF alkylation reactor settler drum at a petroleum refinery in Texas City, Texas. Vapors were emitted under pressure for about two hours and the vessel was plugged and drained aproximately 44 hours later. A plume from this accidental release passed through residential areas, damaging some vegetation (brown lawns), and spawning a class action law suit. An extensive analysis was conducted to determine the total inventory loss and to model the blowdown process and the concentrations of HF in the plume. Since the discharge rate was decreasing with time, a peak concentration of HF in the emitted vapors occurred just before the water spray mitigation system became fully operative. Consequently, the mitigation efforts were more effective late in the response when concentrations were already low. The predicted plume concentrations are consistent with observed vegetation damage effects, with concentrations below Emergency Response Planning Guideline Level 3 past 3/4 mile from the source. These results support a policy of sheltering in place during such an event.
RMP hazard assessment for compliance with EPA's risk management program regulation: OxyChem's experience
Authors: Riswadkar Raj , Mukhopadhyay Nik
Published: June 2004

EPA's Risk Management Program regulation, promulgated in June 1996 as 40 CFR Part 68 requires subject industries to submit Risk Management Plans by June 1999. This plan requires hazard assessment of the operations of a facility using worst case scenarios and alternative releases. EPA has provided an Off‐site Consequence Analysis (OCA) guidance to help facilities in their hazard assessment.

OxyChem will be significantly impacted by the RMP rule. This paper outlines OxyChem's general experience and its strategy in planning to comply with this rule. OxyChem's approach in the development of the scenarios required by the rule is described in this paper. Limitations involved in the use of EPA's look‐up tables or a single modeling solution for conducting all of the OCA are discussed. A three tiered OCA approach is presented as a possible alternative.
Development of an inclined plate jet reactor system
Authors: Leigh A. N. , Preece P. E.
Published: June 2004

A new design combines reaction or extraction and separation in one unit. Here are practical working details.
Cogeneration in a nitrogen fertilizer complex
Authors: Arnold D. W. , Borzik D. M. , Montgomery L. K.
Published: June 2004

The generator is powered by a natural gas fired turbine. Exhaust gases with supplemental firing are used to produce 41 40 kPa steam. Overall energy efficiency is 84 percent.
Operator training for startup
Authors: Wetherill F. E. , Wallsgrove C. S.
Published: June 2004

The factors that are important when a major new facility is erected at an existing site and some of the solutions to the problems.
Problems with leakages at large flanges in the BASF new ammonia plant
Authors: Sötebier Dieter L. , Rall Wolfgang
Published: June 2004

Leakage from large diameter flanges had occurred several times in a new 1360 t/d ammonia plant. One such incident resulted in a large fire. The causes of this incident are examined.
Severe carry‐over phenomena in 1,200 MTPD methanol plant
Authors: Kobayashi Y. , Kobayashi T. , Coombs K. M.
Published: June 2004

Malfunction of a perforated plate installed above the demister in the steam drum caused severe carry‐over of sodium phosphate.
Sequential completion of plant construction to allow early production
Authors: Smet E. J.
Published: June 2004

Waiting until the total plant is completed before beginning start‐up preparations can lose valuable time and delay revenue.
Investigation of damage and repair of a 1000 MTD horizontal ammonia converter
Authors: Rao Subir , Wilttzen R. C. A. (Bob) , Jacobs Wesley
Published: June 2004

An operational upset caused by a diapharagm failure in the high pressure casting of the synthesis gas compressor resulted in major pressure/flow surges in the synthesis loop.
Failure of high pressure synthesis pipe
Authors: Prescott G. R. , Blommaert P. , Grisolia L.
Published: June 2004

The circumstances leading to the failure and the corrective action that has been adopted to avoid similar accidents in the future.
Major fire in a steam‐methane reformer furnace
Authors: McCoy C. S. , Dillenback M. D. , Truax D. J.
Published: June 2004

Causes of a major fire which resulted when a pigtail ruptured on a 10‐year old hydrogen plant reformer and led to the destruction of 54 catalyst tubes.
Property insurance considerations in loss prevention expenditures
Authors: Norstrom Gail P.
Published: June 2004

Certain components comprise the Property Insurance premium. The sensitivity of those components to changes in the risk are analyzed considering the insurance market. The cyclic nature of the insurance market can also impact a Property Insurance program in other, less tangible, ways. Tangible premium charges and other intangible costs of risk which are dependent upon Loss Prevention expenditures are broadly quantified. Those factors which can be useful in determining the cost effectiveness of loss prevention expenditures are discussed in detail.
Early on‐line detection of exothermic reactions
Authors: Hub L. , Jones John D.
Published: June 2004

On‐line supervision exhibits in many respects properties complementary to those of established off‐line safety tests. Thus, on‐line methods are powerful tools for increasing the safety of chemical processes, especially in situations where unexpected hazards could occur. Known on‐line supervising methods are described and their advantage and disadvantages are briefly discussed. The abilities of various on‐line methods are demonstrated on a real case.
NOx in the cryogenic hydrogen recovery section of an olefins production unit
Authors: Henstock W. H.
Published: June 2004

Union Carbide has been investigating the fate and possible hazards of NOx compounds in cryogenic gas separation equipment. It has been learned that trace amounts of NOx in the process streams can accumulate in the equipment under certain conditions. Although mixtures of condensed NOx and condensed hydrocarbons can be ignited with a strong ignition source, the combination does not seem to present an imminent hazard. No explosive NOx‐hydrocarbon “gums” have been found yet, but the investigation is still continuing. We recommend that equipment which is exposed to NOx compounds be monitored to detect accumulations and prevent possibly hazardous situations.
Inspection of ammonia plants
Authors: Madhavan S. , Sathe S. Y.
Published: June 2004

Safe operation of an ammonia plant and high on‐stream factor depend, to a large degree, on proper and timely inspection of the equipment to detect mechanical degradation. This paper addresses the inspection techniques, monitoring techniques, frequencies and interpretation of the results for all major pieces of equipment where problems have occurred in the past. This inspection can be a shutdown inspection or an on‐stream inspection.
The interaction of shock waves in cylindrical structures
Authors: Brown D. M. , Nolan P. F.
Published: June 2004

An experimental investigation into the validity and use of the hydraulic jump analogy for studying the interaction of shock waves in air with cylindrical structures.
Correlation of acid gas‐ethanolamine equilibrium using ionic concentrations
Authors: Maddox R. N. , Diers James , Bhairi A. M. , Thomas‐Cooper P. A. , Elizondo E. M.
Published: June 2004

Experimental equilibrium measurements are modeled using a Davies‐like ionic strength correction term for the reaction equilibrium constants. Calculated and experimental results are in much better agreement when the ionic strength correction terms are used.
Future requirements for unrestricted entry into confined spaces
Authors: Keller Charles L.
Published: June 2004

An overview of the current requirements for confined spaces. Special attention is given to the toxic levels and applicability of the threshold limit values to the requirements for entry into confined spaces.
Flame barrier valves
Authors: Stalder Hans
Published: June 2004

Application of quick closing valves for separating of plant parts and for section‐like protection of pipe lines in case of dust explosions.
Environmental compliance without sacrificing customer requirements
Authors: Pollard‐Cavalli Roberta I.
Published: June 2004

Reformulation of paraformaldehyde has reduced exposure while improving product properties. Solvent substitution and process modification in product lines have resulted in reduction of benzene emissions and more favorable product specifications.
Health, safety and environmental protection: A new audit program
Authors: Scheid Daniel C.
Published: June 2004

In September, 1985, Union Carbide established a new, comprehensive corporate‐level audit program. The development of this program included careful consideration and incorporation of current and emerging practices in the field of health, safety, product responsibility and environmental auditing. Union Carbide's efforts in this area are but one element of its overall health, safety and environmental management system.
Estimation of catastrophic quantities of toxic chemicals by atmospheric dispersion modeling
Authors: Costanza Peter A. , Hagen George L. , Kalagnanam Ramesh S. , Komosinsky Paul J.
Published: June 2004

In response to the Bhopal disaster and several repeated chemical releases (even though of less dangerous magnitude) in New Jersey, the state of New Jersey passed a bill on January 8, 1986, which is aimed at the prevention of such catastrophic releases in the state. This bill is officially referred to as the Toxic Catastrophe Prevention Act (TCPA).

The TCPA identified eleven specific Extraordinarily Hazardous Substances (EHS). Table 1 lists these eleven EHS identified in the Act and their reportable quantities. The TCPA aims at the prevention of the release of these EHS into the environment. The Legislature did not provide the basis and background of the development of the reportable quantities of these eleven EHS.

The TCPA mandates that the New Jersey Department of Environmental Protection (NJDEP) shall expand the list of these EHS and shall “… correlate the substances with the quantities required to produce the potentially catastrophic circumstances.”
Waste reduction at Du Pont: Business opportunities
Authors: Hollond G. J. , Weber W. F.
Published: June 2004

A Corporate Waste Minimization Committee at Du Pont has a charter to coordinate common concerns and solutions for reducing waste and to increase the awareness throughout the organization of the potential opportunities and economic benefits for minimizing waste.