Russell Ogle

Molten sulfur is one of the most frequently transported hazardous materials (hazmat) in North America. Typically, molten sulfur is transported by rail tank cars or over-the-road tank trailers. According to the U.S. Department of Transportation Research and Special Programs Administration’s hazmat incident database, there have been 326 reported releases of molten sulfur in transportation between the years 1993 to 2003, inclusive. Some incident reports indicate that high levels of hydrogen sulfide gas were released during the initial stages of unloading preparation. In a few reported cases, the concentration of hydrogen sulfide was high enough to cause unloading personnel to lose consciousness, which then lead to further injury. A review of the Occupational Safety and Health Administration (OSHA) accident report database confirms that over the last twenty years there have been four reported fatalities from hydrogen sulfide exposure associated with molten sulfur containers. Over the la...

Over the last 25 years the chemical process industry has invested a great deal of effort to promote process safety and security in their production facilities. In that same time frame, the chemical supply chain has become increasingly more vulnerable to disruptions. Business factors such as reduced inventories (“lean manufacturing”), sole-source contracting, globalization, and aging transportation infrastructure have conspired to make supply chains extremely vulnerable to delays or interruptions in the flow of materials. The challenge of managing supply chain disruptions is complex since they can be caused by a broad array of events including accidents, natural hazards, and sabotage. Thus, while the threats to production capacity from hazards have been brought under a higher level of control, the potential frequency and severity of external hazards has actually increased. In this paper we illustrate how some of the tools developed for chemical process hazard analysis can be adapted ...

The automation of chemical processes has both positive and negative features. Computer automation can be a powerful tool for safety management. On the other hand, it provides new opportunities for human error both in design and in operation. The interaction of process equipment, control systems, and operators can be complex. This is especially true with the discrete control of batch systems. In this paper we investigate an accident with an automatically controlled batch dryer that resulted in an explosion and fire. The batch dryer contained a heat transfer subsystem. The heat transfer subsystem consisted of a combustible oil circulated continuously in a closed loop. The purpose of the heat transfer subsystem was to maintain a plate heat exchanger at a constant temperature. The process dryer was programmed to dry a batch of material in contact with the slab by advancing through several stages of operation. The dryer was controlled by a supervisory control and data acquisition system ...

Emergency response personnel who responded to a smoke alarm at a manufacturing facility were injured when a cryogenic refrigeration system overheated and then exploded. The refrigeration system was a skid-mounted package unit that relied upon liquid nitrogen as the cryogen, a heat transfer oil as the secondary refrigerant, and electrical resistance heaters as a heat source to provide split-range control over the heat transfer oil temperature. The incident investigation revealed that the event was not the result of a simple single cause. Detailed root cause investigation and failure analysis was performed to identify the underlying causes. The explosion was caused by the thermal expansion of trapped liquid. It was determined that several elements of good engineering practice that are considered for basic safety measures in chemical processing plants were not considered by the equipment designers. The following deficiencies were noted: The freezing point of the heat transfer oil was l...

Frank-Kamenetskii thermal ignition theory has been used to model the self-heating behavior of solids. The theory does not account for the effects of internal convection in the case of a porous body. A lignocellulosic solid (wood flour) experimental program was conducted to investigate the self-heating properties. The apparent kinetic parameters and physical parameters for the wood flour thermal ignition were developed from that study using the approach of Frank-Kamenetskii. The self-heating solid was modeled using FLUENT as a porous solid body with uniform thermal boundary conditions. Based upon comparing the density of the wood flour to solid wood, the porosity was calculated as 0.63 for the porous body with the balance consisting of air. The model was given a sensitivity analysis on permeability ranging from 10-6 m2 to 10-20 m2 (effectively impermeable) to investigate the effects on the self-heating behavior of the porous body. Changing the permeability was found to affect the loc...

Determining safe storage conditions for a self-heating material requires knowledge of the reaction kinetics governing its decomposition under potential storage conditions. Several thermal hazards analysis techniques are available, but most require kinetics analysis at a high temperature and micro-scale quantities. In contrast, isothermal calorimetry (i.e., isothermal oven tests) has proven to be a convenient method for conducting experiments with material quantities in the 0.1 to 1000 kilogram range at conditions more closely resembling the potential storage environment. The isothermal oven test protocol determines the critical temperature for several different sample sizes. The resulting data are then analyzed using the Frank-Kamenetskii variables to yield estimates for the activation energy and the pre-exponential factor. The classical Frank-Kamenetskii solution of the self-heating problem assumes that heat generation, described by zero order reaction kinetics, is balanced by heat...

The American Institute of Chemical Engineers (AIChE), the Chemical Safety Board (CSB), and the Occupational Safety and Health Administration (OSHA) have all emphasized the importance of advancing inherently safer design concepts into chemical process plants. Incident investigations offer an important opportunity to identify, evaluate, and correct potential shortcomings in the design, construction, operation, and maintenance of a chemical process unit that has experienced a release. This paper focuses on the inherently safer design principle of simplification. The case studies share the common theme of storing or handling liquids. Each case study illustrates how a design flaw led to unintended flow, reverse flow, or overfilling of a vessel which ultimately led to a fire, explosion, or hazardous release. Based on the incident investigation experiences of the authors, the paper illustrates how application of the simplification principle could have prevented these incidents.

The hazards from a boiling liquid expanding vapor explosion (BLEVE) include the formation of a blast wave and the projection of missiles. To understand the maximum work that can be obtained from a BLEVE, the authors have investigated in previous publications certain aspects of BLEVE behavior using exergy analysis. One of the key limitations in relating exergy calculations to more realistic behavior is the lack of knowledge of how the exergy of the explosion is partitioned into various types of work that occur in the BLEVE process. Some of these work terms include the formation and propagation of a shock wave, the strain work of vessel deformation and rupture into missiles, the initial kinetic energy of the missiles, and the surface work of aerosol droplet formation. In this paper we explore one of these work terms, the surface work performed in transforming the bulk liquid into aerosol droplets. The advantage of using exergy analysis to evaluate the maximum work of an explosion is t...

Following the work of Crowl on calculating the energy of explosions using exergy (thermodynamic availability), we examine the explosion energy of boiling liquid, expanding vapor explosions (BLEVEs). A number of investigators have proposed schemes for calculating the maximum work that a BLEVE can perform on its surroundings. Their proposed evaluation schemes yield varying results because they depend significantly on the precise specification of the thermodynamic path taken by the vaporizing, expanding mass. We demonstrate how to evaluate the maximum theoretical work associated with a BLEVE as a function of the fluid's thermodynamic properties and its equation of state. We consider two specific forms of BLEVE: nonreactive and reactive (combusting) fluids. Finally, we give numerical examples to compare the availability of a BLEVE with some of the proposed schemes suggested by others. The advantage of using exergy analysis to evaluate the maximum work of a BLEVE is the rigorous and ...

This paper explores an infrequently encountered hazard associated with liquid fuel tanks on gasoline-powered equipment using non-vented fuel caps. Depending on the location of fuel reserve tanks, waste heat from the engine or other vehicle systems can warm the fuel during operation. In the event that the fuel cap is not vented and if the fuel is sufficiently heated, the liquid fuel may become superheated and pose a splash hazard if the fuel cap is suddenly removed. Accident reports often describe the ejection of liquid from the fuel tank opening as a geyser. This geyser is a transient, two-phase flow, vertical jet of flashing liquid. This could create a fire hazard as the geyser could result in splashing flammable liquid onto any bystanders. Many fuel tank systems are vented to ambient through the fuel tank cap and, in addition, may incorporate other features that contribute to pressure relief. Venting of the pressurized vapor inhibits the vapor-liquid mixture in the fuel tank from ...

ABSTRACT Deficiencies in conduct of operations and operational discipline can lead to a decline in the quality of an organization's process safety culture and an increase in the likelihood of process safety incidents. A process safety assessment is one tool especially suited for identifying and correcting organizational safety culture deficiencies. Both AIChE/CCPS and API offer recent guidance documents on how to conduct effective assessments of process safety management systems. This article first introduces some basic concepts from game theory and applies them to the methodology of process safety assessments. A conceptual framework for the implementation of the process safety assessment process with balanced positive and corrective actions will be described. Assessment guidelines typically focus on the negative outcomescorrecting deficiencies. This article argues that the assessment process must also use the positive outcomesthe compliance successesto provide positive reinforcement to the process safety culture. Implementing this strategy is consistent with pragmatic management practices and is supported by empirical studies in behavioral science. Finally, this article discusses how these ideas fit within the framework of AIChE/CCPS and API guidance documents. (c) 2013 American Institute of Chemical Engineers Process Saf Prog 33: 148-151, 2014

ABSTRACT The role of process safety in the undergraduate and graduate curriculum is a critical component of preparing chemical engineers for their future careers. In 2011, the Accreditation Board for Engineering and Technology (ABET) amended the requirements for Chemical, Biochemical, Biomolecular, and similarly named Engineering Programs. The change added a clause, indicating that the curriculum of said programs should not only include the engineering application of chemistry, physics, and/or biology to the design, analysis and control of processes, but also the hazards associated with those processes. Departments were then compelled to adjust their curricula to meet the new requirement which would go into effect during the 2012–2013 Accreditation evaluations. Herein, we present findings related to the major milestones and challenges associated with updating the chemical engineering curriculum to include process safety components at both the undergraduate and graduate level. First, a survey of publicly available information regarding curriculum requirements, course syllabi, and program developments at US universities will be discussed. Next, insights from evaluating the challenges associated with adding new content to an already overloaded curriculum will be discussed. Lastly, recommendations for continued improvement in the process safety education provided to undergraduate and graduate students will be presented. © 2015 American Institute of Chemical Engineers Process Saf Prog, 2015

ABSTRACT The 1984 Bhopal tragedy involved the toxic and reactive chemical methyl isocyanate (MIC). The enormous human toll of this tragedy spurred the development of the concept of inherently safer design (ISD), and several published studies have since demonstrated the application of ISD concepts to the Bhopal process. In 2008, the U.S. Chemical Safety Board (CSB) investigated a fatal explosion at a chemical plant in West Virginia, for which a potential (unrealized) outcome was the loss-of-containment of the large inventory of MIC stored onsite.