RESEARCH HIGHLIGHTS2016-2017

Making Safety Second Nature

The Mary Kay O’Connor Process Safety Center was established in 1995 in memory of Mary Kay O’Connor, an

operations superintendent killed in an explosion on October 23, 1989. The center’s mission is to promote safety as

second nature in industry around the world with goals to prevent future accidents. In addition, the center develops

safer processes, equipment, procedures and management strategies to minimize losses within the processing

industry. Further, the center realizes that it is necessary to advance process safety technologies in order to keep the

industry competitive. Other functions of the center include serving all stakeholders, providing a common forum, and

developing programs and activities that will forever change the paradigm of process safety. The funding for the center

comes from a combination of the endowment, consortium funding and contract projects.

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Chemicals play a key role in today’s high-tech world. The modern chemical industry is linked to every technologically advanced industry. Only a handful of the goods and services we enjoy on a daily basis would exist without essential chemical products.

Safe use of chemicals creates a healthier economy and a higher standard of living, but unsafe use threatens lives, businesses and ultimately our world.

To that end, our programs and research activities enhance safety in the process industries. Our educational activities are aimed at making safety second nature to everyone in the industry. In addition, we develop safer processes, equipment, procedures and management strategies to minimize losses.

Center personnel conduct studies pertaining to general issues of process safety as well as specific interests of the center’s consortium members. Overall research goals are to develop:

Note from the DirectorWithout a doubt, one of the most rewarding aspects of my job as director of the Mary Kay O’Connor Process Safety Center is working to educate and prepare the next generation of engineers. Towards this goal, the center continues to play a pivotal role in engineering education at Texas A&M University, helping produce exemplary professionals with a strong commitment to safety in the workplace and at large.

The students working with the Mary Kay O’Connor Process Safety Center are talented, dedicated and ambitious, as evidenced by the wide breadth of research areas in which they are involved. From important studies on safety climate to critical research on liquefied natural gas hazards and dust explosions, our students are applying sound science to real-world issues vital to the process industries.

I invite you to peruse this publication and learn more about the center and our students who truly are “making safety second nature.” As always, feel free to contact me with feedback or questions at 979.845.3489 or via email at mannan@tamu.edu.

Industry Research Activities

• Systematic identification and evaluation risk, based on severity of consequences and probability of occurrence, to prioritize projects related to certain processes; types of process, storage and transportation systems; and various chemicals

• Projects to most effectively address the risks identified

• Inherently safer process schemes for the most common and most hazardous processes

• Technology and methods to develop engineering design concepts and implement such processes

• Devices, systems and other means for improving safety of chemical operations, storage, transportation and use by prevention or mitigation

• Improved prediction and analysis of behavior of hazardous chemicals and the systems associated with them

Dr. M. Sam MannanDirector,Mary Kay O’Connor Process Safety CenterRegents Professor, Chemical EngineeringHolder of the T. Michael O’Connor Chair I

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The Mary Kay O’Connor Process Safety Center provides a neutral forum to discuss difficult issues related to process safety. Toward that goal, the Chemical Safety Program Assessment Project is a significant effort that brings together a diverse group of stakeholders. Objectives include identifying national chemical safety goals; identifying and implementing activities necessary to accomplish these goals; and establishing a measurement system to help gauge progress toward these goals.

In addition, the center serves as an information resource base for process safety, acting as a library and software laboratory. It provides consultation services for small and medium enterprises, government agencies, institutions, local emergency planning committees and others agencies. Independent accident analysis services are also available to industry and government agencies, particularly for accidents suggesting new or complex phenomena.

Resources

Service

Expertise

The Reactive Chemicals Laboratory is equipped with several calorimeters for studying thermal behavior of reactive systems. With this experimental capability, the thermal behavior of wide ranges of reactive systems and systems of questionable chemical compatibility can be investigated. The Aerosol Laboratory can be used to study the behavior of fluid aerosols leaking from manufacturing processes. Additionally, the center is linked to tremendous resources throughout The Texas A&M University System, including:

Dr. Sam Mannan, center director, is an internationally recognized expert on process safety and risk assessment. In addition to his many professional honors and achievements, Dr. Mannan has served as a consultant to numerous entities in both the academic and private sectors. He also has testified before the U.S. Congress on multiple occasions, lending his expertise on matters of national security as it relates to chemical safety and infrastructure.

Other center researchers include leaders in the fields of process safety management; liquefied gas safety; ammonia and fertilizer plant safety; refinery and chemical plant safety engineering; and risk assessment for the process industries.

Center personnel are active in technical committees of professional societies such as the American Institute of Chemical Engineers, the American Society of Mechanical Engineers, the American Society of Safety Engineers, the Systems Safety Society and the National Society of Professional Engineers.

In addition, the center Steering Committee provides guidance to the operational activities of the center, while the Technical Advisory Committee reviews and refines the research agenda.

• Texas A&M University experts in chemical engineering, chemistry, industrial psychology and other departments

• The Hazard Reduction and Recovery Center, the largest research center in the world for studying the effects of natural and technological hazards

• The Department of Aerospace Engineering’s Low Speed Wind Tunnel, a self-contained research facility capable of conducting a wide variety

of tests for industry, governmental agencies, educational institutions and private individuals

• The state-of-the-art Brayton Fire Training Field, which includes full-scale buildings, towers, tanks and industrial plant structures for training simulations for career and volunteer firefighters and fire marshals

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Relationship between Inherently Safer Design and Equipment Reliability

Modeling Cryogenic (e.g., LNG) Vaporization Source-Term

Executive Order 13650 issued by the President of the United States in May 2014 recognizes inherent safety as the top most node in the hierarchy of elements of safer technology and alternatives for a chemical plant. However, making a process inherently safer can have an effect on the overall reliability of the process; thus, ultimately affecting the financials of the chemical plant. The impact of inherently safer principles towards risk reduction is paramount in the process selection and conceptual stages of the chemical plant. Thus these stages prove to be ideal in magnifying the effect of implementing inherently safer design principles on the overall reliability of the chemical plant. This research deals with the effect of implementation of the inherently safer principles of intensification, substitution, attenuation, limitation & simplicity on plant economics in the process selection and conceptual stages of the chemical plant by affecting the overall reliability of the chemical plant. This work also provides a methodology to optimize the plant economics through reliability analysis during the process selection and conceptual stages of the chemical plant while keeping the risk associated with the chemical plant below a specified level by implementing inherently safer principles.

Nilesh Ade

Vapor formation due to boiling is one of the major areas of concern in source-term modeling. The realistic estimation of cryogenic release consequences (e.g., LNG and LN2) primarily depends on the accurate determination of its boil-off rate due to the heat transfer from the substrate. The computational estimation of the boil-off rate during the developing stage of the pool is not trivial because of the complicated physics of boiling regimes, the time-dependent nature of pool spreading, the nature of the substrate, etc. The aim of this study is to simulate pool boiling of cryogenic mixtures for more accurate estimations of LNG source term modeling. To accomplish this, user-defined physics functions of boiling and CFD are used.

Monir Ahammad

Polymers are widely used in our day-to-day lives and we often are unaware of the fire hazard posed by these materials made up of hydrocarbons. Polymer nanocomposites have the potential to lead the way for satisfying material performance with enhanced flame retardancy in terms of char production. The main objective of this research is to gain a fundamental understanding of the flame retardancy of polymers through the study of thermal stability, flammability, and char yield. For this purpose, the in-situ polymerization method for synthesizing polymer nanocomposites have been developed, which will be further subject to characterization techniques for thermal and kinetic studies. Thermo-gravimetric analysis equipment is used for the purpose of thermal studies, whereas Cone calorimeter is employed for flammability studies.

Lubna Ahmed

Synthesis and Characterization of Polymer Nanocomposites for Fundamental Understanding of Flammability and Thermal Degradation Kinetics

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Tennessee Eastman Problem - Process Control and Alarm Design

Dust explosions have been persistent in industry, claiming lives and causing significant property damage. These explosions are characterized by severity [Pmax, dP/dT, Kst] and ease of ignition [MIE, MEC, MIT]. Studies have found that these characteristics depend upon particle size, chemical composition and dispersity. However, the dependence of the explosion characteristics on shape and morphology has not been studied. Although the variation of explosion characteristics with particle size is well understood for micro-dust, those variations cannot be extrapolated to nano-size regime due to agglomeration and non-uniform dispersion of nano-dusts. The understanding of dispersion phenomena and its effect on agglomerate size and explosion characteristics of combustible nano-dusts is limited. The main objective of the current research is to address the influence of particle shape and morphology on the dust explosion characteristics such as Pmax, MIE, Kst etc. It also aims to study the effects of dispersion, and the shear associated with it, on the nano-dust agglomerate size, particle size distribution and its explosion characteristics. This research will help to fill a gap in understanding dust explosion dependence on its particle properties and the dispersion effect on nanoparticle size and explosion characteristics.

Pranav Bagaria

There have been many recent developments in the field of process control and instrumentation in the last few decades. A number of incidents that happened in the recent past could have been controlled if not for the multiple alarms that arose simultaneously in the operator panel during an upset condi-tion known as ‘alarm flooding’. This research focuses on developing a scientific approach to alarm design on the Tennessee Eastman problem that constitutes a pressurized system with exothermic reactions and a recycle stream. The highly integrated nonlinear process provides a good platform for studying effective alarm design that not only prevents alarm flooding during abnormal situations, but also guides the operator in order to contain the scenario from reaching undesired consequences that could cause human/property loss or environmental damage.

Joshiba Ariamuthu

Venkidasalapathy

Effect of Morphology on Dust Explosion and the Effect of Shear Force while on Dispersed Combustible Nano-Dust

Hydrate formation has been seen as one of the most challenging problems in deepwater production operations because of the low temperatures and high pressures found in deepwater environments. Hydrate formation and its agglomeration in subsea production equipment can cause severe operational issues, lead to substantial asset damage (i.e., high economic cost), and most importantly, hydrate formation can cause significant process safety and environmental issues. Examples of the problems caused by hydrates include blockage in wells, risers, flowlines and manifolds. These blockages can increase the pressure in the system causing equipment damage (e.g., rupture) and potentially resulting in loss of hydrocarbon containment into the environment. This research analyzes common subsea production systems in order to identify different scenarios in which hydrate formation could occur and lead to safety and environmental problems. The goal is also to identify potential measures to prevent and control the formation of hydrates in order to increase the reliability and safe operations of deepwater subsea production systems.

Susana Leon Caceras

Process Safety Problems Caused by HydrateFormation in Deepwater Production Operations

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Bayesian Network (BN) has become increasingly popular to incorporate changes during operational phase of the project. Operation of an offshore oil and gas production platform is complex and dynamic in nature which makes the probability of process safety incidents estimated during the design phase obsolete. The Bayesian technique allows new information such as process safety leading and lagging indicators, equipment degradations, and human factors to be used for obtaining the posterior probability. Bayesian data analysis has proved to be an effective approach in dynamic risk assessment but the quantitative comparison between different hazard identification techniques was not found. This research compares the likelihood of process safety incidents between HAZOP-BN and Bowtie-BN at offshore oil and gas production platforms. Process safety leading and lagging indicators are also incorporated to reflect changes in process safety performance and provide framework for continuous updating of probability and risk of process safety incidents in the future. Pakorn Chaiwat

Liquefied Natural Gas (LNG) pool fires pose a major risk to LNG facilities. The radiant energy from an LNG pool fire can be sufficiently high to threaten the structural integrity of the facility, plant personnel, fire fighters, and potentially surrounding community. Current safety analysis involves the use of empirical models to assess the effects of a pool fire. Application of these models to pool fires of different size poses significant uncertainty in terms of underestimation of key parameters. This research develops a methodology using a CFD model to advance the knowledge of LNG pool fires. The Fire Dynamic Simulator (FDS) code is applied to pool fires of various sizes. The model is validated by experimental data obtained from pool fire experiments performed at the Brayton Fire Training Field (BFTF) in College Station, Texas.

Dushyant Chaudhari

Application of Computational Fluid Dynamics (CFD) to Simulate LNG Pool Fires

Dust explosions continue to provide a constant hazard to the process industries; thus, mitigation remains an important field of research. Studies have found that the minimum ignition energy (MIE) of a dust is influenced by factors such as temperature, pressure, oxygen concentration and particle size. Industrially, partial inerting has various advantages over other mitigation techniques and is one of the lesser explored areas in dust explosion mitigation. There is limited understanding of the dust explosion mechanism and less available literature in this area. The objective of the current research is to study the effect of inerting on Minimum Ignition Energy (MIE) for different family of materials. The study also aims to develop a model considering the molecular (bond energies) and macroscopic (limiting oxygen content- LOC) aspects to explain the ignition behavior of dusts under varying conditions.

Purvali Chaudhari

Effect of Partial Inerting on Minimum Ignition Characteristics of Dusts

Comparison of HAZOP-BN and Bowtie-BN for Offshore Production Platform

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Corrosion is the primary factor that leads to the aging and deterioration of pipelines, which then evolves to ruptures, leaks, and possible catastrophic damage, serious economic loss and fatalities. In order to prevent corrosion-related incidents, an improved prediction model for risk-based inspection in corrosion is needed. With this research a Bayesian Network modeling the kinetics of corrosion is developed to obtain a credible evaluation of the risk, making it possible to establish a statistical model of the kinetics of each corrosion point and to estimate the probability associated with the risk of failure. Thus, it can help anticipate an optimal planning of the in-line inspection intervals, which can decrease failure risk of the pipeline to an acceptable level and achieve cost-effective pipeline integrity management.

Yan Cui

Compared to the petro-chemical and bulk chemical industry, where continuous processes are widely applied, the pharmaceutical industry still primarily relies on traditional batch processes due to the characteristics of pharmaceutical manufacturing (complex substance, multi-step operation, low-volume production, unstable product). Driven by the contrasting factors of increasing demand for drugs and a less efficient production mode, pharmaceutical industries are trying to transform from a traditional batch process to a continuous one. Some trials aimed at transitioning from a lab-scale to a small factory have proven the practicability of continuous processing. Additionally, related economic analysis and environmental analysis have been done. This research aims to identify the main factors that affect safety in a continuous pharmaceutical process, and provide a comprehensive analysis of the continuous process in the pharmaceutical industry.

Shiqi Chen

Application of Inherent Safety in the Pharmaceutical Industry

Large amounts of substances are transported in pipelines worldwide. This activity represents a hazard that needs to be quantitatively assessed. The industry needs release models that are capable of accurately predicting the discharge rate from a pipeline. The expansion following the rupture causes some liquids, such as dense phase CO2, LNG or LPG, to produce a two-phase release. Current models cannot describe the behavior of a multiphase outflow following a pipeline puncture. Usually, when there is a puncture in a pipeline, the decompression rate is lower in comparison to a full bore rupture and the stratified regime predominates. Most of the models in the literature assume a homogeneous equilibrium approach which cannot describe this scenario accurately. Current research does not demonstrate a comprehensive understanding of the cavitation process during the puncture of a pipeline transporting volatile substances. More specifically, there is a research gap in the study of the cavitation phenomenon around the orifice of the release. This research topic will provide a better picture of the phase transition when a pressurized pipeline is punctured. It will clarify how the inner flow regime changes from dispersed to stratified. Furthermore, the study of cavitation may provide a fundamental understanding about the functionality of the discharge coefficient. Usually, this parameter is assumed to be constant during the puncture, while it is generally understood to vary with the functionality currently unknown.

Tatiana Flechas

Modeling of Flashing Fluids Discharging Through a Pipeline Puncture

Application of Bayesian Network in Risk Assessment of Corrosion

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Flammability Characteristics of Light Hydrocarbons and its Mixtures at Elevated Conditions

Flammability limits of combustible gases like hydrogen, methane and propane can be influenced by many factors such as temperature, pressure and humidity. When combustible gas mixtures are ignited, large amounts of reaction energy will be released in a short period of time, which can cause deflagration or even detonation. Moreover, the highly exothermic reaction poses threats to the facility and people. The objective of this research is to study the flammability characteristics of combustible gases at elevated conditions (high temperature and high pressure) and propose corresponding methods to handling them safely. By using both experimental data and theoretical calculations, an improved Le Chatelier Law is postulated and tested to better predict the flammability limits of combustible mixtures.

Ning Gan

Systems Approach to Improve Learning from Incidents

Although companies and regulators have been working in the development of incident investigation methodologies, it is not evident that significant improvement has been made in the learning process. Incidents such as the Mexico City explosion (1984), BP Texas City Refinery (2005), and West, Texas (2013) continue to occur. This history of incidents reflects a need for strengthening human and organizational learning processes. This research will develop an appropriate approach to learn from incidents and identify the gaps in current incident investigation practices. A systems approach will be applied to analyze the problem in a holistic way. To achieve these goals, this work will be focused on understanding the learning process of individuals and organizations and how organizations are communicating and sharing lessons learned to prevent future incidents.

Juliana Guarguati

The presence of atomic hydrogen in metals plays an important part in a number of fracture mechanisms in metals in the process industries, including embrittlement and corrosion mechanisms. In addition, grain structure also plays an important role in determining the strength and mechanical properties of metals. The generation, migration and diffusion of hydrogen is difficult to assess strictly on an experimental level, and its interaction and synergistic effects with multi-grain systems is less-well understood. The interaction of hydrogen with metals important to the process industries is being carried out in four stages: 1) A multigrain random, but periodic 3-D model of a metal is developed with a customized computer model written for the research using Molecular Dynamics. The model can be set to position any type of metal crystal or alloy with varying concentrations of hydrogen introduced. 2) The model is validated using a pure metal versus previous work. In this case, palladium is studied to compare to previous research and validate the multi-grain character is as expected. 3) The palladium modeling is repeated at varying levels of hydrogen present to check the behavior of the grain hydrogen interaction. This also allows comparison to previous work performed for single crystal behavior. 4) The validated model is applied to an alloy of interest to the process industry, such as nickel-chrome alloys or steel alloys and the hydrogen effects studied under different process conditions.

Richard Gustafson

Effects of Hydrogen on the Strength and Fracture Characteristics of Multigrain Metals

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Cumulative Risk Assessment Model to AnalyzeIncreased Risk due to Impaired Barriers in Offshore Drilling Rigs

In today’s sizeable facilities, the whole picture of risk cannot be obtained based on identifying only the major incident hazards. There is an increased potential for adverse consequences resulting from equipment, procedure or a person not doing the work properly. The threat from the cumulative effect of a number of such deviations (such as delayed maintenance, aging assets, loss of redundancy, and insufficient competency) can be significant. In order to assess total risk, we need to consider technical, operational, human and organizational factors. At the same time, risk assessment should address the complexity and size of the system along with temporal aspects and dependencies of components and uncertainties of parameter estimation. However, the literature review performed found that although certain models and framework existed that covered part of the requirement, none of the models could quantitatively accommodate all of the factors mentioned above. Current research, thus, focuses on developing a framework that integrates technical, operational, human and organizational factors and developing a model based on the framework such that the model is quantitative, dynamic, addresses dependencies, and is capable of handling uncertainties.

Zohra Halim

A large percentage of the raw materials, intermediates, and finished products in the chemical process industry are solids. Processing of the solids often results in dusts which, when suspended in air, have the potential to result in a deflagration if the concentration is adequate and a minimum amount of ignition energy is present (MIE). This situation becomes more complex when a flammable gas or vapor is present along with the dust, resulting in a hybrid system. The hybrid minimum ignition energy (HMIE) is the smallest amount of energy required to ignite a dust/gas system. There is limited understanding of the interactions between combustible dust and flammable gas during the ignition process. Models to predict the HMIE are limited in the research literature. The objective of this current research is to study the fundamental contributions of the hybrid flammable dust/gas systems for various families of materials to develop better prediction models.

Haitian Han

Layer of Protection Analysis (LOPA) is a semi-quantitative method to identify and analyze the significance of potential major incident scenarios associated with the processing or handling of highly hazardous chemicals. As a risk assessment method, LOPA has some disadvantages, mostly connected with limited availability and uncertainty of the failure rate of all safeguard systems and with the assumption that the severity of consequences remains constant with the activity of independent protection layers (IPLs). These research gaps will be filled by a hybrid fuzzy logic and probability theory method. Fuzzy logic, a method to deal with uncertainty and imprecision, is an efficient tool to solve problems where no sharp boundaries are possible.

Yizhi Hong

A Hybrid Fuzzy Logic and Probability Theory Method to Quantify the Uncertainty in Layer of Protection Analysis

Dust-Gas Hybrid Minimum Ignition Energy Prediction

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Resilience Analysis Framework for Process Design and Operations

Alkylpyridine N-oxides are used in the pharmaceutical industries to synthesize analgesic and anti-inflammatory drugs. Currently, the N-oxides are produced in semi-batch reactors where alkylpyridines are oxidized with hydrogen peroxide (35% solution) and a phosphotungstic acid catalyst. However, the N-oxidation is accompanied by the undesired, condition-dependent decomposition of hydrogen peroxide. A runaway of this reaction may result in a rapid generation of oxygen and temperature rise in the alkylpyridine flammable environment, with the additional potential to over pressurize the reaction vessel and/or trigger secondary decompositions of the product. The decomposition of hydrogen peroxide is exacerbated during the N-oxidation of higher order alkylpyridines due to the mass transfer resistance caused by the formation of an organic phase and an aqueous phase. The water-soluble catalyst causes severe decomposition of the peroxide, jeopardizing the safety of the process, and reducing its efficiency.

This research is focused on predicting the phase equilibrium for an alkylpyridine-N-oxide-water-catalyst system. According to previously published literature, the N-oxide increases the solubility of alkylpyridines in the water phase. The equilibrium studies would identify the component compositions for which a homogeneous system prevails. The improvement in the selectivity and yield of the N-oxide synthesis reaction, when conducted homogeneously, will also be studied.

Increasing process safety and risk management challenges in the process industries and change in the public perception of hazards and risk globally have necessitated exploring tools for efficient risk management. The application of the resilience engineering perspective is gradually being explored as an approach for considering the dynamics of socio-technical aspects based on systems theory. The resilience methodology emphasizes non-linear dynamics, new types of threats, uncertainty and recovery from upset or catastrophic situations. The main focus of this research is to propose a holistic method to integrate both technical (process parameters variations) and social (policy/regulations, human and organizational) factors including prediction, survival and recovery analysis for process facilities. The framework developed in this research is called Process Resilience Analysis Framework (PRAF) comprising of four aspects: early detection, error tolerant design, plasticity, and recoverability. PRAF would be applicable to both onshore and offshore installations, primarily focusing on early detection of unsafe zones, assessment of aggregate risks and prioritization of safety barriers during abnormal situations, and reduction in response time resulting in enhanced recovery and mitigation of consequences.

Prerna Jain

Sunder Janardanan

Phase Equilibrium Studies on N-oxidation Systems to Identify Inherently Safer Operating Conditions

This research serves as a quantitative assessment of the LNG Floating Storage and Regasification Unit (LNG-FSRU). Compared to other loading/unloading facilities, the LNG-FSRU system has some outstanding advantages on both building and operation phases; it is a cost-effective and time efficient LNG solution and it has a minimal footprint since it brings few impacts to the surrounding environment as well. The main objective of this research is to incorporate the MADA approach in the infrastructure layout parameters to optimize the construction location. Many typical approaches of system safety engineering such as Process Hazard Analysis (PHA), cause-effect tree and Analytic Hierarchy Process (AHP) are applied in the risk-based analysis among a wide range of scenarios. Based on the previous data, the software R and AgenaRisk will be applied to simulate the outputs of different scenarios.

Chenxi Ji

Quantitative Risk Assessment of LNG-FSRU SystemBased on Multi-Attribute Decision Analysis (MADA) Model

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Microbiologically Influenced Corrosion (MIC) is a form of corrosion that is either caused or accelerated by the presence of microbiota on the surface of metals and other materials of construction. It is a widespread problem due to the fact that these industries routinely employ large-scale use of fluids, which are inherently contaminated by microorganisms. This problem is further exacerbated by the recent surge in fracking operations that also use large quantities of water, and makes it imperative to detect and mitigate MIC. MIC control is achieved primarily through the use of biocides, which come with associated economic and environmental costs. Hence, an early-detection system which is real-time/pseudo real-time would be a great tool to help combat MIC at an early stage before it becomes widespread through bio-film formation. This early detection is important for systems that use fluids in hard-to-access and harsh environments, such as sub-sea pipelines. The objective of this research is to develop a sensor based on a nanowire matrix which is functionalized with bio-molecules to detect these microorganisms on a real-time basis. These sensors are aimed towards high precision and specificity owing to their large surface areas functionalized with bio-molecules and may be mounted on pigs (devices used in maintenance of pipelines) or at multiple locations where MIC is suspected. This would be a great tool for devising mitigation strategies; thus, reducing environmental and economic cost of MIC.

Pranav Kannan

Microbially influenced corrosion (MIC) is a major problem in various sectors including chemical process plants, onshore and offshore oil and gas, pipelines, marine and aviation industries. Annual losses associated with MIC in the United States are estimated to be $50 billion. MIC often develops as a result of biofilm formation by multiple microbial species that form well-defined and organized structures. Development of effective mitigation strategies for MIC requires a fundamental understanding of how biofilms are formed. This study investigates the factors underlying formation and development of dual-culture biofilms. Using Shewanella oneidensis and Vibrio natriegens as the model aerobic biofilm forming species and Desulfovibrio vulgaris as the model anaerobe and sulfate reducing bacterium, we investigated the dynamics of biofilm formation using a microfluidic flow cell. The experimental system consists of a flow channel in a microfluidic device made of polydimethylsiloxane that is bonded to a glass slide with coated metal electrodes. Co-culture biofilms of S. oneidensis, D. vulgaris, V. natriegens developed in this system are used to develop a correlation between the biomass of the biofilm as measured by confocal laser scanning microscope (CLSM) and impedance measurement from electron impedance spectroscopy (EIS). These parameters measured are analyzed along with SEM images of the metal electrodes to give an understanding of the extent of MIC from a biofilm perspective. The effect of hydrodynamic factors like flow rate and shear stress on biofilm dynamics is then investigated. In addition, the effect of various typical biocides on these co-culture biofilms is studied with respect to biocide penetration, efficacy of the kill and biofilm regrowth.

Susmitha Purnima Kotu

Development of a Smart Sensor for the Detection and Mitigation of Microbiology Influenced Corrosion (MIC)

Integration of Electron Impedance Spectroscopy and Microfluidicsfor Investigating Microbially Influenced Corrosion Using Co-Culture Biofilms

Flash point is widely used as the parameter to categorize liquid flammability in various standards. However, this categorization methodology does not consider liquid behavior under extreme conditions, e.g., high pressure and high temperature. When a liquid is released from containment under such conditions, aerosol or mist will form, and the flammability of aerosol is still not clearly defined even though it has been studied for decades. Since the potential hazards of aerosol are not recognized and addressed properly, the consequences of aerosol hazards may be more severe than flammable vapor hazards. Moreover, the flame speed of aerosol may be higher than that of vapor under certain conditions. Therefore, several hydrocarbons are being tested and the trend of their flame propagation speeds is also being studied to resolve the contradiction between different theories.

Yan-Ru Lin

Flame Propagation Speed of Aerosols Generated by Electrospray

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Teflon lined pipes are widely used in industry to transport highly toxic and corrosive materials. This lining has dielectric properties which can allow the accumulation of energy in the fluid giving rise to the generation of electrostatic discharges known as propagating brush discharges. The release of energy is capable of creating pinholes in the insulating material, thus leaving the steel pipe exposed. This can be a concern in the case of a batch process where a pipe can be used for multipurpose transport of chemicals. If both non-conductive and corrosive fluids flow through the same pipe, the potential of loss of containment may be present. This research studies corrosion on Teflon lined pipes which have been pierced in order to understand the reduction of the life span of the pipe to help design an adequate inspection and maintenance plan in process facilities.

Edna Mendez

A number of oil and chemical industry companies use SP P&ID (Smart Plant Piping and Instrumentation Diagram) program instead of an AutoCAD-based program. This new technology helps recognize the most current state of a plant or project more easily with relevant process data. Utilizing the inserted data on SP P&ID, hazard identification can be conducted automatically. Hence, with the use of this Smart P&ID and Blended HAZID software, this research will focus on abnormal scenarios and/or updated current conditions with preceding accumulated data.

Sunhwa Park

Blended HAZID in System Approach

Corrosion on Teflon Lined Pipes Pierced by Propagating Brush Discharge

Pipelines have been the most common and preferred method of transportation for various chemicals including natural gas due to its safe and economic advantages. However, pipeline incidents remain a factor for the public and environment exposing industries to scrutiny. From 1996-2015, the number of pipeline incidents had been more than 250 per year on an average and has resulted in a loss of more than $6.3 billion, implying that a problem exists and should be addressed. This research is aimed at identifying hazards and risks associated with pipelines, assessing risk quantitatively using a mathematical model and comparing the results with a real-time framework of pipeline incidents.

Visalatchi Palaniappan

Development of a Tool for Pipeline Risk Assessment

Land-use planning (LUP) is the process of identifying and assessing the potential hazards that oil, gas, and chemical facilities may pose to surrounding areas in an effort to ensure that the impact of potential incidents are taken into consideration when decisions are made concerning the siting of new facilities, modification of existing facilities and the proposal for new developments in the vicinity of establishments. Incidents such as Bhopal, India (1984), West, Texas (2013) and Tianjin, China (2015) highlight the need for a solution. However, there is no easy solution; multiple approaches, factors, and regulatory climates exist throughout the world. This research is aimed at reviewing existing countries’ LUP policy, identifying best practice and how to improve LUP in the United States.

Jake Marek

Land-Use Planning in Relation to Chemical Facilities and Associated Issues

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Although spontaneously combustible substances (like some peroxides) have been used extensively in most chemical industries, there is a need to provide methodologies for the safer handling of these chemicals. The same properties that make a chemical hazardous also make it useful. Thus, a systematic approach to handle these types of chemicals with an individual hazard review, consequence analysis, and risk assessment will help us understand these materials better. This research is aimed at identifying the best practices for handling spontaneously combustible materials.

Abhishek Proddutoor

Systematic Analysis of Spontaneously Combustible Substances

Out of the 281 combustible dust incidents identified by U.S. Chemical Safety and Hazard Investigation Board between 1980 and 2005, 66 have been attributed to ‘Wood and Paper dust’. Despite intensive research focus devoted to this area, dust explosions in wood and paper products industries continue to occur, which emphasizes that a major portion of the physics behind the wood or paper dust explosion phenomena is yet to be clearly understood. The objective of this research is to understand the physics behind wood and paper dust explosions and develop computational fluid dynamics models to study relevant characteristics of dust explosions to reduce combustible dust hazards in an industrial setting.

Bharatvaaj Ravi

Wood and Paper Flammability and Explosion Modeling

Supply chain network design and optimization is very important in decision making, which gives the power to stakeholders to assess the gigantic supply chains to increase profit while minimizing risks. Risks in supply chains arise from various sources (e.g., demands, supply). One of the important sources is the supply chain disruptions caused by chemical and process hazards during the transportation, manufacturing and storage of chemicals. Quantification of chemical and process hazard is necessary in decision making and is one of the challenges faced by the chemical process industry. Moreover, due to the complexities of the process and limited understanding of the chemicals, the risk and hazards posed are uncertain in nature. Robust optimization is a technique used to take into account the uncertainty in parameters of the model. This study proposes to develop a novel framework of multi criteria decision making (MCDM) and analyzing supply chain network design and process safety holistically while accounting for the uncertainties. This work shows how the hazards in the supply chain will not only drive the upper bounds on the flow for each entity in the supply chain, but also as an overall basis. Secondly, the general supply chain formulation has been revised to integrate these bounds. The supply chain formulation used is a mixed integer linear programming model with a case study in ammonia supply chain. As future work, robust optimization will be used to extend the MILP formulation formed to account for the uncertainties in the hazard quantification.

Nitin Roy

Incorporation of Process Safety in Design and Optimization of Hazardous Chemical Supply Chain Networks

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The Integration of Consequence Modeling and Flammability Limits into Process Design and Control

With the use of heat transfer fluids in heat transfer systems the risk of fire is always present due to the presence of fuel, air & ignition source. In addition, the presence of foreign contaminants can increase the rate of thermal degradation of HTF or lead to mechanical failures of these systems. The goals of the research include understanding these systems, the properties of HTFs, the existing safety practices and the identification of associated hazards to work towards developing an inherently safer design of heat transfer systems.

Richa Sarkar

Safety in Design of Heat Transfer Systems

Terephthalic acid is an aromatic carboxylic acid used principally as a precursor to polyester. A large majority of the production of terephthalic acid (TPA) is via a commercialized process commonly known as the AMOCO process which is a homogeneous oxidation reaction of p-Xylene with air as oxidant and acetic acid as solvent, catalyzed by cobalt and manganese together with bromide compound as a promoter. This process is conducted at a high temperature (175–225 °C) and high pressure (1.5-3MPa), with a hazard of corrosion due to the corrosive nature of acidic medium. Concerns about environmental issues and process safety have driven studies to find milder oxidation reactions of p-Xylene. The objectives of the research include a comprehensive safety assessment of the p-Xylene oxidation to terephthalic acid and find inherently safer conditions for TPA production.

Yueqi Shen

Inherently Safer Conditions for the Oxidation of p-Xylene to Terephthalic Acid

This research incorporates flammability limits and risk-based consequence modeling in the optimization of design and control algorithms. Flammable substances that undergo exothermic reactions are prevalent in the chemical and petrochemical industries. Flammability limits describe the composition of gas that can propagate a flame and are an important constraint to consider at each stage in plant design. Fire and explosion incidents can occur if process variables exceed flammability limits, resulting not only in a safety incident, but also in economic losses such as the destruction of property and shutdown of the plant. Despite this, there has been limited work in the incorporation of flammability limits as a hard constraint in process design and control. Furthermore, consequence analysis is necessary to determine the levels of mitigation and protection needed in critical process areas. However, the current literature has not succeeded in incorporating risk-based consequence models in plant design and control algorithms. The success of this research will assist in reducing the cost of operation while maintaining low levels of risk.

Denis Su-Feher

15

Scale up of Reaction with Runaway Potential

Thermal runaway reactions may cause severe fire and explosions incidents. The 2007 T2 Laboratories Inc. explosion in Jacksonville, FL is one example, which was caused by a runaway chemical reaction and cooling system failure. Often, when dealing with a chemical reaction with thermal runaway potential on a small-scale, the reactions can be controlled. However, when it comes to industry large-scale opeartions, safety issues are critical. This research is aimed at studying, experimentally and theoretically, chemical reactions with thermal runaway potential and the thermal and kinetic behavior of different chemical reactions at different scales. The findings will be used to provide a better understanding for scale-up of chemical reactions with runaway potential and to propose measures for reducing the risk of a thermal runaway.

Yue Sun

Leading indicators are effective organizational tools that can identify vulnerabilities in a risk management system and predict potential process safety events. Offshore drilling operations and well activities have always been very challenging due to technological and operational complexities, and it is quite difficult to develop well specified risk indicators for these high risk operations. This research aims to develop a leading risk indicators model for offshore drilling and other well activities (e.g., workover) to predict gas kicks and possible blowout scenarios. Upon analyzing different guidelines and drilling practices, a comprehensive categorization of leading indicators is proposed considering the complexities of the drilling and well activities. This work proposes a cause-based approach to develop sets of leading indicators for different categories and organizational levels. For example, real-time/instantaneous indicators have been identified for operational or rig-site use and long-term indicators based on organizational safety practices and performances have been developed for management use. Simple decision support algorithms have also been constructed correlating physical observables and associated causal factors with actions required for early gas kick detection. This work continues to build a comprehensive risk model combining real-time indicators with operational and organizational aspects to predict and prevent blowout incidents.

Nafiz Tamim

A Framework for Developing Leading Indicators for Offshore Blowout Incidents

This research will look at flare radiation criteria and development of generalized methodology for flare design. During the design of flares, facilities meet the flare radiation criteria, but vendors only provide data for thermal radiation from the flare and discount the effect of solar radiation. This research will look at bridging this gap. A general practice can be simply adding the maximum incident solar radiation to thermal radiation from the flare, but the results will not be accurate. To improve upon this conservative approach, the geometric configuration factor and environmental conditions that affect the contribution of solar radiation to the overall radiation from flare will be considered. Another area to be analyzed is with regards to the fact that the sun and the flame emit radiation over different bands of wavelength.

Ankita Taneja

Flare Radiation Criteria and Flare Design

16

Modeling the Aerosol Generating Process by Electrospray and Controller Design

The degree of process intensification for the reactor must be optimized. The intensified reactor, though more efficient with enhanced mass and heat transfer, is usually subject to higher probability of failure because of its higher heat generation and more concentrated hazardous materials. This is not guaranteed to be safer than the large scale process. Besides, chemical process safety cannot be viewed in isolation from other process and plant design criteria. The chemical plant must meet many requirements for workers, owners, customers, neighbors and government. Considering all the above mentioned issues, an interesting optimization problem in terms of degree of process intensification can be established, which will incorporate both the safety and economic objectives so as to achieve a safer and more profitable chemical process.

Data mining is a process used to explore patterns and extract useful information from big databases. It has been widely used in business and marketing for many years, and it is becoming even more widely used in the field of engineering. In contrast to some data giants, such as Amazon and Google, who treat data as high-value assets, process industries collect massive operation data from sensors, but this data is seldom explored deeply or is only analyzed after incidents occur. However, incidents do have an incubation period during which events develop and accumulate without being detected. Some of the events are called weak signals since they are difficult to recognize, but they are early indications for incidents. Thus, the goal of the research is to apply data mining techniques in process industry to detect weak signals, so that corrective actions can be taken and prevent incidents.

Jingyao Wang

Mengxi Yu

In reactors, the release of hydrocarbons at high pressure can generate aerosol particles with a size distribution, which determines the minimum ignition energy for explosion. Hence, for safety purposes, regulating the size distribution of the aerosol particles is of interest. Initial efforts will be focused on the development of a high-fidelity model that describes the spatiotemporal evolution of the size distribution of aerosol particles generated by electrospray. The developed model will be validated against experimental data. Specifically, the test fluid will be stored in syringes and dispensed through a syringe pump. Ten nozzles will be assembled on a small metal plate which is connected to a high voltage electrode (HV1). Also, a metal mesh will be placed right beneath the metal plate, which is connected to a second-high voltage electrode (HV2). The high voltage difference between the two electrodes will ionize the fluid. After model validation, a reduced-order model of this high-fidelity model will be derived and used to design a feedback control system that produces aerosol particles with a desired size distribution.

Shuai Yuan

Reactor Inherently Safer Design by Process Intensification

Weak Signal Detection Using Data Mining Techniques

17

The Use of Finite Element Method (FEM) in Modeling Mechanoelectrochemical Effect of Corrosion

Corrosion can cause significant failures in pipelines which results in serious consequences in safety (e.g., Chevron Richmond Refinery Pipe Rupture and Fire in 2012 and Silver Eagle Refinery Catastrophic Pipe Explosion in 2009). In this research, the finite element method (FEM) is applied, in which the electrochemical and mechanical models are coupled to evaluate the mechanoelectrochemical effects regarding the corrosion defects, including concentration, potential/current and stress field distributions. This research will help understand controlling factors, anticipate a reliable method to predict the corrosion defects on pipelines under complex stress and strain conditions, and develop recommendations for risk assessment and integrity management.

Lihan Zeng

Nitro Aromatic Compounds are important intermediates in the chemical industry. Mononitrotoluene (MNT) and Dinitrotoluene (DNT) are two typical nitro aromatic compounds used in the production of dyes, rubber chemicals, flexible foams and agricultural chemicals. However, incident history demonstrates inadequate recognition and evaluation of reactive hazards of nitro aromatic compounds. Tests prove that nitro aromatic compounds, if held at elevated temperatures for an extended time, are susceptible to thermal decomposition and may react at temperatures lower than the predicted ‘onset temperature.’ Moreover, contaminants such as nitric acid, sulfuric acid and traces of salts may lower the thermal stability of nitro aromatic compounds. Therefore, MNT or DNT, if held at elevated conditions, may result in temperature and pressure runaway. Accordingly, a comprehensive risk assessment for the nitro aromatic compounds in the presence of other chemicals is essential to prevent incident occurrence. Wen Zhu

Sour Gas Dispersion Modeling

Due to the increasing demands for energy, the oil field operators and developers have turned their interests toward sour gas fields to explore more natural gas. Sour gas fields have high concentration of hydrogen sulfide (H2S), which is very toxic and flammable. If sour gas leaks to the air it behaves as a heavy gas; thus, the cloud will disperse by falling to the ground, affecting human health and the environment. Therefore, it is paramount to study the behavior of the dispersed sour gas cloud and to predict the concentration of H2S in the cloud. The current literature mostly models the sour gas cloud as pure H2S rather than a mixture (H2S and CO2), which could lead to an inaccurate prediction of H2S concentration in the dispersed cloud. The objective of this research is to study the dispersion phenomenon of H2S mixture in the air and be able to characterize the phenomenon using the fundamental mathematics transportation model. The developed model will be applied to improve the prediction of H2S concentration in the dispersed cloud, and thus, to provide a better assessment of the consequences of H2S releases.

Jiayong Zhu

Thermal Risk Analysis of Nitro Aromatic Compounds in the Presence of other Chemicals

18

Nanowires are one-dimensional nanostructures with diameters less than one hundred nanometers and a length-to-width ratio greater than one thousand. Nanowires can be used in a wide variety of applications, including thermoelectric electricity generation, which involves applying a temperature gradient across a thermoelectric material to produce current. Thermoelectric generators can be a viable source of clean energy and bolster the nation’s energy security amid dwindling reserves of conventional fossil fuels. A major advantage of using thermoelectric generators is that they have no moving parts, making them silent, robust and reliable. However, these generators currently operate at very low efficiencies. Nanowires are promising for thermoelectric electricity generation, as they have been shown to improve the efficiency of thermoelectric generators over bulk materials. An increase in the efficiency of thermoelectric generators will lead to an increase in the economic feasibility of processes such as waste heat harvesting in aircraft and cars, resulting in accelerated commercialization of the generators. Innovation in the production of thermoelectric generators

is especially important in space related research, as these devices can be used to reliably power probes in deep space, where photovoltaic cells are ineffective. In fact, radioisotope thermoelectric generators currently power NASA’s Voyager and Cassini spacecraft. In conclusion, nanowires produced from novel materials have the potential to increase the efficiencies of thermoelectric generators and pave the way for widespread use of these generators in both terrestrial and space applications. Currently, research is being performed for producing nanowires from various materials such as silicon and magnesium silicide.

Ali Azhar

Large-scale synthesis and assembly of nanomaterials, e.g., nanowires, is one of the major challenges of commercial applications of nanotechnology. For instance, zinc phosphide (Zn3P2) nanowires, which are synthesized on a zinc foil and manually scraped from the substrate, contain an appreciable amount of bulk zinc metal when they are assembled into a pellet form by hydraulic press. This results in loss in quantity of Zn3P2 nanowires and reduction in performance of the device. Herein, a simple approach to synthesizing a bulk-scale assembly of Zn3P2 nanowires is developed. In this method, a zinc pellet with sacrificial salt is directly converted to a Zn3P2 nanowire pellet. This technology can be applied to other types of nanomaterials and allows the assembly of nanostructured materials into bulk form without introducing any byproduct.

Yixi Chen

A Novel Approach of Large-Scale Synthesis and Assembly of Nanostructured Materials

In order to serve all of its stakeholders, the Mary Kay O’Connor Process Safety Center has developed a group of faculty with expertise in various fields of research. This group includes Texas A&M University faculty members from Industrial Psychology, Chemistry, Chemical Engineering and Mechanical Engineering. In addition, the center brings in visiting scholars from throughout the world to work with its students and research staff. Students in the Faculty Fellows Program are involved in important safety-

related research efforts supported by the center.

Nanowires for Thermoelectric Applications

FACULTY FELLOWS PROGRAM

19

Following Amundson and Bilous’ landmark paper in 1955, which treated the stirred tank reactor as a dynamic system and used Lyapunov’s method of linearization to give a pair of algebraic conditions for local stability and to depict the global picture on the phase plane, two streams henceforth have dominated most of the work of understanding stirred tank reactors behaviors. Based upon the methods of singularity theory, the static current focuses on the systematic determination of the maximum number of steady-state solutions of a CSTR where several chemical reactions occur simultaneously and prediction of all possible types of diagrams describing the dependence of a state variable of the reactor on a design or operating variable. The dynamic branch emphasizes the question of stability of steady states and/or undamped oscillations in the form of limit cycles and exhibits the dynamic behaviors via phase plots. The present work aims at identifying hazards of the reaction of N-oxidation of alkylpyridines by hydrogen peroxide in a CSTR from the perspective of the multiplicity of steady states and the dynamics of the reacting system, and proposing an inherently safer and more efficient

reactor configuration of thermally coupling the exothermic reaction of the N-oxidation of alkylpyridines by hydrogen peroxide with a selected endothermic reaction in the same volume to achieve reactive cooling effect, i.e., the enthalpy released by the exothermic reaction is recovered in the chemical bonds of the endothermic reaction products. Furthermore, the benefits of the design would be verified and compared by proper risk and economic assessment methods.

Xiaohong Cui

Steady-state and Dynamic Analysis of N-oxidation of Alkylpyridines by Hydrogen Peroxide in a CSTR

Workplace safety has been receiving increasing attention by both researchers and organizations, as it is a source of substantial costs to organizations. Incidents may result in bodily injuries and property damage. One individual factor that may be responsible for incidents is safety behavior. Little is known about how individual mental models influence safety behaviors and the mechanism of such relationships. The current study aims to examine the impact of one kind of mental thought, counterfactual thinking, on safety behavior and several important predictors of safety behavior (e.g., safety knowledge and safety motivation) proposed as explanatory mechanisms for this association. This study will provide important evidence regarding the underlying mechanisms explaining why counterfactual thinking promotes safety behavior.

Yimin He

Counterfactual Thinking and Safety Behavior

20

Finding fundamental properties, such as flammability limits and burning velocity, of flammable gas and combustible dust are vital to understand and prevent incidents involving aerosols that can occur in manufacturing. In traditional aerosol experiments, there is an unknown amount of turbulence and uniformity, which results in facility dependent data that is less reliable when building models and predicting dust explosions. To improve on this, a schlieren system is being used in conjunction with the spherically expanding flame method to photograph the propagation of the flame front during the experiment. This allows the flame speed to be determined from both pressure and optical data. Having such a large optical access allows verification that the experiment is laminar and opens up the possibility of using new methods to check for repeatability and uniformity. These improvements will lead to more quantitative experiments and better measurements to prevent future catastrophes.

Travis Sikes

Burning Velocity of Suspended Dust Mixtures

Surface modified single ZrP (Zirconium Phosphate) nanosheets can be used to stabilize either emulsions or foams, which are called Pickering emulsions or Pickering foams, respectively. Pickering emulsions and foams have found various applications in areas as diverse as the food industry, oil industry, polymer and ceramic fields, paint products, fire distinguishing materials, and pharmacy areas. They are becoming the most popular type of soft matter, attracting world-wide attention. Here, we are trying to extend the use of ZrP nanosheet-based foams to the area of expansion foams as a mitigation measure for LNG spills and fire, and use the ZrP nanosheet-based emulsions for oil spill treatments. The optimum conditions for the application of the Pickering foam or emulsion are studied based on the particle size, the surface modification, and the choice of gas (for foam) or oil (for emulsion).

Xuezhen Wang

Pickering Emulsions and Foams for Process Safety

21

Mary Kay O’Connor Process Safety Center - Qatar

Study of the Infiltration of Toxic Gases in Non-process Areas

Although the majority of incidents involving toxic gas release in process industries occurs outdoors, nearby buildings and indoor environments are also at high risk. Particularly, non-process areas such as administration buildings and central utility plants are often the least protected, even though they are in the vicinity of potential sources. Toxic gas ingress in such areas takes place through cracks, openings and ventilation networks. Despite the significant risks posed by such events in process facilities, there is still a lack of data and comparative studies concerning the appropriate models and mitigation methods that can be utilized to study the ingress phenomena. The aim is to develop a model that can predict the ingress of toxic gas in a non-process area using a combination of multi-zone, CFD, and empirical models and explore the suitable mitigation methods in the event of a toxic gas release.

Atif Ashraf

Study of Polyethylene Dust and Sulfur Dust Explosion Characteristics

In a finely divided form, a combustible solid material suspended in air can, under certain conditions, present an explosion hazard. Over the last decades, many incidents in the process industries involving combustible dusts (e.g., chemicals, food, fertilizer, plastics, metal processing) have demonstrated that dust explosions can have catastrophic consequences including fatalities, severe injuries, damage to facilities, disruption of businesses and major financial losses. This research will include an experimental and theoretical study of polyethylene and sulfur dust explosions including the study of the influence of particle size distribution, dust concentration, and humidity on explosion behavior properties. This research also includes looking at the applicability of current dust models to both polyethylene and sulfur dust explosions. These explosion behavior properties would provide information in designing both preventive and protective measures in processes which use polyethylene or sulfur dust. Mohamed Kazmi

22

Modeling of LNG Pool Spreading on Land

The first stage of consequence modeling of liquefied natural gas (LNG) releases, also known as source-term modeling, is determining the release mode and the release rate of the hazardous materials. LNG is flammable, cryogenic and poses asphyxiation risks. The model is useful for scenarios such as the leakage of LNG from pumps, pipes and storage tanks in LNG facilities. While many models have been developed for LNG vapor cloud dispersion, its source-term models have not received as much attention. Experimental data for LNG spills on land is highly limited and mostly at small-scale. Current source-term models of LNG releases have only been validated against such data. The objective is to develop a source-term model that takes into account the effect of vaporization and conduction heat transfer during the spreading of an LNG pool on land. Large-scale liquid nitrogen spills will be conducted to validate the model.

Nisa Ulumuddin

Emergency relief systems (ERS) are the ultimate mitigation method to prevent vessel explosion following the runaway reaction. In the case of the runaway of gas producing chemical systems, ERS sizing requires the assessment of the maximum gas production rates. Significant work was performed in the 1980’s by the Design Institute for Emergency Relief Systems (DIERS) to develop vent sizing methods for runaway reaction cases. While, vent sizing methods developed for vapor systems provided relatively good results, the one developed for gas generating systems (hybrid or gassy) tend to be oversizing and still need to be improved. A very significant part of this work includes the improvement of current methods for the measurements of the maximum gas production rate for such systems. The objective of this research is to experimentally study the decomposition of a gas generating system under runaway conditions using adiabatic calorimetry and assess the maximum gas production rate corresponding to the runaway. A critical analysis of the current methodologies to interpret experimental data to compute the maximum gas production rate was done. The decomposition of Cumene Hydroperoxide (CHP) in Cumene is used for the study.

Nepu Saha

Assessment of Maximum Gas Production Rate of an Untempered System Under Runaway Conditions

Mary Kay O’Connor Process Safety CenterRoom 200, Jack E. Brown Engineering Building

Texas A&M University, 3122 TAMU • College Station, TX 77843-3122

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