Chemical Process Safety Research Articles

Fault Diagnosis of Chemical Processes Using Artificial Immune System with Vaccine Transplant

Chemical process accidents have tremendous impacts on the environment, as well as the sustainability of the chemical industry. Fault detection and diagnosis (FDD) are important to ensure safety and stability of chemical processes. However, the scarcity of fault samples has limited the wide application of FDD methods in the industry. In this work, we present an artificial immune system (AIS)-based FDD approach for diagnosing faults in the chemical processes without historical fault samples. This approach mimics the vaccine transplant in the medicine discipline. Historical fault samples collected from other chemical processes of the same type are used to generate vaccines to help construct fault antibody libraries for the diagnosis objective process. Case studies on the Pensim process and laboratory-scale distillation columns illustrate the effectiveness of our approach.

A novel multimode process monitoring method integrating LCGMM with modified LFDA

Complex processes often work with multiple operation regions, it is critical to develop effective monitoring approaches to ensure the safety of chemical processes. In this work, a discriminant local consistency Gaussian mixture model (DLCGMM) for multimode process monitoring is proposed for multimode process monitoring by integrating LCGMM with modified local Fisher discriminant analysis (MLFDA). Different from Fisher discriminant analysis (FDA) that aims to discover the global optimal discriminant directions, MLFDA is capable of uncovering multimodality and local structure of the data by exploiting the posterior probabilities of observations within clusters calculated from the results of LCGMM. This may enable MLFDA to capture more meaningful discriminant information hidden in the high-dimensional multimode observations comparing to FDA. Contrary to most existing multimode process monitoring approaches, DLCGMM performs LCGMM and MFLDA iteratively, and the optimal subspaces with multi-Gaussianity and the optimal discriminant projection vectors are simultaneously achieved in the framework of supervised and unsupervised learning. Furthermore, monitoring statistics are established on each cluster that represents a specific operation condition and two global Bayesian inference-based fault monitoring indexes are established by combining with all the monitoring results of all clusters. The efficiency and effectiveness of the proposed method are evaluated through UCI datasets, a simulated multimode model and the Tennessee Eastman benchmark process.

The meaning and importance of process safety competency

Process safety competency is subject to regulation in some jurisdictions, such as in the United Kingdom by the Health and Safety Executive (UK HSE) under the Control of Major Accident Hazard regulations. Process safety competency is one of 20 elements in the risk-based process safety (RBPS) management system developed by the Center for Chemical Process Safety (CCPS). However, competency as used in this RBPS element is not the same as the competency regulated by the UK HSE. The RBPS competency element addresses managing a knowledge base of process information and not competency as defined by other CCPS publications which use the term with a similar meaning to the UK HSE. This makes for a confusing situation for companies interested in improving their management of process safety competency. The scope of the RBPS element should be revised to address true competency. Currently, the U.S. Occupational Safety and Health Administration's Process Safety Management Standard and the U.S. Environmental Protection Agency's Risk Management Program rule do not address competency. However, both regulators are considering revisions to these regulations, including the incorporation of additional elements from the CCPS RBPS management system that are not currently in the regulations. One of these elements is process safety competency, as defined in the CCPS RBPS management system. This action would result in an inadequate treatment of competency. If a competency element is incorporated into the regulations, it should address true competency. © 2015 American Institute of Chemical Engineers Process Saf Prog 35: 171–175, 2016

Thirty years of leadership: The Center for Chemical Process Safety

Thirty years of leadership: The <scp>C</scp>enter for <scp>C</scp>hemical <scp>P</scp>rocess <scp>S</scp>afety

Justice for Bhopal! And No More Bhopals! Three decades of national and international campaigning

Dissatisfaction with the responses of the responsible corporation, Union Carbide, and the Indian government to Bhopal resulted in a campaign by national and international NGOs (non-governmental organisations) over the past three decades. While initially the Indian and international campaigns were separate, over time greater international cooperation took place. In the immediate aftermath of the disaster local NGOs prioritised health, justice and rehabilitation issues, while international NGOs used Bhopal to question chemical industry process and environmental safety in their own countries, as well as internationally. Indian NGOs called on international NGO resources to gain legitimacy for their campaign, to use NGOs as proxies and to extend the geographical scope of the campaign, while international NGOs used Bhopal as an example to advance NGOs analyses and policies. Over the period of the campaign, Indian NGOs became more sophisticated in their campaigning. The international campaign has increasingly become an online campaign, involved in an image or reputational war with Dow Chemical, which took over Union Carbide, while the original campaign issues of justice and reparations over the process safety disaster were joined by similar issues related to environmental safety of abandoned toxic waste.

The Activities of Center for Chemical Process Safety and their Implications toSafety Competency of the Chemical Industry in Japan

The Activities of Center for Chemical Process Safety and their Implications toSafety Competency of the Chemical Industry in Japan

How a plant simulator can improve industrial safety

Keeping the systems and processes safe is of paramount importance for all industries around the world. Process industry is a socio-complex system constituted of dynamic chemical processes, sophisticated computer algorithms, modern human machine interfaces, and teams of operators working at different locations. The decisions of the operators directly or indirectly influence the safety and production of chemical processes. The article presents and discusses a solution for immersive training of industrial operators that allows experiencing the multifaceted scenarios of (real) plant operations. This tool, called Plant Simulator (PS), combines a process simulator and an accident simulator to simulate dynamically both normal and abnormal/accident scenarios. These simulators are the engines that work behind the curtains of an Immersive Virtual Environment and make possible the realism of the simulated operations in the plant. The article explains the features of PS and discusses two case studies that show the potential improvements achievable in processes safety. © 2014 American Institute of Chemical Engineers Process Saf Prog 34: 237–243, 2015

On‐going developments in addressing combustible dust hazards

The National Fire Protection Association (NFPA) continues to play an important role in creating guidance for identifying and controlling hazards associated with combustible dusts. Five separate standards address hazards associated with wood‐related materials, metals, agricultural products and foodstuffs, sulfur, and all other combustible dusts (e.g., paper, plastics, chemicals, pharmaceuticals). This article will address a number of developments in NFPA's initiatives addressing combustible dust hazards. Topics to be addressed include: The status of, and recent revisions to, NFPA's combustible dust standards; NFPA's plans for a new combustible dust standard, which will address the common issues associated with controlling combustible dust hazards, leaving the commodity‐specific standards to address the issues unique to their scope; A new technical correlating committee, which will help ensure greater consistency between the approaches addressed in the various combustible dust standards; The increasing inclusion of process safety management (PSM) principles in the combustible dust standards; and The increasing allowance provided to users of NFPA standards for the use of risk‐based decision‐making in the selection of combustible dust hazard control options. Options exist for AIChE to provide technical support to a number of the above areas. The article will also preview a new Center for Chemical Process Safety project for providing tools for addressing combustible dust hazards. © 2014 American Institute of Chemical Engineers Process Saf Prog 34: 24–30, 2015

Lessons learned from case studies of hazardous waste/chemical reactivity incidents

The treatment of hazardous waste poses some unique chemical reactivity hazard management challenges. Hazardous waste in the United States is regulated by the Resource Conservation and Recovery Act, typically due to potential environmental and health hazards. However, hazardous waste can also have chemical reactivity hazards associated with storage, handling, or mixing with other materials. The U.S. Environmental Protection Agency has been active in communicating chemical reactivity hazards to the regulated community and has identified numerous sources for additional information. The Center for Chemical Process Safety has also been very active in providing advisory materials and monographs on the safe management of chemical reactivity hazards. Other federal government agencies, such as the Chemical Safety Board and the Occupational Safety and Health Administration, have also taken up the call for increased awareness of the hazards of unintentional chemical reactions.Despite these efforts, history of incidents indicates that reactive chemical hazards associated with hazardous waste still go overlooked. In this article, we review hazardous waste incidents through case studies and public sector reports through the lens of chemical reactivity hazard management. In each incident, inadvertent heating resulted in an unintended chemical reaction, and sufficient information existed or could have been obtained to identify the hazards. © 2014 American Institute of Chemical Engineers Process Saf Prog 33: 395–398, 2014

Hazard analysis of tetrahydrofuran and dimethylsulfoxide mixture solvents for efficient use in reaction processes

Organic solvents are often used in mixture solvent systems to optimize synthetic reactions. However, they may also produce unexpected effects, some of which may be hazardous and cause a runaway reaction and/or lead to an accident. Thus, the proper accident scenarios and thermal risk assessment models are needed to use mixture solvents more safely and efficiently. For chemical process safety, Stoessel suggests the systematic assessment of accident scenarios. However, if scenarios are changed by the properties of mixture solvents, Stoessel’s concept does not cover them. Our previous study evaluated characteristic scenarios of mixture solvents based on Stoessel’s model. In this study, as a characteristic scenario pattern, we focused on the energy release of the solvent and the material derived from degraded solvent and investigated them experimentally using tetrahydrofuran (THF) and dimethylsulfoxide (DMSO) as a representative mixture solvent. From hazard and scenario identification of THF and DMSO, we assumed that THF peroxide and DMSO play roles in energy release. THF containing peroxide and DMSO were mixed, and thermal analysis and chemical composition analysis were performed. Our results indicated that DMSO promotes the decomposition of THF peroxide, and the decomposition temperature of DMSO decreases upon mixing with degraded THF. Therefore, we verified the scenario pattern of energy release of solvent and the material derived from degraded solvent.

Organizational change management for process safety

It has long been acknowledged that when not properly evaluated and controlled, changes to physical equipment in a facility can lead to serious incidents with potentially severe consequences. Management of change (MOC) systems, replete with a variety of electronic systems, flow charts, and checklists, have been developed by a number of reliable organizations throughout the world to manage these physical changes. It is less commonly recognized that other types of changes such as changes in job responsibilities, loss of key personnel, or even changes in shift hours can have an adverse impact on process safety. These and other nonphysical changes, collectively referred to as Organizational Changes, can lead to serious incidents with potentially severe consequences. Due to their focus on managing physical changes, most MOC systems have overlooked or only superficially address organizational change management (OCM) and the impact of organizational changes that affect process safety.Organizational change is an unavoidable aspect of doing business. There is a large variety of changes which fit under this umbrella of organizational change. Any of these types of changes could result in catastrophic consequences if the changes are not successfully administered. Effective OCM procedures must include a system for managing potential modifications to a variety of organizational aspects.The Center for Chemical Process Safety recently published a new guideline book covering OCM. This presentation will highlight some of the key concerns related to OCM which are covered in this new publication and which should be included in a successful OCM program. © 2014 American Institute of Chemical Engineers Process Saf Prog 34: 89–93, 2015

Process safety leading indicators survey–February 2013: Center for chemical process safety–white paper

This article provides an update on the Chemical Industries use, direction, and effectiveness of leading indicators and provides recommended leading indicators to help drive performance in a common direction. As the use of leading indicators is in its nascent stages, it is anticipated that additional surveys and updates will be published on a biannual basis. © 2014 American Institute of Chemical Engineers Process Saf Prog 33: 247–258, 2014

Study on the Effect of a Comic on Understanding of Education about Chemical Process Safety

Study on the Effect of a Comic on Understanding of Education about Chemical Process Safety

Loss prevention at the startup stage in process safety management: From distributed cognition perspective with an accident case study

Organizational artifacts such as rules, procedures, or codes of practice play important roles in chemical process safety management. The violation of an organizational artifact can lead to major accidents. It is thus essential to understand the underlying significance of violations to coordination of organizational artifacts. Currently, there are rapid changes and development of chemical products which require developing new process in chemical plants. The pre-startup stage in the chemical process is especially prone to errors due to ill-defined work processes and the variety of jobs involved at this stage. However, human errors and understandings in the stage have not been given much of attention it deserves. This paper focuses on human errors in pre-startup stage: (1) An analysis of major industrial accidents in Korea was conducted. (2) A survey of related personnel in chemical plants was carried out to understand conditions of safety management on human error. (3) An accident case study at the pre-startup stage in a Korean chemical plant was conducted by applying the Fault Tree Analysis method to reveal failures of coordination of organizational artifacts. This paper adopted distributed cognition theories to analyze the underlying implications of such failures because these theories have the power to examine the relationship between human operators and artifacts in a system.This study highlights the importance of considering organizational artifacts related to human error in safety management. The results may help people, who are related to a process of pre-startup stage in chemical plants, to improve safety of the work.

The Business Case for Process Safety

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 157592, ’The Business Case for Process Safety,’ by Scott Berger, Center for Chemical Process Safety, prepared for the 2012 SPE/APPEA International Conference on Health, Safety, and Environment in Oil and Gas Exploration and Production, Perth, Australia, 11-13 September. The paper has not been peer reviewed. Over its 27-year history, the Center for Chemical Process Safety (CCPS) has observed that the first step toward implementing a strong process-safety-management program is obtaining top-management commitment. The CCPS has learned that communicating the business case for process safety is an important part of the process of obtaining this commitment. Using a fictional incident as a case-study example, this paper will illustrate that process safety can have financial, as well as ethical and professional, benefits. Introduction The CCPS has identified four dimensions in which process safety can influence the value of the business: Corporate responsibility Business flexibility Risk reduction Sustained value These dimensions affect financials in both quantitative and qualitative ways, addressing both cost savings and revenue enhancement. Table 1 illustrates the alignment of these four dimensions. The Incident One January day several years ago, a major process vapor line ruptured in the core unit of the Phlogiston Chemical Company Western Plant. Minutes later, a serious explosion ripped through the unit. The blast wave dislodged a nearly empty vessel, ripping it from its connecting piping. The vessel contained a toxic material that dispersed downwind, along with thick black smoke from the fire that resulted from the explosion. The company’s emergency-response team, along with local firefighters, responded rapidly. While residents took shelter, the responders set up a water curtain to mitigate the toxic release and worked to extinguish the fire. Unfortunately, when the response team sounded the all-clear signal 4 hours later, nine workers and one town resident were dead. Another 25 families gave thanks that their loved ones would recover from their injuries. Ultimately, investigators determined that a main flange in the vapor line had been bolted incorrectly and that the mounting brackets of the vessel containing the toxic material had corroded. A root-cause analysis showed that the technician assigned to the plant’s mechanical-integrity program had simply been “checking the boxes” for the previous 5 years and that management never spot-checked the mechanical-integrity program to verify that it was being practiced as written.

Special Feature Section on Safety of Chemical Processes

Special Feature Section on Safety of Chemical Processes

So we all have been implementing process safety metrics-what next?

Industry over the last two to three years has put a lot of effort into implementing Process Safety Metrics. This is a good practice but, now that we have metrics data, how are we utilizing them to improve process safety performance? Air Products has been monitoring process safety performance for the last five years using combined Center for Chemical Process Safety and American Petroleum Institute RP 754 metrics. This article will highlight the approach we have applied, both through our lagging and leading indicators, to drive our process safety performance improvement programs. It will review the programs we initiated, leading indicators we identified, and how it also helped to improve our process safety culture. This article will also look at the importance of measuring severity and its impact in driving leadership behaviors. We will also discuss future opportunities to improve process safety performance via metrics analysis and follow-up initiatives. © 2013 American Institute of Chemical Engineers Process Saf Prog 33: 172–178, 2014

Characteristics of companies with great process safety performance

The Center for Chemical Process Safety's (CCPS's) Vision 20/20 describes the characteristics of companies with great process safety performance in the future. This work is extremely important to the process industries and other industries that handle toxic, flammable, and explosive materials because it establishes targets to which companies will aspire for years to come. In developing the vision, it was also recognized that there are issues beyond the scope of individual companies that need to be addressed to enable improved process safety performance. Therefore, in Vision 20/20 there are activities that go well beyond any individual company, indeed beyond the industries. The purpose of this article is to share CCPS's Vision 20/20, begin the process of engaging the broader community in the vision and the steps to achieve it and provide an opportunity for companies to begin comparing their current characteristics to the vision. © 2013 American Institute of Chemical Engineers Process Saf Prog 33: 131–135, 2014

Hydrazine and Aqueous Hydrazine Solutions: Evaluating Safety in Chemical Processes

This contribution provides a summary of the hazards of hydrazine and its aqueous solutions and an understanding of the important role dilution plays in increasing the inherent safety of aqueous hydrazine solutions. Rather than provide an extensive description of the hazardous properties of hydrazine, the intent is to provide enough information to allow the reader to decide if hydrazine may be acceptable for a given application, and if so, what concentration range may provide an acceptable safety and environmental risk. Calculations are used to explore the favorable effect of dilution on the risk of fire, explosions, runaway reactions, and toxic exposure. Examples are provided to illustrate the strong effect catalysts can have on decomposition reactions. An analysis indicates the previously published lower flammability limit (LFL) is nonconservative.

Fault Detection and Diagnosis for Non-Gaussian Processes with Periodic Disturbance Based on AMRA-ICA

Fault detection and diagnosis is important in ensuring the stability and safety of chemical processes. However, limited studies have focused on strong periodic disturbance and non-Gaussian process monitoring. By utilizing the data-driven monitoring method, we have proposed the residual analysis independent component analysis based on average multivariate cumulative sum (AMRA-ICA) method to avoid the influence of periodic disturbance in non-Gaussian chemical processes with periodic disturbance. Average multivariate cumulative sum (AM) is introduced in the AMRA-ICA method for disturbance cycle synchronization. Residual analysis (RA) is employed to remove the disturbance in the data set and to obtain the normal residual. The independent component analysis (ICA) method is then utilized to monitor the residual, and an improved contribution histogram method is proposed to identify the cause of the fault. The proposed method has been applied to the classic benchmark Tennessee Eastman process with and without per...