Guidelines for Process Safety During the Transient Operating Mode

Managing Risks during Process Start-ups and Shut-downs

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• Publisher: Wiley-AIChE
• Year: 2020
• Print ISBN: 9781119529156
• eBook ISBN: 9781119529170
• Edition: 1
• Topic: Technology & Engineering
• Subtopic: Chemical & Biochemical Engineering
• Index: Technology & Engineering

Prevent operational incidents and reduce risks with an essential CCPS guide

You can help your company reduce its operating risks by learning how to effectively manage transient operations and avoid major incidents. Startups and shutdowns, known as transient operations, can be high-risk periods for manufacturing facilities. Guidelines for Process Safety During Transient Operations offers useful guidance in preparing for the safe startup and shutdown of chemical processes.?With an understanding of the risks involved, you can work proactively to prevent fatalities, serious injuries, reduced productivity, and costly damage.

This essential guide for plants provides clear examples of how to anticipate and avoid major issues. The book examines safe shutdown procedures in the event of an emergency. You will also gain direction on how to resume operations safely after an unexpected shutdown. The book supports anyone tasked with regulating and overseeing chemical plants and procedures, whether you are an engineer, manager, or government professional.

• Minimize operating risks through the effective management of transient operations
• Establish safe start-up and shutdown procedures for chemical processes
• Be ready to safely shut down processes in the event of an emergency
• Learn from real world examples of start-up or shutdown incidents
• Review procedures and engineering controls that help prevent or reduce the effects of incidents involving transient operations

Guidelines for Process Safety comes to you from The Center for Chemical Process Safety (CCPS), which offers advanced thinking in the critical area of process safety. The organization develops technology and management practices for companies seeking to reduce hazards within the chemical and petrochemical industries.

1
Introduction

1.1 Introduction

This chapter discusses the scope of, the audience for, and the benefits for the readers of this guideline. For readers unfamiliar with the CCPS Risk Based Process Safety (RBPS) approach, this chapter also includes a brief overview of its framework, including how lessons learned from experience (one of the RBPS pillars) are incorporated into each chapter. The last section in this chapter provides the reader with the guideline's framework: how the chapters are organized based on the types of operations at a facility (normal, abnormal, and emergency) and how the risks associated with each transient operating mode—the subject of this book—depends on which mode of operation the process is undergoing at that time.

1.2 Scope

The scope of this guideline addresses process safety activities that are essential for effectively managing the risks associated with the different transient operating modes, recognizing that not all activities will apply to every mode. Since the risk of incidents can be high during the start‐ups and shut‐downs for normal operations in most manufacturing facilities, this book presents incidents that occurred during start‐ups and shut‐downs, providing insights as to why they happened and guidance on how to minimize the risk in the future. The important distinction between “transient operations” and the “transient operating mode” should be understood. This guideline defines the transient operating mode in the context of normal, abnormal, and emergency operations, providing a clear and understandable terminology of what is a “transient operating mode.” Details on this distinction will be provided in Chapter 2.

The other “transient operations” do not apply to the scope of this guideline. These transient operations include, among others, “infrequent or non‐routine activities” and “workarounds.” The distinction is critical for understanding of this guideline's scope, as the term “transient operations” means many different things depending on the context and views of those who are noting such transition times.

For example, “transient operations” include a major grade change in a polymer reactor or summer to winter operating mode change for a refinery. These tend to be routinely practiced, have well documented procedures and are usually done without a shut‐down. These types of transient operations are not covered in this guideline either.

It should be noted that the hazards and risks associated with non‐routine activities, performed less frequently than normal activities, should be understood by everyone performing the infrequent task. As discussed in this guideline's Foreword, “many dedicated safety professionals…have borne witness to the human cost, property damage and environmental destruction…” when non‐routine, infrequent tasks are not performed safely.

In addition, workarounds can be defined as “creative solutions made to overcome an issue without actually solving it.” Well‐intentioned workarounds can be small, quick, and simple “one‐minute” changes which create “bad memories” at a facility [2, pp. 209‐234]. In other words, incidents have occurred – and will occur ‐ when those performing the infrequent tasks or making simple material or procedural changes have not thoroughly refreshed their understanding of the task's hazards and have not thoroughly addressed the task's risks.

Another way to describe the scope of this guideline is to recognize that transient operating modes are planned, anticipated activities, even though some of them, such as an emergency shut‐down, are prevented as much as possible. Whether during normal operations or when in transition, all operating modes need to have developed procedures which are documented, reviewed, and practiced through training and on‐the‐job exercises. By contrast, there are other transient operating modes that are not planned, and therefore should be handled ad hoc by use of rigorous change management and hazards assessment procedures for the specific situation at hand. For example, a batch reactor that has been fed the wrong reactant by mistake and has created a viscous material which cannot be removed by normal cleaning procedures would not have a written procedure applicable to this situation. In this case, a team of experts would be needed to develop specific, non‐routine actions to recover from this deviation. This team of experts would understand potential hazards and assess their associated risks, ensuring that the non‐routine activity will not place people at risk to a loss of control of a hazardous material or energy.

In short, if the abnormal operation has a procedure associated with it (even if it is only “hit the shut‐down button and evacuate”), it is covered by this guideline. If not, then the activity is outside the scope.

Clear definitions help establish a consistent language between practitioners when discussing the transient operating mode‐specific risks and how these risks can be effectively managed for each of the transient operating modes. Since the scope of this guideline is limited to the transient operating mode, other references are noted as additional resources [3] [4] [5] [6] [7] [8] [9]. In particular, some of the incident data summarized from the 1990's includes the following:

“…emphasizes the need for start‐up and shut‐down procedures to be in sufficient detail to cover known pitfalls and contingencies. In the case of maintenance, good communication is essential so than everyone knows what others are doing at any time and what responsibilities each has. Split or unclear responsibilities are a recipe for disaster. [3, pp. 3‐4] “

“To [help] prevent these types of incidents from occurring, facilities should employ effective communications, provide workers with appropriate training, and have in place strong and up‐to‐date policies and procedures for hazardous operations such as start‐ups and shut‐downs [5, p. 1].”

When the equipment is being shut down (th...

Table of contents

• Cover
• Table of Contents
• Guidelines for Process Safety During the Transient Operating Mode:
• Copyright
• List of Figures
• List of Tables
• Acronyms and Abbreviations
• Glossary
• Acknowledgments
• Dedication
• Foreword
• Preface
• 1 Introduction
• 2 Defining the Transition Times
• Part I: Normal Operations
• Part II: Abnormal and Emergency Operations
• Part III: Other Considerations
• AppendixTransient operating modes: incident review and guidance
• References
• Index
• End User License Agreement