Natural Gas Processing from Midstream to Downstream

12 Process Safety in Natural Gas Industries

Monir Ahammad and M. Sam Mannan

Mary Kay O'Connor Process Safety Center, Artie McFerrin Department of Chemical Engineering, Texas A&M University, USA

Chapter Menu

1. Introduction
2. Incident History
3. Process Safety Methods
4. Equipment and Plant Reliability
5. Facility Siting and Layout Optimization
6. Relief System Design
7. Toxic and Heavy Gas Dispersion
8. Fire and Explosion
9. Effective Mitigation System
10. Regulatory Program and Management Systems for Process Safety and Risks
11. Concluding Remarks

Introduction

Natural gas streams may contain H₂S and organic volatiles (i.e., mercaptans) that have toxic health effects. Refrigerants (e.g., ammonia and propane are often used for lowering process temperature in LNG facilities) can also have both toxic and flammable effects when released to the environment. The American Industrial Hygiene Association (AIHA) has issued Emergency Response and Guidelines (ERPGs) for air contaminants such as H₂S, NH₃ and methyl‐mercaptans. An exposure of H₂S at a concentration level of 100ppm up to an hour is considered as life threatening for human beings. Process Safety is the science, technology, and management system to prevent, and mitigate unwanted events such as exposure of H₂S.

The application of process safety principles begins with the identification of hazards. A hazard can be a material, or an activity, or a procedure that can cause harm to human, or environment, or incur economical loss. ...