Integrating flare gas with cogeneration systems: Operational risk assessment

A multi-perspective process safety risk assessment with hybrid risks

In this paper, we assert that the process safety risks vary based on the identity of the stakeholders involved, for example, employees, management, regulators, community members, insurance companies, and environment. These risks differ in perceptions, magnitudes, and ramifications across an array of stakeholders. Hence, the process safety risk assessment taken from a single perspective, as is often the case, is inadequate and perhaps misleading. Instead, a more realistic approach is a multi-perspective risk assessment by considering the interactions existing among different perspectives and by building concurrent and compatible models explicitly. This marks the first innovation of the current research work. The second innovation centers on the hybrid nature of risk analysis. We recognize the distinction between safety risks impacting human well-being and risks affecting facilities, properties, capital assets, and the environment. The research introduces a hybrid safety-facility risk assessment to address different types of risks. Still, developing multiple models to represent hybrid risks from different perspectives is complex, time-consuming, tedious, and very costly. In addition, results from multiple models may become incompatible, confusing the stakeholders. To avoid such difficulties, a comprehensive model is developed initially, which, while impractical itself, allows for the extraction of practical perspective-based models through reduction. The methodology was illustrated and validated by examining a city gas pressure reduction station from 12 different perspectives, illustrating different risk results and highlighting the necessity of a multi-perspective and hybrid risk approach for accurate process safety risk analysis. However, the methodology is widely applicable across different risk assessment areas, not limited to the process safety of a city gate station (CGS). Furthermore, the twelve perspectives considered are specific to the context of the CGS case in a suburb of Tehran and may vary in other situations. By incorporating these practices, organizations can ensure a more comprehensive, inclusive, and accurate assessment of process safety risks, ultimately leading to better risk management and decision-making.

Why is the risk of industrial non-routine activities high and how can it be evaluated? An integrated approach

Non-routine activities such as startup, shutdown, maintenance, and operation commissioning require increased human interaction with the corresponding process. Owing to operator or procedural violations, the risk of accidents can be high during non-routine activities, even though they are performed less frequently. To identify and evaluate the hazards of non-routine processes, an integrated method combining job hazard analysis (JHA), hazard and operability analysis (HAZOP), and deviation degrees is proposed. JHA is applied to break down an operational process into steps, which are further defined as nodes in HAZOP for hazard scenario analysis. The concept of deviation degree is defined by integrating the operational and control function deviations to quantify the deviation analysis. Finally, the heating-furnace startup process in an oil and gas gathering and transmission station was selected to illustrate the proposed integrated method. The results show that this method constitutes a systematical and intuitive approach to identify hazard scenarios and evaluate risks, as well as to establish preventive measures for non-routine processes.