Process safety and optimization

Industrial accidents, sadly, are frequent occurrences, resulting in harm to workers and sometimes to nearby populations and the environment.

Numerous studies over the last five years show that companies that view Environmental, Health and Safety (EHS) as vital to their Operational Excellence objectives outperform those that don’t, financially, in terms of EHS compliance and accident levels.

These higher-performing companies are achieving this by effectively harnessing and aligning people, processes, and technology.

Process safety

The construction and operation of industrial processes present hazards to people and the environment. Risk assessments identify potential hazards and subsequently identify failure scenarios that allow potential hazards to result in actual accidents. They determine the level of risk for each hazard and determine if that level is tolerable or not. They also recommend action to address those risks that are not tolerable, including modifications to eliminate risk, or establishment of risk mitigation measures.

Typically, comprehensive risk mitigation relies on multiple independent layers of protection, which can be physical or procedural. For example:

• Plant design – addresses issues such as equipment access and site transit risks
• Policies and procedures – deter workers from hazardous actions
• Training programs – educate personnel to apply appropriate safety measures when performing hazardous work
• Sensors providing a safety function – detect potentially hazardous conditions and form part of a safety system to prevent, limit, or recover from those hazardous conditions
• Monitoring, inspection, and maintenance activities – provide ongoing assurance of physical integrity and the ability of monitoring and control equipment to behave on-demand.
• Human-machine interface (HMI) design – minimizes operator error at high-stress moments

Nonetheless, things do go wrong, because each layer of protection is imperfect. However, this defense-in-depth approach typically ensures that at least one of the layers of protection effectively mitigates any risks.

Occasionally, however, events conspire so that flaws in multiple layers line up, allowing a particular failure scenario to play out unnoticed, until what was a potential hazard becomes an accident.

Our perception of tolerable risk also continuously evolves as we increase our understanding of the harmful effects of specific activities, gain evidence that new approaches work, or see opportunities and risks that technology brings.

Risk mitigations will never be perfect, but by using a layered and dynamic management system that continually seeks to identify and track changing risk, and update or establish measures that plug or shrink those holes, we can build increasingly resilient and safer systems.

One example of using gas analyzers to support process safety is combustion management in control fired heaters. Control fired heaters are integral to many hydrocarbon processes and are highly dependent on reliable continuous measurement of excess air.

Efficient operation of larger, fuel-hungry heater units, such as those on ethylene crackers, involves a delicate balancing act to remain on the safe side of a tipping point from efficient, low-emission operating conditions to potentially explosive low-oxygen and fuel-rich conditions.

Accurate, reliable gas analysis enables this balance to be achieved and maintained, ensuring both efficiency and safety.

The search for ways to do something better, faster, or cheaper than others never ends. Often, the reason that a better, faster or cheaper approach hasn’t been possible before is because the balance between risk and reward hasn’t been sufficiently favorable.

Innovation creates ways to even up the balance and stay in control. For example, the invention of brakes was an enabler for faster cars, while online banking was enabled by careful application of number of security measures.

This is equally true for production process optimization. The reason is clear: there can be numerous benefits, including reduction of costs, energy use or emissions, increased product quality, or increased yield.

Improvements in gas analysis could enable processes to run more optimally while maintaining current safety margins. Greater accuracy of measurement without reliance on filtering, and increased speed of response are two options.

New opportunities to affect these could result from digitalization, allowing new data sources to be integrated into measurements, or allowing measurement points to be less centralized and therefore more optimally sited near the process conditions.

In this way, advances in digitalization would significantly improve the capability of gas analyzers, not only to provide process safety measurements, but also to optimize processes in an even safer way.