To keep the transition to net zero on track, we must ensure that process safety is at its heart.
Our work is about learning from events such as the Buncefield Fire and Explosion on 11 Dec 2005, which resulted in numerous injuries, damage to assets and the environment so we do this by trying to make processes inherently safe. As my university lecturer and Process Safety guru Trevor Kletz said, in summing up inherent safety: “What you don’t have, can’t leak.”
How to make processes inherently safe
• Minimise – reduce the amount of hazardous material present
• Substitute – replace one material with another of lower hazard
• Moderate – reduce the strength of an effect
• Simplify – eliminate problems by design rather than adding additional equipment or features to deal with them
• Error tolerance – design to withstand faults and deviations from design
• Resilience – limit consequences of failure by designing:
– Against knock-on effects
– To make incorrect assembly impossible
– To make status clear
– For ease of control.
Kletz also goes on to share a further key message, “Organisations have no memory – only people have memories and after a while they move on taking their knowledge and experience with them.” This is why process safety requires continual attention.
The net zero economy will require key industrial chemicals, such as hydrogen which can be considered inherently unsafe. However, they can still be used in processes that are themselves inherently safe by building process safety into every aspect of a project, from management systems to human factors, and every stage of a project, from inception to decommissioning.
This continuity is crucial because it’s during times of change that mistakes can happen. For example, with the introduction of new environmental laws in the 1990’s to reduce emission of volatile organic compounds (VOCs), some companies linked vents together through collection systems to form a single vent from which to remove contaminants. However, plant components weren’t originally designed to be connected and joining them together magnified any potential incident. The risks weren’t always assessed and mitigated, leading to several explosions at plants around the world.
Net zero process safety: hydrogen
Hydrogen projects are now being progressed as a decarbonised energy vector for example in the process industry sector and as transport fuels. This means that these chemicals will be handled and utilised in settings that are in some cases unfamiliar and out with current practice.
A focus on process safety can prevent and control incidents in the processes at the heart of the UK’s plans for net zero – and by doing so, build and maintain social acceptance of them. Such a focus has been achieved after past incidents, with companies appointing directors responsible for process safety and creating separate departments to focus purely on process safety, irrespective of timescale and cost.
As we continue to move towards net zero, and new companies deploy new technologies, we must not let this focus slip; we must not forget the process safety lessons of the past. The processes we need for net zero can be inherently safe, if we design, engineer and operate them that way.
AXIOM are currently supporting companies who are progressing towards net zero particularly in the area of considering the viability from an operation and process safety point of view in switching to Hydrogen. This includes assessing what are the Materials and Mechanical Engineering considerations in repurposing existing equipment vessels, furnaces, pipework etc for Hydrogen along with Process Safety in terms of Hazardous events, consequence assessment and effect on Area classification.
Peter Hunt, Director – AXIOM
peter.hunt@axiom-ltd.com www.axiom-ltd.com
Reference list Kletz, T.A. (1993) Lessons for Disaster – How Organisations Have No Memory and Accidents Recur, Rugby: Institution of Chemical Engineers.
Published in Chemicals Northwest Elements Magazine