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Hydrogen is the most common chemical element in the universe. Industries are adopting new ways of generating energy, and hydrogen is key among them. It’s also carbon dioxide neutral, which translates to no emissions. But hydrogen is an energy carrier, not a primary energy. Handled incorrectly could lead to hazardous events, so processing hydrogen safely is critical.
To help address this, I spoke with Thomas Menze, senior consultant at ARC Advisory Group, during a webinar to discuss: hazard and operability studies, new energies and new risks, driving profits in the safest manner possible, and how emerging technologies like digital twins can simulate various scenarios. I also dive into how safety instrumented systems play a major role in hydrogen processing safety.
Below are some of the topics I discussed during the webinar.
(Editor’s note: This transcript has been edited for clarity and length.)
Why is process safety important?
When it comes to processing hydrogen safely, there are three key influences:
- Rising safety incidents bring a renewed safety focus
- New technologies bring new risks and threats
- The digital divide beings a different expectation of working over traditional ways
There’s been a decrease in the number of hours that are being worked, but an increase in the number of safety incidents and the fatal accident rate. So, over the last couple of years, that trend, unfortunately, is going the wrong way. That’s worrying.
The second element is that new technologies are being introduced into the chemical and energy industry. The risk profile is now not just the threats that we manage, but the profile of the risk we manage – i.e., the distribution, point of sale, mass storage, mass consumption –is different. So new technologies bring new risks which further complicates it.
And the third element is what I call the digital divide. We’ve got a workforce in transition: a new generation of early career professions who are “digital natives” replacing a workforce that is retiring and taking their experience and expertise with them. This brings a very different expectation. So, we’ve got to take this opportunity to look ahead and plan.
It’s a unique set of challenges at this moment in time.
How is processing hydrogen different?
The main risks with hydrogen are managing fire, explosion, and electrocution.
This really all comes down to the very fundamental thing about risk and risk management. Risk is the likelihood of something happening and the consequence. What can go wrong? What is the likelihood of it happening? And if it does happen, what is the consequence?
So, the simple question is: What do we have to do to mitigate or reduce those new risks to a lower level?
The good thing is we are already aware of hydrogen, and a how to manage those risks. Electrolyzers themselves are tricky rascals because hydrogen is close to high electrical current loads. So, we have an ignitable gas source, with oxygen, next to a “spark” source, which is never a good combination.
Let’s look at the risks that we must manage on a typical hydrogen plant: 1) the electrolyzers for hydrogen production and 2) the balance of plant. Typically, this includes batteries, cooling, water treatment and storage, compression facilities, switchgear and transformers, firefighting, etc.
And then there are several hazards typical to the process:
- Membrane high temperature
- High separator level
- High O2 gas in H2
- Rectifier high current
- Compressor low or high pressure
- Compressor low or high temperature
- And others
What can we do differently?
The first thing is to make sure we understand the hazards, risks, and threats. Typically, we follow a systematic approach, e.g., a process hazard analysis (PHA) to identify and analyze hazards associated with the processing or handling of highly hazardous materials.
To do this, Schneider Electric takes the process and breaks it down into nodes. We then have a team of experts, chemical engineers, process engineers, and automation engineers ask what can go wrong (deviations). We identify what the consequences would be, and what the likelihood and impact (safety, environmental and commercial) would be. That’s the traditional set of process risks.
The second thing, in today’s world, are not just process related, but also cyber risks and threats. We follow a similar systematic process with a cyber HAZOP, break the system architecture down into sections, and ask what deviations might occur. And the third element to the risk equation are electrical systems. Again, we follow a similar systematic approach, take the line diagrams of the electrical systems and, similarly, break it down into nodes and sections. We look for deviations and understand the consequence.
This is all about making sure the hazards and the risks we are mitigating and protecting against are known and understood because that defines what risk reduction measures we place.
Today, we can create a digital twin and simulate both the process side and the energy side. We can make it dynamic and put them into simulation mode to test our deviations. We have this ability to now get a much better understanding of the interdependencies between the scenarios and the deviations between the power and the process side, resulting in a more rigorous and robust risk assessment than can normally be achieved with static drawings and documents.
Adding more robust layers of protection
Once we have comprehensively qualified and quantified the hazards, risks, and threats, then we can implement our risk reduction measures, our “layers of protection.” Now we can exceed traditional barriers, and implement more robust, stronger defense in depth.
For example, because as there is so much interdependency between process and electrical control, we can unify the basic process control system (BPCS) with the electrical systems. This provides not only operational benefits, but can also reduce energy consumption, a key requirement in the drive towards net zero.
And finally, we can implement one of the world’s best safety instrumented systems, Tricon CX, for both emergency shutdown and fire and gas. Using the same technology for both applications, saves space, engineering, documentation, training, support costs, etc.
Learn how Tricon CX Safety Instrumented Systems can help your plant process hydrogen safely.
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