Part 3: Incendiary Insights

Hydrogen in the Frame

Parts 1 and 2 of this series looked at how the prospect of domestic hydrogen had become a contentious issue online. The focus of this ire was a QRA conducted and reported by engineering consultants at ARUP+ on behalf of the UK government department BEIS.??

For the rest of this series of articles, I will be deconstructing an opinion piece about this report, to show, that with just about every line, it contributes to a misunderstanding of the issues.?First I want to explain why it matters that you read on.?

The Misinformation Threat and Why You Should Care

Nobody has the bandwidth to respond to every item of misinformation that comes their way, so most of it goes unchallenged, which puts it into a self-reinforcing cycle.?If you are adopting a minority view and choose to slug it out in the comments to some post, realistically your contributions will just get buried in the thread, or by the algorithm.??

Misinformation is far more likely to be shared than facts, it is produced more quickly and is unhampered with the inconvenience of verification, plus the imagination can have full reign. This makes it easier to replicate because humans are more interested in stories than truth; there are some interesting papers that explore this phenomena.?

However, this is not a complaint about social media because that after all, is just the environment that we are operating in.?It is up to us to protect what is important including our options for mitigating climate change through transitional technologies.??

You have surely noticed that there is growing trend of obstructionist rhetoric that is ready to ambush any kind of innovation.?Every initiative you can think of has its own specialised anti-lobbyists.?It is easy to pick holes in schemes but very much harder to defend them.?Collectively, we don’t just reap what we sow, but lose what is not nurtured.?Important things can be strangled by what we don’t bother to weed out.?

The QRA Review Published in Hydrogen Insight

The article, ‘Is it safe to burn hydrogen in the home? Let’s look at the evidence’ was published in October 2022 by Hydrogen Insight and written by Tom Baxter. Months later, some astounding known errors remain in the piece, but it seems that they are not going to be corrected willingly. An almost identical article was published by The Chemical Engineer a few weeks later under the title, ‘Home Hydrogen: Is it Safe?’, and to their credit, some of the most obvious errors in chemistry were trapped by better standards of copy editing.

Whilst I applaud Mr Baxter’s commitment to recycling, I don’t understand why he did not pass on those corrections to Hydrogen Insight, unless of course, misinforming his readership i.e. you, is less of an issue than admitting to a mistake.??It was strange therefore, to see such heavy weather of the fact that Cadent Gas Limited had recently retracted a fact-check for corrections, viz.

However, I think there are more errors, half truths and inconsistencies that need corrected.

Tom Baxter, LinkedIn

At least that is something we can agree on.

In Part 4 I describe these schoolboy howlers and explain why they are such a good example of confirmation bias. They have everything, a misunderstanding of the chemistry, a misreading of the literature and a failure to grasp what it all adds up to.?In the comments to his many posts, I have never witnessed the author correcting people who support him, even when they are obviously wrong.?This seems to be part of the same worrying flaw.?

Ostensibly, Mr Baxter is providing a critical review of the ARUP+ report, but his exploration of the evidence is selective and superficial. It reaches conclusions that I almost entirely dispute - which is something that reading the report entitles me to do.?

My main purpose is not to single out this article as being spectacularly wrong (which it is), but to offer it up as an example of the beguiling and apparently credible forms misinformation can take. Yes I know it is an opinion piece but the facts matter.

So let’s start with the conclusion the author discloses in his first few paragraphs:?

The simple answer is that hydrogen is inherently less safe than natural gas from a fire and explosion standpoint.

‘Is it safe to burn hydrogen in the home? Let’s look at the evidence’ Hydrogen Insight, Tom Baxter

This touches upon something discussed in the previous article in this series:

Intrinsic safety relates to the source of ignition not the fuel.?Even calling a gas ‘inherently safe’ is something of a misnomer, because even if it is non-flammable, non-toxic and unpressurised there are still safety risks. Any gas in high proportions can cause asphyxiation and even oxygen at concentrations approaching 100% is toxic.?How is this relevant? Simply that the safety of all gas in any application, has to be engineered-in, because it is never ‘inherent’.??

Part 2: Hydrogen, Agendas and Anxiety, LinkedIn, Michael Vigne?

Mr Baxter goes on to list some hazards that differentiate hydrogen from natural gas:

It has a much broader explosive range, it is much more prone to leak, a much lower ignition energy level and can produce higher blast overpressures in explosions.

‘Is it safe to burn hydrogen in the home? Let’s look at the evidence’ Hydrogen Insight, Tom Baxter

The term ‘explosive range’ is often used, this is acceptable, but it is perhaps more useful to talk about it’s equivalent, flammable range. The flammable range has a Lower Limit (below which the fuel/air mix is too lean to burn) and an Upper Limit (above which the fuel air mix is too rich). Between those limits combustion can occur, or you might say, we are exposed to ignition events. Why do I say this??Because a small pocket of flammable mixture may ignite briefly without starting a ‘fire’ or it may burn without causing an explosion, depending on a raft of initial conditions, particularly the availability of fuel.??

So, a leak will not necessarily ignite and an ignited gas i.e., one that is implicitly within flammable range, will not necessarily burn or explode.?It depends what the conditions will support. We have to be careful about conflating the different risks of gas leak, ignition and explosion, because to do that is to ignore the conditional steps in between, or to put it another way, the intervening probabilistic states that separate them. How do we inhibit those state transitions??Well in general terms we call them mitigations.?

A gas explosion is a rapid release of energy which produces pressure waves.?In domestic situations it is typically unplanned but it is dependent on initial conditions, including air/fuel ratio, temperature and pressure. Overpressure is a result of an explosion in confinement.??Mitigations therefore include designed modifications for regulation, equipment, parameters and the environment.?

Historical Data

Whereas the historical data for natural gas safety has been gathered over many decades, no such body of empirical evidence exists for domestic hydrogen, but fortunately there are ways to make sensible comparisons.?Out of respect for the uncertainty, ARUP+ have been necessarily conservative in its approach, but opponents have not given this the credit it deserves because it is unhelpful to their case.?Mr Baxter gets everything positive he has to say about hydrogen into a single sentence.

In its favour is its buoyancy; it will disperse more easily than natural gas and there is no carbon monoxide emission risk with hydrogen combustion.?

‘Is it safe to burn hydrogen in the home? Let’s look at the evidence’ Hydrogen Insight, Tom Baxter

Hydrogen has lower atomic weight than flammable compounds (in fact any compound) and readily disperses, but its ultimate dispersion relies upon ventilation, which is largely provided within existing building regulations for reasons primarily concerned with damp. Suddenly people are finding these vents to be an issue. The minor regulatory accommodation for hydrogen in this respect is likely to be the requirement that vents must be sited within 0.5m of the ceiling.?

Besides the absence of carbon monoxide (as noted by Mr Baxter), hydrogen combustion is not accompanied by any carbon compounds, including carbon dioxide (CO2).?Conservatively, CO has been excluded from the QRA portion of the study, so the differential benefit of hydrogen in term of toxicity is mentioned but not included in the analysis. However, given the Hydrogen Insight article supposedly concerned with the relative safety of domestic hydrogen, is this an aspect that should be glossed over???

In Parts 4 and 5,?I will explore the role of NOx in climate change, how it is assessed and explain the main mechanisms for its production during combustion.??I will also uncover two jaw-dropping errors.

Next - Part 4: NOx and Greenhouse Warming Potential

Department for Business, Energy and Industrial Strategy (BEIS),? Jon Saltmarsh , Mark Neller?Dr Angela Needle FEI, Cadent Gas Limited Hello Hydrogen