Cool growth for air quality

London-based Dearman has enjoyed remarkable growth over the last 18 months and believes its liquid nitrogen cold and cooling technology can play an important role in reducing transport emissions. Michael Holder speaks to Dearman’s group managing director, Michael Ayres.

London-based Dearman has enjoyed remarkable growth over the last 18 months and believes its liquid nitrogen cold and cooling technology can play an important role in reducing transport emissions. Michael Holder speaks to Dearman’s group managing director, Michael Ayres.

Michael Ayres, Dearman group managing director

Michael Ayres, Dearman group managing director

Only three years ago, the then-newly-formed Dearman Engine Company Ltd’s three founder directors were among a handful of staff sat in a small Central London office planning the build of their first liquid nitrogen engine — the technology which the firm develops to produce low emission cold and power for a number of transport applications.

Since building that first engine in 2013, Dearman has grown hugely, with well over 50 staff in its own, larger dedicated office in Covent Garden. And, on top of this, it is also close to opening its own 1,000 square metre industrial research facility in Croydon.

Considering Dearman group managing director Michael Ayres describes the roots of the company as “very much a garden shed venture” when engineer Peter Dearman — now involved at the firm as a research consultant — first invented the technology in the 1960s, things have certainly taken off recently.

“We’re particularly excited because I don’t think there is anything like this in Europe,” says Mr Ayres of the Croydon facility, adding:

“I don’t think there is anyone else in Europe who has got a combined cold and power research centre at this scale.”

The Dearman engine works around the principle that liquid nitrogen — or ‘liquid air’ — expands 710 times between liquid and gas phases, and this expansion process can be used to drive the pistons of an engine, much like steam engines. The difference is that the low boiling temperature of liquid nitrogen means that low-grade heat sources can be used, which Dearman says eliminates the need for traditional fuel and makes it a cheap, zero emission power source.

The company’s swift growth in staff and premises has also been matched by its rise in prominence on the international green business agenda, with Dearman chief executive Toby Peters having just delivered a speech on cold and cooling to the annual Renewable Energy Finance Forum (REFF-Wall Street) in New York.

Meanwhile, the government has started to recognise the environmental and air quality benefits of cooling technology, too, as Dearman has successfully secured a slew of grants for various projects over the last year — including backing from Innovate UK to help trial its transport refrigeration system.

Transport refrigeration

Indeed, while the company is developing liquid nitrogen power and cooling technology for a variety of applications, Dearman’s transport refrigeration system and auxiliary power units are perhaps the most exciting with regards to air quality.

The former system can be retrofitted to replace diesel-powered refrigeration units on heavy goods vehicles (HGVs), which transport cold goods such as food, drink and other produce. The latter, meanwhile, can be used to improve the energy efficiency of trucks and buses, providing cooling for conditioning, as well as power for the likes of electrified braking, steering assistance, electric doors and lighting.

Dearman's Cool E zero emission transport refrigeration system

Dearman’s Cool E zero emission transport refrigeration system

According to Dearman, the majority of transport refrigeration units are powered by diesel or fossil fuels and are “poorly regulated”, contributing to air pollution.

Mr Ayres describes it as an “extension of the idling issue”, explaining that the auxiliary power units used on lorries to keep goods cool while unloading on streets emit around six times more NOx and 29 times more particulates than even the vehicle’s main Euro 6 motor engine.

“If you have a small diesel engine driving it, which many of them do, then those diesel engines are covered by NRMM [non-road mobile machinery — e.g. forklift trucks etc] legislation,” he says. “And while it might make sense to have a very low air quality standard when you only have one or two of these in the countryside, you only have to look around Covent Garden at about 8am in the morning to see queues of these trucks all parked up and unloading their stuff with these small diesel engines chugging away while people work. You get quite a disproportionate air quality effect from them.”

He continues: “I don’t really understand what the justification is for these units being classed in the same category as agricultural machinery, as they are in exactly the same place as the vehicles which are very heavily regulated.”

However, the company claims that its own system is zero-emission at the point of use — eliminating nitrogen oxides (NOx) and particulate matter as well as carbon dioxide (CO2) from the refrigeration process.

Mr Ayres says:

“If you manage to replace the 150,000 transport refrigeration units in the UK, in air quality terms that would be about the same as taking four million trucks off the road.”

Furthermore, Dearman claims the refrigeration technology is economically viable to retrofit (costing around £15,000-20,000) to existing HGVs and will also save fleets money in the long run, as will the auxiliary units.

“If a normal truck costs £90,000 a year to run,” he explains, “you’re probably talking about a £190,000 truck or a £300,000 truck over a few years. And you can roughly double the cost of a bus if you turn it into a full hybrid.”

At present, government-backed on-vehicle testing of the Dearman refrigeration system is currently underway before on-road trials start later this year.

“We are pretty excited about the trials that are going to start,” says Mr Ayres, who adds that the technology is performing well, with a plan to see extended commercial trials start in 2016.

Demographics InfographicDiesel

Not that Dearman is against diesel per se. Mr Ayres accepts that it is “probably here to stay”, as it is often the best way of powering larger vehicles travelling long distances.

But, he adds: “I think what we do need to do, though, is examine ways in which we can use diesels in both more efficiently and in a way which reduces its impact. We see the Dearman in some ways looking to compliment the diesel engine in order to make it more efficient and reduce the environmental impact.”

The company is certainly a strong believer in the power of the green business to improve the environment, while also boosting the economy and creating jobs, having called on the new government after the election to continue investing in industry-led research.

There is now an opportunity, Dearman said, for the government to “support the development and manufacture of clean technologies that will have significant, quick, positive environmental and economic impacts” which could also help he UK “make a name for itself in the cleantech industry”.

Indeed, should Dearman see continued growth and a wide roll-out of its technology, it could certainly benefit both the economy and the environment. Nevertheless, Mr Ayres also recognises the scale of policy work also needed to tackle the wide range of air pollution sources, advocating the likes of stricter emissions limits and a “harmonised” network of low emission zones.

Mr Ayres concludes: “We think of ourselves as part of the solution but not a silver bullet.”

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