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A new 'split cycle' engine that uses liquid nitrogen to achieve thermodynamic performance is claimed to save operators up to £9,000 per truck each year and slash harmful tailpipe emissions.

Researchers have demonstrated that by storing and injecting liquid air into split-cycle engines, fuel consumption is reduced by up to 30%, with both NOx and PM emissions also lowered.

CryoPower, developed by tech firm Ricardo and the University of Brighton, uses a thermal-power engine cycle: air is compressed in one cylinder, then heated by burning a fuel and expanded in a second cylinder.

By splitting these processes into separate cylinders, scientists say the engine is more efficient and can be controlled to minimise toxic emissions such as NOx.

Trials have produced a 20% reduction in fuel consumption against the most fuel-efficient lorries and a 30% reduction against the average fleet.

Researchers estimate the new engine could bring an estimated fuel saving of £9,000 per annum per truck.

They claim the new technology could enable long-haul HGVs to fully comply with inner-city emission restrictions, saving hauliers thousands of pounds per year.

Researchers on the project believe that electric power for trunking HGVs is unrealistic right now due to the weight and payload restrictions of a battery large enough to power a truck.

Dr Rob Morgan, lead researcher at University of Brighton, said: “Even if a significant breakthrough in battery technology were achieved in the future, the strains on the recharging infrastructure and power grid may still be prohibitive.

“On any sensible scenario, diesel-fuelled power generation will be around for many years. Our research is a potential game-changer.”

He added that the recuperated split cycle engine can achieve “world-leading” levels of thermal efficiency, which would “massively reduce the use of fossil fuels in the short to medium term and the demand for precious renewable fuels in the long term”.

To bring the technology to market in the next few years, Ricardo has set up a spin-off company called Dolphin N2, with plans to attract new investors to help take the concept forward.

“CryoPower is a potentially game-changing, commercially and environmentally attractive technology whose time really has come,”said Simon Brewster, CEO of Dolphin N2.

“The development of the conventional heavy-duty engine is reaching the point of diminishing returns with regard to fuel efficiency and CO2; to go significantly beyond the current state of the art requires a completely new approach.”

He added that CryoPower offers a “step change” improvement in both fuel efficiency and operating costs.