Ricardo, UK-based global strategic engineering and environmental consultancy that specialises in the transport, energy and scarce resources sectors, has formed spin-out company Dolphin N2 Ltd, to exploit potentially game-changing liquid nitrogen (LN2) engine technology.

The Ricardo CryoPower concept uses new engine technology which aims to substantially increase the fuel efficiency while reducing operating costs and CO2 emissions, for long haul trucks and other heavy-duty applications.

The technology has been the subject of active R&D by Ricardo for approximately 10 years and has demonstrated the potential to reduce operating fuel costs and fuel usage by, respectively, 20 and 30% in comparison with today’s heavy-duty engines

Cryopower overview

The Ricardo CryoPower split-cycle engine concept completely redefines the processes of internal combustion to enable significantly improved internal thermal efficiency in comparison with today’s state-of-the-art engines. It is based on the use of a separate induction and compression cylinder from that used for combustion and exhaust. This enables recovery of otherwise wasted exhaust heat to the working gas after the end of compression. The compression process is carried out isothermally, cooled via the injection of a small amount of LN2. The LN2 is thus both a coolant and an additional energy vector, which offsets some of the fuel requirement. The combustion process utilises either renewable or traditional fuels, liquid or gaseous, and delivers heat energy back to the chilled and compressed intake air. Its most important benefit, however, is to enable otherwise unachievable improvements in fuel economy, reduced CO2 and other emissions through improved internal thermal efficiency.

Cryopower schematic

LN2 as an energy vector for renewable energy

CryoPower requires LN2 to operate, with a usage and refilling requirement broadly in line with that of the fuel used to power the vehicle. Liquified N2 is already routinely produced in electrically powered air separation units (ASUs) by the industrial gases industry, both directly and as a by-product of the production of liquid oxygen (O2) from air. It is thus readily available. For commercial reasons, this production process already tends to be operated so as to maximise the use of ‘wrong time’, cheaper rate energy, and it would be comparatively straightforward to develop an expanded supply chain for LN2 based on both this and on intermittent renewable sources. Using LN2 generated in this way as an energy vector by CryoPower truck engines, would thus offer arguably one of the most effective pathways by which renewable energy could be deployed in long-haul, heavy freight road-based transportation.

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

“we are now seeking further investors to join us in taking this exciting concept forwards towards commercial development,” Brewster concluded.