While hydrogen has been gaining attention in the automobile world, liquid nitrogen is another alternative fuel source which has been rapidly developing in the last ten years. As the automobile world continues to search for alternative engine solutions to combat climate concerns, innovative solutions are emerging to replace fossil fuel in vehicles. While electrical engines continue to dominate, other projects like liquid nitrogen fueled engines are beginning to garner attention.
Liquid nitrogen engines: Over a decade of developments
While some companies have been looking at alternative fuel sources like hydrogen while others are looking at ways to improve the internal combustion engine, the Dearman Engine Company (DEC) has gone a different route. DEC has been developing and researching a liquid nitrogen engine solution for over a decade. Formed in 2011, DEC’s vision is to bring the “Dearman Liquid Air Engine” to the market as an alternative engine solution to current internal combustion engines which still dominate the roads and other transportation sectors.
Beginning in 2014, DEC embarked on a project in collaboration with Ricardo, E4tech, MIRA and leading UK academic and research institutions to develop a novel, zero emission, piston engine that runs on liquid nitrogen with the exhaust being cold air. According to DEC, the benefits of the technology are as follows:
- Simple design with low production costs, utilizing a significant portion of the existing powertrain supply chain.
- Requires minimal maintenance with no loss of capability over its lifespan.
- Environmentally friendly with zero tailpipe emissions and low overall greenhouse gas emissions, including well-to-wheel and embedded emissions.
- Fast refueling time which are comparable to petrol or diesel vehicles.
- Established fuel distribution infrastructure to support pilot programs and initial deployment.
- Capable of harnessing waste heat from the coolant loop and integrating with other waste heat recovery systems.
- Can provide both propulsion power and cooling.
DEC has stated that the technology has three core areas where it has significant potential to be applied to: combined power and cooling; waste heat recovery; and zero emission engine for vehicles. DEC has also stated that the technology is highly relevant for industrial application, mining, inland waterway applications, and the built environment.
How does the DEC engine work?
The DEC liquid air engine uses liquid nitrogen as fuel, emitting cold air as its exhaust. This is conducted through the vaporization and expansion of cryogenic fluids. Ambient or low grade waste heat is used as an energy source with the cryogen providing both the working fluid and heat sink. The heat is introduced to the cryogenic fluid using direct contact heat exchange with a heat exchanging fluid inside the engine.
A major construction advantage the DEC engine has is that it is made almost entirely from the components of a conventional piston engine, requires little maintenance and has limited environmental impact. In an age where adaption of alternative engine solutions is challenging, it is critical that the engine possess as little complications as possible in order to get industry onboard with its adoption.
10 years on: The future of liquid nitrogen applications
While the DEC engine has not been widely applied as much as the company would have hoped, liquid nitrogen as a fuel source still holds a strong possibility for future widespread applications, particularly when it comes to cooling innovations. The DEC engine has been implemented in cooling trucks around London, which could significantly improve how food is transported and make these trucks more environmentally conscious.
Innovation like that from DEC holds the key to the future of a decarbonized world. It is important to remember that engines are not just limited to passenger vehicles and that electrical solutions may not be the most applicable in certain sectors. Continuing to advance technological solutions to meet climate goals is critical, as a wide range of solutions will be needed to be applied to ensure that the world goes green.
