Liquid air could help the road transport industry reduce its emission of greenhouse gases according to the European Road Transport Research Advisory Council (Ertrac).
Air can be made into a liquid by cooling it to -196C. But on heating the liquid turns back into a gas, expanding 700 times in volume. This expansion can be used to drive a turbine or piston.
The Dearman Engine Company is testing a small engine using liquid air at Imperial College London. Trials will soon begin on an articulated refrigerated trailer unit at independent vehicle engineering consultancy MIRA’s test facility in Warwickshire.
Liquid air will probably not be appropriate for heavy duty applications as a primary fuel but could be used in waste heat recovery from internal combustions engines.
Ertrac’s report ‘Energy Carriers for Powertrains’ sets out a road map for the reduction of greenhouse gases in the road transport sector by 80% by 2050 compared to 1990 levels.