There is ‘a compelling business case’ for introducing vehicles equipped with liquid air engines in Britain, says a new report.
In addition there would be significant benefits from reduced local air pollution and noise.
The ‘Liquid Air on the Highway’ report was published on 4 June by the Liquid Air Energy Network, the Centre for Low Carbon Futures, and the University of Birmingham.
The report explores the potential benefits and implications of introducing liquid air engines in commercial vehicles in Britain over the next decade. Among its findings, it states that adoption of liquid air technologies in trucks and buses more broadly could save Britain 1.3 billion litres of diesel, over a million tonnes of carbon and £115m by 2025, net of all costs.
Several engine concepts are under development, but the two closest to commercial deployment are a zero-emissions ‘power and cooling’ engine for truck and trailer refrigeration and a diesel-liquid air ‘heat hybrid’ engine for buses, trucks and other commercial vehicles.
The Dearman Engine Company is working on both applications, based on a two-stroke engine developed by inventor Peter Dearman that uses the rapid gasification of liquid air or nitrogen to drive the piston.
A Dearman refrigeration engine begins on-vehicle testing this summer in a project led by MIRA with funding from the Technology Strategy Board.
On-highway testing is expected next year, with low-volume commercial production scheduled from 2016.
Also under development is Ricardo’s split cycle engine, which uses liquid nitrogen to increase the efficiency of a diesel internal combustion engine. An on-highway prototype could be ready by 2020.
Although liquid air is not yet produced commercially in significant quantities, liquid nitrogen is readily available, and there is enough spare production capacity to satisfy the market until demand grows enough to justify new investment. Ultimately, liquid air would be cheaper to produce because there would be no need to separate nitrogen from oxygen.
Coinciding with the report launch, the Dearman Engine Company announced an agreement with Hubbard Products Ltd, a leading supplier of refrigeration for commercial vehicles and refrigerated vans, to manage the vehicle integration of Dearman’s transport refrigeration system.
In a statement, the companies said: “The objective of this collaboration is to advance the technical, commercial and industrial development of the Dearman engine transport refrigeration system to a stage where Hubbard can manufacture, integrate and market cooling systems incorporating the Dearman engine in commercial volumes.”
The specific first objective is for the partners to deliver “approximately five” field trial prototypes of the refrigerated vehicle system to an end-user in the UK, early next year. Dearman is already engaged in discussions with two major supermarkets.
While outside the scope of this report, the company says Dearman engines could also be developed as “prime movers” in certain niche applications such as mining, where emissions consisting of clean cold air would be particularly beneficial.