Could a new liquid nitrogen-powered engine revolutionise our refrigerated transportation fleet? We think it might.
Diesel engines have long been the default solution to power the cooling systems in refrigerated trucks. They’re reliable, but they’re not environmentally friendly, generating carbon dioxide emissions and vast quantities of wasted heat. On top of this is the pressing concern around the impact of poor air quality in crowded cities.
The Dearman Engine Company has developed an alternative. Its patented Transport Refrigeration Unit (TRU) is the world’s first ‘clean-cold’ engine driven by the expansion of liquid nitrogen to produce clean power and cold air with zero emissions.
18,000 km powered by clean-cold technology
Dearman’s technology is not yet commercially available, but we have committed to trialling it in our supply chain.
For six months in 2017, we fitted a Dearman TRU in one of our ice cream transportation trucks in the Netherlands, and it was a resounding success. Over 26 weeks, the truck spent 661 hours on the road and travelled more than 18,000 km to collect and deliver Ben & Jerry’s and Ola ice cream – all powered by clean, cold air.
Throughout the trial, the on-board refrigerators maintained the perfect temperature to keep our ice creams at their best, and the technology was able to deliver with zero emissions in the urban areas where our trucks operate. It was efficient, and our logistics teams found the technology quiet, safe and easy to use. It was a win not just for the environment, but from a business perspective too.

Finding sustainable solutions in logistics
“Although Dearman’s technology is not due for commercial rollout until later this year, by opening up our logistics network to this innovation, and collaborating in this way, we have provided our partner with a great opportunity to test a revolutionary product under real-life conditions,” says Raghuraman Ramakrishnan, VP Logistics Europe.
“Reducing the environmental impact of our logistics network is an integral part of the Unilever Sustainable Living Plan and our goal is to make sure that our transport and distribution systems are as green as possible. We are committed to advancing sustainable solutions in logistics and leveraging new technologies once they become commercially available, in order to achieve this,” he adds.
A recent report from the University of Birmingham in the UK showed that ‘clean cold’ could help deliver against almost all 17 of the UN’s Sustainable Development Goals.