Energy demand and environmental impacts of alternative food transport refrigeration systems

This paper considers the use of liquid carbon dioxide and liquid nitrogen based cryogenic refrigeration systems for temperature controlled food transport applications and provides a comparative assessment of these systems with conventional vapour compression systems driven by an auxiliary diesel engine. Two refrigerated vehicles (one rigid and one articulated), two food products (one chilled and one frozen), and three delivery schedules (long multi-drop delivery, continuous multi-drop delivery, and short delivery) are used for assessment purposes. The analysis indicates that for all cases investigated more cryogenic fluid is required for food transport refrigeration compared to the quantity of diesel. For all delivery schedules, the Well to Wheel environmental impacts of cryogenic systems will be of the same order as those of diesel driven refrigeration systems. Uncertainty of diesel and cryogenic prices in the future makes investment in cryogenic systems difficult on economic grounds alone, and the unavailability of charging infrastructure currently hinders the use of cryogenic refrigeration systems for long distance transportation.