The GIZ (German Society for International Cooperation) is collaborating with Thermo King ‒ a brand of Trane Technologies that manufactures refrigerated containers ‒ on a project to develop a proof of concept for propane (R290) maritime refrigerated shipping containers, or reefers.
The Greener Reefers Project is a €2.9 million ($3 million) endeavor commissioned by the International Climate Initiative and the German Federal Ministry of the Environment, Nature Conservation, Nuclear Safety and Consumer Protection. With a completion date of April 2026, the project seeks to develop safety standards and performance modeling and validation for propane refrigerated marine containers.
“The project aim is to show the shipping industry that R290 reefers are possible,” said Kirsten Orschulok, Greener Reefers Project Lead at GIZ, during a presentation at the ATMOsphere (ATMO) Europe Summit 2024. The event was organized by ATMOsphere, publisher of NaturalRefrigerants.com, and held November 25–26 in Prague, Czech Republic.
Other entities involved in the project include the University of Valencia (UV) in Spain and the governments of South Africa and Costa Rica.
The current state: With various agencies and governments seeking to phase out PFAS (per- and polyfluorinated alkyl substances), the marine cargo industry needs a natural refrigerant solution for chilled and frozen cargo.
- In 2017, the Danish shipping company Maersk Line started using CO2 (R744)-based reefers, but it has said that they currently do not meet its energy consumption needs.
- An R290 reefer has not been developed in part because the flammability increases costs due to the need for specialized risk assessments and certified technicians, Orschulok noted.
Addressing safety: GIZ is proceeding with an operation, maintenance and risk assessment of R290 reefers as outlined by the existing safety standard for thermal containers with flammable refrigerants ISO (International Organization for Standardization) Standard 20854:2019.
- “We are going to harbors and asking technicians and captains what are the risks and then assessing if it is a real risk,” Orschulok said. She added that a refrigerated reefer will contain a maximum of 2kg of R290.
- The assessment per the ISO standard includes three analyses: hazard and operability, failure mode and effects and fault tree.
- “We are working with training centers in South Africa and Costa Rica to train reefer technicians to handle R290 safely,” Orschulok said.
Design/validation: Performance objectives for the project use Thermo King’s R134a Container Fresh and Frozen (CFF) as a baseline, with a 6.4kW (1.8TR) cooling capacity at −18°C (−0.4°F) in an ambient temperature of 38°C (100.4°F) and a refrigerated range from −30 to 30°C (−22 to 86°F) in outside temperatures between −30 and 50°C (−22 and 122°F).
- The temperature control must be within CFF’s 0.25°C (0.45°F) in chiller mode and 1°C (1.8°F) frozen.
- The energy efficiency objective requires the R290 unit to outperform the R134a CFF by 10%.
- Trane Technologies and UV will conduct modeling, simulation and testing of the developed R290 unit, with a third-party certification verifying energy consumption.
Quotable: “We have this constant dialogue going on regarding the design to make the flammable refrigerant as safe as possible,” Orschulok said. “Customers want to buy a product that is safe and tested. We are building that bridge between the operation, maintenance and risk assessment and the energy performance modeling and simulation.”
