CO₂: A growing option in industrial refrigeration

Traditionally, ammonia (NH₃ or R717) is the typical choice for large-scale refrigeration systems. It has great thermodynamic properties and no global warming potential (GWP). However, advancements in CO₂ (R744) refrigeration technology make it a suitable option for some of these applications on the lower end of the capacity range.

R744 systems have been primarily made for commercial refrigeration, but they can also be used in larger systems, as reported by Accelerate America, in an article about Henningsen Cold Storage’s pioneering use of transcritical CO₂ in industrial refrigeration. (Accelerate Americais published by shecco, the publisher of this website.)

R744 can effectively be used in two formats for industrial applications: cascade systems and transcritical systems. It is the fastest growing refrigerant in this market, according to markets and markets. 

Combining R744 and R717

A cascade system uses ammonia as a primary refrigerant, which cools the secondary refrigerant CO₂. Danish component supplier Danfoss observed that this option can be used in applications where a smaller ammonia charge is needed. The company praises this system’s efficiency, especially in low temperature applications, adding that R744 is excellent as a brine. 

Pioneers in large scale transcritical CO₂

Transcritical CO₂ is another option for industrial refrigeration that’s gaining attention. In 2018, a new storage facility in Hamburg, Germany, runs entirely on it. The natural refrigerant provides the facility with 2 mW of cooling power. It has a significantly lower global warming potential (one) than HFCs and is non-toxic and non-flammable. Thus, it is not subjected to regulatory burdens. It also has great thermodynamic properties. Due to this, companies such as Carnot Refrigeration report growing demand for R744 in industrial applications. 

R744 and R717 are both safe and efficient refrigerants, if used correctly. However, one can be preferable over the other in certain settings. For example, U.S.-based Henningsen Cold Storage, selected transcritical CO₂ for two of its plants. 

R744’s  growth can currently be observed in smaller industrial applications. But if the current development continues, larger compressors for more cooling power will enable its use in bigger applications. 

To find out more about CO₂ in industrial applications, read the articles below:

Taking on Transcritical in Cold Storage

Dorin: 'CO2 growing fast in industrial market'


South African butchery capitalises on CO₂