In chemical terms, a hydrocarbon is a naturally occurring basic compound of carbon and hydrogen, and is typically to be found in large crude oil concentrations. The non-toxic hydrocarbons are now widely used as a modern refrigerant, being an eco¬-friendly alternative to ozone damaging CFC/HCFC/HFC fluorocarbons.
The following three main types of hydrocarbons are widely utilised as refrigerants:
- Propane R290
- Isobutane R600a
- Propylene R1270
The installation and maintenance of all refrigeration systems that contain flammable materials like the above should only be carried out by authorised persons who are certified for that kind of work.
The Chemical Properties of Hydrocarbons
Isobutene and propane, the two most utilised hydrocarbons
are compatible with materials used in HFCs and standard oils. One significant exception is propene (or propylene) as it is not neoprene compatible. Consequently, with this refrigerant, special O-rings have to be employed.
Because they belong to the category of natural refrigerants, hydrocarbons have negligible GWP and zero ODP. Essentially, they are by-products coming from the petrochemical sector.
The Efficiency of Hydrocarbons
Because of their excellent thermodynamic characteristics, hydrocarbons are good and perhaps even superior contrasted against refrigerants of both HCFC and HCF in the majority of applications.
Due to their flammability potential, hydrocarbons are the subject of safety legislation and guidelines internationally. All hydrocarbon systems manufacturers must adhere to equipment safety guidelines. The service personnel must comply and understand specified procedures for safe handling.
Strict specifications as well as safety legislation have stressed on the need for leakage-simulation verification and testing when it comes to the sealing of any electrical components near hydrocarbon flows. Additionally, the majority of commercial and domestic appliances like fridges and freezers, and motor compressors are always subject to globally enforced safety directives.
In general, the usage of ignition sources should be avoided inside the application. The majority of hydrocarbons are in fact non-toxic, the main safety concern only emanating from their high flammability. However, hydrocarbons gases are generally heavier than standard air and may displace the air in your lungs.
The hydrocarbons impact has been felt most in fridge and freezer domestic applications where what is referred to as the 'Greenfreeze' isobutane (R600a) refrigerant is now being widely used on an international scale. Refrigeration in the commercial sector has also followed suit, basically going for propane (R290) in place of ozone-damaging refrigerants, especially in major supermarket systems.
Typical hydrocarbons applications are:
- Domestic and commercial refrigerators/freezers
- Beer and bottle coolers
- Beverage dispensers
- Ice cream freezers
- Heat pumps
- Small air conditioners
- Supermarket refrigeration
The relative hydrocarbons systems cost largely are determined by the application. In light commercial and domestic usage, the cost is comparable to that of HFCs systems. However, in industrial and commercial applications, HCs systems tend to be comparatively more costly because of the need for installing explosion-proof electrical equipment enclosures.