All You Need to Know About Isobutane (R600a)

Isobutane is a hydrocarbon and an isomer of butane used in various applications, including as a refrigerant, more commonly known as R600a. Despite its high flammability, R600a refrigerant is non-toxic, safe when handled properly, and eco-friendly, making it a critical consideration when looking for cold storage units for homes, laboratories, and pharmacies.

What is the Difference Between Butane and Isobutane?

Isobutane is a colorless and odorless gas, alternatively known as 2-methylpropane, methylpropane, or i-butane. It is a structural isomer of butane and shares the same 58 g/mol molar mass and chemical formula C₄H₁₀.

However, isobutane is a branched molecule, while normal butane can have either a branched or linear molecular shape. It also has a boiling point of -11℃, much lower than the 1℃ of n-butane.

With these characteristics, isobutane serves various functions, including acting as a diluent in producing high-density polyethylene (HDPE), a feedstock used in alkylation units in petroleum refineries, and a propellant for aerosol spray cans. Beyond these uses, it is utilized as a refrigerant, referred to as R600a, in domestic and commercial laboratory freezers and refrigerators.

What is R600a Refrigerant?

R600a, which will also be referred to as isobutane throughout the article, is a hydrocarbon (HC) with low global warming potential (GWP). It is also known for having zero ozone depletion potential (ODP), making it a superior and popular alternative to more harmful hydrofluorocarbons (HFCs) like R12 and R134a.

However, this HFC-free refrigerant is flammable and can be dangerous in volatile environments if it leaks. To address this safety hazard, manufacturers equip their cold storage units with compressors designed explicitly for butane and propane and require working with qualified professionals for proper installation and maintenance.

What Are the Benefits of Isobutane?

Low Global Warming Potential

GWP is an indicator of how much a gas contributes to climate change. It measures the energy absorbed by emissions of 1 ton of a gas over a specified duration relative to the emissions of an equivalent mass of carbon dioxide.

In this context, R600a stands out with a GWP of 3, much lower than the common HFC refrigerants: R134a has a GWP of 1430, while R12 registers a staggering 10700. Its minimal impact on global warming makes it an ideal choice.

Zero Ozone Depletion Potential

Chlorofluorocarbons (CFCs) and halons released into the atmosphere cause ozone depletion. This reaction thins the ozone layer, increasing the ultraviolet radiation at the Earth’s surface.

Unlike traditional refrigerants containing chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs), R600a does not contribute to ozone layer thinning, making it an alternative sustainable choice for manufacturers.

Energy Efficient With Enhanced Cooling Performance

Isobutane provides excellent cooling performance while consuming less energy. As a result, it ensures optimal sample and material protection while reducing electricity costs and greenhouse gas emissions.

An R600a refrigerator, for example, can quickly reach the desired temperature and efficiently maintain it over time. The refrigeration system demands less work, resulting in less energy waste and minimized carbon footprint.

What is the Difference Between R134a and R600a Refrigerant?

R134a is a synthetic HFC refrigerant with better cooling efficiency and higher refrigeration capacity than R600a. However, it is being phased out worldwide because of its high GWP and significant impacts on climate change.

On the other hand, R600a is a non-toxic natural refrigerant and is environmentally friendly with its low GWP and zero ODP. It has a higher energy efficiency and volumetric cooling capacity while requiring lower compressor power and operating at a lower discharge temperature. Unlike R1341, R600a is flammable and requires safe handling.

Are R600a Refrigerators Safe?

Despite being designed for domestic and commercial use, R600a refrigerators require careful installation, maintenance, and disposal by qualified professionals.

Isobutane belongs to the A3 group in ASHRAE Standard 34, indicating lower toxicity but higher flammability in the event of a leak. Recognizing this safety hazard, manufacturers follow product safety standards that ensure R600a is hermetically sealed within the system. By doing so, cold storage units using isobutane are guaranteed safe and, even better, less harmful to the environment.

Are you looking to upgrade to refrigeration solutions that use HC refrigerants? TLD offers safe and environmentally friendly laboratory freezers and refrigerators to help meet your laboratory and pharmacy needs. If you need any assistance, contact our expert team at 1-800-733-2522, Email, or message us via Live Chat, available on our website.

Sources:

https://www.epa.gov/ghgemissions/understanding-global-warming-potentials

https://www.atamanchemicals.com/isobutane_u26644/

https://medium.com/@unitedrefrigerants/environmental-benefits-of-r600a-refrigerant-532e62b06260

https://medium.com/@unitedrefrigerants/r600a-vs-r134a-comparing-eco-friendly-refrigerants-143d5cd243d5

https://pediaa.com/difference-between-butane-and-isobutane/

https://gmsarnjournal.com/home/wp-content/uploads/2015/08/vol2no1-5.pdf

https://www.jetir.org/papers/JETIR1701076.pd