Tuesday, July 28, 2015

Hydrocarbon... future or not?

The natural refrigerants ammonia and sulfur dioxide were the earliest in use.
CO2 was too difficult to use. We then had methyl chloride, which exists in the nature as well.

Freon replaced those owing to its non-flammability and non-toxicity.

Ammonia still continues to get used in large systems for its efficiency and favored over explosive gases such as R-290 or R-600a.

When R12 became restricted, explosive underworld refrigerants based on propane/isobutane popped up. 134a, 404A and 410A were then considered environmentally green. They all live on for now, but all destined to be phased out.

It's now technically reasonable to use CO2. HFO-1234yf will replace HFC-134a in auto AC in a few years.

Now the greenies are wanting to go back to petroleum gases. There's no evidence that petroleum HCs have consistent efficiency merits over HCFCs or HFCs.

HFO-1234yf which is set to replace HFC-134a in auto ACs in the next few years have a GWP of 5 or 6... and efficiency levels similar to 134a. A mixture of HFC-32 and 1234yf/ze can support everything form 134a to 410A and research is ongoing to switch over to 1234yf and CO2

While HCs are touted as natural, I'm uncertain as to how we ought to define natural since this is where they come from. So... why do some view HCs as "the future" ?

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