yup natures best refrigerant R-290!

I used to use a small rig made out of an old fridge compressor and a bunch of filter driers to clean up the BBQ grade R-290, came out squeaky clean and stench free (Aside from the good ol smell of old minerol oil)

Offers low compression ratios, low discharge temp and damned good cooling, I'd pick it over R-22 any day of the week!