There are multiple answers/comments to this question.

  1. Does the compressor have to comply with typical petrochem specifications?
  2. Propane is just another refrigerant, however due to the flammability of the refrigerant you need explosion proof wiring, motors, and controls.
  3. Oil dilution can be a problem. Make sure you use a good quality oil that takes into account the oil dilution of the oil/propane mixture at the operating conditions required.

I would call Howden.