Air dryer

This is the simplest and best. Get a compressor tank 30 gallon minimum. Usually you can get a junk compressor for free. 60-80 gallon works best. Plumb your compressed air into the other tank. As the air moves from your compressor tank to the auxiliary tank, the moisture will condense in that tank. a smaller filter/dryer and desiccant pot will dry your air better than a refrigerant dryer. You also get the benefit of more stored compressed air.