The invention teaches a purification system which uses a series of operations, in a single unit, to purify air, while extending the life of the purification units. Air is passed through a coarse water trap to remove liquid. The semi-dry air, is then passed through adsorbers, which remove the remaining moisture and all the carbon dioxide in a purification process. The present invention flows the air to be purified through adsorption columns twice, before and after passing the air through an oxygen catalyst unit. The flows of air are then rotated to a third column, which is thermally regenerating with the facilitation of a regeneration air supply from the purified air.