 The sweetened product from the caustic settler vessel flows through a water wash vessel to remove any entrained caustic as well as any other unwanted water-soluble substances, followed by flowing through a salt bed vessel to remove any entrained water and finally through a clay filter vessel.The clay filter removes any oil-soluble substances, nonmetallic compounds (especially copper) and particulate matter, which might prevent meeting jet fuel product specifications.The pressure maintained in the reactor is injected air will completely dissolve in the feedstock at the operating temperature.