 The caustic-disulfide mixture then flows into the separator vessel where it is allowed to form a lower layer of "lean" Merox caustic and an upper layer of disulfides.The vertical section of the separator is for the disengagement and venting of excess air and includes a Raschig ring section to prevent entrainment of any disulfides in the vented air.The disulfides are withdrawn from the separator and routed to fuel storage or to a hydrotreater
unit.