PROCESS AND SYSTEM FOR RECOVERING AND STORING A LIGHT HYDROCARBON VAPOR FROM CRUDE OIL

摘要

A process and a system for recovering VOC vapor from crude oil during loading of crude oil in a tanker and during transportation and subsequent unloading of the crude oil, and full or partial utilization of the vapor as an energy source on board the tanker. VOC-vapor released from the crude oil contained in one or more oil tanks on board the tanker is passed to a hydration unit wherein it is subjected to a hydration reaction in contact with water and under hydrate-forming pressure and temperature conditions. The formed hydrate is cooled by direct contact with a highly liquid cooling and carrier liquid on hydrocarbon basis and is stored in the form of a suspension or slurry of hydrate in said cooling and carrier liquid, at lowered temperature and at a pressure near the ambient pressure. Stored, cooled hydrate slurry is then heated as required on board the tanker for dissociation of the hydrate and release of VOC vapor trapped in the hydrate, which VOC vapor is then used as an energy source, particularly as a fuel for the engines and boilers of the vessel.