Abstract: In ethylene steam cracking technology, methanol is often used as the sealing fluid for methane pump in cryogenic zone, and the pressure of sealing liquid is required to be higher than the outlet pressure of the pump. Methanol may leak into the medium and be entrained by the process medium into equipment and pipe fittings with relatively small aperture in the cryogenic zone, resulting in frozen blockage and then a dramatic increase in ethylene loss, thus increasing the potential hidden danger of temperature runaway of the mathanation reactor. This paper summarizes the impacts, judgement and countermeasures for methanol leakage.

Key words: methane pump, methanol, cryogenic zone, frozen blockage