Monoethylene glycol (MEG) is widely applied in oil and gas production. One of applications is prevention of hydrates. There is possibility of hydrates buildup in multiphase pipeline during gas and condensate transportation from LUN-A offshore platform to Onshore Process Facility (OPF) of Sakhalin-2 Project. To prevent hydrates the platform injects MEG water solution into pipeline at concentration of 85 mass%. OPF separates and regenerates MEG. Regenerated MEG returns to platform via dedicated pipeline. OPF MEG regeneration process schematic.
Prior to regeneration rich MEG is fed into two-phase separator to remove gas and remove solids on MEG filter. Then MEG is warmed up in the reflux condenser by vapor to 75°С and in lean MEG /rich MEG heat exchanger to 100°С. Then MEG solution comes to reboiler where water in glycol is evaporated to the required concentration of glycol. MEG solution in reboiler is heated up to 126°С at atmospheric pressure. Working temperature of heating element surface in reboiler is 170°С, maximum temperature (without cooling down by MEG solution) – 210°С. Regenerated MEG is cooled down using air coolers and pumped to storage tank (not shown on Figure 1) for subsequent supply to offshore platform.