Dehydration and hydrate-control glycols u2014 TEG, MEG, and DEG u2014 plus methanol as a thermodynamic hydrate inhibitor for natural gas and pipeline service.
Dehydration glycols are hygroscopic diols that remove water vapor from natural gasnso it meets a pipeline water-content limit, typically around 7 lb of water per MMscf.nTriethylene glycol is the standard contactor solvent for this duty. A second, related job isnhydrate control: monoethylene glycol injected into wet gas lines depresses the temperature atnwhich gas hydrates form. Match the glycol to the job u2014 TEG for dehydration towers, MEG fornhydrate inhibition.
nnTEG dominates gas dehydration because it regenerates cleanly at the reboiler temperatures anglycol unit can reach. Diethylene glycol is the older, lower-boiling option and still appearsnwhere regeneration temperature is limited, though it carries more vaporization loss. Both run asnthe working fluid of a closed contactor-and-regenerator loop, so makeup volumes are modest once anunit is charged. Specify TEG for new dehydration service and reserve DEG for existingnlow-temperature units.
nnFor hydrate inhibition the real choice is MEG versus methanol. MEG can be recovered andnrecycled through a reclamation unit, which favors continuous, high-volume injection on subseantiebacks and long flowlines. Methanol is cheaper per gallon and effective for startup ornintermittent duty, but it is usually lost to the hydrocarbon and water phases and can createndownstream specification problems. Choose MEG when injection is continuous and recovery pays back;nchoose methanol for short, low-volume duty.
nWe use cookies and similar technologies for analytics and to improve our Site, and — with your consent — for marketing and B2B visitor identification. Choose what to allow. See our Privacy Policy.