A
system for recovering glycol from glycol and brine mixtures produced from oil or
natural gas wells that combines energy efficiency with a capability for handling salt and other solids contained in the mixture. The
system comprises three effect
evaporator systems in series. Each effect
evaporator system comprises an
evaporator, a separator vessel, product pumps, and a solids removal system.The process utilizes the system to remove salt and other solids as well as
excess water leaving a glycol
stream that can be reused as a
hydrate inhibitor. The process begins by preheating a glycol / brine
stream comprising approximately fifty percent (50%) glycol. The
stream is then subjected to three
evaporation cycles. The first
evaporation cycle comprises introducing the preheated stream into a suppressed
boiling point evaporator where the stream is heated under a
constant pressure. The stream pressure is then dropped to cause a portion of the water contained in the stream to vaporize or flash. The flashing stream is then introduced into a separator vessel where the
water vapor is separated from the remaining liquid stream. The
water vapor is removed from the separator and condensed. The remaining liquid glycol / brine stream is then pumped from the separator vessel through a solids removal system where precipitated salts and solids are removed. These steps are repeated two additional times. Each time the remaining liquid stream becomes more concentrated with glycol until the finished product is approximately ninety percent (90%) glycol.