REGEN® technology processes regenerable rich caustic streams produced in the refinery allowing it to be recycled thereby significantly improving caustic utilization. Typically REGEN® is coupled with extractive THIOLEX™ technology to regenerate the mercaptide-rich caustic purged from the THIOLEX™ system and returns a lean caustic stream for additional mercaptan removal. Depending on the stringency of the treated product specifications, the REGEN® design will employ disulfide oil (DSO) gravity separation and/or solvent washing step(s) to minimize the impact of DSO back-extraction. In addition, REGEN® technology is equally effective at reviving rich/spent caustic streams emanating from conventional refinery treating units.
REGEN® technology was first licensed in 1980 and to date Merichem has granted 151 unit operating licenses world-wide. Moderate levels of sodium sulfide (salt of hydrogen sulfide/H2S) can be accommodated in the rich caustic and many times negates the need for a H2S pre-wash stage in the hydrocarbon extraction section of the treating unit resulting in less capital expenditure.
The design of the system is based on more than 75 years of first-hand operating knowledge gained from Merichem-owned plants. This when coupled with Merichem’s extensive licensing experience, makes REGEN® the technology-of-choice.