High amine losses, high H2S in the fuel gas, and poor unit reliability were the norm for the amine regeneration units at the Aruba refinery. In 2003, the three amine units were revamped to increase capacity, to improve unit operation and reliability, and to minimize the losses. The three high pressure amine absorber systems at the hydrotreaters were also revamped. These changes (revamps) resulted in significant reduction in amine losses; the amine purchases went from 1,791,060 (2002) Lbs/yr to 178,120 Lbs/yr (2005) after the revamp. No amine was purchased in 2006 and 2007, this resulted in significant amine solution savings of $4O6,000/Year.
Subsequent to the revamps and unit restarts, frequent rich amine cartridge filter replacements and high Heat Stable Salts (HSS) were observed. An AMIPUR (HSS removal skid) was installed to remove the HSS, and rich amine acid gas loadings were targeted to 0.35 mo! H2S/mol MDEA maximum. The AMIPUR operation and the new operating targets for the amine system resulted in significant filter costs savings of 65% on the rich amine filters and 34% on the lean amine filters. A savings of $119,000 per month amounting to annual savings of about $1.5 Million were achieved by continuing to operate the units on lower rich amine acid loadings and lower HSS contents.
The amine losses also reduced further due to less filters being changed out. Besides the economical benefits, fewer filter change-outs resulted in safety and environmental benefit because of the reduced potential for H2S exposure and release.
`Amine unit`s improvements at the Aruba Refinery`