Also known as:
Onsan is a very large, medium complexity refinery in South Korea
It is owned and operated by S-Oil, a subsidiary of Saudi Aramco
Complexity: 7.7
Onsan is a medium complexity plant with upgrading from resid hydrocracking and RFCC as well as high severity VGO FCC. It also has base oils, aromatics and asphalt. Although this gives it a significant amount of conversion capacity, it is small relative to the very high distillation capacity.
Major process units:
Atmospheric distillation - 669 kbpd - 3 units: No 1 (90 kbpd), No 2 (240 kbpd), No 3 (250 kbpd)
Condensate splitter - 89 kbpd
RCC - 73 kbpd - No 2 RFCC - produces 200 kMTA of propylene
Resid hydrocracker - 75 kbpd
FCC - 76 kbpd, high-severity FCC
Reformer - Continuous (CCR) unit
VGO hydrotreater - 40 kbpd
Resid hydrotreater - 3 units: No 1 RHDS (52 kbpd), No 2 RHDS (57 kbpd), No 3 RHDS (63 kbpd Hynahl unit)
Oxygenates plant - MTBE - 279 kMTA
Aromatics extraction - Benzene of 150kMTA, Toluene of 350 kMTA, and Xylene of 450 kMTA
Base oil plant - 2 plants: 14 and 31 kbpd
Paraxylene - two plants - 750kMTA and 1.1 MMTA
Benzene - three plants - 150, 300, and 72 KMTA
1980 - Refinery commissioned (No 1 CDU and No 1 HDS) by Korea Iran Petroleum Company
1981 - Base oil plant added (#1 LBO)
1991 - No 2 CDU and No 2 HDS added
1991 - Reformer and BTX plant added
1991 - Aramco acquired 35% interest in company
1992 - No 3 CDU added
1995 - No 3 HDS added
1996 - Hydrocracker and No 1 resid hydrotreater added
1997 - RFCC and VGO HDS added
1997 - Paraxylene plant added
2002 - No 2 Resid hydrotreater and second base oil plant (#2 LBO) added
2011 - Condensate splitter added with second paraxylene plant
2014 - Aramco acquired 65% interest in company
2018 - Added No 3 resid hydrotreater, High-severity FCC, alkylation and MTBE (RUC/ODC project)
2026 - Aramco plans to commission a 46 kbpd crude to chemicals train at the plant