S-Oil Corp is preparing for a significant maintenance shutdown at its No. 1 residue fluid catalytic cracker (RFCC) unit in Onsan, South Korea, which could temporarily tighten propylene supply in the region.
According to a source, the company is expected to commence maintenance on the unit by mid-October 2025, with operations likely to remain offline until the end of November 2025. Market participants indicated that while the turnaround was anticipated, the length of the outage will be closely monitored given its potential impact on regional propylene balances during the fourth quarter.
The Onsan-based RFCC unit has a crude processing capacity of 73,000 barrels per day and produces approximately 200,000 metric tons per year of propylene, a key feedstock for polypropylene and other derivatives. The unit’s extended downtime comes at a time when Northeast Asia’s olefins market is already navigating a mix of supply constraints from cracker maintenance and persistent weakness in downstream demand.
Traders noted that although current propylene fundamentals remain subdued due to sluggish consumption in polypropylene, acrylonitrile, and oxo-alcohols, supply disruptions of this magnitude have the potential to stabilize or even firm spot sentiment if demand shows signs of revival later in the quarter. Others, however, argued that the market’s oversupplied condition could mute any immediate bullish response, with buyers likely to remain cautious until clear signals of recovery emerge in downstream sectors.
The upcoming turnaround highlights the role of South Korea as a major player in the Asian propylene market, with S-Oil’s production decisions having ripple effects across regional trade flows. Market observers will be watching closely for updates on the progress of the maintenance schedule, as well as how other regional producers position their supply strategies in response to the outage.
