May 25, 2012:

A sulfur recovery unit (SRU) malfunctioned on Friday at Valero Energy Corp's 292,000-barrels-per-day Port Arthur, Texas, refinery, according to a notice filed by the refinery with the Texas Commission on Environmental Quality on Thursday. The filing said operations were working to stop emissions caused by the SRU No. 543 snag, while the cause of the upset was under investigation.

By Reuters