Formosa Petrochemical Corp. has shut a crude distillation unit at Mailiao for 6-7 weeks of scheduled maintenance. A crude distillation unit is the main part of a refinery that separates oil into its various fuel components. Formosa also plans to shut a residual fluid catalytic cracker, which has capacity of 84,000 barrels per day, and an 80,000 bpd residual desulphurization unit for planned repairs. The two secondary facilities convert heavier streams of refined oil into higher-valued fuel products. The closure of the 180,000 barrel-a-day facility will last between 40 days and 50 days.