(Adds Motiva not available, details)
HOUSTON, Jan 12 (Reuters) - Motiva Enterprises' 600,250 barrel per day (bpd) refinery is scheduled to shut downits 92,000 bpd gasoline-producing fluidic catalytic crackingunit on Wednesday for a planned seven-week overhaul, sourcesfamiliar with the refinery's plans said on Monday.
An 18,000 bpd alkylation unit that makes octane-boostingcomponents for gasoline, will also be shut on Wednesday, thesources said.
Next week Motiva will shut a sulfur recovery unit and a49,000 bpd catalytic reformer, which like the alkylation unitconverts refining byproducts into octane boosters, as part ofthe project, the sources said.
During the overhaul, the top of the main column on the FCCUwill be cut off to replace the unit's reactor during seven weeksof work, according to the sources.
Since late October, contract workers have been preparing forthe overhaul, the sources said.
The Motiva refinery is the largest in the United States.Motiva is 50-50 joint venture between Royal Dutch Shell Plc and Saudi Aramco [SDABO.UL}. (Reporting by Erwin Seba; Editing by Diane Craft and GunnaDickson)