The 110,000-bpd gasoline-producing FCC and 23,000-bpd diesel-producing HCLA hydrocracker were shut on Saturday for the two-month long overhaul, the sources said.
Exxon spokesperson Lauren Kight declined to comment on operations at the refinery on Monday.
The shutdown of the FCC and hydrocracker begins a planned multi-unit overhaul called El Toro involving both the refinery and the adjoining Exxon chemical plant in the Baton Rouge Complex, the sources said.
Exxon is also planning an overhaul of two of the refinery's four crude distillation units (CDUs) in the third quarter of this year.
The 90,000-bpd PSLA-7 is scheduled to shut first in the third quarter, the sources said.
Once work is completed on PSLA-7, the 210,000-bpd PSLA-10 will be shut for an overhaul, according the sources.
CDUs begin the refining process by breaking down crude oil into feedstocks for all other units in a refinery. PSLA-10 is the largest CDU at the Baton Rouge refinery.
Hydrocrackers use a catalyst under high heat and pressure in the presence of hydrogen to convert a feedstock, most often gas oil, into diesel and other motor fuels. There is only one hydrocracker at the Baton Rouge refinery.
FCCs use a fine powder catalyst to convert gas oil into unfinished gasoline. There are two FCCs at the Baton Rouge refinery. Each has a capacity of 110,000 bpd.
