The 92,000-bpd gasoline-producing fluidic catalytic cracking unit (FCCU) malfunctioned on Tuesday night, tripping that unit and the 16,500-bpd alkylation unit out of production, the sources said.

Energy industry intelligence service Genscape said the flaring began on Tuesday night with the shutdown of the FCCU.

The alkylation unit converts refining by-products into octane boosting components of gasoline.