Marathon Galveston Bay, Texas, refinery shuts HCU, alky unit for work: sources

HOUSTON (Reuters) - Marathon Petroleum Corp shut the hydrocracker (HCU) and alkylation unit at its 585,000 barrel-per-day (bpd) Galveston Bay Refinery in Texas City, Texas, by Thursday as part of a multi-unit overhaul that began on Saturday, said sources familiar with plant operations.

Marathon spokesman Sid Barth declined to comment.

The 60,000-bpd hydrocracker, called Ultracracker 4, and 31,500-bpd alkylation unit were shut along with a sulfur recovery unit and a 47,500-bpd aromatics recovery unit, the sources said.

The first units shut were the 65,000-bpd Ultraformer, as the reformer is called, a 60,000-bpd residual oil hydrotreater and an aromatics unit, the sources said. The first shutdowns began on Saturday.

The overhaul is expected to be completed as early as mid-July but may extend through Aug. 1. Because of the COVID-19 pandemic, the overhaul has twice been delayed from an initial start date scheduled in late March.

Hydrocrackers use a catalyst under high heat and pressure in the presence of hydrogen to produce diesel from gas oil along with other motor fuels. Alkylation units convert refining byproducts into octane-boosting components added to gasoline.

Reformers also convert refining byproducts into components used to boost octane in gasoline through a different process from that in reformers. Hydrotreaters use hydrogen to reduce sulfur in motor fuels in compliance with U.S. environmental rules.

Reporting by Erwin Seba; Editing by Chizu Nomiyama and Diane Craft