The Delayed Coker Unit at ExxonMobil's 320,000-b/d Antwerp refinery in northwest Europe has emitted visible levels of coke dust into the surrounding area since 2018, the government of Flanders has confirmed, but ExxonMobil says the unit is now operating as planned.

The 1 billion euro, 50,000-b/d DCU was built to convert heavy, high-sulfur fuel oil products into cleaner fuels, but began to blow coke dust into the harbor water by the refinery shortly after coming online in October 2018.

One Amsterdam-Rotterdam-Antwerp barge operator who loaded at the refinery last year said that coke dust accumulations had lasted for more than a year.

ExxonMobil "paid the costs" for cleaning the barges, the source said.

Sources with knowledge of the refinery say that some vessels stationed next to it in June became "filthy" because of dust accumulation, but they had not witnessed similar visible dust formations since then. Those sources say that measures such as erecting windscreens have been taken to prevent coke dust blowing out of the site, as part of what workers at the refinery refer to as the "Dust Mitigation Project".

A spokeswoman for the environmental department of the government of Flanders, an autonomous region of Belgium, told OPIS that ExxonMobil noticed dust formation shortly after the coking unit went into service.

"During 2019 and the beginning of 2020 different measures were implemented to prevent dust formation," the spokeswoman said in a statement last week. "The situation is currently under control due to the different measures taken."

"Substantial release of dust to the environment...is an unwanted phenomenon.

Studies however indicate that petroleum coke dust does not have much chemical properties, is chemically stable and inert, and is not considered hazardous," the department said in a statement Wednesday. "Since the implementation of several measures to reduce dust spreading, there has been observed a noticeable reduction of both the frequency and magnitude of release events," the statement said.

A U.K.-based spokesman for ExxonMobil told OPIS last week: "This is old news - operations there are back to normal."

"We started up the new DCU unit in Antwerp refinery last year. Following some operational adjustments, as is common during the start-up phase of a large new unit, the operations are now (going) according to plan," the spokesman said this week in response to further questions. The spokesman confirmed that these adjustments included the installation of a windscreen.

ExxonMobil declined to confirm that these efforts to combat emissions of coke dust are referred to by employees and contractors as the "Dust Mitigation Project".

Petroleum coke typically contains 90% elemental carbon and 3-6% elemental sulfur in addition to trace amounts of metals, according to the website of the U.S. Environmental Protection Agency.

 

--Reporting by Anthony Lane, alane@opisnet.com;

--editing by Rob Sheridan, rob.sheridan@ihsmarkit.com

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