This photograph dates back to 2001 but was brought to our attention only in 2007. It shows one of the smoke rings that we ourselves managed to photograph on August 14 of 2001 (see VO-RI-01 and VO-RI-02).
The photo was taken by Walter SYSMANS, a production coordinator who was at work at the petrochemical complex when the rings appeared. Mr. SYSMANS confirmed that, on that particular evening, one of the flare stacks wasn't functioning as it should.
[© Walter SYSMANS - photo used with permission (image found at ls.kuleuven.ac.be)]