Royal Dutch Shell has shut its one-year old 800,000 ton-per-year (tpy) ethylene cracker in Singapore following operational issues, and has declared force majeure on some chemical supplies, a spokeswoman said on Monday.

"We have declared force majeure under some of our chemicals contracts," the spokeswoman said.

"This is because the ethylene cracker unit on our Pulau Bukom manufacturing site is facing operational issues and this has affected our ability to supply product to some of our customers."

"The rest of our operations at Bukom are not affected," added the spokeswoman who did not give a time-frame on when the cracker will resume operations.

Traders said the unit was shut since last Friday.

"Shell could have encountered some operational issues after the unit restarted following maintenance," said a trader. The unit was shut for approximately a month for maintenance since mid-February.    

Ethylene is a feedstock for chemical products including monoethylene glycol (MEG), which is used to produce consumer and industrial goods including polyester fibers used for clothing and furnishings as well as PET bottles.

Shell operates a 750,000 tpy MEG unit in Jurong Island, and gets its ethylene from the Bukom cracker via pipelines.

The Bukom cracker, unlike conventional units in Asia which use mainly naphtha, has the option to use a range of feedstocks other than naphtha, and these include liquefied petroleum gas and heavy liquid hydrocarbon such as hydrowax.