Victoria Vaughan Straits Times 2 Sep 10;
Flaring at Shell's oil refinery on Pulau Bukom seen from Pulau Semakau, about 2km away, in February. -- PHOTO COURTESY OF RIA TAN
A LARGE flame topped by a plume of black smoke has been spotted shooting up from a chimney at Shell's oil refinery on Pulau Bukom for the last six months.
The National Environment Agency (NEA) says it is aware of the situation known as 'flaring' and that the emission of dark smoke from a chimney is against the law outside agreed limitations.
While Shell says it is within the limitations, an NEA spokesman said: 'We are working with Shell to understand and stem this unusual spate of smoke emissions from the flare stacks.'
Flaring burns off chemicals in crude oil (hydrocarbons) which are not being used. It also helps prevent fires and explosions in a plant due to a gas build-up.
'Black smoke is emitted by a flare when there is insufficient steam to burn off the hydrocarbons in a smokeless manner.
'It is the responsibility of the plant operator to ensure that sufficient steam is produced to keep the flare smoke-free,' said the NEA spokesman.
The steam provides the oxygen to allow the hydrocarbons to burn without smoke. NEA says the flare at Pulau Bukom has 'not impacted the air quality on the main island of Singapore so far, and there is no cause for concern'.
Mr Dai Nguyen, Shell's health, safety and environment manager, said flaring acts as a 'safety relief valve' to allow the combustible gases to be burned and released as water and carbon dioxide, which are not hazardous. He said: 'We understand that the sight of such a large flame can cause concern... but we want to assure everyone that flaring at the site is a vital part of keeping the plant safe.'
The dramatic sight has caused some consternation with nature blogger Ria Tan, who runs the WildSingapore blog. She has been commenting on the flaring since she first saw it in February.
Ms Tan said: 'I have been visiting the south islands for about 10 years and I have seen flaring before but not as often or as large as this.
'The smoke goes up into the sky and comes back down into the water and gets dispersed, it affects everything not just marine life. I want to be assured people are keeping an eye on it.'
The Straits Times' citizen journalism website Stomp has also been receiving regular posts about the flare since March.
Tug boat captain Thomas Heng sent in a photo of the flare last month. 'I do see flares from time to time... but not with so much smoke and not for such a length of time,' he said.
Related links
More about flaring and incidents of flaring on Bukom on the wild shores of singapore blog.