A massive piece of equipment to be installed as part of a £140 million investment at Mossmorran has arrived on site.
The 170-tonne regenerator, measuring 45 feet by 20 feet, was driven to the plant by road.
It followed a 700-mile journey from the Netherlands.
ExxonMobil will install it at Fife Ethylene Plant as part of its work to reduce the impact of flaring.
The regenerator is described as “a clever piece of engineering” that heats and cools air from the plant’s gas turbine.
Exxon has also submitted plans for an enclosed ground flare.
The work comes after hundreds of complaints about noise, vibration and air pollution during bouts of flaring.
The regenerator travelled from the Netherlands to Burntisland by ship, arriving at the Fife town’s east dock on February 1.
Three days later, with a full police escort, it began the final stage of its journey via the A909 to Mossmorran.
Roads through Burntisland were closed for a short period to allow the huge flatbed truck and its cargo to pass safely over the hill towards Cowdenbeath.
Project manager Billy Hogg said: “The journey was well captured by residents in Burntisland.
“The streets were mobbed, windows were wide open and even babies were being well wrapped up and taken out into the street to watch it passing by.”
Exxon’s multi-million pound improvement works were due to start at Mossmorran last year.
However, they were delayed by Covd-19 restrictions.
The Scottish Environment Protection Agency (Sepa) has warned ExxonMobil about noise, light and air pollution during flaring episodes.
Flaring is a safety measure which sees excess gas burnt off.
However, during the worst episodes the flame from the elevated stack can be seen right across eastern Scotland.
And a further episode in October last year drew more than 700 complaints from the public.
In addition, more than 1,100 people have signed a petition calling for the Exxon and Shell plants at Mossmorran to close.
They say the site is devastating communities and have urged all candidates standing at May’s Scottish Parliament election to commit to setting up a just transition board.
Exxon says it has no plans to wind down the plant, which produces petrochemicals, such as food packaging and medical products.
Its investment includes 14 points for improvement which should reduce the plant’s impact on neighbours.