Chancellor Rachel Reeves is set to announce up to £14.5m in investment for Grangemouth in the Budget.
Scotland’s only oil refinery stopped processing crude oil at Grangemouth in April, after a century of operations.
The UK government has been accused of failing to deliver £200m pledged to Grangemouth from the National Wealth Fund.
The money will go towards the site’s transition into a clean energy hub.
A Treasury source said: “We said we would stand squarely behind communities like Grangemouth, and we meant it.
“And we’re building on what we have done already by putting millions in as a starter to help put the community on a firm footing and strengthening its places as part of the clean energy revolution.
“These investments will help deliver a fair transition for Grangemouth, securing jobs for local people way into the future.”
Petroineos announced the refinery at the central Scotland facility would close and transition to become an import terminal after reporting massive losses.
Redundancy letters were sent out to staff at the refinery at the beginning of this year, with just 65 of 500 jobs expected to be retained.
Approximately 2,000 people were directly employed at the site – 500 at the refinery, 450 on the Forties pipeline from the North Sea and a further 1,000 in the Ineos petrochemicals business.
A £1.5m report into the feasibility of Grangemouth becoming a low-carbon energy hub, known as Project Willow came up with nine ideas that could be developed with private sector investment.
This included alternative uses for the site such as hydrothermal plastics recycling and anaerobic digestion.
The prime minister pledged £200m to the site at the Scottish Labour conference telling delegates it was an “investment in Scotland’s industrial future”.
In August, Unite the union said the money hadn’t been delivered and workers felt abandoned.
Last November, the Scottish and UK government also signed the Falkirk and Grangemouth growth deal which promised £100m for the area through measures like a skills transition centre to get locals into work.
The UK government said work on delivering the investment continues, and this newly announced money is on top of the funds already promised.
First Minister John Swinney also announced £25m of new funding in a statement to Holyrood in February.
This latest Grangemouth commitment builds on investments in Scotland’s clean energy industries, including £17.3 million of the Aberdeen Energy Transition Zone and headquartering GB Energy in Aberdeen.
More details will be announced in the Budget on Wednesday.