MOL finishes reconstruction of fire-damaged AV3 distillation unit at Danube Refinery, with production restart planned for October
MOL has finished rebuilding the AV3 crude oil distillation unit at its Danube Refinery in Százhalombatta, Hungary — almost a year after a fire knocked the unit offline. The restoration wrapped up in September 2026, came in at an 18 billion forint repair budget, and puts the refinery on track to return to full production. For Hungary and the broader region, that matters quite a bit.
Construction completed on schedule
MOL announced the completion of all construction work on the AV3 unit, and the project landed exactly where the company planned. Getting a rebuild of this scale done on time is genuinely difficult — the 18 billion forint budget gives you a sense of just how much work was involved.
Now that construction is done, the focus shifts to clearing equipment from the site. That has to happen before commissioning and testing can start. It’s not glamorous, but it’s the necessary bridge between a finished rebuild and actual crude oil flowing through the unit again.
Before crude oil can be introduced, a structured commissioning process has to play out, and MOL has been specific about what that looks like.
Once commissioning goes smoothly, the Százhalombatta refinery is expected to return to full-capacity operation — restoring a key piece of Hungary’s domestic refining infrastructure and giving MOL more flexibility to meet regional fuel demand.
October 2025 fire triggered comprehensive restoration
The scope of this reconstruction makes a lot more sense once you know what the fire actually did. The blaze in October 2025 caused serious damage to the AV3 unit — serious enough that the damaged reinforced concrete structure had to be completely demolished before any rebuilding could begin.
What followed was roughly a year of intensive work. MOL didn’t just patch what broke.
The numbers lay it out clearly. Workers installed 27 new high-capacity pumps and replaced 5 miles of piping throughout the unit. Beyond that, 62 miles of electrical cables were laid, and the affected control and electrical systems were fully restored. The reinforced concrete structure itself had to be rebuilt from scratch. This was a rebuild in the truest sense — touching nearly every system in the unit.
Commissioning and phased restart planned for October
Finishing construction doesn’t mean the unit is ready to run. Before crude oil can be introduced, a structured commissioning process has to play out, and MOL has been specific about what that looks like.
First, systems get flushed and pressure-tested. These steps confirm that the rebuilt pipework and equipment can handle operating conditions without leaks or failures — nothing moves forward until those checks clear. After that, functional tests of the process control and safety equipment are conducted, and auxiliary power supplies need to be connected. These aren’t formalities. They’re how you verify the unit will actually behave as designed once it goes live.
AV3 operations also need to be coordinated with associated facilities across the Danube Refinery. A distillation unit doesn’t run in isolation — it feeds into and depends on other systems across the site. Getting that coordination right is part of what makes a safe restart possible. Every stage comes with rigorous operational safety inspections, and only after those inspections clear will crude oil be introduced. Production is expected to resume step by step in October.
Regional energy context adds strategic weight to restart
The timing of this restart carries weight beyond the refinery fence. MOL Senior Vice President Krisztián Pulay pointed directly to a broader backdrop when commenting on the milestone, citing the effects of the war in Iran and a global energy crisis that’s already reached the region.
“Everyone is competing for alternative sources,” Pulay said, “which increases the value of every reliable supply route and European refining capacity.” That framing puts the AV3 restart in a different light — not just an internal operational recovery, but a real contribution to regional energy resilience.
During the outage, MOL kept fuel supply going through diversified procurement and import options alongside its own production. The company says that period demonstrated supply can stay on solid footing even without the unit running. Even so, losing AV3 capacity was a genuine constraint, and its absence was felt.
With the unit coming back, the Danube Refinery is expected to become more flexible. Pulay said the restart gives MOL “greater leeway in meeting domestic and regional demand” — a phrase that reflects how the refinery fits into a supply picture that’s grown considerably more complicated over the past year.
Full-capacity operation expected to follow
MOL has completed the full reconstruction of the AV3 crude oil distillation unit at its Danube Refinery in Százhalombatta, Hungary, finishing on the preliminary schedule with a total repair budget of $50 million. The restoration followed a fire in October 2025 that caused extensive damage, requiring demolition and rebuilding of reinforced concrete structures, installation of 27 new pumps, replacement of 5 miles of piping, and laying of 62 miles of electrical cables.
Next steps involve removing construction equipment, then moving into a structured commissioning process — flushing, pressure testing, functional checks, and coordination with associated refinery facilities. Production is planned to resume step by step in October, with full-capacity operation expected to follow successful commissioning. MOL has framed the restart as strategically significant given the increased competition for fuel supply across the region.
Kelly is an experienced writer with 15 years of experience exploring the big stories that shape our world, from tech breakthroughs and space exploration to climate, energy, and the fascinating quirks of science. She has a talent for turning complex ideas into sharp, memorable insights that stay with readers long after they’ve finished reading.
