When the largest renewable diesel producer in America goes down, it affects the market.
Industry sources tell UCO Markets that Diamond Green Diesel plans a turnaround at its Norco, Louisiana complex in August for a catalyst upgrade. The company has not publicly confirmed the timing or scope.
A turnaround is a planned shutdown. Crews take the unit offline, swap out spent catalyst, inspect vessels, and do the work that can't happen while the plant is running. Typical duration is a few weeks.
The mechanism is simple. A plant that isn't running might not be buying.
Norco is one of the largest single points of feedstock demand in the country. Used cooking oil, tallow, distillers corn oil. When it pauses, that pull disappears from the market for the length of the outage.
Imports have not slowed down. Roughly 30,000 metric tons of tallow from Australia and New Zealand landed in the Gulf earlier this month, with similar volumes arriving from China just last week. Cargoes booked months ago keep coming regardless of what the plant does in August.
That doesn't mean prices collapse. Turnarounds are planned well in advance, and buyers usually build inventory ahead of one. Some volume gets redirected to Port Arthur or to other Gulf Coast plants. But the regional balance loosens, and sellers without a home for their gallons feel it first.
Catalyst upgrades also cut the other way. A plant comes back from one running better than it went in, sometimes with more throughput. The demand that leaves in August may come back stronger in the fall.
For collectors and brokers, the practical question is contract structure. Anyone selling spot into the Gulf in August has less leverage than they did in June. Anyone under contract likely doesn't notice.
Watch for confirmation from Darling or Valero on their next earnings call, and watch Gulf Coast UCO basis through July. If the turnaround is real, the basis tells you before the press release does.
