Broad US tariffs on Chinese imports that took effect today may reshuffle trade flows between the world's two largest economies, but demand for the once-pivotal US biofuel feedstock Chinese used cooking oil (UCO) was already waning.
China exported 2.7bn lbs of UCO into the US over the first 11 months of 2024, more than any other foreign supplier, up from 1.6bn lbs in 2023 and just 100,000 lbs in 2022, according to US customs data. Clean fuel standards in states like California, Oregon, and Washington, along with a federal tax credit that rewards biofuels that produce fewer greenhouse gas emissions, spurred refiners to look beyond domestic supply and import low-carbon wastes from abroad.
The US' new 10pc tariffs on Chinese imports could discourage further imports, since US refiners have a range of feedstock options for renewable diesel and sustainable aviation fuel (SAF) production. The US trade representative did not immediately confirm the tariff rate for UCO, but there was already an 8pc tariff on UCO from all origins and an additional 7.5pc tariff on China-origin UCO before even factoring in the new surcharge on all imports.
Both countries have also recently taken steps to curb Chinese UCO exports, making further growth in UCO trade less likely, even if tariffs go away.
China late last year cancelled a 13pc export tax rebate for UCO, reducing a key incentive to send the feedstock abroad at a time when the country is aiming to use more SAF domestically. The administration of former president Joe Biden then took steps to cut off US demand, closing off opportunities for fuels derived from foreign UCO from claiming a tax credit crucial for production margins.
That incentive, known as "45Z," offers increasingly generous subsidies to fuels as they produce fewer emissions, which was initially expected to benefit refiners sourcing UCO over first-generation crop feedstocks. But the new government emissions model that road fuel producers must use to claim the credit for now offers no pathway for fuels derived from foreign UCO. The US Treasury Department justified the restriction by saying it had "significant concerns" about distinguishing imported UCO from palm oil, which is ineligible for 45Z.
The guidance is only preliminary, meaning President Donald Trump will have the final say on how the government enforces rules around the credit. But the new administration is likelier to pursue even more sweeping restrictions on foreign feedstocks, which Republican lawmakers have argued are hurting demand for US crops that can also be refined into fuel.
Republicans could use budget legislation this year to change the credit too, and key lawmakers on the House tax-writing committee have already floated potential restrictions on foreign feedstocks.
There are some caveats to US biofuel markets that mean UCO imports will not entirely go away absent more muscular trade restrictions. US biofuel producers with foreign UCO on hand can still sell into state low-carbon fuel standard markets like California, which have not restricted the feedstock. And the current guidance around 45Z allows producers of SAF — but not road fuels — to use an alternative lifecycle emissions model known as CORSIA, which does not restrict any sources of UCO.
Valero senior vice president Eric Fisher said last week on an earnings call that the current restrictions on road fuels derived from foreign UCO claiming 45Z would not affect Diamond Green Diesel, the refiner's joint renewable fuels venture with Darling Ingredients.
Foreign UCO has "always" been directed to meet SAF demand in Europe and the UK, Fisher said, and the recent guidance "does not really change what we were going to do strategically with that feedstock."
Europe and the UK have 2pc SAF mandates starting this year, though requirements do not become significantly more stringent until 2030.