How Used Doughnut Oil Becomes Renewable Energy for Transport

• Carnival season means peak volumes of used cooking oil: Münzer processes collected cooking oils into biodiesel.
• Dispose properly, not down the drain: Used cooking oil does not belong in sinks or toilets — only separate collection enables sustainable reuse.
• Circular economy starts at home: With simple collection systems, Münzer makes proper disposal easy and closes the loop from the kitchen to mobility.

Carnival season is a time for frying, baking, and cooking. As doughnuts and other traditional treats fill kitchens, restaurants, and commercial kitchens, enjoyment rises — but so does the volume of used cooking oil. This is exactly where Münzer comes in. The Austrian company is a pioneer in circular economy solutions and processes collected used cooking oil into biodiesel, a renewable fuel that directly replaces fossil components in transport.

For this cycle to work, one simple but crucial step is required: used cooking oil must not end up in the drain. When oil is poured into sinks or toilets, it causes buildup and blockages in pipes and can damage wastewater infrastructure. Carnival season therefore provides an ideal opportunity for Münzer to raise awareness — and to demonstrate how a kitchen byproduct can become a valuable energy carrier.

From frying oil to renewable energy

Used cooking oil is generated every day — but especially during carnival season, when frying activity increases significantly. What many still regard as waste becomes a valuable raw material when collected correctly. Münzer treats the collected oil in its own facilities and processes it into biodiesel. This turns a residual material into a meaningful contribution to renewable mobility — and transforms improper disposal from an avoidable problem into a sustainable solution.

“Carnival season clearly shows how quickly large quantities of used cooking oil accumulate,” says Managing Director Ewald-Marco Münzer. “Anyone who collects it properly helps prevent problems in the sewer system while at the same time creating the basis for renewable fuels.” The message of the family-owned company is deliberately practical: circular economy does not begin with complex technologies, but with everyday decisions — such as those made in the kitchen.

How to dispose of used cooking oil correctly

The process is simple. After cooling, used cooking oil should be poured into a tightly sealed container — such as a plastic bottle — and then taken to a collection point. “Across Austria, we have placed our yellow collection boxes at publicly accessible locations,” explains Münzer. “This makes proper disposal easy for everyone.”

Every carnival season highlights how quickly enjoyment turns into waste — and how big the difference is between oil poured down the drain and oil returned to the circular economy. Münzer therefore uses this time as a reminder: used cooking oil is not a problem material when collected properly, but a valuable resource that can be reused sustainably within closed loops.