What actually happens to the oils and fats that accumulate after use in restaurants, canteens, snack bars, hamburger stores, etc.?
They go into so-called grease separators and are regularly collected by specialist disposal companies.
In Fulda, Hesse, there is the company Biokema, which operates a small biorefinery in Thuringia. The company specialises in cleaning these residual fats and oils from the food industry and using them for a second use under the Biokema brand name: as recycled wax for tea lights, candles, barbecue lighters, etc.
Combustion is CO2-neutral, because Biokema does not process petroleum-based fats or the palm oils that have come under criticism.