Mixed fuels are used in particular in waste incineration plants or refuse derived fuel plants. A clear separation between biogenic and fossil fuels is not possible. Therefore, the climate-neutral CO2 must be determined in a process.
For this purpose, the 14C fraction can be determined on the emitted CO2. Fossil fuels do not have a 14C fraction. The ratio of carbon-14 to total CO2 emissions thus provides a highly precise statement on the proportion of biogenic CO2 in the flue gas of a plant. Other methods, which are often based on estimates and empirical values do not offer such accuracy. However, the more precise the determination, the better the opportunities to profit from biogenic CO2.