Determination of biogenic component in liquid fuels by the 14C direct LSC method by using quenching properties of modern liquids for calibration

The fraction of biogenic component within various types of materials that can be used as fuels for energy production and transport can be determined by measuring their C-14 activity. The method is based on different C-14 signatures of the biogenic and the fossil components: while the biogenic component reflects the modern atmospheric C-14 activity, no C-14 is present in fossil fuels. A direct measurement of the C-14 content in liquid fuel by liquid scintillation counter is a simple and fast technique but has a main disadvantage: different liquid colors cause different quenching properties and affect the measurement efficiency. We propose a new evaluation technique that uses liquids of different colors to construct modern and background calibration curves. Various binary mixtures of biogenic liquids have been used to verify the relation between the count rate and the quenching parameter. Mixtures of a biogenic and a C-14-free liquid demonstrated the potential of the proposed technique for determining the biogenic fraction of a mixture. (C) 2016 Elsevier Ltd. All rights reserved.