LSC Method Development for Measuring Changing Diesel Sample Matrix

Abstract

Neste Corporation is one of several oil companies that have proceeded to develop clean and long-term solutions to minimize CO2 emissions. The quantity of renewable diesel in a fuel mixture may be determined using conventional analytical methods used to identify chemically different components using Liquid Scintillation Counting (LSC) and Accelerator Mass Spectrometry (AMS) to determine biogenic content. Biogenic proportion can be determined due to the decomposition of radiocarbon. Radiocarbon 14 (14C) is a radioactive isotope of carbon that is unstable. The purpose of the thesis was to develop a method for the determination of the biogenic content of carbon using Liquid Scintillation Counter (LSC). The practical part of the thesis was performed in Neste Corporation's quality control laboratory in Porvoo. A changing biobased sample matrix (CBM) was created containing fossil diesel, renewable diesel, and FAME biodiesel fuel, and 11 standard samples were prepared according to CBM series. Another 11 samples were prepared according to changing fossil matrix (CFM) containing renewable diesel, fossil diesel and fossil GTL fuel. Liquid scintillation cocktail was added to each sample in ratio 1:1. Each sample was then measured with the LSC, and biogenic carbon content calculated. A few samples from each series measured with liquid scintillation counter were sent to an external Helsinki University accelerator mass spectrometry (AMS) laboratory and these sample results were used as reference measurement. The validation parameters used were the linearity of the method and accuracy. The method was determined to be suitable for biogenic content measurements of fuel containing 0-50 vol % of GTL and for fuel contain 0-5 vol % of FAME. It was realized by filtering color from FAME samples, color quench during measurement in LSC decrease.