Tracking Biogenic Carbon in Liquid Fuel Blends using Conventional Mass Spectrometry and Infrared Spectroscopy

This work demonstrates the analytical basis for an IR (isotope ratio) laser measurement system with the potential to perform routine quantification of biogenic carbon content in liquid fuel products at working refineries. We will present the performance potential for routine quantification for mixtures of C3 and C4 biogenic carbon sources mixed with fossil feedstock.  We will show the progress toward an operational on-line portable monitor. Initial work employed a predilution stage that required challenging transfer techniques to suppress fractionation.  More recent work has explored the potential for the IR based apparatus to directly quantify stable isotopologues that are isobaric in IRMS (isotope ratio mass spectrometry) instruments. The IR system results for ¹³CO₂/¹²CO₂ compare favorably with gold-standard IRMS.