Ranking Renewable and Fossil Fuels on Global Warming Potential Using Respiratory Quotient Concept

Figure 9

Carbon fraction (atom or mass) contribution by gasoline in gasoline : ethanol blend. -axis: ethanol volume percentage; -axis: carbon atom fraction contributed by gasoline in blend. The curve is almost linear for small ethanol volume fraction. Gasoline is assumed to be CH_2.25. RQ from exhaust analysis needs to be multiplied by C fraction from gasoline to estimate CO₂ contribution by gasoline.