Despite their green intentions, buyers of blended biofuel may not be getting quite what they are paying for.
Chris Reddy, an environmental chemist at the Woods Hole Oceanographic Institution in Massachusetts, has developed a test which reveals the proportions of biodiesel and conventional diesel in the fuel mix. It works by detecting the radioactive isotope carbon-14, which is present in biodiesel but not in fossil fuel.
His team tested samples of blended fuel bought in 2006 and found that many contained the wrong amount of biodiesel. The problem was worst for B20 blends, which are supposed to contain 20 per…
