The makers of automobile parts, also known as the original equipment manufacturing (OEM) community, as well as emission controls firms want to know how much metal is in biodiesel.
This article from Biodiesel Magazine says the National Renewable Energy Laboratory has been able to improve detection of sodium and potassium … two elements that can compromise catalysts and diesel particulate filters (DPF) by causing ash buildup … to into the parts per billion range, even recognizing sodium leached from glass storage devices:
Another NREL study, “Impact of biodiesel ash loading on DPF performance,” collected 100 samples of ASTM biodiesel. The study, led by NREL engineer Aaron Williams, concluded that with the metal content found in biodiesel, it is highly unlikely that ash build-up would result. “No biodiesel produced right now has these levels of metals.” Williams said at the 2010 National Biodiesel Conference & Expo in Grapevine, Texas, last week. Nevertheless, NREL asks, does the ASTM spec for alkali metals need to be lowered to satisfy catalyst and diesel particulate filter manufacturers?
The original equipment manufacturing (OEM) community and emission controls firms are especially interested in knowing metal limits. “We wanted to see how low we could go,” Alleman said. “If we reported that there was less than 1 ppm in biodiesel, [stakeholders] wanted to know: ‘Well does that mean .9 or .09? Can you qualify that any better?’”
The best news is that biodiesel, even when spiked at 26 times the ASTM limit, still ran amazingly clean.