Retrofit verifications extend to biodiesel, crankcase filters, purinox

Diesel Fuel News, June 9, 2003 by Jack Peckham

U.S. EPA last month officially "verified" diesel emissions reductions achievable with biodiesel blends and crankcase filtration systems; the Lubrizol "PuriNOx" emulsion also officially moved onto EPA's "verified" list following an earlier EPA technical analysis (see Diesel Fuel News 1/20/03, p12).

Until recently, the only officially "verified" technologies included oxidation catalysts and diesel particulate filters (DPFs), but these were "grandfathered" thanks to earlier test programs created by Northeast States for Coordinated Air Use Management (NESCAUM), the "father" of EPA's diesel retrofit program.

EPA supervises a rather complex and lengthy "Environmental Technology Verification" (ETV) program that requires testing at Southwest Research Institute. To achieve "verification" on broad families of engines can require very extensive and costly testing on multiple engines, for multiple applications (both highway and non-road).

To the chagrin of some competitors who've already spent plenty of money on tests following draft "ETV" test protocols, EPA didn't require any ETV testing for biodiesel.

Rather, EPA issued a "generic" verification (for highway diesels only) based on an EPA literature review study issued last fall (see Diesel Fuel News 10/28/02, p10). That study found a 20% biodiesel blend ("B20") could cut particulate matter (PM) emissions by about 10% but cause an increase in nitrogen oxides (NOx) by about 2%.

The "generic" verification includes a calculation to determine actual emissions impacts depending on percent biodiesel in the blend. The range cited is 0-to-47% PM reduction and a 0-to-l0% increase in NOx, EPA says.

Any individual company making any claims for a special biodiesel blend (with a NOx reduction additive or component, for example) would still have to go through the ETV testing process prior to getting any EPA "verification," explains EPA official Steve Albrink, who spoke about diesel retrofits at Society of Automotive Engineers government/industry meeting in Washington, DC last month.