EGR corrosion could trigger EPA relief petition

Diesel Fuel News, March 17, 2003 by Jack Peckham

Charleston, S.C. -- A research study at U.S. Department of Energy's Oak Ridge National Laboratory potentially could prompt U.S. EPA to allow engine makers to turn-off exhaust gas recirculation (EGR) systems periodically, to avoid sulfuric acid corrosion.

The joint study with engine maker John Deere indicates sulfuric acid corrosion of EGR is "quite aggressive with the onset of water condensation" during certain portions of an engine's duty cycle.

Tests with ordinary 350-ppm sulfur diesel fuel, as well as the 3,500-ppm sulfur non-road diesel fuel, indicate steep rises in metal loss from sulfuric acid corrosion under certain conditions, a first-round experimental study showed. Problem: These engines won't be using ultra-low sulfur diesel (ULSD) for several years, under current EPA deadline requirements.

So, "Deere plans to use results [from further tests at ORNL] to obtain a concession from EPA to disable EGR under potentially corrosive conditions," DOE clean-diesel programs expert Steve Goguen told the Energy Frontiers International (EFI) conference here.