Web exclusive posted Sept. 22, 2008 at 3:54 p.m. CST
On Sept. 15, the U.S. EPA issued a special diesel fuel waiver specific to Texas and its low emission diesel (TxLED) requirement as a result of disrupted fuel supplies from back-to-back Hurricanes Gustav and Ike. The waiver allows diesel fuel to temporarily be suspended from being required to meet TxLED criteria, which is separate from the federal ultra low sulfur diesel (ULSD) mandate.
TxLED, implemented in October 2005 to help reduce air pollution from nitrogen oxides and hydrocarbons in the populous eastern portion of Texas, requires diesel fuel to meet certain criteria beyond that which is required by federal law.
The Texas diesel fuel standard has been a contentious issue for biodiesel producers, distributors and users because of the state's initial reliance on unrepresentative EPA emissions tests conducted several years ago on biodiesel blends, the results of which purported that biodiesel blends increase nitrogen oxide emissions compared to straight petroleum diesel.
Fuels certified as TxLED-approved must meet several requirements, including a minimum cetane number of 48; contain no more than 10 percent aromatic hydrocarbons by volume; and contain a nitrogen content of no more than 10 parts per million.
The Texas-specific waiver on low emission diesel fuel is in effect through Sept. 30. For more information on biodiesel and its history with the TxLED requirements and Texas Commission on Environmental Quality, visit
http://biodieselmagazine.com/article.jsp?article_id=194, and
http://biodieselmagazine.com/article.jsp?article_id=91.