The Alternative Diesel Fuels (ADF) regulation establishes a comprehensive, multi-stage process administering the commercialization of alternative diesel fuels in California. The ADF regulation governs the introduction and use of innovative alternative diesel fuels in California while preserving or enhancing the public health, environmental, and emission benefits of the existing motor vehicle diesel fuel regulations. The ADF regulation includes specific provisions designed to control potential increases in oxides of nitrogen (NOx) emissions that could otherwise be caused by the use of biodiesel under certain circumstances. Those provisions include a process for certification of additives or alternative diesel fuel formulations that have been shown to mitigate NOx increases from the use of biodiesel. Several additives have been approved and certified pursuant to Appendix 1(a)(2)(H) of the ADF regulation as providing emissions equivalence for blends of 20 percent biodiesel and below.
The purpose of this study was to confirm results of regulatory certification testing for two recently certified biodiesel additive packages, test the emissions from those two additives certified under Appendix 1 of the ADF regulation, and examine the potential efficacy of these, and other additives, in reducing NOx.