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Yet more tests highlight NOx concerns over biodiesel
The discussions about biodiesel emissions go on and on... Just a few weeks after a German study by the Federal Agricultural Research Centre (FAL) and the Steinbeis Transfer Centre for Biofuels and Environmental Analysis found that biodiesel did not increase emissions of ultra-fine particles, an official correction by the US Environmental Protection Agency (EPA) has renewed concerns about biodiesel and nitrogen oxides (NOx) emissions.
The EPA found in an updated investigation and re-examination of earlier studies that biodiesel does indeed cause higher NOx emissions, especially as engine load increases.
Significantly higher
In a paper presented to the Society of Automotive Engineers Commercial Vehicle Congress in Chicago in late November, EPA presented the results of a series of seven tests using ordinary diesel fuel and soy-methyl-ester (SME) biodiesel blends of 5% to 50%.
Two models in studio staring in disbelief at latest biodiesel research results
Results showed that biodiesel blends caused NOx emissions to increase between 1% and 6.6% with B20 (20% biodiesel), and up to 17% in the B50 tests.
It follows a study from Chalmers University of Technology which found that another type of biodiesel, rape-methyl-ester (RME) biodiesel, causes significantly higher NOx emissions than either ultra-low sulphur diesel (ULSD) or Fischer-Tropsch (gas-to-liquid) diesel. What’s more, fuel efficiency fell by 10% with a 100% RME fuel.
Sounds like a perfect excuse for yet more research, more studies and more tests…
Frustrating
Meanwhile, in a glaring example of the frustrating duplication that often occurs in the field of alternative fuel research, a report from Australia's Commonwealth Scientific and Industrial Research Organisation (CSIRO) revealed that using pure biodiesel or blending biodiesel with standard fuel could reduce greenhouse gas emissions from the transport sector.
The report’s author, Dr Tom Beer, said that, “the results of this study show biodiesel has the potential to reduce emissions from the transport industry.”
Australia may be far away, but didn’t we already know that?
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