Validating the Need to Test Real-World Fuels

While much of the industry’s energy has been focused on issues like Reid vapor pressure relief, a new technical paper demonstrates the need to focus on aromatics, and the fact that ethanol can reduce the need for other carcinogenic octane enhancers.
By Steve VanderGriend | June 12, 2020

OK, I’ll admit it. Around the office and at most meetings, I can get rather passionate talking about ethanol and test fuels. I may have harped on these issues to the extreme, but I make no apologies. Understanding fuel properties and the impact on emissions is going to determine the future of ethanol. The Environmental Protection Agency has the ability to stop ethanol in its tracks if it rules that ethanol pollutes more than gasoline, and EPA is headed in that direction.

But there is some good news. A recently published peer-reviewed technical paper in the Journal of the Air & Waste Management Association validates core arguments we have been making at the Urban Air Initiative with respect to the way fuels are tested.

Historically, studies on emissions from ethanol blends have not used what we consider market (i.e., real-world) fuels, but are instead tested with fuels that match-blend ethanol to selective gasoline properties.

This new technical paper looked at several major ethanol emission studies, all of which assume a standard fuel is being created. The problem lies in the fact that market, or real-world fuels, rarely resemble test fuels, with octane being a key variable since toxic aromatics are used to raise octane. Splash blending ethanol at the terminal immediately dilutes the aromatic content which, in turn, reduces emissions. The aromatics are directly tied to particulate matter emissions, which this peer-reviewed paper confirms are significantly reduced when modeling real-world fuels.

What this new paper makes clear is the aromatic reduction resulting from increased ethanol volumes provides significant health benefits from lower particulate emissions. Comparing a baseline E0 fuel to E10 and E15 shows the ethanol blends are significantly better when real-world fuel blending conditions are used. This is critically important with respect to the anti-backsliding study that EPA is preparing, which could, as noted earlier, stop ethanol in its tracks.

While much of the ethanol industry’s energy has been focused on issues such as Reid vapor pressure relief, this new technical paper demonstrates the need to focus on aromatics and the fact that ethanol can significantly reduce the need for these carcinogenic octane enhancers. Clean octane from ethanol is already replacing more than 8 billion gallons of aromatics annually with E10.

The fuel economy rules from the Trump administration missed an opportunity to include a minimum octane standard, but the need for octane remains. While many automakers are devoted to developing electric vehicles, they are realistic about the timeline to get there. They know gasoline engines will remain and high-octane fuels can help achieve the modest mileage increases the administration is calling for. Future light-duty vehicles will continue to be designed for high-octane fuels in order to increase efficiency and reduce emissions, suggesting a growing demand for clean-octane, low-carbon ethanol.

So, in a cycle of less-than-great news, a peer-reviewed technical paper supporting our long-held beliefs regarding the importance of using real-world fuels is welcomed news.


Author: Steve VanderGriend
Technical Director
Urban Air Initiative