Independent Third Party Tested Tailpipe Emissions Under Real-time Driving Conditions
A new study confirms what the biofuels industry has long advocated: As the amount of ethanol increases in the fuel supply, we see the benefits of cleaner air and improved air quality conditions for human health.
University of California – Riverside (UCR), an independent third party, conducted the study to compare tailpipe emissions of ethanol to aromatics, which are both octane components in the fuel supply.
While ethanol comes from renewable resources, aromatics are derived from petroleum and include compounds such as benzene, toluene and xylene that are highly toxic and known carcinogens. Ethanol is a direct substitute for aromatics in gasoline and is used to raise the octane level that prevents premature ignition, known as knocking, that can damage engines.
“What this study definitively says is that aromatics are causing the toxins and pollution in the air, and ethanol reduces the amount of aromatics, which subsequently reduces the toxins in the air,” noted Doug Berven, Vice President of Corporate Affairs for POET.
The study shows that the more ethanol (and less aromatics), the cleaner the air in terms of nitrogen oxides, carbon monoxide and other pollutants. Notably, harmful levels of particulate matter are also significantly reduced. Particulate matter are microscopic particles in the atmosphere that, once inhaled, can affect the heart and lungs and cause serious health effects.
Steffen Mueller, PhD, Principle Economist at the Energy Resources Center at the University of Illinois at Chicago, said the UCR study provides key insights about emissions reductions, while reinforcing other studies that show how ethanol contributes to cleaner air.
“On the one hand, the study confirms and reinforces observations from other studies which show, for example, reductions in carbon monoxide and secondary organic aerosol levels with higher ethanol blends. On the other hand, my takeaway from this study is that a low aromatic, higher-level ethanol-blended gasoline such as E15 (and higher) seems to provide a sweet spot for emissions reductions in fuel formulations.”
Beyond the positive results from this study that show ethanol is a cleaner-burning fuel and better for human health, this study is cutting-edge because of its methodology, which mirrored real-world fuels, cars and driving conditions.
“This is the first time we have used actual cars and real-world fuels and studied actual emissions in a speciated format to prove the air quality benefits of ethanol,” Berven said. This type of test is broken down by the chemical make-up of emissions.
While other emissions studies have relied on methodology that may not replicate actual fuels or driving conditions, which can affect the accuracy of results, University of California – Riverside’s approach tested tailpipe emissions under simulated driving conditions on five late-model, gasoline direct-injection vehicles: a Honda Accord, Chevrolet Impala, VW Jetta, Kia Optima and Ford Fusion.
For the study, eight gasoline fuels were tested, including a range of ethanol levels from zero up to E20, along with a range of aromatic targets. These variables are important because gasoline components change significantly from state to state, region to region, and season to season.
Berven explains more about the study in the following interview.
Why did Growth Energy [the biofuel industry’s largest advocacy association] want to do the study?
We’ve always known it to be true that ethanol is better than gasoline from an emission standpoint, but we wanted something definitive from an independent analysis to quantify how much better or to what degree ethanol had an edge. So, we worked with the University of California – Riverside, which has the unique ability to do atmospheric and emissions tests with realworld cars, real-world engines.
What we found was that ethanol reduces particulate matter, black carbon, carbon monoxide and many kinds of pollutants in the air that are linked to everything that’s bad for the environment and everything bad for our human health. The overall purpose of the study was to prove these claims, and this study does that.
Why is this study so important? What does it mean for the future of the environment?
EPA puts out a model that each state must use to determine their air quality. If the model is flawed, it’s going to skew the results on air quality. To put it simply, if states use a model that shows ethanol creates more emissions, they’re going to use less ethanol, which means they’re going to use more aromatics and their air quality is actually going to be worse, and human health is going to be worse.
We want states to be using a model that is accurate, and that shows going from E10 to E15 actually improves air quality, improves human health. Going from E10 to E20 or E30 improves air quality just that much more. The more ethanol you have in the fuel system, the cleaner your air is going to be, the healthier humans will be in your state. It’s just that simple. Right now, the EPA model is not that clear, and we need to make sure that it is that clear.
How do they test emissions?
Basically, they hook up an apparatus to the tailpipe, and every element that comes out of that tailpipe is measured — everything from carbon dioxide to the amount of benzene to the amount of particulate matter and types of particulate matter. Literally hundreds of different compounds are being measured that come out of a tailpipe.
Why did you compare ethanol with gasoline in this way?
It’s important to understand that gasoline is extremely variable all around the country. A gallon of gasoline consists of hundreds of different chemicals, and those chemicals vary dramatically from state to state, region to region, station to station, based on refining economics and all kinds of other factors. You never put the same gallon of gasoline in your gas tank. Ethanol is the one constant in the fuel supply at 10 percent of the U.S. fuel supply, and ethanol is a constant molecule.
What this test did was give us an understanding of the reaction of ethanol along with all these other compounds, and how ethanol can reduce toxins in the air. This was a unique study in that it was done by an independent group — not an ethanol group, not an oil group. UCR is a university without an agenda. And that’s what we wanted, because a lot of the studies that have been done in the past have been influenced by oil interests and they don’t give ethanol a fair shake.
What did you learn through the study, and were there any surprises?
I don’t think it was very surprising that ethanol is a much cleaner fuel and much better for human health. We all knew that; we just hadn’t had a study that definitively proves that. And we also knew that ethanol was a high-performance fuel that burns more efficiently and makes up for any BTU loss [British thermal unit, a traditional unit of heat] that the fuel may offer. But this study goes that next step in proving that ethanol is cleaner. Along with its lower cost and high-performing characteristics, it should be the fuel of our future, for sure, in higher blends.
There were things that were subtle surprises. For example, a lot of people want to compare ethanol to gasoline based on BTU content. They say that ethanol can’t get the same mileage as gasoline because it has less energy content in the fuel. Well, this study says that more ethanol does not necessarily correlate to less mileage. In fact, we got the same mileage basically on 20-percent ethanol as we did on zero-percent ethanol.
Were there any specific findings that consumers should know?
Ethanol reduces particulate matter that we breathe into our lungs and gets into our blood stream, causing all kinds of diseases. Aromatics are linked to cancer, autism, asthma, premature birth, brain disorder. The more ethanol we have in the fuel supply, the less bad actors come out of the tailpipe. That’s just a simple fact, demonstrated by this study.