HEI Takes Hard Look at Ethanol vs Aromatics
On a cold mid-December day in Chicago, while most people were getting ready for the holidays, 50 people gathered to talk about the effects of fuel composition on particulate matter (PM) emissions.
As someone who has spent many years working to protect public health through the use of cleaner burning fuels like ethanol, I was honored to participate as a director of Siouxland Ethanol, and an advisor to the Urban Air Initiative. It was an invitation-only workshop sponsored by the prestigious Boston-based Health Effects Institute. It opened a lot of eyes.
Attendees included a “Who’s Who” from the auto industry, the U.S. EPA, the California Air Resources Board, refining industry, fuel experts and academia. It was candid and informative. There’s a glimmer of hope that we may have turned a corner with EPA on the increasingly important role higher ethanol blends have to play in making cleaner fuels.
As its name implies, the Health Effects Institute is a research organization that funds and conducts research to understand the sources and effects of mobile source air pollution. As you might expect, HEI receives significant funding from EPA. I know that EPA’s failure to fairly assess ethanol’s true effects on gasoline emissions has had a lot to do with why HEI has not acted more quickly to deal with the health threat from gasoline aromatics.
More than 15 years ago, HEI was charged with overseeing the EPA Blue Ribbon Panel on Oxygenates in Gasoline, which investigated the MTBE water contamination controversy in California and other states. Enormous progress has been made since then, including advances in agricultural practices, ethanol production technologies, vehicle power-trains and gasoline infrastructure and dispensers.
Automakers are telling us that ethanol has superior octane properties that were not fully recognized until recently. Automakers have pleaded with EPA to provide them with higher-octane fuels that the turbocharged, downsized vehicles of the future will desperately need, but to no avail.
Unlike private sector innovators, EPA regulators plod along at glacial speed. But as noted, we may be turning the corner. In Chicago, EPA officials grudgingly admitted that there is a direct connection between gasoline aromatics, particulate matter emissions and air toxics. They also conceded that direct injection could make those emissions worse unless gasoline composition was significantly improved.
Even while attempting to defend their defective models that perversely blame ethanol for aromatics’ PM emissions, EPA acknowledged that higher-octane ethanol splash-blends would reduce particulate-bound toxic emissions. In the real world, ethanol is splash-blended, so EPA’s devotion to its much-maligned, match-blending protocols is curious, indeed.
The more we reflect on the workshop, the more hopeful we are that consensus is beginning to emerge on many points:
• Intelligent policy requires the use of real-world fuels and driving conditions and must be based upon real-world emissions.
• When testing higher blends of ethanol, the differences between splash- and match-blending techniques cannot be ignored. When ethanol is splash-blended, emissions are reduced, as in the real world. When ethanol is improperly match-blended in the lab, harmful emissions get worse.
• Rapid adoption of gasoline direct-injection technology will significantly worsen PM, secondary organic aerosols (SOAs), and polycyclic aromatic hydrocarbon (PAH) emissions unless fuel quality is improved, which ethanol accomplishes.
• PAH emissions are regarded as an increasingly dangerous health threat. Ethanol replaces aromatics.
• Gasoline aromatics are the predominant source of SOAs and PAH. Ethanol replaces aromatics.
• Deposits pose a major challenge to gasoline direct-injection engines. Aromatics exacerbate deposits, thus another reason for higher levels of ethanol in fuel reformulation.
• Fuels, power-trains and after-treatments must be addressed as an integrated system. The U.S. DOE’s Co-Optima work should be accelerated and incorporated into EPA’s thinking, which favors high-octane fuels, such as ethanol provides.
• EPA’s failure to properly account for and control SOAs from gasoline aromatics requires immediate attention, for which ethanol is a solution.
• Policymakers must find ways to allow cleaner fuels, such as higher blends of ethanol, in legacy vehicles, to improve our environment.
This is progress. I believe it’s possible that HEI’s workshop opened a window for high-octane, low-cost fuels in 2017.
Author: David Hallberg
Siouxland Ethanol board member
Urban Air Initiative advisor