WASHINGTON — High octane, low carbon (HOLC) fuels can play an important role in helping automakers comply with increasingly stringent fuel economy (CAFE) and greenhouse gas emission standards in the 2022–2025 timeframe, according to comments submitted Monday to the Environmental Protection Agency (EPA) and National Highway Traffic Safety Administration (NHTSA) by the Renewable Fuels Association (RFA). In order to realize the benefits of HOLC fuels, however, EPA and NHTSA must ensure CAFE and GHG regulations treat fuels and engines as integrated systems, the RFA said.
“This is an important process because it will determine the path forward for future energy efficiency and environmental goals,” said RFA President and CEO Bob Dinneen. “EPA has correctly identified technologies that will effectively improve energy efficiency and reduce greenhouse gases. But the agency has failed to appropriately consider the fuels that will enable those technologies. That is an omission that must be addressed moving forward if future vehicles can in fact help us address climate change without backsliding on other critical air quality and public health priorities. We look forward to working with EPA and NHTSA as this process continues,” he added.
In 2012, EPA and NHTSA promulgated final regulations establishing the CAFE and GHG standards for 2017–2025. Included in the final rule was a requirement that the agencies conduct a “midterm evaluation” for the 2022–2025 standards and determine whether the standards established in 2012 are still appropriate in light of the latest available data. The first step in the process was the release this past July of the draft Technical Assessment Report (TAR) for public comment. RFA reviewed the TAR and commissioned a technical analysis by engineering and technical consultancy Ricardo, Inc.
According to RFA and Ricardo, many of the advanced internal combustion technologies examined by the two agencies would experience increased fuel efficiency and generate fewer emissions if operating on fuels with higher octane ratings than today’s regular grade gasoline, which has an octane rating of 87 (anti-knock index). According to the Ricardo analysis, “It is clear that implementing a high octane fuel standard would provide opportunity for increased engine efficiency and hence reduced greenhouse gases, and doing so by blending with ethanol provides an even greater benefit due to ethanol’s high heat of vaporization combined with the inherently low carbon footprint of ethanol. Many of the technologies discussed in the Draft TAR, including ones with the highest expected penetration rates, could produce greater GHG and fuel economy benefits if paired with fuels offering higher octane ratings and an inherently higher charge cooling characteristic.”
Meanwhile, automotive engineers and executives, Department of Energy researchers, the National Research Council and academia have also called for the introduction of high octane low-carbon fuels in an effort to increase fuel economy and decrease greenhouse gas emissions.
Additionally, growth in turbocharging has already resulted in an increased demand for higher-octane fuels. According to recent analysis from the Energy Information Administration, more stringent fuel economy and greenhouse gas standards caused automakers to increase the market penetration of turbocharging from 3.3 percent in 2009 to 17.6 percent in 2014. The surge in turbocharging was accompanied by an increase in the demand for high octane premium gasoline, according to EIA. In fact, premium gasoline sales rose from 7.8 percent of total gasoline sales in June 2008 to 11.3 percent of total gasoline sales by September 2015.
RFA outlined a handful of recommendations to the agencies:
- EPA and NHTSA should treat engines and fuels as integrated systems during the midterm evaluation process and beyond;
- As a sensitivity case to the central compliance demonstrations, the agencies should assess the fuel economy and emissions impacts associated with using HOLC fuels in advanced IC engines with high compression ratios;
- A comprehensive cost-benefit analysis of various CAFE/GHG compliance pathways including both engine and fuel technologies should be conducted. Such analysis should include a pathway for HOLC fuels in advanced IC engines;
- EPA and NHTSA should ensure the Proposed Determination fully accounts for the Co-Optima initiative’s recommendations for “candidate fuels” that best enable advanced IC engine technologies and maximize their efficiency; and
- The agencies should “heed the call” for HOLC fuels. EPA and NHTSA should use the MTE process to establish the roadmap to broad commercial introduction of HOLC fuels in advanced IC engines beginning in 2025.