The Renewable Fuel Standard (RFS), always a contentious topic, is once again in the spotlight. On October 3, the Environmental Protection Agency (EPA) released a proposed rule change to RFS that aims to support further growth of the program. EPA will be accepting comments on the proposed rule, called the Renewables Enhancement and Growth Support (REGS) rule, for sixty days following its publication in the Federal Register.

Key Changes Proposed


One of the major changes proposed in the rule would allow for biofuel feedstocks to be partially processed at one location and refined at another. Currently, many of the reporting requirements of the RFS assume that biofuel production takes place at one facility. However, EPA has found in the years since implementing these requirements that many companies would like to have a more flexible system.

Some companies have suggested that certain facilities could produce a biointermediate feedstock, which could be further processed at another facility to produce the finished renewable fuel. EPA pointed to Sweetwater Energy and Ensyn as examples of companies that could use biointermediates, and said the use of biointermediates “is a reasonable and positive development in this developing industry and holds considerable promise for the future growth in production of the cellulosic and advanced biofuels.”

In the proposed rule, a renewable fuel feedstock must meet the following criteria to be defined as a biointermediate:

  • It is derived from renewable biomass.
  • It does not meet the definition of renewable fuel and RINs were not generated for it.
  • It is produced at a facility that is registered with the EPA, but which is different than the facility at which it is used to produce renewable fuel.
  • It is made from qualifying feedstock and will be used to produce the renewable fuel in accordance with the process(es) listed in the approved pathway.
  • It is processed in such a way that it is substantially altered from the feedstock listed in the approved pathway.


New Feedstocks

The proposed REGS rule also expands the list of feedstocks approved for cellulosic or advanced biofuels. New additions include short rotation poplar and willow trees, as well as biodiesel produced from compressed cellulosic feedstocks mixed with petroleum or from non-cellulosic separated food waste.

Flex Fuel Vehicles

The rule also aims to increase the use of higher ethanol blends in flex fuel vehicles (FFVs). FFVs are able to run on blends of up to 85 percent ethanol, called E85. EPA estimates that FFVs currently make up around eight percent of the U.S. passenger fleet. However, these cars only use an average of 13.4 gallons of E85 each year, because of limited availability.

The proposed rule changes the quality standards for higher level ethanol blends, from E16 to E85. These blends would not be fully subject to gasoline quality standards, as their ethanol content is high enough to not be considered in the same category as neat gasoline. However, it sets new standards to specifically address these fuels, ensuring their “quality and environmental performance.”

Initial Reactions to the Rule

Several stakeholders have given their initial reactions to the 374-page rule. “Our goal is to ensure the final regulations do not unreasonably impair the ability of blenders and retailers to offer ethanol flex fuels like E85 to consumers,” said Renewable Fuels Association CEO and President Bob Dineen. “Ethanol flex fuels are the lowest-cost, lowest-carbon, and highest octane liquid fuels on the market, and it is imperative that these EPA regulations help—not hinder—broader commercial introduction of these fuels.”

Mitchell McAdams, president of the Advanced Biofuels Association, gave a positive review, saying, “This is a rule we really needed to have. We’re delighted to see it.”

However, Growth Energy CEO Emily Skor was more wary. “While we are reviewing the details of the rule, we are concerned about the impact of this proposal on the hundreds of retailers who are successfully selling E15 in the marketplace today,” she said. “If this proposed rule is finalized, this regulation would leave E15 as the only ethanol-blended fuel that does not have Reid Vapor Pressure (RVP) relief. RVP is the measure of a fuel’s volatility and EPA regulates vapor pressure/RVP to prevent increased ozone or smog from vehicle emissions.”

Author: Rebecca Chillrud

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