When Will The EPA Act On The RVP?

  • Thursday, 21 July 2016 13:08

On Tuesday, we reported that E15 usage in Minnesota in May hit an all-time high of 603,530 gallons. But chances are high we won't be celebrating another record-breaking achievement when the numbers for June are released by the Minnesota Department of Commerce. 

Why? As most of our readers are well aware, E15 cannot be sold from June 1 to Sept 15 because the EPA sets what is known as a reid vapor pressure (RVP) limit during this period. The RVP limit (9.0 PSI) is set to reduce evaporation of fuel from cars and storage and transfer equipment during the summer months. When gasoline evaporates, it contributes to smog.

According to the Department of Energy's National Renewable Energy Laboratory (NREL), the PSI for E10 increases by 1 in the summer months. But Congress extended a RVP waiver to E10 back in 1990, enabling E10 to be sold in the summer. It's important to note that ethanol has a lower RVP than gasoline. But the PSI in E10 increases because of the blending of ethanol and gasoline (you can read the scientific explanantion here) and because of the RVP of the gasoline blendstock that is used. If a gasoline blendstock with a lower RVP was used, then the PSI does not increase by 1 nor is an RVP waiver needed. 

What about E15?

The RVP waiver is only for E10, not E15. But NREL says that based on it's analysis, the RVP of E15 is indistinguishable from E10 and that there is no technical reason to treat E15 differently from E10. 

As we noted above, E15 sales in May were the highest ever and it would probably continue increasing throughout the summer as demand for fuel increases due to the summer driving season. But thanks to the RVP, fewer gallons of E15 will be consumed (only flex fuel vehicles are allowed to use E15 in the summer months) thus increasing greenhouse gas emissions. 

Speaking of the EPA, one of its favourite arguments for altering the RVOs in the RFS is because there aren't enough retail stations offering E15. Well, part of that problem is the fact that not many retailers find the idea of investing in a fuel that can only be sold nine months of the year very attractive. 

If the EPA is truly serious about supporting the RFS and reducing harmful greenhouse gas emissions, it needs to work to extend the RVP waiver to E15 so that it can be sold all year long. Of course, that's assuming the EPA is actually serious about the RFS or reducing greenhouse gas emissions.