Sulfur Standard – 10 ppm
The EPA’s Tier 3 rule for Sulfur content in fuel were finalized three years ago. The Tier 3 rule requires the ethanol industry to meet the new 10 ppm standard by January 1, 2017.
Ethanol producers have likely been meeting this standard as California adopted the standard in 2003 and the RFA encouraged all ethanol producers to meet that standard at that time. As the primary source of sulfur in ethanol is from the denaturant, meeting this standard has not been an issue. Natural gas denaturant is most common and ranges between 50 – 120 ppm. Using denaturant in a 2 percent blend should not pose a problem to meet the standard.
For ethanol producers it is more of a bureaucratic issue to make sure paperwork is properly submitted. At this time the EPA has not published the reporting mechanism.
Changes to ASTM Standards
There may be changes forthcoming to ASTM standards to meet new requirements for inorganic sulfur content. EPA’s 10 ppm is dealing with organic sulfur. For ethanol producers the primary sources of inorganic sulfur are sulfuric acid for pH control and bisulfites used to control aldehydes for air compliance. US Water services is urging ethanol producers to join the auto and oil industries in being involved in the process so they can too have a word in how the standard is written.
See the August 2016 issue of Ethanol Producer Magazine – page 44 and 45 for more information.