EZFlap wrote:> ...
Re-edit: After visiting your website, I see that mogas meeting ASTM D4814 without ethanol is approved for use in aircraft with the appropriate STC. Is there any proof one way or another that removing the ethanol from a fuel originally meeting D4814 makes it no longer meet D4814? In other words, does D4814 require the addition of ethanol?
If so, how did the pre-ethanol auto gasolines meet D4814 when the STC was first done?
The only ASTM spec for unleaded auto fuel is, "ASTM D4814 - 11 Standard Specification for Automotive Spark-Ignition Engine Fuel
" Just like the only spec for all avgas, no matter what the octane rating, is ASTM D910.
ASTM D4814 has a list of approved additives. Ethanol blended up to 10% is one of the approved additives. But the gasoline does not have to have ethanol in it to be D4814 compliant. Clearly that addition of ethanol was a later addition to the spec, but I don't know what year. Notice that ASTM D4814 does not allow any blending level above 10%, so ASTM D4814 is only for unleaded gasoline up to E10. It does not cover E15 on up to E85. Right now there is no ASTM spec for E15.
So what happens when you "wash" the ethanol out of E10. That all depends on what the refiner started with. The refinery does not have to start with legal "finished" gasoline to make E10, they only have to end up with gasoline meeting ASTM D4814 once they add the 10%, or so, ethanol. And that's the rub. When the federal RFS mandate for blending large quantities of ethanol into gasoline hit the books in 2008, refineries were not making much dedicated blendstock for oxygenated blending, or what they call BOB. They were primarily making it in those areas of the country that require Reformulated Gasoline, which is a large chunk of CA and other large urban areas like New York. In fact 99+ % of all RFG made today is E10, and it represents about 1/3 of the gasoline pool.
However now it is a different story. You have several states the have mandatory E10 laws, MN, MO, HI, FL and my state Oregon. When Oregon's mandatory E10 law went into effect late in 2007, the refineries in WA that supply most of the state weren't making BOB, so the legislature gave the terminals a 1 lb. Reid Vapor Pressure (RVP) waiver so they could blend ethanol into finished legal gasoline and still meet state RVP requirements. (Ethanol at the 10% level will raise the RVP of gasoline about 1 lb.) Of course that also meant that the resulting gasoline was giving away "octane" too because ethanol at 10% will raise the AKI of auto gasoline about 3 points. Obviously the gasoline producers do not like to give away octane so BOB is a sub-octane blending stock with lower vapor pressure and some other trade secret tweeks so that when E10 is made at the terminal, it comes out as legal finished gasoline meeting ASTM D4814. So when you "wash" the ethanol out of E10, you end up with something approaching whatever the refiner shipped to the terminal, and that wasn't necessarily any legal finished gasoline that we know of. It certainly doesn't have to be. Two of the four refineries in WA, that supply OR and WA now only make suboctane BOB and the only product coming down the single major pipeline from WA to OR carries only BOB for Oregon terminals.
The point is you don't know what you have left when you "wash" ethanol out of E10 and it will vary from producer to producer and the season of the year. Which is why you would have to send a specimen of every washing to a lab to see what the "octane" level is and to verify that it is still ASTM D4814 compliant if you want to use it in an STCd aircraft.
Of course you can use the product in a homebuilt, but you would need to put a label on the gas tank indicating that you are certifying that your homebuilt will run on Washed E10 swamp gas. It truly is your butt when you do this stuff.
Your time and effort would be better spent lobbying the FAA and aviation alphabets to get mogas on airports and to lobby the EPA to insure that there will be a source of ethanol free unleaded auto fuel. As it stands today there are no state or federal laws that require producers to make any ethanol free finished gasoline and by the end of 2012 the ethanol quotas in EISA 2007 will swamp the gasoline pool and it may become impossible to find E0, while the producers will be swimming in ethanol going forward, because the ethanol quotas increase every year until 2022.
BTW, it is possible that by the end of the year, up to three airports in CA will have mogas again. Now whether than can find a supplier at the end of next year is anybody's guess.