Now, as for areas that legislatively require gasoline blended with oxygenate, decades ago the market proved MTBE and similar fuel ethers to have economic advantage on top of such ethers also being far less hygriscopic than ethanol. Fuels blended with such ethers could be shipped as finished blends to terminals whether by pipeline, marine transport, or rail. MTBE was legislatively banned in the US with a root cause problem of leaking underground storage tanks and the etger component being a very effective biocide versus bacteria that other wise temediated such gasoline that did not have such an oxygenate component. Ethanol is also a very effective biocide but the effects of similar concentrations of ethanol in water supplies was deemed innocuous.
https://archive.epa.gov/mtbe/web/html/
Such ethers are widely used outside the US including Western Europe not only to filfill oxygenate requirements for the technical and evonomic reasons already described, but also as a competitively economic source of a high octane gasoline blending component in areas that don't require oxygenate. And at the time they were ysed, the majority of such ethers used in the US were manufactured in the US. Lyondell on the Houston Ship Channel still operates their world scale MTBE unit, but now solely for export. Most other refiners converted the MTBE and similar ether units to other purposes to not have completely stranded capital investment. With the surfeit of natural gas and NGL's we now have in the US, manufacture of such fuel ethers would be even more economically attractive than it was in their prior heyday here. Ethanol can easily be converted to ETBE which has the same lack of phase seperation when blended into gasoline and much lower attraction for water as MTBE. No extra capital required for point of delivery splash blending storage, metering, etc. and no economic penalty for seperate rail transport to the point of final blending. for delivery
The US MTBE ban legislation is therefore an additional part of the legislation that props up ethanol plants in the US especially corn based. With today's standards on leak detection and containment, I see no technical reason why the US couldn't use MTBE and similar ethers to a similar level of effectiveness as Western Rurope, except for the ban legislation and an artificial penalty imposed by the RFS in the US.
Along those same lines, with rare boutique exceptions, gasolines blended with ethanol are given a waiver on the volatility increase the addition of ethanol introduces, another penalty to E0 and any other gasoline blending oxygenate used. Yes, E10 has higher VOC emissions than the same basis E0 whether blended with a different oxygenate or no oxygenate at all (i.e. conventional gasoline). This waiver is a part of legislation giving preferential treatment to ethanol.
Simple, easily verifiable facts. Just like how Hawaii never had a fuels ethanol blending plant and has repealed gasoline ethanol blending requirements.
