How did the hydrous ethanol blending discovery come about?
Process Design Center was investigating means of improving process technologies used for ethanol dehydration, leading its researchers to explore and advance the science of water tolerance of ethanol/gasoline mixtures and the conditions under which phase separation occurs. In principle, a liquid-liquid extraction column can be used to extract ethanol from an ethanol-water mixture into a gasoline stream. This presumes that the two liquids can be totally separated, but researchers found this was not the case with hydrous ethanol. In the top of the extractor, the densities of the two liquids were similar and took a long time to completely disengage, which led to prohibitively large extractor volumes that were operationally too expensive. An idea immediately surfaced: If we can’t get the water out, then let’s see if we can leave it in! The further investigation that followed revealed previously undocumented aspects of ethanol-water-gasoline fuel blending properties, and unrealized potential
