Bioethanol and ETBE

Bioethanol is bio-fuel substitute of gasoline, i.e., it is ethanol obtained from biomass, not from fossil fuels, and is used as a gasoline blend. 

Pure bioethanol (ElOO-fuel) is the most produced biofuel, mainly in Brazil and the USA. More widespread practice has been to add up to 20% to gasoline by volume (E20-fuel or gasohol) to avoid the need of engine modifications. Nearly pure bioethanol is used for new versatile fuel vehicles. (E80-fuel only has 20% gasoline, mainly as a denaturaliser.) Anhydrous ethanol ( 0.6% water) is required for gasoline mixtures, whereas for use-alone up to 10% water can be accepted. 

ETBE (ethanol tertiary butyl ether, CgH, 0, density = 760 kg/m, LHV = 36 MJ/kg) is a better ingredient than bioethanol because it is not so volatile, not so corrosive, and has less affinity for water. ETBE-15 fuel is a blend of gasoline with 15% in volume of ETBE. ETBE is obtained by catal5dic reaction of bioethanol with isobutene (45%/55% in weight), noting that isobutene comes from petroleum. The other gasoline-substitute ether, MTBE (methanol tertiary butyl ether, (CH3)3-CO-CH3), is a full petroleum derivate (65% isobutene, 35% methanol). 

Bioethanol is preferentially made from cellulosic biomass materials instead of from more expensive traditional feedstock such as starch crops. Obtaining it from sugar-feedstock is even 

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In this scenario biodiesel, bioethanol and ETBE (ethyl tert-butyl ether), the ether obtained from bioethanol and isobutene, are the compounds normally utilized as fuels. In particular, ETBE is playing an increasingly important role in the gasoline pool composition owing to its superior properties, which represent a trade-off between the needs of refiners and the severe expectations and regulations of environmental stakeholders. 

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