Men med kompressions-höjning i etanolmotorn borde verkningsgraden kunna bli högre (jämfört med att köra etanol i en flexi-fuel motor). Forskningen från USA på detta verkar indikera att man kan köra helt på etanol och komma upp i ungefär lika mycket effektivitetsvinst via högre kompression som man "förlorar" på energi-innehållet (alternativt få ut mer hästkrafter).
Typ detta projekt (finns ett till som jag glömt namnet på)
http://news.pickuptrucks.com/2009/03/ri ... motor.htmlCitat:
Ricardo calls its new engine technology Ethanol Boosted Direct Injection. Its goal is similar or better fuel economy, with the same peak of 660 pounds-feet of torque, found in today’s GM 6.6-liter Duramax V-8 diesel, but from a 3.2-liter flex-fuel V-6.
Ethanol, however, has a higher octane and heat-of-vaporization point than gasoline, meaning it combusts at a higher temperature and with greater force (higher compression) than gasoline, while also having a greater capacity to cool the fuel/air mix in the cylinder before combustion. This allows a larger charge to be drawn into the cylinder before ignition. This inherent efficiency is what enables a smaller-displacement engine to perform with the same power as a bigger motor if the engine is built to take advantage of it.
Tyvärr har jag inte sett Scania göra särskilt mycket offentlig reklam för de där motorerna, så hur väl de fungerar vet jag inte.
Angående diesel-etanol mix hittade jag denna studie från 2001:
http://www.oxydiesel.com/sae2001-01-2475.pdfCitat:
E-Diesel blended fuel formulation contains between 83-to 94-percent No. 2 diesel fuel, 5- to 15-percent ethanol and 1- to 2-percent Puranol.
The ethanol and Puranol impart premium diesel characteristics to the No. 2 diesel fuel such as reduced exhaust emissions, superior cold-performance, improved lubricity (which relates to engine life extension) and long-term storage stability.
E-Diesel is an economically attractive fuel. It does not require dedicated or special-purpose production facilities since it can be blended “in-line” at the terminal or splash blended in the storage tank or tank truck just prior to delivery. Furthermore, Puranol is commercially available, and in full-scale use the E-Diesel would be available at a price that is only marginally higher than No. 2 diesel, and yet less than the comparable premium No. 1 diesel.
A 23-percent ethanol in diesel would render all cetane property of No. 2 diesel (with a base of 40 cetane) useless. In other words, while a large volume of ethanol in diesel significantly improves emissions, it would impact negatively three of the major properties of the blend—cetane, flash point, and lubricity.
Low lubricity can result in fuel pump failure and injector degradation at an accelerated rate even when ethanol is used in as small a quantity as 5%. Puranol is designed to address both lubricity and cetane property limitations
Denna rapport har en redogörelse över leverantörer av olika e-Diesel alternativ:
http://www.epa.ie/pubs/reports/research ... el_web.pdfSe sidan 7.
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