<Will biofuels always be hopeless? The Oil Drum DrumBeat: May 27, 2006>

97 comments on More on biofuels

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frenk26 on October 24, 2006 - 5:52pm Permalink | Subthread | Parent | Comments top
One of the constraints on biodiesel will be the low penetration rate of diesel passenger vehicles in the North American market. For example, VW sold just 29,000 diesel powered cars in the USA last year. Diesels took just 3.2% of the US market last year. Contrast that with the situation in Europe, where more than half the new cars sold are diesels.
Diesels have been held back in North America by the high concentrations of sulfur in fuel. Sulfur poisons catalytic converters. Its oxides are corrosive and increase the concentrations of particulates (sooty smoke) in the exhaust. Diesel cars have been unable to meet the emissions standards in five states, including CA and NY.

The advent of low sulfur diesel this fall would have changed this situation, except that EPA continues to stack the deck against diesels in passenger cars. The upper limit of sulfur in diesel will be going from 500 ppm to 15 ppm, which would have opened the door to European engines and emissions control technology for the 2007 model year. However, EPA has mandated that diesel cars must meet the same emissions standards as passenger cars, beginning with the 2007 model year. Sounds fair, but it's a big technological problem.

Diesel engines typically return 25-40% better fuel economy than gasoline engines. One of the main reasons is the higher energy content of the fuel, mentioned by HO. The combustion process can normally be optimised to minimise NOx (oxides of nitrogen) or minimise unburned hydrocarbons, but it's inherently difficult to minimise them both

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frenk26 on November 9, 2006 - 6:07pm Permalink | Subthread | Parent | Comments top
Ikivo SVG   
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97 comments on More on biofuels

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