One of the most obvious problems of fuel quality is from redundant olefin fraction of gasoline in China, which is attributed to the high proportion of FCC gasoline with ample olefins in gasoline pool.

我国燃料油质量方面较为突出的问题之一是汽油中烯烃含量较高，而催化裂化汽油的高烯烃含量和汽油调和组分中过高的催化裂化汽油比例是我国目前成品汽油中烯烃含量高的主要原因。

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In 2005, total U.S. ethanol production was 3.9 billion gallons, or 2.9% of the total gasoline pool.

FORBES

But butane also adds to the total gasoline pool, so that means that gasoline supplies increase in the winter as more butane is added to the mix.

FORBES: Why Spring Means Higher Gasoline Prices

The percentage of biofuels blended into gasoline is projected to account for 4.3% of the total gasoline pool by volume in 2007, 7.5% in 2012 and 7.6% in 2030.

FORBES: Big Win For Biofuels