Sunday, April 8, 2012

Ford puts faith in higher ethanol blends

EthanolCorn_thumb Substantial societal benefits could be the result of using higher volume blends of ethanol, according to the Ford Motor Company.

It wants to see the higher blends to leverage the inherent high octane rating of the alcohol – and this can be used to produce ethanol-petrol blends with increased octane numbers.

At the moment, ethanol is blended into a petrol blend-stock with a lower octane rating. However, the higher octane rating could be used in a mid-level ethanol blend to increase its minimum octane number, according to the Ford researchers writing in a new paper published in the journal Fuel.

It is believed that both ethanol and methanol have performance issues in petrol blends: for example, they have a lower energy density and potentially higher or lower vapour pressures; as well as altered distillation properties. However, their high research octane number and motor octane number is an advantage: the octane number reflects its ability to resist knock, which results from premature auto-ignition.

So it is hoped that higher octane numbers can enable greater levels of thermal efficiency and more aggressive turbocharging and downsizing: helping existing engines with more aggressive spark timing in certain conditions.

For example, an increase in the blend-stock RON from 88 to 92 could offer higher RON increases in E10 from 92.5 to 95.6 with additional ethanol content.

The Green Car Website