New Study: Blended Ethanol Has a 43.4 g/MJ Carbon Intensity Rating or Lower When Accounting for Aromatics Reduction

BLOG | BY: TAMMY KLEIN

Two studies conducted by my firm, Transport Energy Strategies (TES), and THiggins Energy Consulting show that gasoline blended with ethanol lowers carbon intensity (CI) even more than what is modeled today and what is shown in recent studies. The first study addresses tailpipe carbon emissions, the second well to wheels GHG effects. A key finding in both studies is that blended ethanol not only displaces some of the gasoline but enables a reduction of aromatics in all of the gasoline in the blend. Aromatics have a high CI, and their reduction further decreases the GHG impact of the E10. This advantageous blending attribute is due to ethanol’s high octane rating and has been neglected in prior literature.

Refinery modeling, economic considerations, availability of feedstocks and examination of gasoline properties supported the conclusion in Quantifying Ethanol CI Benefits in Gasoline Composition that as ethanol is blended into gasoline, so aromatics are reduced to maintain a constant octane rating. CI reductions based on fuel composition were found for ethanol blending using a surrogate three-component mixture of ethanol, toluene and iso-octane.

Read the full story here