Advanced BioFuels USA

by Ron Cascone and Steven Slome (Nexant/Biofuels Digest) The term “fatty acid methyl ester” or FAME has been synonymous with biodiesel for the better part of the last two decades that have seen its widespread promotion and use. This has been due to the historical low price of methanol, and the low technological hurdles of transesterification technology, but this has not produced a fully renewable fuel. FAME biodiesel only contains about 90-95 renewable carbon, because of using fossil carbon-based methanol. While FAME has been an important “green” fuel, it should be seen as transitional, as there are better options for a fully renewable (and more closely drop-in) diesel fuel emerging, including:

• Fatty Acid Ethyl Esters (FAEE) – Utilizing the same technology of transesterification of fats and oils, and switching bioethanol for fossil methanol will produce a fuel with higher cetane numbers and comparable properties otherwise.

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• HVO – Utilizing technology similar to conventional petroleum refining, triglycerides are hydrotreated to remove oxygen (and unsaturation). The result is a drop-in diesel substitute, which is comprised of highly paraffinic hydrocarbons. Bio-jet and bio-naphtha cuts may be produced as byproducts as well.

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• Biomass Gasification and Synthesis – Utilizing biomass gasification to produce syngas, which is either converted to methanol (for making fully-renewable FAME) or FT (Fischer-Tropsch) liquids.

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• Fermentation – Several developers have produced and tested a bio-based diesel-range product via fermentation (e.g., Amyris’s Farnesane), … 

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Until bio-methanol production becomes both widespread and economically competitive, FAEE represents the “lowest hanging fruit”, as it would be the easiest to implement without additional capital expenditures. FAME production can be easily switched to FAEE production with the simple replacement of methanol (and a sodium methoxide catalyst) with ethanol (and a sodium ethoxide catalyst).

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From the ethanol viewpoint, FAEE represents a large market that has been untapped. FAEE is more renewable, as it likely has a carbon footprint advantage over fossil methanol. From the national security and trade viewpoint, which appears to be increasingly important to the current administration, it represents a domestic product (ethanol), as opposed to a largely imported product (methanol).

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• Profit: Economic Sustainability – Nexant has analyzed the current prices of the feedstocks and products for both FAME and FAEE in the United States, Brazil, Asia, and Western Europe and found that FAEE is basically at parity with FAME in all regions, with slight advantages to FAEE in the US and Brazil ($3-5 per ton), and slight advantages to FAME ($5-12 per ton) in Asia and Western Europe.

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While ethanol prices are around 15 percent higher on a mass basis and approximately 40 percent more ethanol than methanol is required per ton of product, a significantly lower amount of the much higher-priced plant oil is required per ton of product as well. This leads to the slight discount for FAEE in the United States.

For more on the longer term options for renewable diesel, please see the Nexant report, Biorenewable Insights: Renewable Diesel, due out later this year.  READ MORE