(The ATJ Task Force in ASTM D02-J6, initiated by Gevo in 2010, focused on two main fuel products: ATJ-SPK (paraffins) and ATJ-SKA (Synthetic Kerosene with Aromatics). ATJ-SPK has a maximum blend ratio of 30%; ATJ-SKA has a maximum blend ratio up to 70%. SKA is intended to supply additional aromatics compounds to alternative jet fuels blends. Most of the other pathways, including ATJ-SPK, yield products that are too low in aromatic content to be used on their own.)

Source: Pacific Northwest National Laboratory (PNNL). Click to enlarge.

The D02.J Ballot passed two levels of ASTM technical scrutiny: subcommittee and main committee ballot and is in the final stages of Society Review. The ASTM process is substantially complete as it relates to the approval of the D02.J Ballot.

In order to fully complete the process, the ASTM still needs to close the Society Review, perform a final ballot tally, and publish the revision of ASTM D7566 (Standard Specification for Aviation Turbine Fuel Containing Synthesized Hydrocarbons) on its website. It is expected that these final actions will be completed by the ASTM in early April.

Once the revision of ASTM D7566 (Standard Specification for Aviation Turbine Fuel Containing Synthesized Hydrocarbons) is published by the ASTM, Gevo’s ATJ will be eligible to be used as a blending component in standard Jet A-1 for commercial airline use in the United States and in many other countries around the globe. Gevo’s ATJ would be eligible to be used for up to a 30% blend in conventional jet fuel for commercial flights.

We’re pleased that this newly-revised standard now supports isobutanol based alcohol-to-jet aviation biofuels and we look forward to flying it this year. Developing a domestic, competitively priced, sustainable supply of biofuels is fundamental to Alaska Airline’s long term sustainability goals.

—Joe Sprague, Alaska Airline’s Senior Vice President of External Relations

This ASTM revision is a major achievement and supports one of Gevo’s key products. We believe that Gevo’s renewable ATJ provides a clear and cost-competitive path for commercial airlines to reduce their greenhouse gas footprints and reduce their particulate emissions from combustion. For Gevo, this step is expected to open a large and significant market to Gevo around which Gevo expects to build a profitable business.

—Dr. Patrick Gruber, Gevo CEO

Gevo developed proprietary technology that uses a combination of synthetic biology, metabolic engineering, chemistry and chemical engineering to focus primarily on the production of isobutanol, as well as related products from renewable feedstocks.

Gevo has also developed and demonstrated the technology to convert isobutanol into aliphatic and aromatic hydrocarbons using known chemistry and existing refinery infrastructure:

• Isobutanol produced from starch or biomass is dehydrated over an acidic catalyst to produce isobutylene, which is then further reacted to product mixtures of longer chain aliphatic hydrocarbons.

• A portion of this material is reacted separately to form high density aromatic compounds.

• Hydrogen gas, a byproduct of the aromatization reaction, is used to remove unsaturated bonds in the aliphatic material.

• The hydrocarbons then are blended in proportions that can meet all ASTM standards for fuels: isooctane is a dimer of dehydrated isobutanol and is a major component of the premium value alkylates, a key gasoline component; a trimer of the isobutylene (dehydrated isobutanol) is a jet fuel blend stock; a polymer of four and five isobutylenes can make a diesel blend stock.

Resources

• EIA Working Paper: “The Flight Paths for Biojet Fuel” Tony Radich. October 2015