Energy crop company Ceres, Inc. has had its sweet sorghum hybrids successfully processed into Amyris ‘Biofene’, a renewable hydrocarbon commonly known as farnesene.
Farnesene is a 15-carbon isoprenoid hydrocarbon molecule that works as the basis for a wide range of products as varied from specialty chemical applications to transportation fuels such as diesel. When used as a fuel precursor, farnesene can be hydrogenated to farnesane, which has a high cetane number of 58.
Amyris is presenting a summary of the results at the 34th Symposium on Biotechnology for Fuels and Chemicals in New Orleans, Louisiana. The project comes from a U.S. Department of Energy funded renewable diesel effort.
The pilot-scale project uses both the free soluble sugars and the cellulosic biomass sugars from Ceres’ sweet sorghum hybrids grown in Alabama, Florida, Hawaii, Louisiana and Tennessee. To process the soluble sugars that accumulate in the plants, the sorghum juice was first extracted from the stems and concentrated into sugar syrup by Ceres. Then Amyris then processed the syrup at its California pilot facility using its proprietary yeast fermentation system that converts plant sugars into its trademarked product, Biofene.
The DOE’s National Renewable Energy Laboratory (NREL) converted the leftover biomass from Ceres’ hybrids into cellulosic sugars at its Colorado pilot-scale biochemical conversion facility, which Amyris subsequently fermented into renewable farnesene. That put almost the entire plant into the fuel precursor.
Secondary products from the Amyris biorefinery project include lubricants, polymers and other petrochemical substitutes. These secondary products are derived from the same C15 farnesene fermentation intermediate as the Amyris Renewable Diesel, providing opportunities to reduce risk in commercial production.
Spencer Swayze, Ceres director of business development said, “We believe that sweet sorghum could be an important and complementary source of fermentable sugars as the U.S. expands the production of renewable biofuels and biochemicals through the use of non-food crops outside of prime cropland. As an energy crop, sweet sorghum is an impressive producer of low-cost, fermentable sugars. A second stream of sugars from the biomass would be highly compelling.”
Sweet sorghum as a dedicated energy crop has a number of advantages. Its fast growing and can efficiently produce both large amounts of fermentable sugars and biomass. The plants require substantially less fertilizer than sugarcane, and can be grown in drier areas because it utilizes water more efficiently.
Todd Pray, Amyris director of product management said, “The results from these evaluations confirmed that the Amyris No Compromise renewable diesel production process performs well across different sugar sources. Ceres’ sweet sorghum hybrids produced sugars that yielded comparable levels of farnesene as sugarcane and other sugar sources Amyris has utilized. Sweet sorghum can provide timely feedstock flexibility with environmental benefits. We look forward to utilizing Ceres’ sweet sorghum in our commercial-scale production facilities.”
The primary product of the Amyris IBR is Amyris Renewable Diesel, an advanced biofuel registered for use by the US EPA and covered by an issued US patent.
This news is likely a serious step into building a middle distillate range of bio hydrocarbons. Amyris is already working with Total in Brazil working on a 50:50 joint venture company that will have exclusive rights to produce and market renewable diesel and jet fuel worldwide, as well as non-exclusive rights to other renewable products such as drilling fluids, solvents, polymers and specific bio-lubricants. The venture aims to begin operations in the first quarter of 2012.
As for the numbers, which seem to be proprietary, Amyris is scaling up its Biofene production in Brazil, Europe and the United States through various production arrangements with six known to be in hand. Going for the investment at scale indicates that something commercial is worth putting in significant money.
The Ceres feedstock could bring mass production. What the production rates are hasn’t been disclosed yet. But as commercial scale efforts get further underway and efforts to acquire land and farming skill commitments – the values are sure to leak out. How sweet sorghum compares to cotton, peanuts, corn and soybeans is yet to be seen. To be competitive the prices have to support the production switch for terms long enough for the investments to payback and profit producers.
With a great cetane number and no sulfur the diesel product would be very desirable.
One would expect that a built molecule such as Amyris makes for a middle distillate would be more costly than a derived one coming from crushed seed oils and other sources. Time will tell, and the energy rich compression ignition engine will live on.