My October 12, 2016 blog, California Leads the Way in Reducing Carbon Emissions, described California’s LCFS in requiring petroleum refiners and producers to reduce by 2020 the Carbon Intensity (CI) of their products by 10% from a 2010 baseline: where CI is defined as the amount of greenhouse gas (GHG) emissions associated throughout each stage of a fuel’s production and use: i.e. a “life cycle” analysis expressed in grams of CO2 equivalents per megajoule of energy (gCO2e/MJ).
According to California’s Air Resources Board (CARB), the CI of cellulosic ethanol is less than half that of California’s baseline reformulated gasoline, and 60% of corn-based ethanol’s CI. Thus cellulosic ethanol can provide significant credits in helping fuel providers meet their CI requirements. With cellulosic ethanol worth more than $3.00/gallon than conventional corn-based ethanol in California, several companies have announced plans to construct cellulosic ethanol plants specifically for the California fuels market.
One of the announced projects, Element LLC, is a joint venture between The Andersons, who are significant investors in several corn-based ethanol plants located in Iowa, Ohio, Indiana and Michigan and ICM, a technology provider. The plant will incorporate ICM’s Advanced Gasification process as well as its 1.5 generation (1.5 gen) cellulosic ethanol process in a 70 million gallon/year plant located in Colwich, Kansas.
ICM’s 1.5 gen cellulosic technology separates corn fiber from the cornstarch and with the application of advanced proprietary yeast, converts the cellulosic corn fiber into C5 and C6 sugars which are converted into additional ethanol. Its use increases the yield of a conventional corn-based ethanol plant by about 10%; from 2.8 gallons of ethanol per bushel of corn to 3.1 gallons/bushel. However, as expected, the amount of distillers dry grains (DDG) is reduced. The EPA considers corn fiber as an agricultural waste and, as long as its use lowers GHG emissions by 60% compared to conventional gasoline, it may be classified as a cellulosic feedstock. The project is scheduled for completion by the end of 2019.
Another cellulosic ethanol project targeting the California market has been announced by Aemetis, a Cupertino, CA, ethanol and biotechnology company. This project will employ completely different technology than Element’s 1.5 gen corn-based cellulosic project. First of all the cellulosic feedstock is not corn but agricultural waste from the harvesting of almonds and walnuts in California’s Central Valley. According to Aemitis, the 1.5 million acres of almonds and walnuts grown in the Central Valley generate about 1.6 million tons of waste wood and nutshells each year: more than enough to produce over 100 million gallons of ethanol.
Aemetis has licensed InEnTec’s proprietary gasification technology employing a Plasma Enhanced Melter (PEM) to convert the cellulosic waste into synthesis gas; a mixture of carbon monoxide and hydrogen.
InEnTec has successfully implemented 13 units worldwide since 1995. Their technology was initially developed at MIT and the Pacific Northwest National Laboratory with support of the US Department of Energy. Aemitis has also licensed LanzaTech’s gas fermentation technology to convert the synthesis gas produced in InEnTec’s PEM into ethanol. LanzaTech’s gas fermentation technology uses proprietary microbes, which feed on carbon monoxide and hydrogen, converting the synthesis gas into ethanol.
Aemetis owns and operates a 60 million gallon per year ethanol plant near Modesto, California. Their initial plans are to construct a 12 million gallon per year plant using the InEnTec and LanzaTech technologies. They recently received permitting and environmental approval from federal and state agencies for construction of the plant at the former Riverbank ammunition plant near Modesto California. Completion is expected sometime next year.
As shown above the InEnTec gasification process requires both AC and DC electric power for its Plasma Enhanced Melter as well as both steam and oxygen to effect the conversion of the carbon rich agricultural wastes into synthesis gas. The total amount of energy required to provide the required electricity, steam and oxygen may be excessive and, if not provided from renewable sources, may adversely affect the Carbon Intensity of this cellulosic ethanol process.
ICM is not the only company to have developed and implemented 1.5 gen ethanol technology. Among others are D3MAX and Quad County Corn Processors (QCCP). D3MAX plan to implement their technology at the ACE Ethanol facility in Stanley Wisconsin. QCCP implemented its Cellerate technology and first produced cellulosic ethanol at its Galva, Iowa plant in July, 2014. Since then the plant has produced more than 5 million gallons of cellulosic ethanol representing 90% of the total US cellulosic ethanol production in the last three years. Syngenta, which has developed a corn seed that increases the amount of ethanol produced from corn has partnered with QCCP’s subsidiary, Cellulosic Ethanol Technologies and acquired the licensing rights for the Cellerate process.
Recently California’s Air Resources Board announced that it is considering relaxing its 2020 deadline to 2022 for meeting the 10% reduction in CI from 2010 levels (see below)
to give fuel providers more time to meet the requirements. However they’re also considering extending the program through 2030 with a new target of 20% reduction in CI from 2010 levels. If implemented this should only enhance the attractiveness of low CI cellulosic ethanol to the California fuels market.