A Straighter, Shorter Pathway: Confidence Builds in Overcoming the Hurdles Slowing Corn Kernel Fiber-to-Ethanol Approvals.

by Susanne Retka Schill (Ethanol Producer Magazine) Seven years after the U.S. EPA published the final rule for administering the Renewable Fuel Standard, the path to getting corn kernel fiber-to-ethanol approvals appears to be getting much shorter. Edeniq CEO Brian Thome reports it now takes six weeks from the time the data is submitted to the EPA to the time approval is granted to generate D3 RINs (renewable identification numbers). For those plants with efficient producer status, an amended petition process will take another six weeks.

That’s a far cry from the nearly three years it took for the first two companies, Quad County Corn Processors and Edeniq, to get corn kernel fiber approved as a feedstock.

In mid-2014, EPA came out with its rule that defined corn kernel fiber as a crop residue, clearing the way for QCCP and Edeniq customers’ registrations. It also established the rules for cellulosic biofuel from biogas, discussed other issues with crop residue feedstocks and made corrections and modifications to the 2010 rule. On its page of approved pathways, Edeniq’s Pathway approval goes directly to that rule.

He (Edeniq CEO Brian Thome) adds that while the Edeniq Pathway registration process appears settled, every company’s technology will need separate approval and there will be unforeseen issues that could cause delays.

LSCP’s Journey
In January 2017, Little Sioux Corn Processors became the third plant to be approved for D3 RINs under the Edeniq Pathway, but it ran into one of those unforeseen issues that took most of the year—until late November—to iron out.

LSCP was in the first batch of ethanol plants to be approved for generating D6 RINs above its grandfathered volume in EPA’s Efficient Producer Petition Process (EP3). Not only did LSCP’s EP3 approval letter specify corn starch, which needed to be amended, but the agency had to determine how to handle the coprocessed cellulosic ethanol volume in the required 365-day rolling average greenhouse gas (GHG) reduction spreadsheet.

LSCP has been using cellulase enzymes for a couple of years, working with Archer Daniels Midland Co. on trials for ADM’s Clintozyme, says Steve Roe LSCP’s general manager. The cellulase enzyme boosted ethanol yields to better than 2.9 gallons per bushel, Roe says, and improved corn oil yield. Then the company decided to go after the cellulosic ethanol gain. It licensed the Edeniq Pathway, and worked with Edeniq to establish the cellulosic lift.

Once EPA decided how to handle the D3 gallons in the EP3 reporting, Roe says, the remaining compliance plan approval was straightforward, partly because much of it had been determined in the earlier steps.

EPA says that for every 500,000 gallons—or at least annually—the cellulosic lift must be recertified, Roe says. Participating in a RIN quality assurance plan also is likely to be a market requirement.

Two other companies expect to petition EPA in the coming year for their corn kernel fiber-to-cellulosic ethanol technologies: ICM and D3Max LLC.

ICM’s Gen 1.5 Grain Fiber to Cellulosic Ethanol Technology is built on its Fiber Separation Technology.

Gen 1.5 sends the fiber stream from FST through a separate process where it is pretreated and fermented. The fiber fermentation broth is then combined back into the existing ethanol plant’s larger fermenter to complete fermentation. Hartig reports the company is working internally and with others, including the National Renewable Energy Laboratory, to develop open industry standard methods for all processes to use for cellulosic ethanol tests. “ICM thinks this is important for the credibility of this industry,” he says. “ICM will be doing test method validation and third-party engineering review during the course of 2018 and then submit for actual approval immediately after start up.”

D3Max also will be going through the regulatory process this year. The company’s patented pretreatment and fermentation process for wet cake occurs in a separate reactor and fermenter. READ MORE