Building on the success of corn ethanol to corn hydrocarbons

By Holly Jessen | July 27, 2011

Although the U.S. corn ethanol industry is frequently misunderstood and misrepresented, it’s the only domestic renewable fuel industry to reach significant scale and make a measurable impact on the U.S. fuel supply, said Luca Zullo, principal of VerdeNero LLC. Zullo was one of many presenters at the Biomass ’11: Renewable Power, Fuels and Chemicals Conference held July 26-27 in Grand Forks, N.D.

Zullo’s July 26 presentation, put together with information from VerdeNero, JetE LLC and GRT Inc., outlined a vision for expanding the ethanol industry past the limiting factor of the blend wall to produce ethanol and distillers grains as well as drop-in replacement fuels and chemicals. “We believe that the infrastructure and market position established by the corn ethanol industry represents the most logical base on which to build a diversified biorefining industry,” Zullo said.

Unlike other biorefining proposals out there, the model Zullo talked about keeps the ethanol plant in place as is, including production of distillers grains in its current composition and at its current value. “We keep the plant front end unchanged,” he said. From there, two additional technologies could be added to an existing ethanol plant, one of which is commercially ready now and the second in development.

JetE, a St. Paul, Minn.-based company, converts low quality corn oil from the ethanol plant as well as waste vegetable oils and fats when available, into 35 MMgy of drop-in paraffinic green diesel and green jet fuel. Zullo called it a simple process to make better biodiesel or a fuel similar to biodiesel. “We are ready for commercial deployment,” he said.

Technology from GRT, a Santa Barbara, Calif., uses ethanol as a feedstock to produce hydrocarbon fuel. Although the technology is in an earlier stage of development three to four years from commercial deployment, it isn’t completely unknown. Mobil Oil was doing something similar in the 1980s, he said.

Put together at an ethanol plant, the two technologies can turn a 100 MMgy ethanol plant into a 50 MMgy ethanol plant also producing 60 MMgy drop-in replacement fuels. Or, the same plant could be converted completely to 90 MMgy drop-in replacement fuels only. However, in both cases the plant will continue to produce distillers grains.

Zullo talked about several advantages of full integration of an ethanol plant. First, the JetE and GRT technologies can use waste heat from the ethanol plant. Water can also be recycled in the process. Finally, on average, the integrated biorefinery produces more energy per bushel of corn. 

He also pointed out problems with retrofitting ethanol plants for i-butanol, n-butanol, alkanes and other novel fermentation technologies. It’s uncertain if these produces will be accepted in the marketplace, he said. It’s more complex to produce these fuels for them to become a real drop-in fuel and their value and pricing is unclear at this time. In addition, these technologies are highly proprietary and costly. Although distillers grains are produced, it’s likely this source of revenue will be lost, Zullo said, due to the toxicity of the fuels produced and the use of GMO organisms.