Sorghum in spotlight due to drought, pending EPA action

By Holly Jessen | September 14, 2012

For years, National Sorghum Producers have advocated for increasing the use of grain sorghum, or milo, as an ethanol feedstock. Lately, the idea seems to be gaining steam. “There’s been increased interest over the past few months,” said John Duff, renewables program director for the United Sorghum Checkoff Program.

The first driver is drought, which has prompted some ethanol producers to search for alternate feedstocks, Duff said. While sorghum does have its limits, it’s more drought tolerant than corn, said Steve McNinch, CEO of Western Plains Energy LLC. “Corn is like a quarter horse, it will eventually run out of water and die. Grain sorghum is kind of like a donkey, it will wait for a while. You will eventually have to water it but it’s stubborn enough to wait. It’s a tropical plant so it likes the heat a lot better.”

The company’s 45 MMgy plant in Oakely, Kan., has long used some percentage of sorghum, which fluctuates depending on availability. This year the plant is still processing some corn but has relied pretty heavily on sorghum. “The problem with sorghum is the acreage has declined over time,” he said. “As more and more advances went into corn seed technology, some of the marginal areas went into corn.”  

Another alluring factor is possible greenhouse gas (GHG) emission reductions. The U.S. EPA is currently reviewing an analysis that ethanol produced from sorghum at a plant powered by natural gas has an estimated lifecycle GHG emission reduction of 32 percent when compared to baseline petroleum.  The feedstock offers a 53 percent GHG reduction when used along with advanced process technologies, such as biogas digesters and combined heat and power. This would qualify the fuel as an advanced biofuel under the renewable fuel standard. The comment period on this wrapped up in July and it’s currently unknown when the EPA could come out with a final decision, Duff said.

Ethanol production from sorghum is nothing new. Some ethanol plants have utilized a mix of corn and sorghum as feedstocks for years. In fact, there are a few plants that produce ethanol from 100 percent sorghum. The USDA makes payments to ethanol plants producing biofuels from renewable biomass. While corn is not eligible for the payments, sorghum does qualify.

However, there are only a few ethanol plants actively building digesters, regardless of the feedstock. Western Plains is one of those. The company received a $15.6 million grant from the Kansas Department of Commerce in 2011, which it is using to help complete the estimated $35 to $40 million project. “Hopefully we’ll start feeding it in the fall,” McNinch said. (See a 24-hour live feed of construction here.) 

Calgren Renewable Fuels LLC, a 58 MMgy corn-ethanol plant in Pixley, Calif., is considering adding sorghum to its feedstock mix as well as working toward building a digester. While the digester project stalled due to local opposition, the company is confident it will ultimately go forward, said President Lyle Schlyer.

The company’s investigation into sorghum is moving along at a faster pace. Calgren worked with area grain and seed companies, prompting area farmers to plant 1,100 new acres of sorghum, the fruits of which will be tested at the plant this fall. “Because it uses one-half to one-third the amount of water as corn and can be grown on alkaline soils that will not support a corn crop, we see sorghum as an attractive and viable crop for farmers in California’s San Joaquin Valley,” he told Ethanol Producer Magazine. “We anticipate running a modest amount of grain sorghum through our plant this fall and hope to dramatically increase the percentage of grain sorghum used as we go forward.”

The plant currently purchases less than 10 percent of its corn locally, a number Schlyer called “disappointingly low.” The good thing about adding sorghum is that company believes it will be able to do so without any modifications, although an additional enzyme to control foaming may be needed. Calgren was considering sorghum long before the drought but that certainly has highlighted the need to diversify feedstocks. “Our preliminary goal is to process 25 percent grain sorghum,” he said. “The ultimate percentage will depend upon commercial considerations, including how our distillers grain containing sorghum is received by our customers.”

According to a survey released in 2009, about 29 percent of sorghum produced in the U.S. is used for ethanol production. The USCP, which commissioned that study, is currently awaiting the results of a follow up study, expected in a few months, Duff said. The survey showed that the most sorghum was used for ethanol production in Kansas and Texas, where, on average, ethanol producers utilized 48 percent corn and 52 percent sorghum.