Variety in Value

FROM THE SEPTEMBER ISSUE: Value-added components can be separated from the ethanol-production process at multiple stages. Technology developers continue to improve on their systems to expand markets and increase their customers’ revenues.
By Ann Bailey | August 18, 2017

The ethanol industry can reduce market risk by producing more diverse and value-added products, says Michael Regier, vice president of Cereal Process Technologies LLC. “The main benefit is diversification, not only diversification of coproducts, but of the industry,” he says.

CPT has a fractionation technology employed at the National Corn Ethanol Research Center in Edwardsville, Illinois, and in four commercial plants. “The ethanol industry, as a whole, is the only commodities processing industry that doesn’t employ some sort of initial component separation,” Regier says. “The ethanol industry right now just has a few markets: ethanol, DDGS, CO2, distillers corn oil.”

Fractionation can help plants create more value-added products, increase capacity and reduce operating costs. But fractionation isn’t the only option. Separation of valuable components can happen throughout the ethanol-production process, as some technology developers have demonstrated. Multiple systems exist to carry out the task. Some are brand new, while others are available for integration now, but their developers agree: Separating valuable coproducts adds revenue.

Added Value
CPT’s technology was developed in the 1950s for industrial fermentation by a chemical engineer and first employed in the 1960s. The system was implemented specifically for ethanol in 2007 at a 108 MMgy Valero ethanol plant in Jefferson, Wisconsin.

CPT’s process involves milling corn into three components: endosperm, germ and bran. Coproducts include the bran, high-protein distillers dried grains with solubles, food-grade vegetable oil and food-grade dry products such as de-oiled corn germ meal. During the CPT process, conditioned corn is de-germed into four to six large pieces, then the cracked corn enters a roller mill, where the germ remains whole while the endosperm is crushed. The remainder moves along a conveyer to sifting, again passes through milling where the germ and endosperm are sized, and is sent through aspiration for bran removal. The finished streams are then collected, weighed and transferred.

Removing bran and germ results in an endosperm with a 14 to 15 percent higher starch content than corn, Regier says. “With fewer nonfermentables, the resulting DDGS is high-protein.” The higher-protein, higher-quality DDGS have less protein degradation because particles contain less oil, resulting in more consistent drying. The process also reduces the load in the dryer by half, allowing for better control. After the CPT process, the DDGS can be sold as protein replacer, instead of a starch, and marketed at a discount to soybean meal, Regier notes.

The corn germ contains 80 percent of the oil in the corn kernel and is the most abundant unused source of vegetable oil in the ethanol industry, Regier says. The bran provides water absorption for syrup, reduces toxins fermentation and is an ideal combined-heat-and-power system feedstock.

The cost of employing CPT’s technology at ethanol plants is determined on a case-by-case basis. “There are parts of the project that are site-specific that would affect costs significantly,” Regier says. The technology might require a higher capital investment, but the potential return on the investment also is greater than other bolt-on technologies, he says.

 “We market this (technology) to the entire ethanol industry as well as the biochemical industry.”

3 Steps to Separation
ICM Inc.’s technologies focus on separating more starch and oil, through a three-step process: Selective Milling Technology V2; Fiber Separation Technology Next Gen; and Thin Stillage Solids Separation System (TS4).

SMT frees more starch critical for enzyme conversion to sugar by selectively targeting and flaking larger starch particles into smaller ones, or separating starch away from fiber, protein or fats, says Jesse Spooner, ICM process engineer II. Spooner says ICM’s SMT systems are being used at 26 ethanol plants around the world with more coming on board. The system increases ethanol yield by up to 3 percent, with a 15 percent increase in distillers oil, Spooner says. And that means more revenue, too, he adds.

FST has a patent pending and is designed to separate nonfermentable fiber from slurry before fermentation. It is operating in six ethanol plants and results in an ethanol capacity increase of up to 14 percent, as much as a 25 percent increase in oil separation, and more efficient use of inputs per gallon produced, Spooner says. “FST also provides the ability to produce purposely made feed products with the production of tailored distillers grains with a high-fiber stream and high-protein stream, which can bring significant value.”

TS4, recently released with multiple design configurations, is a separation technique set to be installed at its first ethanol plant later this year. It’s designed to remove oil and suspended solids from stillage. The process improves plant efficiency by increasing dryer capacity, improving evaporator operation, and increasing plant throughput, according to ICM.

“Employing the SMT V2 technology has limited impact on an ethanol plant’s operation, while implementing FST Next Gen and TS4 are more involved,” Spooner says. “The ICM technologies are all designed to help a plant capture the value.”

Almost to Market
Harvesting Technology LLC has been developing the bolt-on CoProMax process for five years. The process involves separating distillers corn oil from whole stillage, while eliminating the use of decanters to produce thin stillage, according to Harvest Technology’s George Bolton and Chuck Jepson, both agriculture industry veterans. During the process, whole stillage is diluted, then processed with a fiber separating device and the resulting wet fiber, containing about 80 percent of the corn kernel fiber, is squeezed with a press. This liquid is combined with the effluent from the initial fiber separation and treated with a proprietary polymer, then introduced into a dissolved air flotation (DAF) machine. “As the DAF float is collected, it is heated to about 205 degrees and pumped to a tricanter, which separates the high-protein faction of the distillers grain and the distillers corn oil. The resulting effluent from this process is combined with the 2 percent solids DAF effluent for use as backset for the ethanol process, and also allows for dilution of the incoming whole stillage and provides a low-solids effluent for the evaporators to maintain the water balance of the process,” Bolton says. 

CoProMax provides a greater opportunity to increase coproduct value by starting with whole stillage, Bolton says. “This change allows the production of corn oil to be raised to a new level, about double what the average plant is getting, so we’re looking at around 1.3 pounds per bushel of corn processed,” Bolton says. “That is one of the highest levels available.”

The CoProMax process also produces a 26 percent protein, 6 percent fat distillers grain, called CKFiber, containing more than 60 percent nondetergent fiber (NDF). The product is good feed for high-lactating dairy and feeder cattle. The high levels of NDF also make it an excellent and readily available feedstock for the new cellulosic ethanol technologies being developed, Bolton says. It has a protein level in the range of 45 to 54 percent, allowing for greater pricing and market flexibility. Because it has a substantially higher protein than standard distillers grains, plus a lower level of fiber, it can be used at higher inclusion rates in monogastric animals, making it an ideal feed for the aquaculture and poultry industries, Bolton says. “When compared with soybean meal in poultry diets, CKFiber has about 60 percent more digestible energy,” he says.

Harvest Technology is in the final stages of testing CoProMax. The company will conduct a mass balance in conjunction with the National Corn Ethanol Research Center, which will ensure third-party verification of the mass balance and the materials resulting from the process, Bolton says.

“From there, we plan to introduce it into the commercial market. We expect to be done in two to three months,” Bolton said during a late July interview. “We’re running at a commercial ethanol plant (Adkins Energy in Lena, Illinois) right now. We’re taking a fraction of their whole stillage and proving the process there.

“We’ve had a lot of interest,” Bolton says. “Since we started our commercial pilot operation, there’s been a tour about every day. Our starting goal was to develop a profitable solution for ethanol coproduct production. Our next step will be finalizing novel financial approaches to introduce the CoProMax process to the ethanol industry.”

Author: Ann Bailey
Freelance Journalist