From field to table: Plymouth Oil begins production

(Sentinel photo by Magdalene Landegent) Plymouth Oil production is now underway, and the plant will soon be shipping out corn oil for food use. Here Paul Hartman, a Plymouth Oil employee, checks the expanded corn germ, which is packed into tube-like pellets. After this, the pellets of corn germ are cooled, dried and ready for the oil to be extracted. [Click to enlarge]

After weather and financial delays, the $30 million Plymouth Oil plant is completely constructed and pumping out gallons of crude corn oil, according to Dave Hoffman, chairman of the Plymouth Oil Company board.

At capacity, the plant will daily produce 120,000 pounds of corn oil for cooking use, filling about three-fourths of a rail car, according to Bruce Nanninga, the company's marketing manager.

The plant, which stands next to the Plymouth Energy ethanol plant, will also produce 320 tons of defatted corn germ meal (DCGM) daily, sold to local livestock producers for animal feed.

Plymouth Oil is currently working through the plant's commissioning stage.

While the plant is producing corn oil, it's not yet at food-grade specifications, Nanninga said.

It is temporarily being sold to local cattle feeders and other livestock producers and can also be sold to biodiesel producers.

"Within two weeks we'll be up to food-grade corn oil," Nanninga said. "That's why we're doing the tweaking and adjusting at the plant."

The food-grade corn oil produced at Plymouth Oil is a crude oil. It must be refined before it can be sold to restaurants or grocery stores.

Plymouth Oil's product will likely be sold to refiners in Memphis, Tenn., or exported, Hoffman said.

Corn oil is in demand, especially because it has no trans-fats, Hoffman said.

Plymouth Oil is a certified kosher plant, meaning the oil it produces meets certain Jewish dietary standards.

"Early on we were told if we wanted to be in food business, we had to be kosher," Hoffman said. "It opens the door to certain food markets."

The plant officially started up last December but underwent some redesign work.

Since Feb. 10, it has been producing corn oil.

The plant is designed to refine raw corn germ, a part of the corn kernel not used to make ethanol, into food-grade cooking oil.

"Oil makes up about 4 percent of a kernel of corn," Nanninga said. "But 90 percent of that oil is in the germ."

Corn germ is shipped to the plant already fractionated -- a process that separates the starch from the germ.

Plymouth Oil receives about 300 tons per day, six days a week.

The corn germ is first cooked, flaked in a mill and run through an expander which makes the germ more porous, preparing it for oil extraction.

The expander also packs the germ into tube-shaped pellets.

The pellets are cooled, dried and sent to the extractor.

In the extractor, the pellets are treated with hexane, a petroleum product that draws out the corn oil, leaving behind the defatted corn germ meal (DCGM).

The hexane and corn oil solution is then distilled to separate the hexane and corn oil, then the corn oil is piped to a storage tank ready to sell.

The hexane can then be reused in the extraction process.

"We recycle everything right here," Nanninga said

The Plymouth Oil plant operates around the clock about 350 days per year.

Much of the equipment uses steam from a giant 700-horsepower boiler.

Steam is used to run the expander and both dryers, and it cooks the corn germ after extraction.

Steve Clayton, a shift supervisor at the plant, said Plymouth Oil employees are busy making final adjustments to equipment.

"We've got a pretty good crew here," Clayton said.

At a laboratory on the Plymouth Oil site, employees test the content of the incoming germ, the corn germ throughout the process and the produced oil.

Moisture and oil content in incoming germ are checked and the produced oil is carefully tested to make sure all the hexane has been removed.

Nanninga estimated Plymouth Oil will have about 225 tons of DCGM available to sell daily.

It's an economical feed for livestock producers because the DCGM provides nutrients that otherwise would need to be added with supplements.

For the DCGM to be usable for human food, some modifications would have to be made to the Plymouth Oil plant, but it's a possibility down the road, Plymouth Oil employees said.

"It could be used for situations like what's going on in Haiti," said Barb Waltz, lab manager at Plymouth Oil.

Another goal for the plant is to add a fractionator on the site of the Plymouth Energy ethanol plant to separate the starch (for ethanol) and the germ (for oil), Hoffman said.

Currently the corn germ Plymouth Oil uses comes from other plants in Iowa, Missouri and Wisconsin and is already fractionated.

If Plymouth Energy had the capability to fractionate corn, it would make both plants more profitable, Hoffman said.

But for now the focus is making the finishing touches on Plymouth Oil to bring the product to food-grade standards.

"We're very close," Hoffman said. "It will be soon."