A new soybean processing plant planned in Shell Rock will produce almost half a billion pounds of soy oil annually as feedstock for renewable diesel, the newest fronter in biofuels.

“Renewable diesel is a superior product (when compared to petroleum-based diesel),” said Mike Kinley, CEO of Mid-Iowa Cooperative, one of the investors in the Shell Rock plant. “The technology is superior to other technologies out there. (Renewable diesel refiners) are able to make a fuel out of soy oil that’s identical to petroleum-based diesel. It’s also renewable, and from that standpoint, that represents a long-term sustainable demand curve toward soy oil.”

Kinley said the Shell Rock plant will produce about 1.32 million pounds of soy oil per day, along with other soy byproducts useful as animal feed, once operational in 2022. And much of that supply is already account...