After a decade of research, a little-known company based in Minnesota says it has developed a cheaper, more energy-efficient process to make biodiesel motor fuel from waste oils generated by commercial kitchens and the rendering industry.
Superior Process Technologies is a small research-and-development unit of privately held Baker Commodities, a large, family-owned renderer and waste grease recycler based in Vernon, Calif. Staffed by a handful of chemists and engineers, Superior Process has worked quietly in a small office and laboratory in northeast Minneapolis on a better way to refine grease, tallow and other waste oils into biodiesel.
Superior Process engineers Kirk Cobb and Joe Valdespino, whose innovations draw on decades of experience in the paper and oleochemical industries, now are working toward a big step: constructing a commercial-scale biodiesel refinery.
Baker Commodities plans next year to start building a 20-million-gallon-per-year biodiesel plant in Vernon, Calif., to recycle waste grease into fuel, said Doug Smith, general manager of Superior Process and assistant vice president for R&D at the parent company.
“Our process is superior to the traditional method,” said Valdespino in an interview at the company’s lab and office on NE. Broadway. “It saves energy. It increases yield. … It enables you to use cheaper feedstocks.”
The cheap feedstocks include used deep-fryer oils, rendered animal fats and the contents of grease traps in sewer lines. These waste products, often known as yellow or brown grease, are less expensive than soybean oil, the traditional raw material for biodiesel.
The challenge of converting waste into something useful appealed to Cobb and Valdespino. They met more than two decades ago while working as engineers for Union Camp Corp., a Savannah, Ga., paper company acquired in 1998 by a larger rival. The pine used in pulpmaking generated liquid rosin or tall oil, and the two engineers worked on ways to turn it into profitable products.
A different process
Minnesota, the nation’s No. 3 soybean producer, is home to other pioneers in the biodiesel industry, and has two large and one small biodiesel refineries owned by other companies. Under Minnesota law, the fuel is blended with petroleum-based diesel at rates of 5 or 10 percent.
Superior Process’ work on the biofuel has happened under the radar until now. Cobb first turned his attention to biodiesel in the early 2000s, joining Superior Process in 2004, moving to Minnesota a year later and hiring Valdespino in 2007.
Many of the nation’s 94 biodiesel plants don’t try to refine waste oils. Those that do typically rely on a pretreatment process — known as acid esterification — that uses sulfuric acid to remove free fatty acids that otherwise would interfere with the making of biodiesel.
“The traditional acid esterification process is really messy,” said Valdespino. “It is limited to very small free fatty acid impurities. It is very limited.”
The traditional process also causes water to contaminate another compound, methanol, used in the making of biodiesel. Cobb said the water then must be removed before processing oils into biodiesel, a step that takes more energy.
For years, Cobb and Valdespino have been working on a different process to address this challenge. It relies on heat and glycerin to modify free fatty acids into feedstock that can be refined into biodiesel. The process, called glycerolysis, is not new, and a version of it is employed by at least three U.S. biodiesel plants.
The Minnesota engineers say their process will refine the most challenging of waste oils. They added some proprietary features to the multistep biodiesel refining process, and have done all the engineering work to build a commercial-sized plant.
The biodiesel industry has faced on-again, off-again federal tax incentives for the low-carbon biofuel. A $1-per-gallon tax credit for biodiesel expired last year. That has happened before, only to have the credit retroactively revived.
For now, at least, new plants like the one Superior Process wants to build won’t get the tax credit that helped earlier biodiesel start-ups.
Skepticism of the technology also can be a problem. In 2012, Cobb read an article in an industry journal declaring the traditional pretreatment process for waste oil more energy-efficient than the glycerolysis method championed by Superior Process.
Cobb pushed back with his own data, reporting that the opposite is true. Cobb said skeptics flagged on the fact that glycerolysis relies on higher temperatures, while ignoring how much energy is wasted to strip away water in the acid-based method.
“People misconstrue higher temperature with higher energy use,” Cobb said. “That is not the case.”
Cobb and Valdespino are excited that their ideas are headed toward commercial deployment.
The strategy, said Smith, is to get one plant up and running and showcase the technology. Then the company could go on to build other plants, or possibly license the technology to other companies, he said.
“It is going to be much lower cost; less than $2 per gallon,” Smith added.