A new project in Minnesota would bring combined heat and power generation and add new technology to capture sulfur at one of the Midwest’s largest oil refineries.
Owned and operated by Flint Hills Resources, the $150 million, nearly 50-megawatt project may begin later this year and is expected to allow the company to more efficiently run its Pine Bend facility while reducing greenhouse gas emissions.
Another $150 million will be spent to reduce emissions in order to meet the Environmental Protection Agency’s standard for removing sulfur from gasoline. The sulfur will become a liquid fertilizer known as ammonium thiosulfate, or ATS.
“These are neat innovations we’re excited about,” said Flint Hills public affairs director Jake Reint. Flint Hills is a subsidiary of Koch Industries Inc.
The company consulted with several environmental and clean energy groups before deciding CHP would add efficiency and reduce carbon emissions related to the plant, Reint said.
One of the groups involved was Fresh Energy, which publishes Midwest Energy News. Will Nissen, Fresh Energy’s energy performance director, said the project “will lead to a net reduction in carbon emissions.”
Fresh Energy “supports highly efficient generation, especially when it provides thermal and electrical needs,” Nissen noted. “When compared to large baseload plants, (CHP) is a step forward in efficiency gains and in how we produce our energy.”
CHP uses fuels like natural gas or biomass to produce electricity and steam together to save on energy costs. The “cogeneration” approach eliminates the need for separate steam and electricity plants while bringing energy production closer to where it will be used.
In the state’s last legislative session, Flint Hills received an exemption from Minnesota’s policy that restricts CHP projects to 50 megawatts or less. Although Flint Hills was too far along in planning to increase the output, Reint said, it will likely later add equipment to increase the power capacity as much as an additional 7 megawatts.
“This is one of the better case studies for why combined heat and power makes sense,” Reint said, noting the refinery’s huge power needs.
Flint Hills’ Pine Bend facility processes 339,000 barrels of oil a day and is among the top 15 largest refineries in the country, he said. More than half of Minnesota’s transportation fuels come from Flint Hills, he added, and it has a healthy business from Wisconsin and the Dakotas.
Based in Wichita, Kansas, Flint Hills Resources is a subsidiary of the controversial Koch Industries, which is owned by Charles and David Koch, both major backers of fossil fuel interests who have also undertaken a campaign against the solar industry in Florida.
The Pine Bend refinery, located in the Twin Cities suburb of Rosemount, employs more than 1,000 full-time staff and 400 to 2,000 contractors. If refines fuels such as gasoline, propane, butane and diesel, as well as much of the jet fuel used at the region’s international airport.
The promise of CHP
Research by the Pew Environment Group shows that doubling cogeneration in the United States by 2020 would reduce energy consumption by 3 percent — a figure that doesn’t sound like much but that would actually eliminate the need for more than 200 mid-size power plants.
Minnesota’s Department of Commerce studied the impact of CHP in 2015 and found the state’s plants have a capacity of nearly 1,000 megawatts. A state goal would roughly double that by 2030.
Research by the Microgrid Institute, which worked with the Department of Commerce on the project, suggests combining thermal with electricity generation could cut energy use 35 percent when compared to having those tasks done separately.
Minnesota has a total potential of 3,195 MW of CHP, the institute predicted, and it can pay for itself in less than 10 years. St. Paul-based District Energy’s president and CEO Ken Smith said CHP makes sense in locations with large demands for thermal and electric needs, such as industrial sites, campuses and hospitals.
CHP is “a proven strategy to increase efficiency, increase resiliency and to reduce carbon emissions,” he said.
The Obama administration has also sought to increase the use of CHP through a 2012 executive order, suggesting manufacturers could save as much as $100 billion over the next decade while “strengthening U.S. manufacturing competitiveness.”
Mike Bull, director of policy and communications for the Center for Energy and Environment, said in most cases CHP is a good approach for reducing carbon emissions. The CEE supports Flint Hills because it plans to use the steam the plant generates.
If CHP is not optimized and a user does not use the process’ steam load to the fullest extent, the operation becomes “just a natural gas plant and system emissions can go up,” Bull said.
Flint Hills offered the state clear evidence on how CHP would reduce overall carbon emissions by allowing for a larger plant, he added. Next year CHP advocates hope to propose legislation that would remove some policy roadblocks to expanding such plants in the state, he added.
Another cogeneration project at the University of Minnesota is expected to begin operating later this year. The $96 million plant, which will produce roughly half the power of Flint Hills, is considered a key development in the university’s effort to reduce carbon emissions.
CHP advantages at Flint Hills
The Flint Hills refinery requires roughly 120 MW of power, 24 hours a day to operate, Reint said. Xcel Energy will continue to provide the bulk of that baseload energy with the CHP handling the rest. The advantages of onsite power include no loss of power from transmission lines, which Flint Hills estimates at 7 percent from energy transported from Xcel, he said.
“We’ll still be a big customer of Xcel, but this will give us around 40 percent of the energy required,” he said. “We think this will be one of the most efficient CHPs in Minnesota because of how far the technology has come along. This will make our whole refinery more efficient.”
Without offering specific numbers, introducing cogeneration into the refinery’s energy mix will result in a “fairly significant reduction in greenhouse gas emissions,” Reint said. “If you put it squarely against a coal plant, the reductions are quite dramatic. If you just take the grid average, it’s still a pretty healthy reduction because you’re using cleaner natural gas.”
The plant’s CHP system will also be cooled by air condenser technology rather than the more traditional water-based system, an approach expected to save hundreds of thousands of gallons of water a day, Reint said.
In addition, the CHP can take steam already created in the refinery process and re-use it. “This allows us to take that wasted energy and repurpose it for electricity,” Reint said. “You end up demanding less of the overall system, which benefits ratepayers and the environment alike.”