PacifiCorp confirmed this week it’s moving ahead with a plan that could ultimately retire the iconic smokestacks of its Dave Johnston Power Plant seen to the north while driving between Glenrock and Casper, Wyoming.
The energy experts contacted by Cowboy State Daily offered a range of opinions about the novel oxy-combustion technology and carbon sequestration plans unfolding at the Dave Johnston plant.
“The project is a new generation resource that inherently captures carbon,” said David Eskelsen, spokesperson for PacifiCorp, the parent company of Rocky Mountain Power.
Eskelsen said the utility is focusing on the Dave Johnston location as it moves forward with a partnership involving Siemens Energy, the design and engineering firm Wood and 8 Rivers, which developed what it deems an emissions-free way of burning coal.
The 8 Rivers innovation uses pure oxygen to burn hydrogen and carbon monoxide generated from coal, and this process creates a stream of pure carbon dioxide.
This CO2 is then recirculated through a new type of turbine that will not need smokestacks to release emissions.
8 Rivers CEO Damian Beauchamp told Cowboy State Daily, “If you burn any fossil fuel with pure oxygen, all you get is CO2 and water. And so, the innovation was to take the CO2 from the exhaust and continually recycle it in the system.”
But does this technology really work?
Holly Krutka, executive director at the University of Wyoming’s School of Energy Resources, said she is optimistic and interested to see how it all plays out at the Dave Johnston Plant.
“In my former role at Peabody (Energy), we supported this technology and I have been watching it advance for many years,” said Krutka, former VP of coal generation and emissions technologies at Peabody. “It is exciting they are looking to Wyoming as a potential first site.”
Krutka also cautions, “This is a developing technology, so there are no guarantees, but it is absolutely worth trying. Notably, 8 Rivers invented a similar technology for natural gas, so they have credibility from my perspective.”
What Happens To The CO2?
PacifiCorp announced this week that, “8 Rivers is working to advance a solid fuels Allam-Fetvedt Cycle (AFC) power project.”
“The AFC uses CO2 instead of steam to drive a turbine generator to produce electricity,” according to PacifiCorp. “The cycle also captures CO2 as part of the process that then can be either permanently sequestered or utilized in applications such as enhanced oil recovery.”
PacifiCorp noted the work happening at Dave Johnston, “Is still in the feasibility phase, so a decision to build the facility has yet to be made.”
Cowboy State Daily reached out to Dr. Robert Morris, Lance Energy chair at Montana Tech University, to get his take on 8 Rivers and the idea of adding pure oxygen to the combustion process.
“The question then becomes, what to do with the CO2?” asked Morris. “The present choices are carbon sequestration, which involves injecting it in underground reservoirs. This is presently a prohibitively expensive process.”
Morris said he recognized some oil and gas companies use CO2 for enhanced oil recovery, “so there is an opportunity to defray the sequestration expense by using it for enhanced oil recovery. I know a few companies are experimenting with this.”
Prior cost studies for technologies that lower emissions at coal-fired plants came with a price tag in the hundreds of millions of dollars, said Morris.
An example in Montana is the Colstrip coal-fired plant, he said. It provides more than half of the state’s energy, and without a recent executive order from the Trump administration, the plant was looking at a roughly $500 million expense to achieve emissions compliance.
“At that cost, the Montana ratepayers cannot afford the extra cost to our electric supply,” said Morris. “Perhaps the 8 Rivers team has identified ways to reduce the carbon sequestration expense. If so, the technology would hold promise.”
Is Sequestering A Good Idea?
The oxy-combustion technology 8 Rivers is looking to develop for the Dave Johnston plant is part of a growing body of research and tech, said Dr. Erin Baker, distinguished professor of industrial engineering at the University of Massachusetts-Amherst.
“I believe it is possible, at least theoretically,” said Baker, who offered caution about the notion that what 8 Rivers is developing will become, as the company describes it, “a silver bullet” to solve the problems that come with burning coal to produce electricity.
“Some important points are that it would not be pollution-free. Coal is still very dirty,” said Baker, conceding that perhaps the pollution would no longer be airborne, but “water and soil would still be at risk.”
“Another point is that we have finite storage space for CO2,” said Baker, citing work by Emily Grubert at Notre Dame University.
Grubert argues that whatever CO2 sequestering storage space is available “should be reserved for hard-to-abate” industries like those producing cement, chemicals and steel.
Finally, Baker took aim at the notion that the 8 Rivers technology will transform Dave Johnston into a power plant capable of producing truly “dispatchable” energy.
“This may be true, but it is not clear to me how flexible it will be; that is, how much it will be able to ramp up and down to follow demand,” said Baker. “It may act more like nuclear power than natural gas or hydro.”
8 Rivers CEO Damian Beauchamp is ready with an answer and sales pitch.
When it comes to the technology his company is developing at the Dave Johnston plant, “There's kind of a tangential benefit that you’ll be able to utilize coal, have no particulate emission and now eliminate the CO2,” he said.
David Madison can be reached at david@cowboystatedaily.com.
