BYU researchers turn dead trees into biomass fuel
Researchers at Brigham Young University have discovered new ways to turn dead trees into biomass fuel that can be used at coal power plants.
Andrew Fry, associate professor of chemical engineering at the university and researcher, said biomass materials are something the scientific community has been exploring for a while.
With more frequent wildfires, bark beetles killing trees, and the historic drought in Utah, Fry said this project is beneficial in two ways: it decreases wildfire potential by getting rid of the dead trees and it helps curb carbon emissions at power plants.
“This project was very synergistic because we're removing [dead trees] from our forests that make the forests unhealthy,” he said.
He said traditionally, power plants that use renewable biomass fuel have to change their hardware to process it but his team wanted companies to be able to use existing machinery to use their fuel.
“That's a difficult thing to do because biomass, yes, it burns nicely… But in order to burn in a power plant and in most of our typical power plants, it has to be reduced to a fine powder of particles,” he said.
The researchers created the biomass fuel by using two methods — torrefaction and steam explosion — to break down the wood and mix it with some coal.
The torrefaction method heats the material up until it partially combusts. The steam explosion places the biomass into a pressurized vessel with steam that breaks down the wood. The wood is then made into pellets.
They were able to successfully do this and burn 900 tons of biomass mixed with coal for 24 hours at the PacifiCorp Hunter Power Plant located in Emery County, Utah.
However, there are some issues with transitioning from coal-based fuel to biomass. Some scientists have argued that while this option is renewable, it is not carbon neutral; some power plants aren’t equipped to make the transition; and it can be a pricey option. It has also been known to jam factory machines.
David Eskelsen, a company representative for PacifiCorp, said other options are more cost-effective, like wind and solar.
“Every two years we take a look at everything that's out there that could reasonably be used to generate electricity. And we do an economic analysis of it,” he said. “We have biomass projects on our system now that we'll continue to look at. It typically does not score as cost-effective as other resources.”
Fry also acknowledged cost and said they are planning on looking at these aspects in their research. He stressed that biomass made from dead trees should be used only when it makes sense environmentally.
“The challenge with using biomass as a coal replacement is that if you start doing the accounting and the computations to figure out how much fuel is required to meet our energy needs as a society, you find out that you could very quickly and very easily deforest the planet if you were going to rely on biomass completely,” Fry said.
His team plans to keep researching long-term solutions for using this kind of fuel.
Produced with assistance from the Public Media Journalists Association Editor Corps funded by the Corporation for Public Broadcasting, a private corporation funded by the American people.