A forest with beetle-killed trees as seen from Mt. Fraser, British Columbia. Photo: The Mighty Quill
We've all seen it across the West - entire landscapes covered in the red blanket of beetle killed trees. The mountain pine beetle has destroyed more than 40 million acres of forest in the western United States. (that's about the size of the state of Washington!) Unfortunately, harvesting the wood for lumber is out of the question because the beetle infestation stains the wood and causes the tree to crack on the inside.
A University of Washington team has made new headway on a solution to remove beetle-killed trees from the forest and use them to make renewable transportation fuels or high-value chemicals.
Bio oil made from dead trees. Photo: University of Washington.
Using a method called “fast pyrolysis,” the process involves heating small pieces of organic material in an oxygen-free chamber at about 500 degrees Celsius, until the solid material becomes a vapor. As the vapor rises and moves into other chambers, it cools and becomes a dark brown liquid fuel. Scientists call this “bio oil,” and it is already used in some European countries for heating hospitals.
Researchers, including the UW team, currently are testing whether this bio oil can be upgraded by adding catalysts to convert it into transportation fuels that resemble gasoline and diesel.
The beetle-killed trees are a good fit for making bio oil because the entirety of a tree becomes extremely dry when it is killed by an infestation. That makes for a simpler fast-pyrolysis process, because it isn’t necessary to first dry the wood before heating it to extreme temperatures.
The researchers say this method could be used in mobile pyrolysis units so dead trees can be processed on site, saving on transportations costs associated with tree removal.