NC State Researchers Work to Make Wood a New Energy Source

Is wood the new coal? Researchers at North Carolina State University think so, and they are part of a team working to turn woodchips into a substitute for coal by using a process called torrefaction that is greener, cleaner and more efficient than traditional coal burning.

During torrefaction, woodchips go through a machine

The torrefied wood is lighter than the original woodchips but retains 80 percent of the original energy content in one-third the weight. That makes them an ideal feedstock for electric power plants that traditionally use coal to generate energy for businesses and residential neighborhoods.

While the process of torrefaction is nothing new, NC State’s particular torrefier machine, called the Autothermic Transportable Torrefaction Machine (ATTM), is field portable and self-heated. Traditional torrefier machines are bulky and immobile, but the ATTM lends itself to field-based operations, which reduces the cost of transporting tons of woody biomass to and from the combustion facilities. The ATTM is also largely self-powered, producing a large energy return while also removing carbon from the atmosphere.

Hopkins explains that nearly half of the state’s forests are not adequately thinned because landowners lack a market for small diameter trees, rotten or unusable trees and logging residue. That land could be producing more valuable wood products if it was managed more effectively, he says

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