Biomass plants run on byproducts, not trees

Regarding the guest opinion in the Mail Tribune on Dec. 4 by Alan Journet about woody biomass not being carbon neutral: If the premise for an opinion is flawed to begin with, the conclusion will be wrong.

If one assumes that live trees are harvested as feedstock for biomass power plants, his argument might hold merit. However, this is simply untrue. Biomass power plants are fueled by the byproduct of forest product primary and secondary manufacturing (bark, chips, sawdust, plytrim), tree and shrub trimmings, recovered clean construction and demolition wood, and the byproduct of forest operations, also called slash piles.

There is a market-driven hierarchy of forest products relative to manufacturing logs from a forest operation. If it’s of sawlog or veneer quality, it’s sold to the sawmill or veneer plant. If it’ll make chips, it’s sold to a chipping contractor or a pulp and paper operation. If it won’t make either due to size or quality, it goes into the slash pile and gets burned, is left to decompose, or is processed into proper sizing and shipped to a consumer of hogfuel. The slash left behind after such an operation represents a very minor percentage of the overall volume.

A significant drawback of open pile burning is that it generates emissions of criteria air pollutants (particulate matter, carbon monoxide, volatile organic compounds and nitrogen oxides), greenhouse gases (GHGs) and air toxics such as polycyclic aromatic hydrocarbons and aldehydes, according to a study conducted in 2015 by the U.S. Forest Service and the University of California at Berkeley. In another study conducted by Placer County in California, comparing the impact of emissions from collecting, processing and transporting biomass for burning in a controlled combustion chamber (boiler) equipped with modern pollution control equipment as opposed to open burning the slash piles showed a 98 percent reduction of particulate matter, a 54 percent reduction of nitrogen oxides, 99 percent reduction of nonmethane volatile organics and a 97 percent reduction of carbon monoxide.

As for the byproduct from forest product manufacturing, much of this material is used in the production of composite panels. If unsuitable for this market, it might be sold to a biomass plant. Harvesting live trees for use as feedstock for a biomass plant does not occur, as it is simply uneconomical. Its value for higher and better uses far exceeds the price of electricity generated if used as feedstock.

Forests managed on a sustainable basis not only remove carbon from the atmosphere and store it in a solid form, but once harvested and converted into lumber, plywood or other wood products, store carbon in wood-framed houses, buildings and furniture, creating balanced levels of carbon cycling into and out of the sustainable forest.

Sustainable, working forests are managed for the long term. Foresters manage stands of trees across multiple age classes. A key element in managing sustainably is to maintain forest growth and harvest in balance. Forests managed in such a manner will be absorbing as much carbon from the atmosphere as is removed through harvesting.

The guest opinion says that designating woody biomass as carbon neutral by the federal government “could stimulate massive deforestation.” This is ludicrous. Harvesting costs alone far exceed the current market price for feedstock used in biomass plants. That simple economic fact would not change, even if woody biomass was deemed carbon neutral by the federal government.

The guest opinion indicates that the Environmental Protection Agency has calculated the social cost of carbon to be $36 per metric ton, subsequently “corrected” to $700 per ton without any explanation of a near 20-fold increase, and then uses this figure to show the cost of carbon from an Oregon Department of Forestry timber harvest. Since very little, if any, of the wood removed from this project was utilized as biomass feedstock, the very calculation is inappropriate and misleading. Let me say this one more time: Live trees are not harvested for use as biomass feedstock.

Biomass power is generated on a baseload basis; available 24/7, 365 days per year. In the case of wind or solar power, if the wind isn’t blowing or the sun isn’t shining, no power is being generated. And by the way, if you remove the subsidies provided to solar and wind, their power production costs increase dramatically. If a person is opposed to burning biomass, I can respect that. Employing misleading information to support the argument is just wrong.

— Todd Hansen is a forester and the fuel manager for Biomass One, a local woody biomass-fueled power plant.

 

 

 

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