Biomass: Climate Unfriendly?
I found it interesting that your article (“Biomass Fuel Foibles ,” December 2007) states that biomass plants will reduce greenhouse gas (GHG) emissions. We own several wood (biomass) plants and yes, sulfur emissions are almost zero, but there is always a NO x problem. NO x can be controlled using urea injection and other technologies. But isn’t the main concern over the emission of CO 2, and don’t biomass plants or any process that combusts fuel produce CO 2 that cannot be controlled?
I think the power industry fogs this issue and ultimately it makes us look bad in the eyes of the environmentally conscious public. Cutting trees and mulching them for fuel doesn’t help the net effect. I believe a lot of biomass plants are supplied with at least some portion of their fuel from trees harvested just to support the plant and not just “waste by products.”
Every present day power producer has its environmental warts. We must keep our eye on the ball, and that is to reduce carbon emissions. This includes planes, trains, automobiles, all types of conventional steam power plants and any other processes that emit carbon units. I feel that biomass plants are no better than any other type of conventional steam power plant in terms of GHG emissions.
— Jerry Schaefer, Manistee, Mich.
The Editor Responds:
Mr. Schaefer’s question has been explored in studies such as NREL’s Biomass Energy Production in California: The Case for a Biomass Policy Initiative (November 2000). Cultivation, harvesting and transportation inputs are important, but for biomass wastes—which comprise the overwhelming majority of power-generation biofuels—the key question is this: how would the biomass be disposed if it weren’t converted to fuel?
Eventually all biomass either burns or decomposes. Decomposition yields methane, a GHG believed to be orders of magnitude more potent than CO 2. So burning biomass in an efficient power plant has less effect on atmospheric warming than does allowing it to rot.
Finally, biomass power reduces total GHG emissions when it displaces fossil power, which every day burns prehistoric biomass that took millions of years to sequester its share of the planet’s carbon. Conversely, one day’s worth of biomass electricity yields CO 2 in amounts much closer to one day’s worth of new plant growth. — MTB