Will Burning Biomass With Coal Do Any Good?

A Polish coal plant, which will cofire biomass (burn biomass at the same time as coal) to help reduce its emissions by 25 percent compared with the country’s current coal plants, is due to come online in 2009. A major Polish power group, Poludniowy Koncern Energetyczny, estimates its total cost at €500 million ($735 million).

The power plant, and others like it that combine renewable feedstock with coal, present a new dilemma for green contemplation. The all-investment, all-the-time arm of the green movement believes that we should be throwing money at all viable technologies that could reduce greenhouse gases. So, Vinod Khosla invests up and down the line in ethanol companies because he believes the intermediate steps will help us get to the end goal of second- and third-generation biofuels that are not as bad as corn-based ethanol.

Dropping some biomass into our coal plants, just like ethanol doping our gasoline, will get us a reduction in coal mining and emissions, but raises the question: Will these small steps actually put off the more drastic steps that we’ll need to take to keep our climate on the rails? Or do we need to do something with coal for the next decade, until some type of carbon capture and storage system?

The last president of the American Academy for the Advancement of Science had a brilliant state-of-the-world article adapted from a speech he gave last year in this week’s Science, in which he argued for a truly sustainable approach to the use of land:

We need more studies that combine projected land requirements for food and feed, fiber, biofuels, and infrastructure — rather than pretending that each use can be analyzed separately–and that attempt to reconcile the combined demands with the requirement for enough land covered by intact forests and other native ecosystems to provide the carbon sequestration and other ecosystem services society cannot do without.

Just like with biofuels, we have to ask of biomass for baseload generation: Which feedstock? Where is it grown? How is it grown?

Over at Biopact, a cleantech group lobbying for a green energy pact between Europe and Africa, they run the numbers on one example of a good cofiring feedstock, palm kernel shells grown by Nigerian palm farms. “Palm kernel shells are a waste residue from palm fruit processing; they are easy to ship, don’t need to be densified and can be readily co-fired with coal,” they wrote.

Coal cofired with biomass grown for the purpose might not be a clear winner, but coal burned with waste biomass seems like a pretty good idea. Clearly, technologies like these aren’t going to solve our problems, but by engaging with their design, we can ensure that these intermediate steps are the longest strides possible.


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