Krumdieck on biochar

The idea of turning plantation forests into charcoal then burying it as a way to sequester carbon and reduce the load on the atmosphere has been floated for a long time now. Dr Susan Krumdieck, (Sensible Susan, I call her - in my mind :-) 

Director, Advanced Energy and Material Systems Lab 

Associate Professor, Department of Mechanical Engineering

University of Canterbury 

,gives her (sensible) view, which interestingly, dovetails tidily with that of Geoff, our local expert in the field.

"As an energy engineer I find the biochar concept to be loopy.

 Here are the points:

 1. New Zealand plantation forestry is in no manner sustainable. It has been shielded from scrutiny by sustainable forestry certification because it does not sell lumber of high enough quality to get into USA, Europe and Canada markets. It is a biodiversity, watershed, and ecological disaster. Therefore, basing a future political decision on a past political mistake is not good for society.

 2. Making charcoal (biochar is a new marketing of charcoal) requires high grade thermal energy (high enough temperatures to do many other useful things like boil steam). Charcoal is a higher grade fuel than wood, so the energy investment is warranted when you need a higher temperature, lower bulk, lower emission fuel.

 3. Burying a perfectly good fuel in the ground to sequester carbon is nutty. Particularly if it is to "offset" the carbon produced by digging a fuel out of the ground and burning it. Nutty. 

 4. Pelleting the wood rather than pyrolysis is a much more energy positive approach to waste wood. 

 5. There is not enough wood in the world to make a dent in offsetting carbon emissions from coal and oil. Remember, Europe and the USA have already cleared their native forests and largely to make it into charcoal to run industry. 

 6. The thermal processing of wood to charcoal (pyrolysis) is very polluting if done in the "natural" smouldering way and requires heavy engineering if done in an industrial way. The costs of this are going to vastly exceed the costs of using less fossil fuel by improved efficiencies.

 

My pronouncement = LOOPY

Can we move on? 

 Cheers 

 Susan Dr. Susan Krumdieck Director, Advanced Energy and Material Systems Lab 

Associate Professor, Department of Mechanical Engineering

 University of Canterbury

 Christchurch 

New Zealand +64 3 364 2987 extn. 

7249 www.aemslab.org.nz

 www.signsofchange.org.nz