As a followup to this, I should note that the wood-driven vehicle conversions I referred to don't stop the combustion process at just the right point for biochar but actually burn the stuff down to ash. So this process is properly "gasification" rather than "pyrolysis." As far as I can tell, the difference between the two is a matter of how far the process is allowed to go, but clearly the biochar-producing power plants I was fantasizing about will be a good deal more complicated than the simple wood gasification units that were deployed in WW2.
It still amazes me that you can run an ordinary gasoline engine on wood chips, though. Jon Jon Bosak wrote: > Thanks to Elan for forwarding the "Birth of a New Wedge" article. > Figuring out the carbon accounting is the next step in the growing > terra preta movement we first noticed last year. This is indeed > an inspiring development. > > Biochar is one of two unalloyed pieces of good news to come out of > 2007, the other being the finding that organic farms can be as > productive per acre as conventional farms (albeit much more > labor-intensive). This means that in theory we can decouple food > production from synthetic fertilizers -- a lucky thing for us, > since such fertilizers are created from natural gas, the North > American production of which has been declining for several years > now. The much greater input of hand labor required for organic > farming at this level of intensity suggests that most of us will > eventually have to spend at least part of each day involved in > individual or team-oriented food production -- a small price to > pay when you consider the alternatives. Besides, it's good for ya. > > Biochar is almost magic, and to my mind the most believable > technical fix so far proposed for greenhouse gas reduction. It's > a biomass energy production scheme with a carbon *negative* > byproduct that also appears to be the world's best long-term soil > amendment. So the more energy you extract this way, the more > carbon you sequester from the atmosphere and the more productive > (over a number of years) you make the soil.... which makes the > biomass grow better. This circle almost seems to contradict the > laws of physics, but really all that's going on is an efficient > and intelligently directed use of the sunlight falling on the > growing area. > > Here's a technofix vision for you: a farm tractor run off gases > generated by a wood-chip or grass-pellet pyrolizer (which requires > minimal modification to the engine itself), the carbon-rich > biochar from the pyrolizer fed out directly onto the land as a > long-term soil amendment.... > > A member of last year's peak oil discussion group showed how > easily he converted his mom's pickup to run on a wood-chip > pyrolizer. It's not rocket science; anyone with a welding kit > could do this. During WW2, conventionally powered vehicles all > over the world were retrofitted with locally made pyrolizing gas > generators. It shouldn't take long to engineer pyrolizers that > eject the leftovers at just the right point now that we know what > we're looking for. This would never produce enough gas to run our > current transportation system, but it could certainly produce > enough to keep some tractors running. > > We haven't gotten much really good news on the energy descent > front in recent years, but the prospect of a believable carbon > sequestration scheme that also provides enough to eat and some > farm machinery to help out finds me much cheerier going into 2008 > than I was going into 2007. Now if we can only teach our leaders > the concept of long-term planning.... > > Jon > > Elan Shapiro wrote: > > Birth of a New Wedge > > By Kelpie Wilson > > t r u t h o u t | Report > > > > Thursday 03 May 2007 > > http://www.truthout.org/docs_2006/050307R.shtml > > >>>Also see other articles on Biochar , or Agrichar, in this > > listserve last May, when this article came out > > > > ... Agrichar is the term not for the biomass fuel, but for what is > > left over after the energy is removed: a charcoal-based soil > > amendment. In simple terms, the agrichar process takes dry biomass of > > any kind and bakes it in a kiln to produce charcoal. The process is > > called pyrolysis. Various gases and bio-oils are driven off the > > material and collected to use in heat or power generation. The > > charcoal is buried in the ground, sequestering the carbon that the > > growing plants had pulled out of the atmosphere. The end result is > > increased soil fertility and an energy source with negative carbon > > emissions. > > > > > > _______________________________________________ > RSS, archives, subscription & listserv information for: > [email protected] > http://lists.mutualaid.org/mailman/listinfo/sustainabletompkins > free hosting by http://www.mutualaid.org > > _______________________________________________ RSS, archives, subscription & listserv information for: [email protected] http://lists.mutualaid.org/mailman/listinfo/sustainabletompkins free hosting by http://www.mutualaid.org
