Science & Technology

Gasification and Biochar: Gearhead Tested, Gaia Approved


Back in the May 2008 issue of Reason magazine I wrote of the adventures and travails of a group of Berkeley-based art-gearheads experimenting with gasification and its resulting biochar as means of transportation, power generation, and perhaps even carbon footprint reduction (and running into some troubles with city government in the process). And in October I tagged along as a gasification vehicle tried to win an alt-fuel road rally sponsored by that same crew.

Those ideas continue to gain currency in the enviro-tech world, and in the January 29 issue of New Scientist, famed Gaia theorist James Lovelock declares gasification and the resultant biochar the potential saviors of the planet:

There is one way we could save ourselves and that is through the massive burial of charcoal. It would mean farmers turning all their agricultural waste—which contains carbon that the plants have spent the summer sequestering—into non-biodegradable charcoal, and burying it in the soil. Then you can start shifting really hefty quantities of carbon out of the system and pull the CO2 down quite fast.

…..The biosphere pumps out 550 gigatonnes of carbon yearly; we put in only 30 gigatonnes. Ninety-nine per cent of the carbon that is fixed by plants is released back into the atmosphere within a year or so by consumers like bacteria, nematodes and worms. What we can do is cheat those consumers by getting farmers to burn their crop waste at very low oxygen levels to turn it into charcoal, which the farmer then ploughs into the field. A little CO2 is released but the bulk of it gets converted to carbon. You get a few per cent of biofuel as a by-product of the combustion process, which the farmer can sell. This scheme would need no subsidy: the farmer would make a profit. This is the one thing we can do that will make a difference, but I bet they won't do it.

Even some strong enthusiasts of localized gasification experimentation on a listserv I'm on are saying Lovelock is far too optimistic about the bio-economy-wide results of mass gasification. Jim Mason, the star of my first gasification story, points out that Lovelock is giving "an opportunistic rendering of the numbers. The actual biomass available for thermal rendering is much smaller than this. We can't claim that the total biomass production on the planet is available for biochar making."

Phil Glau, an active participant in both the original gasification experiments I wrote about in May 2008 and the alt-fuel race, points out that farmers often use that "agricultural waste" Lovelock wants gasified as direct fertilizer and thus might be reluctant to change for sensible reasons, from their pespective. Glau also notes that lots of energy and effort would be involved in collecting that ag-waste into usable, gasifiable quantities, and then in taking that resulting charcoal and putting it back in the fields, making the total energy and carbon-reduction qualities of the system as a whole far less certain than Lovelock's optimistic estimates.

Still, an interesting sign that those wild ideas I wrote about, which struggled for experimental space against Berkeley's bureaucracy are growing in currency, whether or not they will eventually change the world for the better.