For some years now I've been keen about using charcoal as a soil amendment. The fact that it is a durable form of carbon in soil was a plus since it would accumulate over time rather than dissipating like the vast majority of organic carbon. The more you dosed a field the better it got. Obviously there's some upper limit, but many tons per acre could usefully be added.

A tertiary benefit is that this in effect sequesters carbon drawn from the atmosphere by plants. The carbon in organic materials that would otherwise have been burned as wastes - quickly in fire or slowly by bacteria - would be captured for centuries or perhaps millennia.

Unfortunately, climate nutters glommed onto the idea and touted it as the solution to the worrisome increase of atmospheric CO2 concentrations. They zealously inflated the idea, proposing massive projects funded by rents from various tax schemes. The resultant backlash by more careful thinkers and the politicization of the idea has obscured the utility of the notion, but some have stuck to the knitting and seem to be making progress.

The re:char team is developing a low-cost mobile pyrolyzer to burn agricultural biomass waste and turn it into biochar, which acts as a fertilizer, in addition to sequestering carbon dioxide. The unit also produces bio-oil, a hydrocarbon fuel that can be used as heating oil, run a diesel engine, or burned to power a microturbine and generate electricity. Technology like re:char's may soon help small, remote farms increase crop growth, generate energy and survive off the grid in one fell swoop. . .

The current prototype can process up to a ton of biomass per day, running full time. Half of the output is bio-oil, thirty percent is biochar, and the rest comes out as gases that are fed back through the system and react further to make more hydrocarbon vapor. . .

Large-scale stationary pyrolyzers are already available on the market, but these are expensive and have a lot of moving parts, which means there are more places where they can break down. Biomass has to be transported to these units, rather than the other way around, which increases carbon output. As far as mobile pyrolyzers go, there are others available. But re:char's design is currently the only small-scale mobile pyrolyzer that makes both biochar and bio-oil. . .

Early-stage projects are already underway. Researchers at the University of Michigan are working with re:char to test a prototype based on Aramburu's design, and a working prototype on a small farm in Norfolk, Connecticut processes waste wood from trees that were destroyed in an ice storm last winter.

I hope that the charcoal fever passes and the zealots and rent seekers move on to the next big fantasy, something like has happened with biofuels in general, but without the over the top aspects. I hope that agricultural researchers continue to increase our knowledge about the use of char as a soil amendment and that engineers and entrepreneurs develop production systems so that one day a char/fuel/power unit of some sort will be as common as wood stoves and compost piles on the farm.

I see this as an aspect of the issues discussed earlier in Fertility Tech - the lack of recent progress in formulations and manufacturing systems for fertilizers. It has been 40 years since most of our current fertilizer technology was developed at the Tennessee Valley Authority. It is important to note that the manufacturing processes are just as important as the fertilizer itself. The same issues apply to the production and use of char. We need better understanding of the properties of chars produced from various materials in various ways, and efficient systems for producing them.