Better living through Biochar?
I’ve been reading more and more about biochar (or agrichar, as it is sometimes called) and I think the subject merits a post.
Biochar has all the makings of a great story and, perhaps, a really great solution to several serious issues – a fabulously low-tech process with a rich and exotic history offers the potential to reduce carbon emissions, improve soil fertility and mitigate agricultural wastes all at the same time. I smell a book deal!
Instead of simply burning biomass (and subsequently releasing all of the stored carbon into the atmosphere), biochar is created through a process known as pyrolysis.
Pyrolysis essentially vaporizes the biomass in the absence of oxygen at low temperatures into three main components: gas (methane and hydrogen), a renewable “bio-oil†(a mix of oxygenated hydrocarbons), and a char that contains more than half of the carbon contained in the biomass.
This char is similar to activated charcoal and is considered highly stable, as well as resistant to chemical breakdown – thereby achieving long-term carbon sequestration. When mixed into topsoil, biochar increases the retention and availability of nutrients and moisture, with the added benefit of increasing microbial activity and soil porousity.
The use of this char as a natural soil additive would have the added effect of reducing the need for man-made fertilizers that currently contribute to marine dead zones via nitrogen- and phosphorous-rich agricultural runoff.
Perhaps most interesting of all, is that the use of biochar dates back hundreds, if not thousands of years to the terra preta of the Brazillion Amazon. In those days, pre-Columbian Indians would cover their fields with the charred remains of their agricultural and day-to-day wastes. This practice boosted the carbon content of these soils from 0.5 percent to 9 percent so that even today, these Amazonian soils are fertile enough for active tilling.
Further investigation into biochar seems warranted and promising. Several companies and universities (Eprida, Best Energies, Dynamotive Energy Systems, Cornell, UGA and Iowa State) are currently investigating and developing biochar production projects and the first ever Agrichar International Conference recently took place in New South Wales, Australia.
I’m certainly interested in what comes out of the biochar idea and relish the thought of adapting anachronistic solutions to today’s complex problems. I would like to see more of these nuanced, low-tech approaches given ample thought in the broadening cleantech space. Biochar may turn out to be a crucial part in the “silver buckshot†strategy of solving several pressing global ills at once.
Considering the global demand for agricultural fertilizer and carbon sequestration, as well as the prospect of producing another source of hydrocarbons from multiple feedstocks, biochar seems well suited for several rounds of financed research and development – especially when you consider that it can bolt on nicely to most existing biofuels operations that generate biomass.
Curtiss P. Martin is ScribeMedia.Org’s Cleantech editor. He can be reached at cleantech [at] ScribeMedia [dot] org.
Now an NYC refugee, Curtiss P. Martin serves as a contributing editor of all things clean and green at ScribeMedia. When he isn't out on the road or in the field researching and reporting on controversial science and tech topics, Curtiss can be found communing with the creative kids at the Elsewhere artist collaborative in Greensboro, NC.
Wow, fascinating! I love processes like this that link different problems and solutions together. It reminds me of those developments they are building in Switzerland and elsewhere, where the byproduct of one processing plant is pumped directly next door to another plant, which then uses that material as its feedstock to make something else, down the line.
This char sounds more promising than the ideas to simply pump CO2 into aquifers in the ground. That kind of thing always sounded really dubious to me. I assume with chars, the carbon gets taken up by living things slowly over time?