A recent symposium (EACU) at the University of Georgia in Athens, GA, USA brought together a group representing scientists from chemistry, archeology, physics, anthropology, microbiology, soil scientists, agronomists, renewable energy research, and representatives from DOE, USDA and industry. The focus was to look at the evidence for massive historical carbon utilization, current research and how carbon
negative energy could be economically deployed today. (www.georgiaitp.org/carbon)
The ability to consider agricultural carbon applications arises from the fact that up to one half of the carbon in our cropland soils has been lost due to intensive agriculture and human induced degradation.
The initial phase of the meetings started with a review of the current knowledge of man made soils called terra preta occupying an area of the Amazon that total to twice the size of Britain. Carbon was added to these soils in the form of a low temperature charcoal. Using low intensity smoldering fires created these charcoals. By analysis, we can tell that they were created 1000-2000 years ago and were part of a soil management practice designed to take a yellow clay soil of limited biological productivity and convert it into some of the richest soil in the world. A thousand years after its creation it is so well known in Brazil, that it is dug up and sold as potting soil.
Dr. Ogawa, from Kansai Environmental in Japan, a division of Kansai Power the 2nd largest electric producer in that country, presented their research on charcoal addition to the soil. Their work, which has been ongoing for more than 15 years, has been studying the causes of the charcoal effect and led to thee Japanese government approving charcoal as an official land management practice. The impact of many
studies in Brazil to Thailand to Japan, showing increased crop yields of 20-50% and total biomass yields increasing as much 280%, led Kansai Electric to fund a reforestation research plantation in Australia with Dr. Syd Shea for producing charcoal and returning it to grow more trees and crops in the arid west of that country.
Low temperature woody charcoal (not grass or high cellulose) has an interior layer of bio-oil condensates that microbes consume and is equal to glucose in its effect on microbial growth (Christoph Steiner, EACU 2004). High temp char loses this layer and does not promote soil fertility very well. Tests by Finnish researcher Janna Pitkien, on highly porous materials like zeolite, activated carbon and charcoal
show that microbial growth is substantially improved with charcoal (opposite to her expectations). Evidence of terra preta's ability to grow and sequester more carbon was undercovered by soil scientist William Woods (U.Illinois). The work is still under investigation in Brazil by over the last 20 years mining terra preta for potting soil
has not decreased its availability. Farmers have learned it recovers a centimeter per year. The possibility those small fractions of char continually migrate down, providing housing for microbes as they process surface-cover biomass. The microbes and fungi live and die inside the porous media increasing its carbon content. What are the limits, we do not know but work at Cornell under the guidance of Johannes Lehman and W. Zech, Bruno Glaser at the University of Bayreuth (Germany) and Emprapa (Manus, Brazil) are investigating these phenomena.
What we know now is that the properly prepared charcoal can increase crop yields and sequester carbon for thousands of years (5000 years is an estimate by Dan Gavin, charcoal dating researcher.(U. of Ill). Its properties can allow even more carbon to be sequestered with more biomass growth and soil carbon from microbial-fungi proliferation.
The economics of this type of carbon utilization can be very simply viewed as the use between carbon-oxygen conversion for energy (ie burning) or its use as a soil amendment. Our estimates using coal as a comparison, at $1.50/MBTU, showed that at 1000lbs/acre with direct injection would be alternately using 10MBTU of carbon in a sequestered form or $15/acre even at double these rates a small increase in crop
yields and decreased fertilizer use produce a positive economic gain for the farm and for future generations are topsoils are restored. Add carbon credits and positive environmental impacts and the rewards justify what a few of us are calling a global Manhattan project of climate change.
But this is just half the story. In 2002 we demonstrated the production of this charcoal from 50kg/hr of biomass while simultaneously producing hydrogen in pilot scale equipment (www.eprida.com ) One of the largest uses of hydrogen today is
for food production via its conversion to ammonia. A demonstration in October 2002 for the use of this charcoal to create a scrubbing system exhaust for CO2, (&, SOx, NOx) (Patent US AP#20040111968 ) while producing a nitrogen fertilizer provides a technique for producing a off gas stream of hydrogen and CO which can be processed into
hydrogen, ammonia and diesel. The efficiency of this system is enhanced by the combination of exothermic and endothermic processes. The conversion of 40% of the hydrogen to ammonia for creating a sequestering carbon value added product leaves a 2.7 moles of H2 to 1 of CO meeting the requirements for a Fischer-Tropsch biomass
conversion process to produce a carbon negative diesel. The resulting carbon sequestration off sets the CO2 produced from the diesel by more than two to one.
If additional biomass or microbial biomass growth is added, and/or the replacement of some non-renewable streams, the impact is substantial.
The questions arise as to the availability of biomass and the areas for usage of this type of soil amendment/fertilizer. On available biomass, (there is a good diagram of this prepared by Michael Obersteiner of the International Institute for Advanced Systems Analysis, Austria) found in the July 7th DC luncheon presentation. "Cutting-Edge Biomass Technologies For Mitigating Acute Climate Change " www.eprida.com/hydro/ecoss/presentations/symposiums.htm
The net is that using current biomass production (in the future we will have much more as we restore our worlds topsoil with essential carbon) we have the capability to go carbon negative today. As we make the switch, it will need to be a global effort as positive feedbacks are kicking in and will likely accelerate.
What about areas for use? Considering the 6.1 gigatons of CO2 accumulation, we would need to utilize this land and biomass production technique on only 10% of the total of biologically productive and human degraded lands per year to attain carbon negative status. If we added desert lands for reclamation the number declines
further. Is is a big number, yes, but it is doable and a culture from 2000 years ago clearly understood its value then. Considering that the majority of new emissions will come from developing countries, what ever we choose, needs to be simple and profitable.
What can you do? Read up on terra preat (some of the published works made a part of the above patent application), look at references in the Eprida website or convince yourself by testing. Grow your favorite plant in two pots, one with 1/3 wood charcoal (soak this in fertilizer for several days), 1/3 sand and 1/3 available soil. Plant the other
with your normal method for potting plants. Fertilize and watch them grow. Watch it for three seasons and note the differences. (Many have noted their best results in the second year as microbial populations increase) Alternately, use a microbe/fungi inoculation to speed the response.
Then tell everyone you know. Even if we can't stop avoid the climate shift we will begun to build an awareness of a solution. If we broaden the understanding that we can produce carbon negative fuels, scrub fossil fuel exhaust of pollutants and C02, reverse the effect of our mining the soil, depleting soil carbon, trace minerals and losing agricultural productivity then we will effect many generations to come. In our lifetime, a 2000-year-old secret is being reborn and its timeliness could never have been more appropriate. It now up to this generation to embrace a plan to work with nature to restore lost soil carbon and rebuild the incredible life at work in our soils. Working together, we can achieve the possible.