preliminary analysis of CO2 emissions
conversion to fertilizer and hydrogen
coal fired Power Plant application
100 million tons of carbon dioxide released annually from a set of
60 fossil fuel power plants.
13.7 million tons or 3.7 million tons of carbon
(13.7% Kyoto Reductions required by Annex
(13.7% Kyoto Reductions required by Annex 1 Countries)
National Renewable Technologies
Laboratory (NREL) and Oak Ridge
National Laboratory (ORNL)
have been separately developing energy and sequestration technologies for
Using direct conversion of flue gas to NH4HCO3, mol wt: 79 would
sequester this amount of carbon with 4.4 million metric tons of nitrogen.
This would be equal to 43% of the U.S. nitrogen consumption and
probably not plausible in very large scale.
ORNL with Eprida/NREL:
Creating a carbon rich fertilizer combining two technologies.
This assumes using biomass to create a leverage of
sequestration. In this
method, the biomass is used to create a sequestered carbon/char (20% by
weight) carrier after removing hydrogen via the process demonstrated
recently in a 50kg/hr experiment in Blakely GA with the NREL biomass to
hydrogen technology. The hydrogen is then used to produce ammonia in
industry standard methods. An advantage of a carbon carrier is that it
allows for the creation of a slow release mechanism as a structural
component of he carbon. Additionally,
it acts as a nutrient reservoir, storing essential nutrients in and around
roots until soil concentrations drop.
This would reduce nitrate run-off and the detrimental effects they
cause to streams, lakes and oceans. The positive aspects of increasing
this type of carbon are in its early stages but over 2000 years ago man
was creating highly productive soils by charring forests and rangeland.
Research work on man-made Brazilian terra preta soils has shown as much as
an 880% increase (Science, August 2002) in the second year plant
productivity with the addition of char.
The characteristics of the char are important and research needs to
be done to quantify differences in manufacture but the benefits are
A slightly active char also provides for farm
chemical runoff protection. Research
work at the University of North Carolina has shown that 200 pounds per
acre could protect even sensitive crops from damage when sprayed with
herbicides. The binding
activity provides the time necessary for chlorinated organics to break
down naturally. A controlled
thermal process releases lower boiling point compounds and creates a
terrestrial carbon reef at a microscopic level. These nanoscale structures
provide safe haven to the microbes that facilitate fertile soil creation,
while sequestering carbon for many hundred if not thousands of years.
The combination of these two forms of sequestration would also
increase the growth rate and natural sequestration effort of growing
plants. According to research at Duke and University of Michigan,
trees growing under the CO2 levels predicted for the future increase
growth rates until reaching a plateau.
The limiting factor was reported to be available nutrients,
specifically the depletion of available nitrogen by the rapidly growing
trees. Efforts that sequester and measurably increase natural
sequestration offer a potential method to leverage investments.
Proven increases in sequestration from land management practices is
another way to achieve reduction targets.
Overview (10% Nitrogen)
A typical 10% nitrogen composite fertilizer made from the sequestered carbon and integrated ammonium bicarbonate would have the following composition.
56.4% ammonium bicarbonate (AB)
This would equal carbon contents of:
8.6% from AB
34.9% from char
(assuming 97% original carbon content)
Totaling 43.5% of ECOSS would be sequestered carbon.
NOTE: A majority of the sequestration comes from biomass. A very positive consequence of this is that it reinforces the sustainable economic roles biomass and renewable resources will play in creating our future. With more farming, and agriculture, we will expand the opportunities that our biosphere can offer.
This sequestered carbon is very stable though research needs to be done to quantify tillage effects that could impact long-term storage. The above percentages can be adjusted to meet market demands and are a starting point for economic considerations.
Below are the breakdowns of component materials necessary to sequester the target 3.7 million tons of carbon for the 60 power plants.
The reality check seems to confirm that it is possible to profitably sequester carbon dioxide. These are rough numbers attributed to US pricing guidelines. Construction costs can vary greatly and where material, land and labor are less expensive, and fossil fuels are not readily available, this solution could prove very cost effective.
Click here for to view a spreadsheet analysis. (This is an interactive spreadsheet. Change the variables and assumptions.)