Energy and Changes in the Environment - Hydrogen and Fuel Cells: Advances in Transportation and Power - page 59

Improved furnace designs and combustion techniques could reduce
NO x emissions from stationary sources by 40-70%. These methods are not
in widespread use now. The processes for removing NO x from flue gases
are in an early stage of development.
REDUCING CARBON DIOXIDE
Reducing the amount of CO 2 in the atmosphere could involve
prescrubbing to take the carbon out of fuels before combustion, leaving
only hydrogen to be burned. Another approach is postcombustion
scrubbing which removes CO 2 from the emissions stream after burning.
Among the prescrubbing techniques is the hydrocarb process, where
hydrogen is extracted from coal and the carbon is then stored for possible
future use or buried. Using this process, only about 15% of the energy in
coal is converted to hydrogen for use as fuel in existing coal power plants.
There is also much residual solid coal material to store.
It is estimated that this would cost about $8,000 per capita in the
United States for 300,000 megawatts of generating capacity to replace the
coal consumed in the U.S. for electrical power generation. Post combustion
scrubbing is a well known but largely unapplied technology.
Removing 90% of the CO 2 from the stack gases would cost about 0.5 to
1 trillion dollars or $2,000 to $4,000 per capita. Removing the CO 2 at a power
plant could use up about half the energy output of the power plant.
Pumping the carbon dioxide produced at industrial plants into the deep
ocean is another technique that could reduce and delay the rise of carbon
dioxide in the atmosphere. But, it would not prevent an eventual warming
as some made its way back into the atmosphere. Reforestation could be used
as a carbon bank to capture carbon from the atmosphere, but the decay or
burning of harvested trees decades later would add some carbon.
In 2000, global warming talks in the Netherlands broke down over
carbon accounting. The United States wanted to use its forest areas to
offset some carbon emissions. This type of trading of carbon rights was
the kind of approach that most mainstream environmental groups in the
United States had promoted in an attempt to give business an inducement
to conserve. In Europe, environmentalists have taken a more adamant
stand against industry and looked at it as a plan for evading responsibility
for cleaning up the global atmosphere.
The growing fossil fuel use in the 20th century changed the carbon