COAL Peat (Scotland) Earth During the Carboniferous Period,
Million yrs ago North America 300 million years ago Ancient Swamps
Carboniferous plants Ancient Swamps Ex/ Coal World reserves of coal
= ~1 trillion metric tons World use of coal = ~7.7 billion metric
tons/year COAL Difference between Reserves and Resources World Coal
Consumption = ~8 billion metric tons/yr World Coal Production = 7.7
billion metric tons/yr Coal Exports Coal Imports Changing Cost of
Coal: Affected by Natural Gas Availability Coal use dates back 5000
years Used extensively by Romans Major use in England in 1200s;
start of underground mining In 1700, 5/6 of coal was mined in
England Led to Englands Industrial Revolution Surface Mining is now
2/3 of US production Globally, 60% is still mined underground
Surface Mining (New South Wales, Australia) Open Pit Mining Open
Pit Mining in India Strip Mining Strip Mine Reclamation (N Dakota):
active mining is lower right, reclamation is upper left. Mountain
Top Removal A critical Augur Mining Modern Underground Mining Coal
Plant, Germany Coal plants are about 35% thermodynamically
efficient, at best. Older grandfathered plants can be much less.
Coal Washing removes soil and rock Removing Soot Integrated
Gasification Combined Cycle Turning coal into coke: Coke is the
solid carbonaceous material derived from destructive distillation
of low-ash, low-sulfur bituminous coal. Coke is used as a fuel and
as a reducing agent in smelting iron ore in a blast furnace. It is
there to reduce the iron oxide (hematite) in order to collect iron.
Existing power generation could capture >95% of carbon in coal
using CCS (CO2 Capture and Storage), also known as Geologic Carbon
Sequestration. The added cost is about 2-4 cents per kilowatt-hour
(~30%)
