29
Role of Water in Recovery and Production of Raw Fuels
While the uranium concentration in sea water is low at 3.3 mg per cubic meter of
seawater, the total amount is large. Several countries such as the United Kingdom,
France, Germany, and Japan are exploring the recovery of uranium from the seawater using inorganic adsorbents such as titanium oxide. Japan is also exploring the
production of adsorbents by irradiation of polymer fiber. Uranium adsorption by the
polymer adsorbent is about ten-fold high compared to that of conventional titanium
oxide adsorbent. In 2012, Oak Ridge National Laboratory (ORNL) researchers
announced the successful development of a new adsorbent material dubbed “HiCap”
that vastly outperforms the previous best adsorbents. They showed that their adsorbents can extract five to seven times more uranium at uptake rates, which are seven
times faster than the world’s best adsorbents. HiCap also effectively removes toxic
metals from water.
2.5.4 CoAl mining And PrePArATion
While coal mining also requires significant use of water and produces acid drainage
that can affect local aquifers, the large use of water in the coal industry is also in
the coal preparation plants [40]. Coal preparation plant requires washing, crushing,
and removal of various impurities from coal. One area where significant water is
used is in the removal of inorganic sulfur (iron pyrites) from coal by the floatation
process. In this process, finely pulverized coal goes through a floatation process in
which iron pyrite particles are removed from coal by gravity separation due to the
density difference between pyrites and coal particles. The removal of sulfur, other
impurities (like ash), and metals is important for the downstream operations for coal.
For example, once the coal is finely pulverized and all ash and metals are removed,
coal-water slurry becomes an important fuel for combustion purposes. The subject
of coal-water slurry combustion is discussed in Chapter 5. The conversion of coal to
oil by direct or indirect coal liquefaction processes also uses a significant amount of
water. For 50,000 barrels per stream day (BPSD), water requirement can vary from
7,300 to 10,500 gallons per minute (GPM) depending on the nature of coal. For
coproduction of Fischer–Tropsch (FT) liquids plus electric power of 25,000 BPSD
and 1,250 MW plant, water requirement can be 20,800 GPM [40].
reFerenCes
1. Duda, J., “Emerging issues for fossil energy and water-investigation of water issues
related to coal mining, coal to liquids, oil shale, and carbon capture and sequestration,”
DOE/NETL-2006/1233 (June 2006).
2. “Water’s growing role in oil and gas,” Global Water Intelligence (Market Profile), 12 (3),
2–8 (2011).
3. “Coal bed methane,” Energy Justice Network, Report published by Oil and Gas
Accountability Project (2012).
4. Rice, D. and Nuccio, V. Water Produced with Coal Bed Methane. USGS Publication, US
Geological Survey, Denver, CO (1999), http://pubs.usgs.gov/fs/fs-0156-00/fs-0156-00.pdf.
5. Kumar, H. and Mathews, J., “An overview of current coal bed methane technologies,”
Report from EMS Energy Institute, Pennsylvania State University, University Park, PA
(2010).
Role of Water in Recovery and Production of Raw Fuels
While the uranium concentration in sea water is low at 3.3 mg per cubic meter of
seawater, the total amount is large. Several countries such as the United Kingdom,
France, Germany, and Japan are exploring the recovery of uranium from the seawater using inorganic adsorbents such as titanium oxide. Japan is also exploring the
production of adsorbents by irradiation of polymer fiber. Uranium adsorption by the
polymer adsorbent is about ten-fold high compared to that of conventional titanium
oxide adsorbent. In 2012, Oak Ridge National Laboratory (ORNL) researchers
announced the successful development of a new adsorbent material dubbed “HiCap”
that vastly outperforms the previous best adsorbents. They showed that their adsorbents can extract five to seven times more uranium at uptake rates, which are seven
times faster than the world’s best adsorbents. HiCap also effectively removes toxic
metals from water.
2.5.4 CoAl mining And PrePArATion
While coal mining also requires significant use of water and produces acid drainage
that can affect local aquifers, the large use of water in the coal industry is also in
the coal preparation plants [40]. Coal preparation plant requires washing, crushing,
and removal of various impurities from coal. One area where significant water is
used is in the removal of inorganic sulfur (iron pyrites) from coal by the floatation
process. In this process, finely pulverized coal goes through a floatation process in
which iron pyrite particles are removed from coal by gravity separation due to the
density difference between pyrites and coal particles. The removal of sulfur, other
impurities (like ash), and metals is important for the downstream operations for coal.
For example, once the coal is finely pulverized and all ash and metals are removed,
coal-water slurry becomes an important fuel for combustion purposes. The subject
of coal-water slurry combustion is discussed in Chapter 5. The conversion of coal to
oil by direct or indirect coal liquefaction processes also uses a significant amount of
water. For 50,000 barrels per stream day (BPSD), water requirement can vary from
7,300 to 10,500 gallons per minute (GPM) depending on the nature of coal. For
coproduction of Fischer–Tropsch (FT) liquids plus electric power of 25,000 BPSD
and 1,250 MW plant, water requirement can be 20,800 GPM [40].
reFerenCes
1. Duda, J., “Emerging issues for fossil energy and water-investigation of water issues
related to coal mining, coal to liquids, oil shale, and carbon capture and sequestration,”
DOE/NETL-2006/1233 (June 2006).
2. “Water’s growing role in oil and gas,” Global Water Intelligence (Market Profile), 12 (3),
2–8 (2011).
3. “Coal bed methane,” Energy Justice Network, Report published by Oil and Gas
Accountability Project (2012).
4. Rice, D. and Nuccio, V. Water Produced with Coal Bed Methane. USGS Publication, US
Geological Survey, Denver, CO (1999), http://pubs.usgs.gov/fs/fs-0156-00/fs-0156-00.pdf.
5. Kumar, H. and Mathews, J., “An overview of current coal bed methane technologies,”
Report from EMS Energy Institute, Pennsylvania State University, University Park, PA
(2010).