CARBON SEQUESTRATION: WHAT'S THE POINT?
[Rachel's introduction: In addition to being pure fiction, "clean coal" is a really dumb idea.]
By Peter Montague
[Rachel's introduction: An earlier version of this essay appeared on Discovery News Dec. 1, 2008. This updated version includes new information, plus documentation.]
Whenever we burn fossil fuels (gasoline, natural gas, oil, or coal) we emit carbon dioxide (CO2) as a waste product.
This waste CO2 contributes to two big problems:
(1) The earth is getting warmer, producing more and bigger storms, more floods, and worse droughts, thus disrupting food production and water supplies. This is serious.
(2) The oceans are growing more acid (CO2 plus water = carbonic acid). Many creatures at the base of the oceanic food chain live inside a thin, hard shell -- and carbonic acid attacks their shell, threatening the base of ocean life. This too is serious.
The ideal solution would be to stop making waste CO2 by phasing out fossil fuels and getting our energy from solar power in all its forms (direct sunlight, wind, and hydro dams). We know how to do this today but solar power remains somewhat more expensive then fossil fuels.
Solar has three big advantages --
(1) the sun shines (and the wind blows) everywhere so it provides "energy independence" for everyone;
(2) using solar emits little waste CO2; and
(3) the supply is endlessly renewable, so we won't run out.
The sun doesn't shine at night but the wind blows at night and a "smart grid" with diverse power storage can keep the energy flowing everywhere 24/7. Today, the sun can provide the "base-load" power we need.
What prevents us from adopting renewable solar power is not the cost; it's the political muscle of the fossil fuel companies (oil and coal). Obviously they want us to keep burning fossil fuels because they're heavily invested.
The people who run these companies aren't dumb -- they know CO2 is a big problem, so recently they devised an end-of-pipe solution: they propose to capture the CO2 and pressurize it until it turns into a liquid, then send it by pipeline to a suitable location and pump it a mile or so underground, hoping it will stay there forever. They call this "carbon capture and sequestration," or CCS for short. To make it sound easy and attractive, they call it "clean coal."
What's wrong with this plan? In a nutshell:
1) The plan entails as many as 100,000 separate CO2 disposal sites in the U.S. alone. This would require creation of a hazardous-waste-CO2 disposal industry as big as, or bigger than, the oil industry.[1]
2) Creating and running an enormous CO2 hazardous-waste disposal industry would roughly double the cost of fossil-fueled electricity. But this would make solar energy cost-competitive, so why not invest in renewable solar power now instead of investing in a dead-end CO2- waste disposal industry?
3) It would take decades to build this huge new CCS industry -- but we need solutions to the CO2 problem soon. Solar power plants can be built much faster than this exp....
4) The coal industry calls coal-with-carbon-capture "clean coal." But in reality coal-with-carbon-capture emits 60 times as much CO2, per kiloWatt of electricity, compared to a wind turbine making the same electricity.
4) CCS itself would require lots of energy. For every four power plants, we would have to build a fifth power plant just to capture and store CO2. This would waste even more coal and oil.
5) Every engineer knows that avoiding waste is far better than managing waste. So CCS is fundamentally bad design. [For example, see the widely-endorsed Principles of Green Engineering.]
6) Instead of solving the CO2 problem that we've created, CCS would pass the problem along to our children and their children and their children's children. Basically buried CO2 could never be allowed to leak back out. We should take responsibility for our own problems, not pass them to our children to manage.
7) Scientists paid by the fossil fuel companies say the CO2 will never leak back out of the ground. What what if they're mistaken? Then our children and grandchildren will inherit a hot, acid-ocean, ruined world.
8) Sooner or later we're going to run out of fossil fuels -- all of them -- so eventually we have to adopt solar power. CCS just delays the inevitable -- a huge waste of time and money. We should skip CCS and go solar today.
==============
[1] If you take just the CO2 from coal (2162.4 million metric tonnes [MMT] in 2007) and compare it to the mass of crude oil produced in the U.S. (258.8 MMT in 2007) plus imported crude oil (512.6 MMT in 2007), you find that CO2 is 8.4 times domestic production, and 2.8 times the combined domestic plus imported. That is mass. In terms of volume, the numbers are larger. If we use 500 kg/m3 [kilograms per cubic meter] as the density of supercritical CO2 (one possible operating point), then 2162.4 MMT of CO2 is 27.2 million barrels, or 15 times domestic oil production, and 5 times combined domestic plus imported oil. Thanks to Earl Killian for these calculations.
[Rachel's introduction: In addition to being pure fiction, "clean coal" is a really dumb idea.]
By Peter Montague
[Rachel's introduction: An earlier version of this essay appeared on Discovery News Dec. 1, 2008. This updated version includes new information, plus documentation.]
Whenever we burn fossil fuels (gasoline, natural gas, oil, or coal) we emit carbon dioxide (CO2) as a waste product.
This waste CO2 contributes to two big problems:
(1) The earth is getting warmer, producing more and bigger storms, more floods, and worse droughts, thus disrupting food production and water supplies. This is serious.
(2) The oceans are growing more acid (CO2 plus water = carbonic acid). Many creatures at the base of the oceanic food chain live inside a thin, hard shell -- and carbonic acid attacks their shell, threatening the base of ocean life. This too is serious.
The ideal solution would be to stop making waste CO2 by phasing out fossil fuels and getting our energy from solar power in all its forms (direct sunlight, wind, and hydro dams). We know how to do this today but solar power remains somewhat more expensive then fossil fuels.
Solar has three big advantages --
(1) the sun shines (and the wind blows) everywhere so it provides "energy independence" for everyone;
(2) using solar emits little waste CO2; and
(3) the supply is endlessly renewable, so we won't run out.
The sun doesn't shine at night but the wind blows at night and a "smart grid" with diverse power storage can keep the energy flowing everywhere 24/7. Today, the sun can provide the "base-load" power we need.
What prevents us from adopting renewable solar power is not the cost; it's the political muscle of the fossil fuel companies (oil and coal). Obviously they want us to keep burning fossil fuels because they're heavily invested.
The people who run these companies aren't dumb -- they know CO2 is a big problem, so recently they devised an end-of-pipe solution: they propose to capture the CO2 and pressurize it until it turns into a liquid, then send it by pipeline to a suitable location and pump it a mile or so underground, hoping it will stay there forever. They call this "carbon capture and sequestration," or CCS for short. To make it sound easy and attractive, they call it "clean coal."
What's wrong with this plan? In a nutshell:
1) The plan entails as many as 100,000 separate CO2 disposal sites in the U.S. alone. This would require creation of a hazardous-waste-CO2 disposal industry as big as, or bigger than, the oil industry.[1]
2) Creating and running an enormous CO2 hazardous-waste disposal industry would roughly double the cost of fossil-fueled electricity. But this would make solar energy cost-competitive, so why not invest in renewable solar power now instead of investing in a dead-end CO2- waste disposal industry?
3) It would take decades to build this huge new CCS industry -- but we need solutions to the CO2 problem soon. Solar power plants can be built much faster than this exp....
4) The coal industry calls coal-with-carbon-capture "clean coal." But in reality coal-with-carbon-capture emits 60 times as much CO2, per kiloWatt of electricity, compared to a wind turbine making the same electricity.
4) CCS itself would require lots of energy. For every four power plants, we would have to build a fifth power plant just to capture and store CO2. This would waste even more coal and oil.
5) Every engineer knows that avoiding waste is far better than managing waste. So CCS is fundamentally bad design. [For example, see the widely-endorsed Principles of Green Engineering.]
6) Instead of solving the CO2 problem that we've created, CCS would pass the problem along to our children and their children and their children's children. Basically buried CO2 could never be allowed to leak back out. We should take responsibility for our own problems, not pass them to our children to manage.
7) Scientists paid by the fossil fuel companies say the CO2 will never leak back out of the ground. What what if they're mistaken? Then our children and grandchildren will inherit a hot, acid-ocean, ruined world.
8) Sooner or later we're going to run out of fossil fuels -- all of them -- so eventually we have to adopt solar power. CCS just delays the inevitable -- a huge waste of time and money. We should skip CCS and go solar today.
==============
[1] If you take just the CO2 from coal (2162.4 million metric tonnes [MMT] in 2007) and compare it to the mass of crude oil produced in the U.S. (258.8 MMT in 2007) plus imported crude oil (512.6 MMT in 2007), you find that CO2 is 8.4 times domestic production, and 2.8 times the combined domestic plus imported. That is mass. In terms of volume, the numbers are larger. If we use 500 kg/m3 [kilograms per cubic meter] as the density of supercritical CO2 (one possible operating point), then 2162.4 MMT of CO2 is 27.2 million barrels, or 15 times domestic oil production, and 5 times combined domestic plus imported oil. Thanks to Earl Killian for these calculations.
Etiquetas: Carbon capture, Energy, Montague
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