Carbon Capture And Storage A Solution To Greenhouse Gases?
Carbon Capture and Storage (CCS) and Carbon Sequestration have been in the news recently, and many people believe that this technology is on the verge of resolving the greenhouse gas problem.
The principle is simple: burning fossil fuels such as coal and oil produces carbon dioxide (CO2), which right now is released into the air. This is where most man-made greenhouse gases come from. What if instead of releasing it into the air, we pumped the carbon dioxide back into the ground? Then we could keep on burning fossil fuels and not worry about greenhouse gases.
Several large-scale demonstration projects have already pumped CO2 into underground formations and more are planned. The three big projects are Sleipner, off the coast of Norway, one near the town of Weyburn, Saskatchewan in Canada, and one at the In-Salah gas wells in Algeria. Although they are the biggest projects in the world, all of them put together do not add up to the capacity required for one typical coal-fired power plant. And none of them uses CO2 that comes from burning fossil fuels, in fact they burn extra fossil fuels in order to capture and store CO2. Two of them take CO2 that occurs naturally in gas fields, bring it to the surface, purify it and put it back underground.
Applying CCS to power plants is more difficult because typically less than 10% of what comes out a chimney is CO2 and it is at low pressure and mixed in with impurities. Before it can be pumped underground, it has to be purified and compressed, and that takes a great deal of energy and of money. It costs over $100 a ton, according to the experts, about half of which is extra energy costs. If you want to clean the emissions from that extra energy, it costs even more. Some high-profile projects have been cancelled recently because of the cost, including the SaskPower 300-megawatt, clean-coal plant near Estevan whose cost went from $1.5 billion to $3.8 billion in a few years, and FutureGen, a 275-megawatt integrated sequestration and hydrogen production plant in Mattoon, Illinois, which would have cost $1.5 billion more to build than its total revenues.
A panel of experts on U.S. Department of Energy's (DOE's) Carbon Sequestration Program, formed by the National Research Council, recently concluded that carbon sequestration could not be implemented unless there were a significant carbon tax, and examined carbon taxes of $100 or $300 a ton. Even then the benefits are not very large. The panel members could find no environmental benefit and no security benefit to DOE sequestration research. To make sequestration a viable alternative you need a high tax on emissions. But those taxes make other low-emission energy even more attractive than fossil fuels. Whatever the price of energy, other sources of energy always give a better return on investment.
One risk factor to investment is public acceptance. The EPA announced in October 2007 that it intends to develop regulations to govern sequestration under the Safe Drinking Water Act, but will people want to have a CO2 capture or sequestration site near where they live? In low concentrations CO2 is safe, but in high concentrations it is deadly. Carbon dioxide sometimes naturally seeps out of the ground, for instance near some volcanoes, and when it does it kills all plant and animal life in its path. Because it's heavier than air it stays close to the ground and suffocates them. Even though experiments show that leakage and seepage should be relatively rare, will the public accept the risk? For instance, the West Pearl Queen experiment in New Mexico went wrong and leaked.
Is the risk necessary because people are never going to consume less energy willingly? The latest figures show that in the US, Canada, Japan, and much of Europe, energy consumption stopped growing and started declining a couple of years ago. The debate on carbon sequestration gives us two options to choose from: either we consume more energy and invest in sequestration technology, literally pouring our money into a hole in the ground, or we decide to use less energy for equivalent economic results. The first gives us the costs and environmental impacts of increasing the world's energy production so that we bury the CO2. The second requires more investment, but means we reduce our energy use, need fewer coal mines and oil wells, and makes us more competitive on the world market when the price of energy goes up.
The principle is simple: burning fossil fuels such as coal and oil produces carbon dioxide (CO2), which right now is released into the air. This is where most man-made greenhouse gases come from. What if instead of releasing it into the air, we pumped the carbon dioxide back into the ground? Then we could keep on burning fossil fuels and not worry about greenhouse gases.
Several large-scale demonstration projects have already pumped CO2 into underground formations and more are planned. The three big projects are Sleipner, off the coast of Norway, one near the town of Weyburn, Saskatchewan in Canada, and one at the In-Salah gas wells in Algeria. Although they are the biggest projects in the world, all of them put together do not add up to the capacity required for one typical coal-fired power plant. And none of them uses CO2 that comes from burning fossil fuels, in fact they burn extra fossil fuels in order to capture and store CO2. Two of them take CO2 that occurs naturally in gas fields, bring it to the surface, purify it and put it back underground.
Applying CCS to power plants is more difficult because typically less than 10% of what comes out a chimney is CO2 and it is at low pressure and mixed in with impurities. Before it can be pumped underground, it has to be purified and compressed, and that takes a great deal of energy and of money. It costs over $100 a ton, according to the experts, about half of which is extra energy costs. If you want to clean the emissions from that extra energy, it costs even more. Some high-profile projects have been cancelled recently because of the cost, including the SaskPower 300-megawatt, clean-coal plant near Estevan whose cost went from $1.5 billion to $3.8 billion in a few years, and FutureGen, a 275-megawatt integrated sequestration and hydrogen production plant in Mattoon, Illinois, which would have cost $1.5 billion more to build than its total revenues.
A panel of experts on U.S. Department of Energy's (DOE's) Carbon Sequestration Program, formed by the National Research Council, recently concluded that carbon sequestration could not be implemented unless there were a significant carbon tax, and examined carbon taxes of $100 or $300 a ton. Even then the benefits are not very large. The panel members could find no environmental benefit and no security benefit to DOE sequestration research. To make sequestration a viable alternative you need a high tax on emissions. But those taxes make other low-emission energy even more attractive than fossil fuels. Whatever the price of energy, other sources of energy always give a better return on investment.
One risk factor to investment is public acceptance. The EPA announced in October 2007 that it intends to develop regulations to govern sequestration under the Safe Drinking Water Act, but will people want to have a CO2 capture or sequestration site near where they live? In low concentrations CO2 is safe, but in high concentrations it is deadly. Carbon dioxide sometimes naturally seeps out of the ground, for instance near some volcanoes, and when it does it kills all plant and animal life in its path. Because it's heavier than air it stays close to the ground and suffocates them. Even though experiments show that leakage and seepage should be relatively rare, will the public accept the risk? For instance, the West Pearl Queen experiment in New Mexico went wrong and leaked.
Is the risk necessary because people are never going to consume less energy willingly? The latest figures show that in the US, Canada, Japan, and much of Europe, energy consumption stopped growing and started declining a couple of years ago. The debate on carbon sequestration gives us two options to choose from: either we consume more energy and invest in sequestration technology, literally pouring our money into a hole in the ground, or we decide to use less energy for equivalent economic results. The first gives us the costs and environmental impacts of increasing the world's energy production so that we bury the CO2. The second requires more investment, but means we reduce our energy use, need fewer coal mines and oil wells, and makes us more competitive on the world market when the price of energy goes up.