March 14, 2007 10:14 AM PDT
MIT: To keep coal, carbon needs to go underground
Coal will remain a pervasive source for generating electricity because it is a relatively high-energy, inexpensive fuel available in many parts of the world, MIT said in a study released Wednesday. But burning coal creates a high amount of carbon dioxide, a greenhouse gas that contributes to global warming.
To ensure that coal can be used to address the world's growing energy needs "in an environmentally acceptable manner," the power industry needs to adopt technologies for capturing and storing carbon dioxide underground, the study concluded.
MIT called on the United States, the largest greenhouse gas emitter in the world, to take leadership in these technologies, referred to as carbon capture and sequestration (CCS).
Demonstration of a commercial-scale power plant with integrated carbon capture and sequestration will show that a "practical carbon mitigation control option exists," said John Deutch, an MIT professor of chemistry who co-chaired the interdisciplinary study.
In addition, the authors of the MIT study, titled "The Future of Coal--Options for a Carbon Constrained World," said that carbon-restraining policies should be enacted in the near term to make CCS technologies more attractive.
Without policies that place a price on emitting carbon, the U.S. government could create a "perverse incentive" where utilities build new coal plants without carbon capture technologies before regulations are enacted, MIT said.
The study sets a target of demonstrating that 1 million tons of carbon dioxide per year can be stored in several locations. It calls for 3 sequestration projects in the U.S. and 10 elsewhere in the world, each of which would cost $15 million per year for a 10-year period.
With CCS, MIT forecasts that in 2050 global carbon dioxide emissions from all energy sources would be only slightly higher than today and less than half of the projected "business as usual" scenario, in which fossil fuel use would continue as it is now.
Not picking winners
The most favored CCS technique today is called Integrated Gasification Combined Cycle, which is being tried in new coal plants. But the MIT study's authors said different, viable technologies may emerge.
"The government should provide assistance to several 'first of their kind' coal utilization demonstration plants, but only with carbon capture," according to the study.
Carbon storage projects are under way, but MIT said these do not have the necessary monitoring to ensure that sequestration can be done safely at a large scale for a long period time.
Indeed, even advocates of cleaner sources of energy have significant doubts about carbon capture and sequestration.
The scale of sequestration could cause "unknown changes in soil chemistry," and the cost of these systems are "grossly underestimated," he said. Also, there are concerns that stored carbon dioxide could leak, causing other unforeseen problems.
MIT said the U.S. Department of Energy's current Clean Coal program does not have sufficient funds to meet the study's objectives. It called on the U.S. to undertake a more aggressive research and development effort.
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