Another use for sequestered carbon: drilling for oil

Here's a novel twist on curbing greenhouse gases. Some scientists and companies are examining ways of using captured carbon dioxide to extract fossil fuels.

It works like this. Carbon dioxide from smokestacks would be captured and compressed, and then shuttled into pipelines to oil fields. The gas would then be forced into oil wells to extract more fossil fuels.

The scenario solves two major problems in the energy field. First, what do you do with all of the carbon dioxide? The leading idea is to store it underground in depleted mines or saline aquifers. By being forced into oil fields, the gas will at least perform an economic function. Second, it would help ameliorate one of the age-old problems facing the oil industry: oil companies only get about 30 percent or so of the oil out of a field. (iRobot is contemplating creating a robot that can help free up captured oil.)

Granted, some of the benefits of sequestration are lost by using it to extract fossil fuels, but conventional cars are going to be with us for a while. Better to use carbon dioxide for this than leave it in the atmosphere and burn oil. Getting permits to lay pipelines will also take quite a bit of time.

Duke Energy is currently building a power plant in Indiana that will come with a carbon sequestration facility. One of the ideas the utility is contemplating is using the gas for enhanced oil recovery, said CEO Jim Rogers at the Clean Tech Investor Summit, held this week in Indian Wells, Calif. Duke is working with Princeton University on sequestration research.

Oil giant BP is also examining a way to pipe carbon dioxide from a hydrogen power plant to oil fields. Hydrogen and BP? It created a hydrogen business last year and has launched experiments.

Steven Koonin, BP's chief scientists (and a former California Institute of Technology professor), noted that underground storage--whether used in oil recovery or not--seems to be the most viable for sequestration. Transforming carbon dioxide into baking soda, which has been proposed by some companies, or other solids, he noted, requires quite a bit of additional raw material and energy.

"There is a good reason CO2 is the end product of combustion. It is a low energy molecule," he said. " Getting rid of CO2 by burying it underground may be the best option."

Still, even there, scientists still don't know if room exists underground to store it all.

Some start-ups are trying to convert the gas into a fuel.