Methane Out, Carbon Dioxide In?
9/26/2013 - University of Virginia - CHARLOTTESVILLE,
Va., Sept. 26, 2013 — A University of Virginia engineering professor
has proposed a novel approach for keeping waste carbon dioxide out
of the atmosphere.
Andres Clarens, an assistant professor of civil and environmental
engineering at U.Va.’s School of Engineering and Applied Science,
and graduate student Zhiyuan Tao have published a paper in which
they estimate the amount of carbon dioxide that could be stored in
hydraulically fractured shale deposits after the methane gas has
Their peer-reviewed finding was published in
Environmental Science and Technology, a publication of the American
The team applied their model to the Marcellus Shale geological
formation in Pennsylvania and found that the fractured rock has the
potential to store roughly 50 percent of the U.S. carbon dioxide
emissions produced from stationary sources between 2018 and 2030.
According to his estimate, about 10 to 18 gigatonnes of carbon
dioxide could be stored in the Marcellus formation alone.
has several other large shale formations that could provide
The researchers’ model is based on historical and projected methane
production, along with published data and models for estimating the
carbon dioxide capacity of the formations.
Clarens said that
production records are available for how much methane gas producers
have already extracted from the Marcellus Shale, as well as
estimates of how much more they expect to extract.
That provides a
basis for determining how much space will be left in the formation
when the methane is gone, he said.
Clarens said gas would be
adsorbed into the pores of the shale and held securely.
“This would be a way of eating our cake and having it too,” Clarens
“We can drill the shale, pump out the gas and pump in the
carbon dioxide.. I think this will get policymakers’ attention.”
He said his work deals with the chemical feasibility of the idea,
and that additional studies must be performed to examine the
economical, political and logistical implications.
“My field is carbon management – high-pressure carbon dioxide
chemistry,” he said. “Right now, we are emitting huge levels of
carbon dioxide, and we need new ideas on ways to store the waste.”
Clarens, who said he has no connection with the oil and gas
industry, knows some in the environmental movement oppose hydraulic
fracturing because of possible risks to ground and surface waters.
However, he thinks this type of extraction is inevitable in many
places and it is important to preemptively develop new strategies
for handling the environmental implications, especially those
related to carbon dioxide.
“There are a lot of people who say we need to get away from
carbon-based fuels, and that may be possible in a few decades, but
right now, fossil fuels power everything,” he said.
“Finding ways to
harvest these non-conventional fossil fuel sources without
contributing to climate changes is a difficult but important
Clarens said he believes he and Tao are the first researchers to
propose this strategy.
He hopes this paper will contribute to a
discourse on how best to responsibly develop this booming resource.
Clarens, who received his doctorate from the University of Michigan,
did his undergraduate work at U.Va., receiving a bachelor’s degree
in chemical engineering in 1999.