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User Spotlight: The Escape Potential of CO2

EMSL user studies CO2 mobility in carbon sequestration

Lin Zuo

Are geological formations storing carbon dioxide similar to a soft drink bottle – when the lid is opened, the gas escapes into the atmosphere?

This is one of the questions Lin Zuo is asking in his study at EMSL on geological carbon sequestration. Zuo is a Ph.D. student in the Department of Energy Resources Engineering at Stanford University.

“My research topic is the leakage potential, because CO2 is soluble in water,” Zuo said. “We worry about the consequence of CO2 escaping the sequestration site – just like opening a bottle of soda and when the pressure releases the bubbles get out of the solution. We want to know whether we have to worry about not only CO2 escaping out of the reservoir but also about water escaping.”

Zuo is working with noted carbon dioxide storage researcher Dr. Sally Benson, director of Stanford’s Global Climate & Energy Project. They are using EMSL capabilities to study an unstable CO2 solution from CO2-saturated brines in geophysical sequestration. The researchers will conduct the experiments at the pore scale to observe the dynamics of and unstable CO2 solution to gain a better understanding of the potential long-term impacts of carbon sequestration.

The Environmental Protection Agency is funding the study. According to Zuo, the EPA considers geological sequestration of CO2 one of the primary ways of curbing global warming, and the agency wants to study any potential for leakage to make sure sequestration is a feasible technique for containing CO2.

Moving Bubbles
A CO2 bubble moves through the micro-model based exactly on the rock used to sequester CO2.

A better understanding of carbon sequestration at a pore scale could have significant societal implications.

“We want to know the potential of leakage of long-term geological sequestration,” Zuo said. “We want to assure people that CO2 pumped underground will stay there for the long term, won’t damage the surface and won’t affect ordinary peoples’ lives.”

Zuo completed the first round of research at EMSL in December. He has collected some interesting images and will continue to investigate the CO2 in solution phenomenon.

Forming Bubbles
A CO2 bubble forms in the micro-model of the rock used to sequester CO2.

According to Zuo, he came to EMSL because the laboratory enabled him to work on a microscopic scale and study individual CO2 bubbles in a medium that replicates the phenomena underground. He worked with EMSL’s microfabrication facility to create a micro-model based exactly on the rock used to sequester CO2. Zuo worked in EMSL’s Subsurface Flow and Transport Experimental Laboratory and used the laboratory’s Raman spectrometer to observe the tiny pore structures and see CO2 forming inside the tiny micro-model.

Zuo’s experience at EMSL has been positive.

“The people here are very knowledgeable and very helpful,” he said. “The technicians in the laboratory are very experienced in helping users.”

Based on his time at EMSL, Zuo would encourage other researchers to use EMSL’s facilities.

“EMSL is a great place to work,” he said. “The people here are very welcoming to outside users, and the facilities here are amazing.”

Watch the video on EMSL's YouTube channel as Lin describes his user experince at EMSL.

Released: February 02, 2012