Thursday, December 6, 2018

Possibilities for capturing, storing, and using carbon dioxide instead of releasing it into the atmosphere

As the land-grant university for the energy-rich state of Pennsylvania, it isn’t surprising that Penn State counts among its core strengths a broad and deep expertise in energy-related research. Today, in areas from materials science to policy, from environmental chemistry to architectural and electrical engineering, the range and quality of our research make Penn State a world leader in energy research.

We've produced a package of five stories that capture just a sliver of that expertise, briefly sampling some of the more innovative ideas of Penn State researchers working together to solve key questions of making and using energy.

Please visit our other posts on:

Generating energy—tapping natural processes to power our future

Storing energy—revolutions in materials to make batteries that charge faster, last longer, and are safer than conventional batteries

The built environment—how new inventions and design principles are making our buildings and appliances more energy-efficient

Pulling it all together—integrating new sources of energy with the traditional electric grid to provide reliable, sustainable power for homes and businesses

And for an inside look at how Penn State students are making a mark in the field of wind energy, see A Shift in the Wind.

Fossil fuels make up 82 percent of the energy we use in the United States. When we burn these fuels, we send carbon that was buried in the subsurface hundreds of millions of years ago up into the atmosphere as carbon dioxide. Atmospheric CO2 levels are rising and contributing to climate change. Simply put, we need to find ways to reduce the levels of this heat-trapping gas in the atmosphere. Penn State researchers are working on a variety of possibilities for capturing, storing, and using carbon dioxide. Here are a few examples of their work.

CAPTURE IT

One promising method builds on the natural process of degradation of organic material, which releases CO2 and methane into the atmosphere. Called bioenergy with carbon capture and sequestration (BECCS), it harnesses the power of anaerobic digesters—microorganisms that break down organic waste—and “captures” the gases they produce. “This mix of concentrated CO2 and methane is called biogas,” explains agricultural and biological engineer Tom Richard, whose research group works on optimizing this process for larger-scale carbon capture. “We can separate the two gases, put the methane into the natural gas pipeline system—natural gas is about 90 percent methane—and inject the concentrated CO2 deep underground rather than letting it escape to the atmosphere.”

Although some facilities such as wastewater treatment plants and large dairy farms use commercial anaerobic digester systems, in the form of lagoons, tanks, or silos, they’re expensive to maintain. Richard’s goal is to make these systems more cost-effective using biomimicry, by adapting the simple yet efficient ruminant system of the cow.

STORE IT

Inside the Earth there’s ample storage space for liquified carbon dioxide. The trick is to find the places where it will stay put. 

At high temperatures and under high pressure, carbon dioxide becomes a supercritical fluid that can be injected underground into sites such as rock formations, coal seams, and mile-deep aquifers with unusable, briny water. Environmental engineer Li Li and her group create models to learn how liquid CO2 moves through, and interacts with, brine and various types of rock. “There’s a lot of capacity in deep geological formations, but it’s a complex system,” says Li.

A primary goal is to evaluate the risks of injecting liquid CO2 underground by comparing laboratory models with real-world constructs. 

Chunshan Song doesn’t see carbon dioxide as a waste product. To him, it’s a raw manufacturing material. A worldwide expert on carbon use, The distinguished professor of fuel science sees potential for using CO2 to create fuels and products.

“In our lab, we use a catalyst to make CO2 react with other molecules such as hydrogen to break the bond of the CO2 molecule and reorganize the carbon,” he explains. Then, that carbon can be used to create sustainable fuels, chemicals, and materials that are traditionally produced from petroleum—things like plastic water bottles, carpet, and wrinkle-resistant fabrics.

To capture CO2 for manufacturing, Song and his colleagues developed a novel technology that uses super-absorbent materials in a power plant’s exhaust stream. A pilot research facility in North Carolina, supported by the Department of Energy, demonstrates how these materials capture and concentrate CO2 efficiently.

USE IT

Chunshan Song doesn’t see carbon dioxide as a waste product. To him, it’s a raw manufacturing material. A worldwide expert on carbon use, The distinguished professor of fuel science sees potential for using CO2 to create fuels and products.

“In our lab, we use a catalyst to make CO2 react with other molecules such as hydrogen to break the bond of the CO2 molecule and reorganize the carbon,” he explains. Then, that carbon can be used to create sustainable fuels, chemicals, and materials that are traditionally produced from petroleum—things like plastic water bottles, carpet, and wrinkle-resistant fabrics.

To capture CO2 for manufacturing, Song and his colleagues developed a novel technology that uses super-absorbent materials in a power plant’s exhaust stream. A pilot research facility in North Carolina, supported by the Department of Energy, demonstrates how these materials capture and concentrate CO2 efficiently.

Tom Richard is professor of agricultural and biological engineering and director of Penn State’s Institutes for Energy and the Environment. Li Li is associate professor of civil and environmental engineering. Chunshan Song is Distinguished Professor of Fuel Science and Professor of Chemical Engineering and director of the EMS Energy Institute. 

This story first appeared in the Fall 2018 issue of Research/Penn State magazine. This story has been reposted from Penn State News.