SciTech

CMU traps carbon dioxide emission

A team of researchers led by professor M. Granger Morgan, head of the Engineering and Public Policy department, received a $1.85 million grant from the New York-based Doris Duke Charitable Foundation (DDCF). The team developed a system that safely captures carbon dioxide and transports it deep underground where it can be permanently stored.

According to a press release from the Carnegie Institute of Technology, the grant is part of DDCF’s $100 million venture, called the “Climate Change Initiative,” which is aimed at creating a cleaner environment.

Development of technologies that help in building an environmentally friendly future is therefore an intrinsic part of this initiative.

While this project is anchored at Carnegie Mellon, researchers from the University of Minnesota, the Vermont Law School, and the law firm Van Ness Feldman are also involved in it.
The team’s primary focus is to reduce the emission of carbon dioxide as a result of excessive electricity consumption.

Most of the electricity in our country is produced by burning coal. However, the burning of coal releases large amounts of carbon dioxide.
This carbon dioxide is usually released into the air. Given the large amount of electricity that is produced nationwide, carbon dioxide levels in the atmosphere are continually increasing. Certain properties that make carbon dioxide unique from other pollutants further add to the problem.

“If we stabilize emissions [of most other pollutants], then concentrations [of the pollutants] also stabilize because those pollutants only live in the atmosphere for a few hours or a few days,” Morgan said. “In contrast, carbon dioxide lives in the atmosphere for a hundred years or more.”

The project focuses on the crucial problem caused by elevated carbon dioxide levels and has come up with a solution to it.
“The basic idea is to capture [carbon dioxide] and put it deep underground, in a suitable geological formation where it will be permanently sequestered,” Morgan said.

Sean McCoy, the project manager of the scheme, said that the carbon dioxide will be transported from industrial power plants through pipelines (on land) or by tankers (at sea) to specific locations. Once it is transported to these locations, it is injected underground into appropriate geological formations, such as a cave or water table.

After this, the carbon dioxide should remain underground for a relatively long period of time. The presence of underground water also helps trap the carbon dioxide in specific underground localities.

“You are injecting [carbon dioxide] so deep underground that the water at that level is saline and is not really useful for any other purpose. [Carbon dioxide] mixes with the brine [water saturated with salt] and this process helps to trap the CO2 and reduces the risk of it escaping,” McCoy said.

In spite of this, there is still a small possibility that the carbon dioxide will leak back out into the atmosphere. However, Morgan asserted that this will not make much of a difference.
“You have to remember that the alternative is 100 percent leakage,” said Morgan. “Normal coal plants leak everything.”

The technology shows prospects of a bright future. In fact, related technology is being implemented on smaller scales in different parts of the world.

Oil companies in Norway have been using similar techniques for some time. These companies extract natural gas, which is often mixed with carbon dioxide.

The process began a few years ago, after the Norwegian government began to heavily tax carbon dioxide emitted from refineries. As a result, if an oil company emitted large amounts of carbon dioxide into the air, it would have to pay a great sum to the government.

In order to prevent the loss of money from carbon dioxide emission, these companies began injecting carbon dioxide into the ground. Norway has been successfully implementing this technology for quite some time.

Although this technology is in use in different parts of the world, what makes the Carnegie Mellon project different from previous attempts is the large scale at which it is being pursued.
“All the pieces for doing this exist at commercial scale, but they have never actually been put together at large scale,” said Morgan.

This project specifically targets carbon dioxide emission due to electricity generation at coal plants. Therefore, the technology that will be developed will involve all the processes, from extracting the carbon dioxide from the power plants to injecting and storing it underground.

Another aspect of the project is reducing the emission of carbon dioxide by implementing different technologies.

“[The project] is a portfolio technology that bonds renewable, conservational and different energy generation technologies,” McCoy said.

Although the project will be affective in reducing the levels of carbon dioxide in the atmosphere, it will not be of much use if large quantities of carbon dioxide continue to be emitted, nor will it be economical.

“This is really only one step. There are a lot of technological changes that have to happen in terms of usage of more energy-efficient appliances,” McCoy said.

Strict regulations on carbon dioxide emission will need to be implemented for this project to be effective.

“The reason why commercial outfits are willing to [capture carbon dioxide] now is that they know that pretty soon there will be restrictions on CO2 emission,” Morgan said.