What if we could stop carbon dioxide emissions from power plants? - Energy Factor
Science & technology

What if we could stop carbon dioxide emissions from power plants?

May 5, 2016

You never know when inspiration is going to strike. A few years ago, ExxonMobil researcher Tim Barckholtz was at home watching an NFC championship title game when he had a eureka moment.

The creative jolt wasn’t facilitated by the broadcast, but by an academic article he was reading during the game about a unique kind of fuel cell. He realized the technology, known as a carbonate fuel cell, could potentially be applied in a different way to improve power generation.

Barckholtz’s eureka moment, which builds on substantial work in the scientific community, then motivated years of research and data analysis, and eventually paved the way for ExxonMobil’s partnership with FuelCell Energy, a Connecticut-based developer of fuel cell power plants. Over the next few years, ExxonMobil and FuelCell Energy researchers will work together to advance the fundamental understanding and test whether fuel cell carbon-capture technology can work on a larger scale.

In theory, carbon capture is simple. Carbon dioxide produced when fossil fuels are burned to produce electricity is captured and then stored deep underground instead of being released into the atmosphere, where they become heat-trapping greenhouse gases. Because large amounts of energy are required to concentrate carbon dioxide molecules together so they can be caught (imagine how much easier it is to grab a handful of feathers when they are in a pillow case versus floating in the air), current carbon-capture technology is expensive. It’s just one of several technical and economic hurdles facing large scale use of carbon capture.

The fuel cell could be a fundamental shift in carbon capture because it can trap the gas while also generating electricity. This is important in power generation, where every percentage increase in efficiency matters.

When natural gas is burned in a gas turbine, the exhaust produced is only about 4 percent carbon dioxide. Carbonate fuel cells can grab that carbon dioxide, concentrate it into a stream that is around 70 to 80 percent carbon dioxide while creating more electricity at the same time. Further processing increases the carbon dioxide concentration to over 95 percent. While that’s a promising start, ExxonMobil and FuelCell Energy are planning to test and improve the technology to further increase its efficiency and demonstrate it at larger scale. The goal is to minimize emissions while maximizing power output.

“This technology could represent a true paradigm shift in carbon capture technology,” Barckholtz points out. “Instead of consuming energy to do the job of separating and storing carbon dioxide, additional power is generated, keeping the efficiency of the process about the same as without capture. It really is a case of eating your cake – and having it, too.”

While carbonate fuel cells are a potentially transformative technology, there is still a lot of work to be done before they could be ready for prime time. First, the partners need to further test in the lab, then advance to a pilot application, and then demonstrate the technology’s effectiveness at larger scales. It will take some time before ExxonMobil and FuelCell Energy will have something that may capture carbon dioxide emitted from large, conventional natural gas-fired plants at full scale.

Advancing economic and sustainable technologies to capture carbon dioxide from large emitters such as power plants is an important part of ExxonMobil’s suite of research into lower-emissions solutions to mitigate the risk of climate change. Moving fuel cell technology from the lab to the power plant could turn out to be one of the keys to meeting the world’s growing energy needs while lowering emissions.