Mon July 21, 2014
New Carbon Capture System at Kentucky Plant Could Be 'Game-Changer'
Kentucky has long been known for coal. But a new project unveiled today has the potential to let the commonwealth also be known for coal technology.
A bevy of scientists and elected officials are in Harrodsburg this morning to cut the ribbon on a new carbon capture pilot project. The project was developed by scientists at the University of Kentucky’s Center for Applied Energy Research, and is being installed at Kentucky Utilities’ E.W. Brown power plant.
First, some basics. “Carbon capture” refers to processes that remove carbon dioxide from power plant emissions. Usually it’s used in conjunction with coal-fired power plants, because burning coal releases more carbon dioxide than other fossil fuels, like natural gas. And scientists have an interest in trying to reduce the amount of carbon dioxide released into the atmosphere, because the gas is contributing to climate change.
Carbon capture technology has already been proven to work. But despite years of research, scientists still haven’t been able to make the technology cost-efficient. It’s expensive to add it on to a power plant; once the technology is installed, removing carbon dioxide takes energy, so power plants actually have to burn more coal to produce the same amount of electricity.
But the project unveiled today in Harrodsburg is unique enough to potentially be a game-changer for the industry, says Michael Matuszewski. He’s the carbon capture technology manager for the National Energy Technology Laboratory—one of the project’s partners.
“For the first time at this scale, what we’re really trying to show is that the capture system and the power plant can play together,” he said. “And hopefully at the end of this project we’ll show that they can play together well.”
Here’s the way carbon capture usually works: some sort of liquid solvent is sprayed onto the power plant’s flue gas, which contains carbon dioxide. The CO2 absorbs into that liquid. Then the solvent is regenerated with a heated vessel, the carbon capture pops off with a higher purity, and it’s compressed and disposed of.
The University of Kentucky’s project follows the same basic steps. But it actually works to make the power plant more efficient, even as it removes carbon dioxide.
“They are actually able to improve the efficiency of the base plant by using the carbon capture system which has typically been labeled as a parasite,” Matuszewski said. Here are three key factors:
- The project integrates some of the heat that’s being generated from the carbon capture system back into the power plant. By reusing some of that heat that would otherwise be lost, it makes the plant more efficient.
- The full-scale system proposes to use two different techniques to extract carbon dioxide from the solvent. Most similar systems only use one: the solvent containing the CO2 is regenerated with a heated vessel, where the CO2 is separated from the solvent. This system also passes air over the solvent in a second vessel. This air-based regeneration removes additional CO2 from the solvent, which means the UK project captures more carbon dioxide from a given amount of solvent.
- Some of the low-level heat produced by the full-scale carbon capture system will be channeled into a drying system that dehumidifies the cooling air in the power plant’s cooling tower. This increases the power generation of the plant and increases efficiency.
So, if the technology works, it means the system could be appealing to power plant operators on several levels. They can reduce the carbon dioxide their plants emit, as well as improving the plant’s overall efficiency.
“That is one of the things that University of Kentucky is trying to do,” Matuszewski said. “They are actually able to improve the efficiency of the base plant by using the carbon capture system which has typically been labeled as a parasite.”
Matuszewski says there’s been a renewed interest in carbon capture technology since the federal government released draft regulations limiting carbon dioxide emissions from power plants.
“It is my perspective that these technologies should be developed just from a responsibility standpoint,” he said. “And finally when emissions regulations are put in place and everybody is required to adhere to them, then we’ll have technology sitting, waiting in the wings, waiting to be put onto the plant.”
The project at the E.W. Brown power plant is small—just 2 megawatts. It cost about $20 million, and $15 million of that was funding from the federal Department of Energy. If it’s successful after several years, it will likely be tested on a larger scale.
Here's the graphic LG&E distributed explaining the technology: