A consortium of European scientists say they have invented a process that will enable natural gas-fired power plants to produce electricity while separating out carbon dioxide emissions without the use of expensive flue gas-scrubbing technology.
Led by researchers at the Vienna University of Technology, the scientists say they have developed a process known as “chemical looping combustion” (CLC), which will enable natural gas power plants to produce electricity at a large scale without CO2 emissions. The Austrian scientists first demonstrated the technology at a test facility several years ago, but working with experts from 16 partner establishments across Europe they have scaled-up the process to the point where it could be deployed in a 10-megawatt demonstration facility.
The new technology divides the combustion of natural gas into two chambers. Air is pumped into one chamber containing metal oxide granules, which extract oxygen from the air. The oxygen-rich particles are then transported to a second chamber into which natural gas is pumped. Oxygen is released from the metal oxide granules in the second chamber and flameless combustion occurs, which generates electricity and emits carbon dioxide and water vapor.
The two-chamber process means there are two separate flue gas streams, and the technology easily separates water vapor from CO2 in the second flue, allowing for the inexpensive capture of the carbon dioxide. The CO2 can then be used in technical or industrial applications, or stored underground in former natural gas wells or other geological formations.
The CLC technology eliminates the need for scrubbers to separate out carbon dioxide, thus saving large amounts of energy, according to Austrian researchers. Conventional carbon capture-and-storage technology currently being tested on coal-fired power plants requires the use of flue scrubber technology. Because natural gas burns more cleanly than coal, the European scientists and engineers were able to develop the CLC technology using natural gas.
The challenge now, researchers say, is finding public or private investors to help build such natural gas-fired power plants on a large scale. The scientists say they are eventually planning to develop CLC technology that can be used to burn biomass for electricity production.