By Chris Wickham
LONDON (Reuters) - Researchers have created a new material that could solve some of the problems holding back projects to combat global warming by capturing and burying carbon emitted from power stations.
The material, made from aluminum nitrate salt, cheap organic materials and water, is non-toxic and requires less energy to strip out the carbon when it becomes saturated, the scientists said.
Carbon capture has not yet been proven on a commercial scale and pilot projects have been hindered by concerns that the ammonia-based materials, or amines, used to absorb carbon can themselves produce toxic emissions.
They are also expensive and need large amounts of heat to boil out the carbon so it can be taken away and stored.
The researchers say their new absorber, dubbed NOTT-300, could overcome all these problems.
"I feel this can been viewed as a revolution to a certain degree," Sihai Yang from Nottingham University, who worked on the project, told Reuters.
"It is non-toxic, and zero heating input is required for the regeneration. There is promising potential to overcome the traditional amine material on both environmental and economic grounds."
Timmy Ramirez-Cuesta, who worked on the project at the ISIS research center at the Rutherford Appleton Laboratory in Oxfordshire, said the new material could simplify carbon capture by using interchangeable filters.
"When the material is saturated, the exhaust gases are diverted to the second container where the process continues," he said."The full container is disconnected from the system and the CO2 is removed using a vacuum and collected. The regenerated container can then be reconnected and used repeatedly."
The team, which also included scientists from the University of Oxford and Peking University in China, say the new material captured close to 100 percent of the carbon dioxide in experiments using a cocktail of gases.
Although the rate could be lower in the "dynamic conditions" of a real power station, it should still be over 90 percent, which is a key test for the viability of an absorber.
The material can pick up harmful gases, including sulphur dioxide, in a mixture, allowing others like hydrogen, methane, nitrogen and oxygen to pass through.
It does, however, absorb water vapor and the researchers are doing further work to overcome the problem, which could reduce its performance with CO2.
Martin Schroeder at Nottingham, who led the research, said NOTT-300 could also be put to use in gas purification. Natural gas often contains 10 percent of carbon dioxide impurity which needs to be removed before it can be used.
The scientists said they are working with companies in the carbon capture business on commercializing the new material.
The research was published in the journal Nature Chemistry.
(Editing by David Cowell)