Scientists in Singapore say they've found a low-temperature, low-energy way to turn carbon dioxide into methanol, providing a potential revenue stream for carbon capture projects in the form of a biofuel and industrial chemical output.
Just how to apply the process to the real-world challenge of capturing the billions of tons of carbon put into the atmosphere each year by coal-fired power plants, factories, vehicles and other sources remain to be seen.
Still, the researchers at Singapore's Institute of Bioengineering and Nanotechnology say the new process is a marked improvement over previous methods of turning the world's major greenhouse gas into a useful product.
The new process uses d N-heterocyclic carbenes (NHCs) as an organocatalyst, then adds hydrosilicane – a combination of silica and hydrogen – and water to make methanol, according to a study published in the journal Angewandte Chemie International Edition.
The process can be done at room temperatures in the presence of oxygen, unlike previously discovered methods using heavy metal catalysts with toxic and unstable components, the scientists said. The new process also uses much less energy and takes less time than previous methods.
Finding a way to capture the billions of tons of carbon dioxide emitted from the world's coal-fired power plants – which make up about half the world's total emissions – and other sources is seen as a critical means of combating global warming.
Transforming carbon dioxide into useful fuels could be a much sweeter way to get that job done, however.
Turning carbon dioxide into methanol, for one, is the focus of a number of research efforts. Honeywell company UOP and the University of Southern California embarked on such a project in December 2007 (see Spinning Pollution Into Liquid Gold).
Iceland-based Carbon Recycling International is seeking to turn carbon dioxide into methanol and thence into other fuels, taking advantage of Iceland's abundant geothermal energy resources to power the energy-intensive process.
Other fuels are on the table as well. Australia-based Linc Energy and BioCleanCoal are seeking to turn carbon dioxide into oxygen and biomass that could be used as fertilizer or for other purposes (see Turning Coal's CO2 Into Biomass).
Capturing carbon dioxide at coal-fired power plants is technically doable but not commercially viable right now, its proponents say (see Clean Coal's Chicken and Egg Problem, Canada to Beat U.S. to Carbon Storage and Vattenfall to Trap Carbon Emissions.)
The primary goal of most carbon capture projects is sequestering the gas in underground caverns or other geological formations, though some research efforts have suggested more novel methods, like chemically altering the ocean (see Carbon Capture Firm Could Use the Ocean to Combat Global Warming).