Scientists have adapted a process called “gasification” which is already used to clean up dirty materials before they are used to generate electricity or to make renewable fuels. The technique involves heating organic matter to produce a mixture of hydrogen and carbon monoxide, called syngas.
However gasification is very energy-intensive, requiring high-temperature air, steam or oxygen to react with the organic material. Heating this up leads to the release of large amounts of carbon dioxide. In addition, gasification is often inefficient, leaving behind significant amounts of solid waste at the end of the process.
To find out how to make the process more efficient, researchers led by Marco Castaldi, at the department of earth and environmental engineering at Columbia University, tried varying the atmosphere in the gasifier. They found that, by adding CO2 into the steam atmosphere of a gasifier, significantly more of the biomass or coal was turned into useful syngas.