Research shows solid materials could assist carbon capture

Research from the US has shown certain solid materials could provide a more efficient way to capture carbon dioxide from power plants.

A team from the University of California, Berkeley, has developed a computer model showing that absorbent ‘zeolite’ materials similar to those used in water purification could reduce the amount of energy used in the carbon-capture process by 30 per cent.

The software provides a way for scientists to rapidly simulate the effectiveness of a different and new materials in the carbon-capture process, and other researchers in the field can upload proposed material structures to a website for analysis by the program.

‘Our database of carbon-capture materials is going to be coupled to a model of a full plant design, so if we have a new material, we can immediately see whether this material makes sense for an actual design,’ said researcher Prof Berend Smit in a statement.

Many existing carbon-capture techniques involve passing exhaust gas from power generation through solutions of chemicals known as amines, which absorb the carbon dioxide.

Solid materials can capture CO2 at lower temperatures and therefore should be more energy efficient than amine scrubbing but materials differ in how tightly they hold onto CO2 molecules so the best process will be a balance of the two techniques, said Smit.

The UC Berkeley group have already tested four million zeolite materials made from silicon dioxide using the software, as well as 10,000 metal-oxide framework (MOF) structures — porous composites of metals and organic compounds.

‘The surprise was that we found many materials, some already known but others hypothetical, that could be synthesised’ and worked more energy efficiently than amines, said Smit.

A key part of the team’s success was using graphics processing units instead of standard computer central processing units. This reduced the time of calculating each structure, which involves complex quantum chemistry, from 10 days to two seconds.

‘The hope is that there is a system set up such that, when someone comes up with a promising material, we can rapidly test it and get it to a readiness level pretty quickly,’ said Abhoyjit Bhown, co-author of a paper on the research published in Nature Materials.