CLIMATE CHANGE

Chinese researchers develop low-cost method of carbon capture

PUBLISHED : Sunday, 22 March, 2015, 8:44am
UPDATED : Thursday, 16 April, 2015, 10:57am

Chinese scientists have developed a material that provides a low-cost, highly-efficient method of carbon capture that could be used in the battle to reduce greenhouse gas emissions.

The material works like a filter and absorbs up to 75 per cent of the carbon dioxide molecules passing through it - a far higher efficiency rating than the next best filter in current use, which can absorb no more than 42 per cent, the German scientific journal Angewandte Chemie ( Applied Chemistry) reports.

Perhaps even more impressive to countries hoping to use the material to cut down their carbon footprint is that the energy source used to fuel this process is free and relatively plentiful - natural sunlight.

Professor Guo Guocong, a researcher with Chinese Academy of Sciences' Fujian Institute of Research on the Structure of Matters and a leader of the project team, said the "magic" of the new material was in its microstructure. The material, a type of photochromic diarylethene, is made of many tiny tubes which enlarge under UV radiation, allowing the large carbon dioxide molecules to enter. When it is exposed to natural sunlight, it squeezes the molecules out.

The energy source for both processes is free - the light comes from the sun, while the UV light can be obtained with the use of a filter. The yellowish plastic material, with the weight and feel of powdered flour, turns dark under UV and returns to its original colour under natural light.

Carbon capture has been proposed as a major solution to reduce greenhouse gas emissions. It works either by storing carbon dioxide in mines or under the ocean or by recycling it for commercial purposes, such as for reuse in chemical factories.

Traditional methods use chemicals such as liquid amine solutions to collect or absorb the carbon dioxide. The amine binds with the carbon dioxide in the atmosphere. But for commercial use a lot of extra energy is needed to heat the amine liquid.

"Our new material has the potential for large scale application, it can function quite efficiently under natural light," Gu said. "But we still need to work out some remaining issues before mass production."

Governments in many countries are funding research on carbon capture and storage but most methods are limited by high operational costs.