SCIENTISTS have developed a new method of carbon capture using solid biomass waste that is more efficient and selective than current treatment methods.
A team from the University of York, UK discovered a porous material called starbons, made from food peelings and seaweed, can be used as a cheaper and renewable alternative for carbon capture. Starbons is created using a simple synthesis involving the expansion of starch into gel and carbonising at 300°C, followed by a temperature increase to 600–800°C, to dehydrate the material into a graphitic form.
The team believes the interconnected mesopores and mircopores allows the structure to selectively trap CO2.
With sufficient mass, current charcoal methods can absorb up to 98% of CO2 from flue stacks. However, the team says starbons are (gramme-for-gramme) 65% more efficient, meaning less material will be required to achieve the same result.
The new process of capture occurs at near room temperature, which is less energy intensive and therefore cheaper than other methods which require high temperatures to function. The team says starbons are also more selective in capturing CO2 when mixed with nitrogen, with results showing a capture rate four times more selective than other methods.
The materials can retain CO2 absorption and selectivity in the presence of water, and have extremely fast rates of CO2 absorption and desorption.
The team says the material has been inexpensive to make at laboratory scale, and they can currently produce around 1 kg/d. The team has a target to scale the production in the lab to 20 kg/d over the next three years, but can be scaled further to order for industry if necessary.
James Clark, head of green chemistry at the University of York, said: “The high CO2 adsorption, high selectivity, rapid kinetics and water tolerance, combined with the low cost and ease of large scale production from waste biomass, gives starbons great potential. We hope to offer the product as a commercial capture agent for separating CO2 from chemical or power station waste streams.”
Michael North, professor of green chemistry at the University of York, told The Chemical Engineer the project is ready to scale up and the team is looking to collaborate with a partner who can supply an appropriate source of waste CO2 to test the real performance of the materials.
Clark also told The Chemical Engineer the team’s continued research will also focus on better understanding the mechanism of adsorption of starbons and fine tuning it to maximise capacity and selectivity. The team will also look at using the material for the adsorption of other critical gases including SOx and NOx.
Angewandte Chemie, DOI: 10.1002/anie.201602226
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