A Brief Summary

Renmin University of China researchers propose a new method to capture CO2 using sunlight as the energy source and modified sawdust as the CO2 absorbent. Their method also avoids using fossil fuels that would create additional CO2. The captured CO2 can be used to generate other products, such as methanol, ethanol and methane. Postgraduate Qianhao Pan, who also participated in the research, adds that they "believe less is more, sometimes a simple preparation process can lead to an effective solution that protects the environment."

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Greenhouse gas concentrations have reached an all-time high, according to the World Meteorological Organization. In the case of carbon dioxide (CO2), despite a 5.6 percent reduction in fossil fuel CO2 emissions due to COVID-19 regulations, growth in 2020 exceeded the average for the previous decade. Our huge consumption of fossil fuels is directly linked to the continuous rise in CO2 levels.

A group of researchers from China's Renmin University proposes a new way to capture CO2 utilizing sunlight as the energy source and modified sawdust as the CO2 absorbent in a study published in the journal Green Energy & Environment. In addition to absorbing CO2, their technology avoids the use of fossil fuels, which would produce more CO2. Importantly, the absorption method they created is reversible, which means the CO2 absorbed may be utilized to produce additional products like methanol, ethanol, and methane.

"While a great number of high-performing CO2 absorbents have been produced in recent decades, people rarely pay attention to the carbon exhaled by the adsorbent during its manufacture," says corresponding author Yapei Wang, a professor in the university's Department of Chemistry. Furthermore, the absorber regeneration process in conventional industrial CO2 capture systems consumes a lot of energy.

"To address these difficulties, we focused on a method that not only fabricates low-energy CO2 absorbents but also regenerates those absorbents using sunlight as the sole energy input."

Sawdust impregnated with an aqueous solution of amine-based polymer was discovered to be an easy-to-obtain CO2 absorbent with two major advantages: it does not require sophisticated production and it can catch CO2 and be regenerated with adequate heating. The sunlight collecting devices also included a reflector and a sunlight absorption layer, which heated the modified sawdust for CO2 capture.

"We were inspired by solar water heaters," said Shiming Zhang, a Ph.D. student who took part in the study. It is more environmentally friendly to use sunshine as an energy source because it reduces the need for traditional energy." "We believe little is more," says postgraduate Qianhao Pan, who also took part in the study. "Sometimes a basic preparation process can lead to an effective solution that preserves the environment," he adds.