Carbon capture is relevant in environment studies to lessen carbon dioxide (CO2) impacts on overall climate juncture. A team of researchers at Oregon State University College of Science, led by Kyriakos C. Stylianou, elaborated the use of nanoparticles to delimit released CO2.
The research entitled ‘CO2 capture from wet flue gas using a water-stable and cost-effective metal-organic framework (MOF)’ was published in Cell Reports Physical Science. The lead author Stylianou highlighted the importance of the study in addressing climate change globally, as emissions of greenhouse gasses (GHGs) has resulted in total warming of the planet.
About MOFs
Technologies to reduce CO2 emissions at the source levels, as in industrial releases have seen significant advancements. A notable technology in such areas is the use of nanomaterials called Metal Organic Frameworks (MOFs). As the flue gasses passes through the smokestacks, the MOFs technology possesses the ability to trap CO2 molecules through the process of adsorption.
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MOFs, consisting of positively charged metal ions encased by organic ligand molecules, are crystalline and porous materials. The metal ions act as nodes, connecting the arms of the ligands to create a repeating structure resembling a cage. Within this structure, nanosized pores exist that function like a sponge, adsorbing gasses
Previous MOFs in Carbon Capture
Although MOFs have demonstrated considerable potential for carbon capture due to their porous structure and flexibility, the conventional synthesis methods often involve the use of detrimental reagents such as heavy metal salts and toxic solvents, which are expensive and harmful for the environment.
Even if the cost-effectiveness and detrimental nature were addressed, the existing MOFs posed ineffective in humid-based environments. These are some of the challenges that Kyriakos C. Stylianou, Ryan P. Loughran and team addressed in their study and successfully overcame them by synthesizing a cost-effective MOF, MIL-120.
Carbon Capture through MIL-120
As per the researchers, MOFs could be designed taking in a variety of components. Their versatility enriches them with a million possible designs and properties. The researchers in the study used aluminum and a ligand, benzene-1,2,4,5-tetracarboxylic acid to synthesize the MOF, which they called MIL-120.
The MOF synthesis occurs in water within a relatively short time frame of a few hours. Moreover, the MOF possesses pores that are comparable in size to CO2 molecules, providing a restricted space where carbon dioxide can be captured. The researchers tested MIL-120 in damp as well as dry conditions, in which their synthesized MOF captured CO2 with uptake capacities of 1.118 mmol/g and 1.215 mmol/g respectively. The affinity of MIL-120 for CO2 was found to be 44kJ/mol.
According to Stylianou, this particular MOF is an exceptional choice for wet post-combustion carbon capture applications. It offers cost-effectiveness, remarkable separation performance, and the ability to be regenerated and reused for at least three cycles while maintaining comparable carbon dioxide uptake capacities.