This simple material could reduce CO2 emissions from power plant smokestacks- here's why

Scientists propose using Aluminum formate (ALF) for removing carbon dioxide (CO₂) from the smokestacks of coal-fired power plants, and preventing it from reaching the atmosphere, according to a new study published today (Nov. 2) in Science Advances.

The study identifies a potential strategy for lowering existing plants' carbon production, which might help lessen their consequences while they are still operating.

Additionally, it offers a metal-organic substance that could be more economical than traditional carbon filtration methods for extracting CO₂ from dried flue gas conditions.

The material's natural porousness allows it to carry out such separations

In the new study, the team focused on aluminum formate, which belongs to the category of materials known as metal-organic frameworks (MOFs). The numerous hydrocarbons in fossil fuels are frequently the organic compounds that MOFs have shown most effective at filtering and separating from one another.

Some MOFs have demonstrated potential in refining natural gas or separating the octane components in gasoline. Others may help lower the cost of plastics manufacture or provide an inexpensive means of changing one material into another. Their intrinsic porousness gives them the ability to perform such separations.

ALF is more effective than other suggested materials at separating CO2 from other chemicals in power stations' chimneys

Researchers now believe that ALF has the ability to separate carbon dioxide (CO₂) from other chemicals that frequently escape coal-fired power plants' smokestacks. Even better, they assert that it does not have the drawbacks of other proposed carbon filtration materials.

"What makes this work exciting is that ALF performs really well relative to other high-performing CO₂ adsorbents, but it rivals designer compounds in its simplicity, overall stability, and ease of preparation," said Hayden Evans in a press release. Evans is a chemist at the National Institute of Standards and Technology (NIST) and one of the study's lead authors.

ALF is 'up to 100 times less expensive than other materials with comparable characteristics'

"It is made of two substances found easily and abundantly, so creating enough ALF to use widely should be possible at very low cost," explained Evans.

Aluminum hydroxide and formic acid, two chemicals that are plentiful and easily accessible on the market, are used to make ALF. Evans estimated that it would be less than 1 dollar per kilogram to produce- up to 100 times less expensive than other materials with comparable characteristics.

The idea is that separated CO₂ could become part of a cycle that makes more ALF

The idea is that CO₂ is converted to formic acid. This might become a step in a cycle where CO₂ is taken out of the exhaust streams by ALF and used to make more formic acid. The subsequent use of this formic acid to produce more ALF would lessen the total effect and expense of the material cycle.

Since a single plant's carbon capture process may require up to tens of thousands of tons of filtration material, affordability is crucial. Subsequently, it would take a vast amount of material to supply the entire world.

Around 30% of global CO₂ emissions come from coal-fired power plants

Power plants that burn coal are responsible for about 30 percent of the world's CO₂ emissions. We know that renewable energy sources that don't produce greenhouse emissions, including solar and wind, are being adopted. However, scientists must create strategies that lower the carbon production of plants still in operation.

Removing CO₂ from flue gas before it enters the atmosphere makes sense, but developing an efficient 'scrubber' has proven difficult. Finding a cost-effective material that can perform the task well has been challenging. This is due to the typical hot, humid, and corrosive gas mixture that runs up the smokestacks of coal-fired power plants.

ALF has potential, but it has yet to be ready for usage

"Put it all together, you need some kind of wonder material," Evans stated. "Here, we've managed to tick every box except stability in very humid conditions. However, using ALF would be inexpensive enough that a drying step becomes a viable option."

ALF has potential, but it has yet to be ready for usage. Engineers still need to work out a way to produce ALF on a large scale. Additionally, a coal-fired plant would require a compatible procedure to lower its humidity before cleaning the flue gas. Still, the researchers claim that progress in these areas would not affect the cost of using ALF.