MIT Engineers Devise a System That Can Remove CO2 From the Air
Wed, April 21, 2021

MIT Engineers Devise a System That Can Remove CO2 From the Air

Humans have emitted more than 2,000 gigatons of carbon dioxide into the atmosphere. If this continues, impacts of the climate crisis will intensify more / Photo by: Gino Santa Maria via 123RF

 

For centuries, greenhouse gases have kept Earth’s climate habitable for humans and millions of other species. However, these gases have accumulated much that their levels are now out of balance with the environment, threatening to drastically change the planet we all call home. The most dangerous and prevalent greenhouse gas, carbon dioxide, continues to become more abundant every month. Reports have shown that its atmospheric levels today are at the highest ever recorded. 

Humans have emitted more than 2,000 gigatons of carbon dioxide into the atmosphere. If this continues, impacts of the climate crisis will intensify more, including forest fires, stifling heat waves, and damaging sea level rise. Almost all countries across the world are contributing to the rise. It was reported that in 2018, three countries, in particular, have contributed the most, with China accounting for more than 4.7 percent of emissions, the US 2.5 percent, and India 6.3 percent.

Christiana Figueres, a Costa Rican diplomat, stated that rising emissions are putting economies and the homes, lives, and livelihoods of billions of people at risk every year. “We have to ensure it is the solution’s exponential curve that is going to win the race,” she said. To avert the most catastrophic effects of climate change, the Intergovernmental Panel on Climate Change (IPCC) stated that it’s necessary to keep global temperature rise to less than 1.5 to 2 degrees C (2.7 to 3.6 degrees F). 

According to World Resources Institute, a global research organization working on six critical goals that the world must achieve this decade to secure a sustainable future, aside from reducing emissions, there’s a need to remove and store some carbon from the atmosphere. Reports showed that we would have to remove billions of metric tons of carbon dioxide annually by midcentury to achieve the goal we want.

Removing Carbon Dioxide From the Air

The IPCC aims to get rid of 100 to 1,000 gigatons of CO2 this century. To do this, countries will be needing carbon dioxide removal (CDR) technologies, which we have various types available. Today, there are a variety of CDR strategies that differ in cost, benefits, and risks. Some of the approaches of CDR employ trees, plants, and soil to absorb carbon have been used at large scale for decades. Meanwhile, those strategies that rely more on technology are still being developed. 

Unfortunately, most CDR strategies require higher concentrations while only a few variations have been developed that can work with the low concentrations found in the air. But a recent tool developed by engineers from the Massachusetts Institute of Technology is significantly less energy-intensive and expensive. MIT postdoc Sahag Voskian, who developed the work during his Ph.D., stated that the device’s binary nature of the adsorbent's affinity to carbon dioxide is its greatest advantage—an advantage that most carbon-capture or carbon-absorbing technologies don’t have. 

The IPCC aims to get rid of 100 to 1,000 gigatons of CO2 this century. To do this, countries will be needing carbon dioxide removal (CDR) technologies, which we have various types available / Photo by: Veerathada Khaipet via 123RF

 

Science Daily, an American website that aggregates press releases and publishes lightly edited press releases about science, reported that the tool can remove carbon dioxide at virtually any concentration level, even down to the roughly 400 parts per million currently found in the atmosphere. The new system is a large, specialized battery that releases carbon dioxide it absorbs from the air by passing over its electrodes as it is being charged up. The researchers stated that the whole charging and discharging cycles can operate at room temperature and normal air pressure.

Voskian described the new system as revolutionary. "All of this is at ambient conditions—there's no need for thermal, pressure, or chemical input. It's just these very thin sheets, with both surfaces active, that can be stacked in a box and connected to a source of electricity,” he said. Co-author T. Alan Hatton, the Ralph Landau Professor of Chemical Engineering, also shared how they have been striving to develop new technologies to tackle a range of environmental issues that will avoid the need for changes in system pressure, thermal energy sources, or addition of chemicals to complete the separation and release cycles. 

The researchers added that this new tool is energy efficient compared to other existing carbon capture technologies. This is because other methods have energy consumption that varies between 1 to 10 gigajoules per ton, while the new system uses about one gigajoule of energy per ton of carbon dioxide only. 

Turning CO2 From Air Into Coal

Scientists are not only working in removing carbon dioxide from the air but also turning it into solid carbon form. A recent study published in the journal Nature Communications revealed a breakthrough technology that will change the way we think about CO2. This new development would efficiently lock away carbon dioxide in a safe and long-term way. This process is called carbon sequestration. 

Carbon sequestration is a procedure that will remove carbon dioxide from the atmosphere and convert it into a liquid or solid form. This inexpensive and large-scale method is both an ideal and appealing approach to mitigating climate change. According to Forbes, a global media company focusing on business, investing, technology, entrepreneurship, leadership, and lifestyle, the researchers used a cerium-containing liquid metal catalyst to convert CO2 into coal. 

The researchers believed that carbon sequestration is the first step toward an abundant and inexpensive method to repurposing carbon dioxide into solid coal. In a press release, RMIT researcher Dr. Torben Daeneke said, "While we can't literally turn back time, turning carbon dioxide back into coal and burying it back in the ground is a bit like rewinding the emissions clock.” 

The tool created by MIT engineers and other CDR strategies has different approaches that offer both promise and challenges. However, we must not rely on these alone. The path to halting the increase of global temperature involves conserving existing forests and grasslands, planting trees, and generally saving our planet from the climate crisis. 

Scientists are not only working in removing carbon dioxide from the air but also turning it into solid carbon form / Photo by: Jaromír Chalabala via 123RF