Methane is a powerful greenhouse gas than carbon dioxide. In the international climate summit in Glasgow, abating methane emissions have become a major priority in order to reduce global climate change.
MIT researchers have developed a method to control methane emissions and removing it from the air. They have used an inexpensive and abundant type of clay called zeolite. The findings have been published in the journal ACS Environment Au.
Atmospheric methane is related with drilling and fracking for oil and natural gas. But scientists have said that those sources only account for nearly 20 percent of global methane emissions. Majority of emitted methane comes from slash-and-burn agriculture, dairy farming, wetlands and coal mining.
Scientists used zeolite clays. This is a very inexpensive material and it is currently used to make cat litter. Scientists have mixed a small amount of copper with zeolite and found that the material have become very effective at absorbing methane from the air.
The new method id simple. Scientists have packed tiny particles of the copper-enhanced zeolite material into a reaction tube. Then they heated it from outside. After this methane ranged from two parts per million up to 2 percent concentration and flowed through the tube. This range cover everything in the atmosphere.
This method has advantages over other approaches to removing methane from air. Other processes use expensive catalysts like platinum or palladium. This also need high temperatures of at least 600 degrees Celsius. Other processes also need complex cycling between methane-rich and oxygen-rich streams. This will make the devices both more complicated and riskier. Because methane and oxygen are highly combustible on their own and in combination.
The new process achieves its peak effectiveness at about 300 degrees Celsius. This also need far less energy for heating than other methane capture processes. The new method can work at concentrations of methane lower than other methods. This can work in small fractions of 1 percent.
The new method turns methane into carbon dioxide. It might sound like a bad thing. But scientists said, carbon dioxide is much less impactful in the atmosphere than methane. Methane is 80 times stronger as a greenhouse gas over the first 20 years. It is also 25 times stronger for the first century.
But methane turns into carbon dioxide naturally over time in the atmosphere. This process method would reduce the near-term climate impact. The new process will convert half of the atmosphere’s methane to carbon dioxide.
Scientists think the ideal location for this system will be a place where there is a relatively concentrated source of methane like coal mines. Coal mines has powerful air-handling systems in place as methane can cause fire, health, and explosion hazard. The U.S. Department of Energy have awarded the scientists with $2 million to continue to develop specific equipment for methane removal.
Also, large volumes of gas do not flow that easily through clay. In the next phase, the scientists will emphasize on ways of structuring the clay material in a multiscale configuration that will help air to flow.