Using light to turn cow farts into liquid fuel

When The Fast and the Furious (now streaming on Peacock!) hit theaters in 2001, no one could have guessed it would have become the weird and wonderful franchise it became. The original film features high-speed chases and high-octane adventure, yet somehow the pressure has only increased over the following two decades. The family, as they’ve come to be known, have made their way from humble quarter mile stretches, all the way into space. They can go anywhere and do anything, as long as they’ve got the fuel.

In the future, they might trade in their gas-guzzling automobiles for ones which use methanol. Doing so might save the world in more ways than one. That’s the implication of a new study published in the journal Chemical Communications. We spoke with Ivo Teixeira from the Department of Chemistry at the Federal University of São Carlos and the Department of Colloid Chemistry at the Max Planck Institute of Colloids and Interfaces, who worked with colleagues to develop a new method of converting gaseous methane into liquid methanol.

Conventionally, methane is used in the petrochemical industry to create hydrogen, but the process requires high temperatures and pressures. The existing process takes at least two steps and requires enough energy to pump up the heat to at least 600 degrees Celsius. The new process developed by Teixeira and the rest of the team achieves methane conversion at temperatures and pressures naturally found at sea level, making the whole endeavor more sustainable. Moreover, the conversion can be powered by sunlight.

“The conductor absorbs light, which could be sunlight, and generates electrons which promote reaction. The tricky part is to oxidize the methane into methanol, which is a partial oxidation. We started with an iron-based catalyst but it over-oxidized methane into CO2. We tested different metals and copper showed a very special activity to convert the methane into methanol. Methanol is much better,” Teixeira told SYFY WIRE.

Globally, methane is a significant greenhouse gas. It traps roughly 25 times more heat in the atmosphere than carbon dioxide when you do a pound for pound comparison. Worse, there’s a lot of it. Researchers estimate that the global stores of methane have twice the energy capacity of all other fossil fuels combined. That means that not only is it a potential source of energy, but that finding better ways to convert it from its gaseous state to a liquid could mitigate a substantial portion of its environmental risk.

“We have so much methane there’s a danger that it starts to leak in the future. For example, there’s methane below the ice in the north pole. Maybe we can find a way to convert it and avoid it going into the atmosphere,” Teixeira said.

In their initial experiments, researchers used pure methane to test the reaction and conversion, but they’re looking toward using their catalyst to capture methane out of the air or from environmental sources. Methane is regularly produced at landfills in the form of biogas, and from agricultural sources in the form of farts and burps from cows and other animals. Having these concentrated sources of gaseous methane provide ready targets for their system.

“In general, it’s hard to collect methane. We know our reaction works with low pressure, which is quite important for this type of application. I think it’s very likely it could work for a diluted source of methane. I can imagine we’ll be able to make huge bubbles, with a pool and our catalyst, the sunlight, will little by little convert the methane and produce methanol,” Teixeira said.

Of course, when it comes to climate change our best bet is to decrease and ultimately cease the continued production of greenhouse gases, but developing technologies to more efficiently capture them probably won’t hurt. Besides, there’s something satisfying about the knowledge that we might be able to concentrate our… um, waste products… such that they can accelerate us at high speeds.