How to lower carbon levels using light

How to lower carbon levels using light

New Iridium is developing photocatalysts from common elements.Credit: Courtesy of

New Iridium in Boulder, Colorado, spun off from Colorado State University, Fort Collins, in 2020.

Even as a teenager, Chern-Hooi Lim worried about the effects that climate change would have on his generation. Now, armed with a doctorate in chemical engineering, Lim leads New Iridium, a company in Boulder, Colorado, that he hopes can use the power of light to remove a significant portion of the greenhouse gas carbon dioxide from chemical production processes — and even turn some of it into useful products.

As a PhD student and postdoctoral fellow at the University of Colorado Boulder, Lim used a supercomputer to model how well various organic photocatalysts would absorb light and transfer electrons to stimulate particular chemical reactions. He took his findings to Garret Miyake, an organic chemist at nearby Colorado State University in Fort Collins, who synthesized and tested them. On the basis of their results, they launched New Iridium, which has been longlisted for The Spinoff Prize 2023; Lim is chief executive and Miyake is chief technical officer.

Conventionally, the chemical industry relies on methods such as steam cracking, in which hydrocarbons derived from petroleum are mixed with steam and then quickly heated to 850 °C or more. The process changes the molecules into products such as ethylene, which can then be used for making everything from absorbent nappies to smartphone screen protectors. The fuel burned to produce those high temperatures releases more than 2 billion tonnes of CO2 each year globally (for context, all of the vehicles in the United States combined emit about 1.5 billion tonnes a year). These methods use metals such as platinum, palladium and ruthenium as catalysts. “They’re very expensive and very scarce and in many cases toxic,” says Brent Cutliffe, co-founder and chief operating officer of New Iridium.

Cutting emissions

Organic photocatalysts, by contrast, are made with safe, common elements: carbon, hydrogen, nitrogen and oxygen. And using light — in this case from blue light-emitting diodes (LEDs) — to power the reactions opens up chemical pathways that don’t require high temperatures, Lim says, cutting both energy requirements and carbon emissions. The scale of the reduction depends in part on whether the electricity that runs the LEDs is produced using renewable sources instead of fossil fuels, but Lim and his colleagues think that their technology has the potential to slash the industry’s emissions in half. The company’s name comes from a promising photocatalyst metal: iridium. The start-up’s less expensive organic version is called new iridium.

The team is working on two types of chemical reaction. One is olefin production, which would create ethylene, propylene and butylene — all used to make plastics. The other is to produce acetic acid, acrylic acid, methacrylic acid and terephthalic acid. These go into a variety of products, from paint to the polymethyl methacrylate used in electronic displays. And because the team’s technology takes CO2 from industrial smokestacks and turns it into long-lasting products, it also removes some of the greenhouse gas from the warming equation.

Sue Sundstrom, a start-up coach based in Clevedon, UK, who is one of the judges for The Spinoff Prize 2023, praises New Iridium’s focus on how to solve a problem rather than on how to sell a scientific development. “It wasn’t a case of doing some research and then going, how are we going to use this?” she says. “The whole thing was designed around the commercial application.”

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