Seeing Silicon | A startup in Berkeley is decarbonising air to solve global warming
In Berkeley, a startup is building a carbon capture device to trap CO2 from the air. And their working material comes from Home Depot.
Carbon dioxide in our atmosphere drives global warming by trapping heat. Take the excessive CO2 out of the atmosphere and we can limit rising temperatures. It’s the perfect idea to build a device, right? But when it comes down to doing it, it’s quite difficult to implement. Though CO2 is pervasive and is created by all things we create or consume, CO2 in the atmosphere as of 2023 is 419ppm – or 0.04% of air – that’s causing our earth to overheat.

To capture this 0.04% of air, you’ve to use a lot of energy to push a lot of atmospheric air through liquid or solid chemical compounds for it to react. For every ton of CO2, you’ve to push at least 5000 tons of air. And once you capture the CO2 molecules, you need to store them somewhere. It’s expensive and inefficient.
It’s a technological feat called Direct Air Capture (DAC) and it is a moonshot of engineering.
About 60-odd startups around the world are attempting to build a DAC machine to capture CO2. Berkeley-based AirMyne is one of them. “We don’t shy away from the fact that it’s difficult,” said Sudip Mukhopadhyay, co-founder of AirMyne.
It’s a bright and windy day in West Berkeley, and we’re at a rather noisy intersection having a cup of coffee at Lama Beans – a Hispanic-owned independent cafe in the area. “Building climate tech is an existence issue and DAC is one of the most challenging problems to solve as an engineer, so we decided to pursue it.”
Mukhopadhyay, who grew up in a farming village about 100 km from Kolkata, is an unusual startup founder. He was reluctant to give me an interview until I categorically explained that I wanted to visit AirMyne’s warehouse and meet the team before I wrote this. Since then, he’s been more welcoming and open about his concepts and his startup. He also uses a term I’ve not heard before – software CEO – to describe most founders who live across the bay from Berkeley – in San Francisco, Palo Alto, Stanford and the South Bay. Software CEOs, according to him, develop software that changes the way we interact online or through our smartphones. He is engineering a deep tech technology to solve global warming.
Mukhopadhyay landed in Berkeley in 2000 to pursue a postdoc in chemical engineering and never left. For 16 years he worked at Honeywell, an aerospace and materials conglomerate on different engineering problems. He improved solar panel efficiency, developed cockpit displays, ran a drone startup project, and collected over 47 patents. His biggest achievement at the company was in co-creating the world’s first low global warming refrigerant (HFO-1234yf) which became an industry norm in vehicles and continues to generate billions of revenues for Honeywell.
During the pandemic, Mukhopadhyay became an advisor to Finnish deep-tech startups. It was while he was in this job that he reconnected with an ex-colleague of his, Mark Cyffka – who Mukhopadhyay calls ‘my brother’. Cyffka wanted them to work on a deep tech startup in the carbon capture space. “Silicon Valley is a unique place,” says Mukhopadhyay, “You find resources, talent as well as money for big ideas. If not here, then where? And if not now, then when?”
Within a year, they had both left their jobs and joined YCombinator, one of the most well-known accelerators in the Valley (where I first found their name). They launched AirMyne in 2022 with an angel funding of $6.7 million. The aim was to prototype a plant to directly capture CO2 from the air. They started with four employees building small-sized DAC prototypes – capturing 1kg of CO2. In the last 15 months, the now 20-employee team has built 37 prototypes from scratch.
Every day small choices make their prototype more efficient and effective– using liquid instead of solid to get maximum kinetics, using low-temperature heat instead of electricity, and using cheap interfacial structures to blow the air through. Most of their materials are sourced from Home Depot, a home improvement retail chain in the USA, or created in-house with the seven 3D printers they own.
“We want to extract high volume CO2 at a lower price,” explains Cyffka, adding that right now, they are already at a cost of $250-300 per ton of carbon capture, down from $34,000 per ton when they started. “All these little decisions will become a crucial key to scaling to prototype plants in the future,” agreed Mukhopadhyay.
But the going is never smooth. As they move towards scale, they face new challenges that need to be solved – through reaction engineering, aerodynamics, fluid dynamics, material science, robotics, physics, chemistry, sensing and automation. That’s where Mukhopadhyay’s connections with the deep tech community in Silicon Valley and various departments at the University of Berkeley and Stanford University come in handy.
Energised with coffee, we walk down the block to enter a five-storied building. The AirMyne office is West Berkeley’s industrial Gilman district is surrounded by car repair shops and beer breweries. Much of their office, which is more of a warehouse, is filled up with earlier prototypes of their devices. The sizes range from suitcase-sized small contraptions to those the size of a car. It’s chaotic but in a good way. Scattered wires, haphazardly kept 3D printed materials, tubes, racks, containers, and makeshift working desks interspersed with a few employees.
Most of the employees are recent graduates from Berkeley and Stanford and have worked in robotics, automation, sensing, aerospace and chemistry. They’re all here for the same reason: To create something cutting-edge that saves the world. One of them, a chemist Sophia Sperman, is the niece of a woman who owns a car repair shop next door. The moment she heard there were scientists doing climate tech, she walked in, interviewed, and got a job doing analytical chemistry. Cynthia Cao, their mechanical engineer, comes with a PhD in robotics and finds climate-tech’s experimental robotics way more challenging than mainstream robotics.
The phrase ‘change the world’ has been oft used by startups in the Valley, but here, even to a dystopia-writing novelist like me, it feels real. If they can make machines that can pull out carbon from our air and do it faster than we produce it, we’ve resolved climate change and literally saved the world.
Shweta Taneja is an author and journalist based in the Bay Area. Her fortnightly column will reflect on how emerging tech and science is reshaping society in the Silicon Valley and beyond. Find her online with @shwetawrites. The views expressed are personal.

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