Heirloom Carbon Technologies is a San Francisco-based direct air capture company that uses limestone's natural CO2-absorbing properties to pull carbon dioxide permanently out of the atmosphere. Their process accelerates a geological phenomenon that normally takes thousands of years into a 3-day cycle: calcium oxide powder absorbs CO2 from ambient air, becomes limestone, gets heated in a renewable-energy-powered electric kiln to release the captured CO2, and repeats. The captured CO2 is then stored permanently underground or embedded in concrete. Founded in 2020, Heirloom opened America's first commercial DAC facility in Tracy, California in November 2023 and has raised over $354 million to expand capacity toward their goal of removing 1 billion tons of CO2 by 2035.
Shashank Samala is the CEO and Co-Founder of Heirloom, the company operating America's first commercial direct air capture facility. A serial entrepreneur who previously co-founded Tempo Automation (raising $100M+ for aerospace-grade electronics manufacturing), he pivoted to carbon removal after a stint as Entrepreneur in Residence at Carbon180. At Heirloom, he's building limestone-based DAC technology to remove one billion tons of CO2 from the atmosphere by 2035, targeting a cost of $50 per ton. The company has raised $354M total, including a $150M Series B in December 2024, and is building two new DAC facilities in Louisiana with combined annual capacity of nearly 320,000 tons.
Zack Bloom is a co-founder of Heirloom Carbon Technologies, the company behind America's first commercial direct air capture facility in Tracy, California. A software engineer turned climate entrepreneur, Bloom previously co-founded Eager - a cloud app marketplace acquired by Cloudflare in 2016 - and served as Director of Product at Cloudflare overseeing Workers, Storage, and Tunnel. In 2020, he pivoted from internet infrastructure to atmospheric infrastructure, co-founding Heirloom alongside Shashank Samala and Noah McQueen. The company has since raised over $354M in total funding, opened its first facility, and secured contracts with Microsoft, Stripe, Shopify, Meta, and JPMorgan.
Darren Bonnstetter is the CEO of Conexiom, a Vancouver-based AI-native platform automating sales order processing for manufacturers and distributors. Appointed in August 2025, he brings a rare blend of mechanical engineering rigor (Iowa State, Stanford MS, Harvard MBA), turnaround consulting at AlixPartners, and climate-tech entrepreneurship - having co-founded and led 280 Earth, a Google X spinout that raised $50M to capture carbon using industrial waste heat. At Conexiom, he leads a 210-person company serving 16 of the top 20 distributors globally, with $170M in total funding backed by Warburg Pincus, Luminate Capital Partners, and ICONIQ Capital.
Charles Cadieu is a serial entrepreneur and computational neuroscientist-turned-climate-tech founder. He is the Co-Founder and CEO of Spiritus, a direct air capture company aiming to slash the cost of carbon removal to $100 per ton - down from the current $600-$1,000 industry standard. Before Spiritus, Cadieu founded Caption Health (AI-guided cardiac ultrasound, acquired by GE HealthCare in 2023) and IQ Engines (AI image recognition, acquired by Yahoo!/Flickr in 2013). Holding a PhD from UC Berkeley and degrees from MIT, he bridges deep academic roots in neural networks with a track record of building and exiting companies that redefine their industries.