Heirloom Carbon Technologies is a new startup in town that is using carbon capture technology to utilize minerals to pull CO2 out of the atmosphere. The company deploys a process known as enhanced weathering in an effort to reduce CO2 levels in the air. Its main business model is selling carbon offset credits to corporations or individuals.
The company also claims it can remove 1 billion ton of CO2 by 2035 and for $50 a ton once it reaches a commercial scale. It reached a milestone of finding its first customer – Stripe that wants to purchase around 250 tons of carbon removal from the company at $2,054 per ton.
The payment processing company has been investing substantially in carbon removal initiatives like CarbonBuilt, Running Tide, Seachange, Mission Zero, and the Future Forest Company. Stripe plans to spend nearly $2.8 million to buy carbon removal credits from the six projects. In addition, it will pay another $5.25 million when or if their efforts reach certain milestones.
Why We Need CO2 Removal
Removing CO2 out of the atmosphere is necessary for the planet to start cooling off. The world will need to take out 10 gigatons every year by 2050 to have any chance of reaching the Paris Agreement goals.
According to scientists, the number of carbon capture companies that address this problem needs to increase dramatically if we have any chance of halting climate change to 1.5 degrees.
“Ten gigatons is a lot—it’s just a massive number, and even in the best scenario, all the companies we have today aren’t going to get us there,” according to Nan Ransohoff, head of climate at Stripe.
Heirloom’s Carbon Capture Technology

Heirloom Carbon Technologies solves the problem natural carbon sinks like soil and forests currently have – less reliability and durability of the carbon being sequestered by them. Heirloom offers permanent and more secure removal of CO2.
Direct air capture companies like Climeworks and Carbon Engineering also provide a viable solution to CO2 removal but they require heavy investments and are hard to scale commercially. If the new company reaches its price target, it could outpace DAC companies with more affordable carbon offsets prices.
Heirloom’s technology works with limestone and electricity-driven kilns combined with natural carbon processes. The company produces limestone which consists of calcium tied up with CO2. Then it heats it at temperatures of 400 to 900 ˚C to break down and release pure carbon dioxide.
That process happens in electricity-driven kilns powered with renewable energy. The CO2 is captured and could be sequestered underground for permanent storage. The leftover oxide minerals, which would be calcium oxide if the process starts with limestone, are then spread out in thin layers, exposed to the open air.
The minerals are very reactive in bonding with CO2 from the air and thus sequester more of the GHG. The company uses enhancements to speed up the process of calcium oxide absorbing CO2 which takes around 2 weeks to normally a year.
The natural carbon sink process converts calcium oxide into calcium carbonate which is the main ingredient of limestone and the process can start again. According to Heirloom, the minerals can be reused 10 times before they degrade and are not able to sequester CO2.
The company is hoping to raise enough funds to eventually build a demonstration plant for its carbon capture technology. Carbon capture investments are critical for an early-stage startup like Heirloom to prove and develop its business model and achieve its carbon dioxide removal targets.
Challenges
However, the company sees a challenge in attracting more clients like Stripe willing to pay the high carbon offset price. The price is crucial for the company to scale up and cut costs. Cheaper forest and soil offsets are currently available for companies to claim they have balanced their emissions, regardless of the actual reliability of those projects.
Generating electricity for the process using renewable energy is also still more expensive than fossil fuel options. Cutting down the time it takes for the oxides to bond with CO2 even further is another challenge as it has a significant effect on economics.
Despite those setbacks, the startup is confident automation, speed of renewable energy getting cheaper and other optimization factors are driving costs significantly. Companies and governments are also increasing their funds into carbon capture technology which will additionally reduce costs and make such projects more attractive.
Carbon capture companies like Heirloom Carbon Technologies are fostering innovation into the carbon removal technology space, eventually creating a whole new industry that supports the economy while addressing the climate change problem.