Carbon Removal Deep Dive: Heirloom Carbon

Taking a closer look at a promising new carbon removal start-up using the MOBILE Framework

Recently, I published the MOBILE Framework - a model I developed proposing a new way of assessing carbon offsets. The model has received an amazing response and constructive feedback from countless individuals throughout the carbon removal community. I view this input as a testament to the dynamism of the community and a reflection of the overwhelming need to make sense of the rapidly changing carbon removal field.

With efforts underway to scale up voluntary carbon offset markets, the timing is critical to ensure that these markets support high quality carbon removal projects that catalyze innovation and improve social equity. Recently, the Taskforce on Scaling Voluntary Carbon Markets released a blueprint for creating a large-scale, carbon credit trading system and has encouraged the public to weigh in on its recommendations around market integrity, transparency and governance structures. However, what gets lost in abstract conversations about markets is our understanding of the underlying carbon mitigation projects and solutions that make up these markets. I believe the recent failures we have seen in offset markets are in part a result of the effort to commoditize offsets and a myopic race to the bottom to buy offsets at the lowest possible price. Reforming carbon markets alone will not steer buyers to supporting high quality, transformative carbon removal projects. That’s where the MOBILE Framework comes in - it gives buyers a clear, understandable, and approachable framework to make better carbon removal purchase decisions.

The MOBILE Framework

I thought I would put MOBILE to the test by reaching out to an exciting new carbon removal company - Heirloom - and running their solution through the model. The Heirloom team patiently and thoughtfully answered a series of questions that I summarized below based on the three major steps of the framework. Here’s how they did:

Enter Heirloom

Heirloom is developing a direct air capture (DAC) carbon dioxide removal process using carbon mineralization. Their evolving process is based on the accelerated mineralization of carbonates and was published in Nature last year. The company was recently selected in Stripe’s latest round of carbon removal purchases, and you can find more technical details about Heirloom’s solution in their application. The company’s projected carbon removal capacity is somewhere between 175 and 750 tons of CO2 per year by the end of 2022. The company believes its process can achieve carbon removal at a scale of <$100/ton of CO2 over the long term. Today, Heirloom’s cost per ton is much higher, but the cost per ton of CO2 removed with a nascent, pre-pilot stage process and capacities this low is largely irrelevant. In my view, only after deploying a few iterations of its technology will it become worthwhile to interrogate whether the company is on track to achieving their target cost.

Okay, let’s dive in:

Step 1: Understand the fundamentals of what you’re buying

1. Mechanism: What is the project’s underlying carbon mitigation approach?

   There is no ambiguity about it - Heirloom’s process is designed to remove carbon dioxide from the atmosphere. Here’s how they describe it: 

   Our process relies on mineral carbonates: the carbonate is first subjected to high temperature conditions (i.e., calcined) where it breaks down into reactive oxides, releasing CO2 in the process. The resulting oxide is then placed outdoors in contact with air to naturally reform carbonate materials. Once the oxides have sufficiently carbonated, they are collected and can be re-calcined. The carbon dioxide from the calcination is captured and stored either in geological reservoirs or by mineralization. The produced oxides can then be carbonated again, and the process can continue cyclically. The process consumes carbon dioxide that is already in the air, resulting in carbon removal rather than avoidance.

2. Outcome: Is the outcome of your solution additional and permanent?
   
   Yes and yes. Heirloom says the funding it receives will help it to accelerate the design, development, testing, and deployment of its demonstration plant. In the long-term, additional funding allows for expansion of the operation to capture additional CO2 that would not have otherwise been removed from the atmosphere. The CO2 from the calcination is captured and stored for 1000+ years, either in geologic reservoirs or by mineralization.

Step 2: Get to know the particulars of the underlying project

3. Benefits: What are the non-climate benefits (or co-benefits) of the project?

   The company says their solution will create local jobs, support innovation in fields including industrial infrastructure, geoscience, robotics, and could potentially utilize mine tailing waste, thereby improving waste management. Other co-benefits are unclear at this time.

4. Impact: What is the quantifiable carbon impact this project will have?

   Here’s where Heirloom’s process has the potential to really shine. The road ahead for the company will be to realize this potential on deployment.

   • Measurability: Very easy to accurately measure CO2 removed
     Accurately measuring the CO2 removed by Heirloom’s process is very easy. The amount of CO2 removed is quantifiable from CO2 flux readings, total carbon analysis, and mass analysis during and in between the calcination and carbonation process.

   • Negativity: Excellent negativity (94%)
     For every 50 tons of CO2 captured, the process will create 3 tons CO2e, with a net of 47 tons of CO2 removed. 

   • Land Use: Low-to-moderate land use, still unclear at large scale
     While Heirloom’s long-term land use requirements are yet to be determined, the technology is designed to minimize land use through an efficiently stacked carbonation system. The company estimates its land footprint (normalized to 1 million tons per year) to be below 1 square km by 2023.

   • Permanence: Highly permanent, low risk of reversal, monitoring plans in place
     Captured CO2 is quantified by measuring the CO2 injection into the geologic storage reservoir and involves post-injection monitoring and verification by a storage provider. Monitoring includes tracking the physical plume of CO2 in the subsurface via seismic imaging, pressure data from injection wells to monitor for pressure buildup and ensure caprock integrity.

   • Leakage Risk: Low risk, leakage monitoring proposed
     Leakage risks after storage are negligible. The company will work with an injection partner to ensure storage sites are properly selected and monitored.

   • Verifiability: Process is not currently verified, but Heirloom intends to apply for permanence certification and for crediting under California’s Low Carbon Fuel Standard with an injection partner.

   • Transaction Costs: No intermediaries, Heirloom manages the project implementation directly.

Step 3: Try to catalyze broader change, rather than just negate your carbon ledger

5. Learning: How does the project improve technologies and catalyze new markets?

   Heirloom’s technology is at the pre-pilot R&D stage, with a proprietary process that it will build out further. They believe that developing its process will help spur innovation in calcination technology, materials handling, automation, and efficient land use design. Indirectly, these innovations may help drive advancements in other industries including agriculture and mining. The company has the support of world class experts in the carbon removal field who have published papers on the technology and plan to continue building the knowledge base.

6. Equity: How does the project advance social equity?

   Heirloom has taken a thoughtful approach to how they envision their solution to benefit regions impacted by a green transition and has the right ideas about engaging and involving communities throughout the deployment of their solution. Here’s how they are thinking about this:

   Heirloom intends to heavily engage and maintain utmost transparency with communities in searching and planning for an appropriate site for the industrial-scale carbon removal plant. Land, water, and energy requirements, building timelines, and environmental assessments will be shared with communities living in proximity to potential plant sites. Community feedback will inform the specific site and design configuration of the plant to minimize its impact on existing local infrastructure, natural ecosystems, and community life. We are proud of our approach limiting resource extraction and other negative impacts, and will continue to work to ensure that happens. 

   One of the primary environmental justice benefits of Heirloom’s technology is that commercial deployments can be sited in declining oil, gas, and coal regions to revitalize communities with better access to high paying jobs. There is significant overlap between non-arable land, injection expertise and infrastructure, and ambient conditions suitable for optimal carbonation rates. Our technology is well suited to operate in these areas. 

   Heirloom’s responses on this issue, like all of their responses, will be tested when the rubber hits the road. But I was impressed with the level of depth they provided on this despite how early in the process they are in implementing their solution.  The company is also thinking about how its solution helps address broader, global climate inequities:

   Direct air capture technology, such as the process that Heirloom is developing, may offer a route to addressing global climate inequity as it would allow for wealthier countries to remove their legacy emissions and in turn abate global temperature rise, the impacts of which disproportionately affect nations and communities that have been made resource- and economically-deprived. 

Closing Thoughts

The MOBILE Framework is not meant to be a carbon removal scorecard, but rather a model to make sure that carbon removal buyers are asking the right questions. While Heirloom’s solution can only be truly validated through demonstration, the results of my analysis leave me excited about its prospects. The company represents a new breed of carbon removal innovators taking a serious approach to permanently removing CO2 from the atmosphere with a laser focus on getting costs under $100/ton. Its underlying process has the support of experts in the carbon removal field, and its recent inclusion in Stripe’s portfolio only adds to its credibility. In my view, Heirloom deserves serious consideration from any company looking to support high quality, catalytic projects that take equity considerations into account. Here are my top-level takeaways from Heirloom’s solution:

• Mechanism: Heirloom’s process is unambiguously carbon dioxide removal.

• Outcome: Their project will lead to additional CO2 removed and stored permanently.

• Benefits (Non-Climate): There are some straightforward co-benefits here, though non-economic benefits and risks need to be further explored.

• Impact: The proposed solution performs well across the board, and appears to take a unique approach to potential land use implications.

• Learning: Supporting Heirloom bodes well for more shared learnings and further innovation in the carbon removal field.

• Equity: Heirloom is forward thinking about equity despite its early stage of development.

Let me know what you think about this deep dive, and what you would like to see in future posts like this in the comments below. Also, reach out to me on LinkedIn if you’d like to run your carbon removal innovation through the MOBILE Framework. And as always, feel free to share this with others!

The views expressed in this post are mine alone and no compensation was received for publishing it. To receive regular ideas and analyses on carbon removal and the new carbon economy, please subscribe below. If you enjoyed this post, please share it with friends. And if you’d like to get in touch, you can find me on LinkedIn and Twitter.