The Role of Biochar as a Carbon Removal Technology
The idea in brief
- Tech-based carbon removal is a crucial component in fighting climate change.
- Biochar is an elegant and highly efficient removal solution that combines nature and technology to permanently draw down carbon.
- Carbo Culture builds biochar technology that can scale to a level that’s relevant for fighting climate change.
- Companies should support carbon removal early so that it can be at scale by 2030.
The challenge is massive: In order to prevent the worst effects of climate change, we need to reduce global annual CO2 emissions from about 35 gigatons per year as of 2020, to net zero by 2050. To accomplish this goal, reducing emissions through the transition to renewables is not enough. We need to remove carbon from the atmosphere.
However, effective carbon removal requires solutions that do not exist at a large scale today, and the market for technical carbon removal is still nascent.
With the emergence of net-zero targets, the private sector has sprung into action with companies like Stripe, Shopify, Microsoft, and Swiss Re taking the lead by buying carbon removal credits from novel technologies to help them get to scale. Much more support is needed.
In this brief article, I will argue that among the many solutions, biochar as a carbon removal technology elegantly combines the efficiency and scalability of natural carbon drawdown with the permanence of advanced technology solutions.
Biochar in context
Biochar technology sits between traditional, nature-based solutions engineered solutions. To accurately understand biochar’s role within the myriad technologies, consider the illustration below.
Broadly speaking, there are two buckets of offsets that companies can choose to support: Traditional offsets and carbon removal. Traditional offsets are long-established and consist of carbon avoidance (for example, improved cookstoves are more fuel efficient than traditional open-fires, hence limiting additional CO2 emissions) as well as forestry credits (forestation involves planting trees over large areas or allowing forests to regrow naturally). These offsets are numerous and cheap, which is why most market players engage with them.
We applaud firms investing in verified forestry credits. However, the urgency of climate change requires us to go further than nature-based solutions. A tree has a set lifetime before it dies and re-releases carbon into the atmosphere; the permanence is comparatively low. Enter tech-enabled carbon removal: ultra-permanent engineered solutions for keeping carbon out of the atmosphere. There are ~10 different approaches out there.
The most famous is probably direct air capture with its signature firm Climeworks. The Swiss company uses fans to pull carbon from the atmosphere and stores it deep underground with their partner Carbfix. Another carbon removal approach is enhanced mineralization, which involves accelerating the natural processes by which various minerals absorb CO2 from the atmosphere. Ocean alkalinization is yet another approach. It involves adding alkaline substances to the ocean, where they absorb CO2. What these solutions all have in common is that they have a technical aspect to them: either machines or chemistry principles help remove and store carbon.
Biochar is an elegant approach at the intersection of nature and engineering
Biochar technology combines natural and engineered approaches for carbon drawdown. It represents the best of both worlds. As they grow, plants capture atmospheric carbon through photosynthesis (we already know how this drawdown process works from forestry offsets). The challenge that biochar overcomes, however, is that the carbon from plants is re-released into the atmosphere once biomass rots or burns. This is where the engineered part of biochar comes in: pyrolysis technology uses high temperatures to ‘shock’ waste biomass into a state in which it becomes ultra stable. In the case of Carbo Culture’s biochar, that permanence is 1000+ years. We believe that this will give humanity sufficient time to massively reduce our carbon footprint.
Another result of the elegant combination of nature and engineering lies in its efficiency. By leveraging the natural processes of biomass to draw down carbon, we do not have to invest in machinery to take CO2 out of the air. We basically get that service for free. All we need to do is make sure that the carbon does not escape back into the atmosphere once plants have drawn it down.
As an output of the process, biochar comes in the form of small, hard pebbles that are safely stored into the soil. The material also has the advantage of being distributed. It’s hard to imagine any way in which the carbon would be re-released before the 1000+ years are over (the only way we could imagine is setting every individual pebble on fire with a blowtorch). Furthermore, the positive effects of biochar in soils are becoming widely understood. Using it in cement could provide a scalable carbon sink in the future.
Carbo Culture brings scale to the biochar world
Biochar technology combines the power of nature to draw down CO2 with the human ingenuity of pyrolysis to fix the carbon. However, there remains one big challenge: scale. Good data on annual biochar production is hard to find, but one estimate put European production at a mere 0.02 million tons per year in 2020. We need to get to hundreds of millions of tons to make biochar an effective tool to fight climate change — 4 orders of magnitude higher!
While biochar has existed for a long time, the industry is only just awakening to its role in fighting climate change. Biochar projects have started popping up, often with a laudable focus on developing countries, using biochar to aid local communities. We believe that this leads to linear growth — one more pyrolyzer here, one more there. However, looking at the numbers we need to get to, we also require a step change to get from linear to exponential growth.
At Carbo Culture, we are enabling this step change. We are piloting a new biochar technology, called Carbolysis, at our site in California that does not rely on significant external energy sources to fix the carbon. We are also increasing the reactor size to ingest more waste biomass and therefore reach a higher efficiency in our operations. Ultra-high heat in the process (800+ degrees Celsius ) enables us to get rid of bio-oils.
By 2024, we will finish our first commercial facility in Europe to demonstrate the global deployability of our technology. From there, we will take a platform approach with multiple facilities, ultimately resulting in the removal of hundreds of thousands of tons of CO2. This step change is not just one of technology, it is also one of finance. That is why we have taken a path of venture funding with partners like True and Cherry Ventures. Lastly, we are also beginning our work on policy together with our partners at the Negative Emissions Platform to ensure that nascent removal technologies receive strong governmental support.
It is becoming abundantly clear that carbon removal will be key to achieving ambitious climate targets. What is also clear is that out of the many carbon removal solutions, biochar is uniquely positioned to merge the efficiency of natural carbon drawdown with the technology needed to store carbon permanently.
To achieve scale, we require partners who understand that biochar urgently requires innovation to become a relevant entity in carbon removal. Partners like patch.io and puro.earth are leading the way in nudging the market toward purchasing sophisticated credits. However, many companies believe that a large amount of technical carbon removal credits will simply appear by 2030 after firms have offset their own emissions. Au contraire: alongside reducing emissions, the revolution to scale technical removal needs to be supported today so that we can have a massive impact by 2030.
If you would like to support Carbo Culture, contact me at tim@carboculture.com
