← Back

Carbon Offsets 101: Biomass Primer

Commons Team
June 4, 2021

Biomass conversion projects can sequester carbon for 100s to 1000s of years. By pairing the ability of plants to absorb carbon dioxide with engineered technology, biomass projects create durable, carbon-rich materials that are easily stored.

How does Biomass Conversion work?

The word biomass is a catch-all term that describes any plant or animal material, such as leaves, tree trunks, and animal waste. Plants increase their biomass by absorbing carbon dioxide from the air and using it to physically grow larger. When part or all of a plant dies, it falls to the ground and breaks down, releasing carbon back into the soil and atmosphere.

Biomass conversion projects take advantage of plants’ natural ability to absorb and store carbon. Instead of letting plant biomass decompose and release carbon dioxide, they convert it into a different form that takes much longer to break down and/or can be stored more permanently. There are many types of biomass conversion projects, including those using biochar and bio-oil injection.

Biochar is a type of charcoal that is made from burning biomass at high heat without oxygen. Biochar is a very stable material, can take several hundred years to break down, and can be added as an enricher to agricultural soil. Many biochar producers use biomass from forest or agricultural waste. CarbonPlan, an independent nonprofit that evaluates climate solutions, estimates that biochar could help sequester 1.1-3.3 gigatons of CO2e per year.

Bio-oil is made in a similar process as biochar. One provider, Charm Industrial, is developing methods to inject bio-oil into deep geologic storage, which will keep the carbon contained in the oil underground for thousands of years. CarbonPlan estimates that projects like these could sequester anywhere between 1-77 gigatons of CO2e per year.

Biomass carbon offset lifecycle

Pros: Long Duration Storage and Community Benefits

Biomass conversion because it stores carbon for a long time. Storing carbon out of the atmosphere for long periods of time will be important as society works to become net zero by 2050.

Producing and storing bio-oil can leverage skills and infrastructure currently used by the fossil fuel industry. Biomass conversion projects can work towards inclusive economic growth by working with communities that may be negatively economically impacted by a transition towards a greener economy.

Cons: Early Stage with Hurdles to Overcome

While they are innovative and based on well-developed technologies, biomass conversion projects have yet to be deployed and proven at scale. Because of this, carbon credits from these projects are also in limited supply.

The process used to generate biochar and bio-oil (“pyrolysis”) involves burning biomass. While this is an established process, projects must take proper steps to ensure harmful air pollution is not being released.

Creating biochar and bio-oil requires growing, collecting, transporting, and burning biomass. Each of these steps generates carbon emissions. It is important for projects to disclose these emissions and to ensure that they are not greater than the amount of carbon being stored.

Commons Biomass Offset Considerations

As many of these biomass conversion projects are early-stage or still being scaled, Commons looks for project owners that are transparent, accessible, and communicative. Our team also looks for projects that demonstrate via a detailed Life Cycle Analysis that their process as a whole is carbon negative.

Projects Commons recommends

Commons supports one biomass conversion project through Charm Industrial. Their team uses waste biomass to create bio-oil through a process called “fast pyrolysis”. This bio-oil is a stable, pumpable fluid that has a high carbon content. Charm leverages Environmental Protection Agency disposal wells to pump bio-oil and other high-carbon industrial byproducts deep underground, sequestering them for thousands of years. Early purchases help Charm scale up their own bio-oil production and come down the cost curve.

See all projects in the Commons Offset Portfolio →


Fact Sheet: Bio-Energy, Carbon Capture, and Sequestration, American University, Washington, DC

Fact Sheet: Biochar, American University, Washington, DC

CDR Primer, J Wilcox, B Kolosz, & J Freeman

Commons Team
June 4, 2021

stay connected

Twice per month we send the latest updates from the Commons app and community.
Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.
Commons Earth icon

Let’s stay connected

Get tips, guides, and inspiration for low-carbon living.
Thanks! You're now subscribed to the Commons newsletter.
Oops! Something went wrong while submitting the form.