BREAKING  Carba closes $6M round led by Rusheen Capital & CanopyGen Microsoft buys 44,000 tonnes of biochar carbon removal $7M U.S. Department of Energy grant - Carbon Negative Shot Certified 1,000+ year durability by Isometric First commercial facility live in Burnsville, MN Goal: remove 1 billion tons of CO2 by 2035
Company Profile Climate Tech Minneapolis, MN Est. 2021
Carbon Removal · Biocarbon · B2B

Carba

They dug carbon out of the ground for a century. This company gets paid to put it back.

Carba logo and tagline: We transform waste into valuable biocarbon

THE SUBJECT: A charcoal-black company logo against strata of stone. Look closely and the layers are the whole pitch - carbon, pressed down, staying put. Carba means to keep it there for a thousand years. Longer than most countries have existed.

$6M
Latest Round (2025)
44,000t
Microsoft Offtake
1,000+
Years Certified
~19
Employees
The Story

A company whose entire product is convincing a dead tree not to rot

Here is a fact about a tree that most business plans ignore: a tree is a machine that pulls carbon dioxide out of the air, for free, using sunlight, and then locks it into wood. This is, if you think about it, exactly the thing that dozens of well-funded startups are now trying to do with giant fans and industrial chemistry. The tree already did it. The problem is that when the tree dies, it rots or burns, and all that captured carbon goes right back into the sky. So the atmosphere gets a refund.

Carba, a company based just outside Minneapolis, has looked at this arrangement and decided the interesting part is not the capture - nature handles that - but the staying put. Its whole business is stopping the refund. You take low-value waste biomass (dead trees, yard clippings, the biogenic stuff nobody wants), you char it in a reactor into a stable, coal-like material called biochar, and then you bury it somewhere with no oxygen so the microbes that would eat it simply can't. Char plus no oxygen equals carbon that sits still. A registry called Isometric has certified that it sits still for more than 1,000 years.

The founders call this "reverse coal mining," which is a good line because it is literally true. Humanity spent about two centuries digging fossilized carbon out of the ground and setting it on fire. Carba proposes to run the tape backwards - carbon in, ground down, sealed up - and to get paid for each ton it re-buries. The buyers are companies with net-zero commitments and, increasingly, hyperscale data-center operators who need very durable carbon removal and are willing to sign multi-year contracts to get it.

The most Carba detail of all is where they bury it: the landfill you already drive past. There is existing infrastructure, permits, and a steady stream of waste biomass showing up daily. And the biochar, it turns out, behaves like an activated-carbon filter on the way down - potentially adsorbing PFAS, mercury, lead, and assorted landfill nasties. One product; two problems solved. That is the kind of quiet double-duty that tends to survive contact with a spreadsheet.

"Reverse coal mining." We dug carbon out and burned it for 200 years.
Carba gets paid to put it back - and to clean the landfill while it's down there.
The Mechanism

How you turn garbage into a thousand-year vault

1

Collect

Locally sourced waste biomass - dead trees, yard waste, biogenic scraps - is gathered near existing landfill infrastructure. The material already captured the carbon; Carba just intercepts it before it rots.

2

Char

Carba's patent-pending autothermal pyrolysis reactor converts the biomass into high-carbon biochar. "Autothermal" means it runs on the energy of its own process - no external power source required.

3

Bury

A patent-pending anoxic burial method seals the biochar in oxygen-starved conditions inside a landfill, where microbes can't degrade it. Certified permanence: 1,000+ years.

What Carba Sells

Two things: certified removals, and the carbon itself

Permanent Carbon Credits

Registry-certified (Isometric) carbon dioxide removal credits with 1,000+ year durability. Corporate buyers with net-zero targets purchase them - most notably Microsoft, on a five-year, 44,000-tonne agreement.

The Carba Reactor

A proprietary, modular pyrolysis reactor designed to be dropped in beside existing waste infrastructure. Energy-efficient by design, it's the piece that makes the decentralized model economically plausible.

Biocarbon for Industry

High-durability biocarbon sold as a fossil-input substitute - for tires and rubber, metals and steel, asphalt and concrete (bitumen replacement), and as filtration media.

Landfill Remediation

Deployed as alternate daily cover, the biochar can adsorb pollutants - PFAS, mercury, lead, PCBs, dioxins, furans - while it stores carbon. The removal and the cleanup happen in the same batch.

The Argument, In One Chart

Why "let plants do the capture" is the whole point

Carbon-removal approaches compete on durability and cost. Biochar's pitch is that photosynthesis already paid for the expensive part - pulling CO2 from the air - so the work that remains is cheap and permanent. Illustrative durability comparison below (approximate, for orientation):

Carba biochar
1,000+ yrs
Geologic DAC storage
1,000+ yrs
Forestry / trees
~decades
Soil compost
~years

Approximate, illustrative only. Durability figures reflect general category characteristics, not certified per-project values.

The People

A "Genius" grant, a Berkeley PhD, and a 20-year lab partnership

AJ

Andrew Jones, PhD

CEO & Co-founder

PhD in Chemical Engineering from UC Berkeley; summa cum laude from the University of Minnesota. Previously founded and sold Activated Research Company to Japan's Shimadzu. Inventor of Carba's pyrolysis and storage technology. Winner of the 2023 MN Cup Grand Prize.

PD

Paul Dauenhauer

Co-founder & Senior Advisor

MacArthur "Genius" Fellow (Class of 2020) and Distinguished McKnight University Professor at the University of Minnesota. Twenty-plus years in biomass conversion research; a serial founder of five startups.

NH

Nick Halla

Co-founder / Founding Advisor

First employee and Chief Strategy Officer at Impossible Foods. Chemical engineering from the University of Minnesota; MBA and MS in Environment & Resources from Stanford.

RB

Rich Baker, PhD

Chief Operating Officer

Leads R&D, engineering, and operations. Former CTO at Protolabs and PaR Systems; PhD in Engineering from Cornell; holds 18 U.S. patents across automotive, aerospace, and medical devices.

Jones and Dauenhauer first met as student researchers at the University of Minnesota in 2005. The company is, in a sense, the twentieth year of a conversation that started in a lab.

Follow The Money

~$6.1M raised, plus a $7M federal grant

Round / SourceAmountDateBackers
Seed / Investment Round$6.0MDec 2025Rusheen Capital, CanopyGen, Groove, Demos Fund, Collaborative Fund, Incite, Grid Catalyst
Project Financing & PRIs$2.5M2025MN Climate Innovation Finance Authority, JLL Foundation, Venn Foundation
DOE Grant (Carbon Negative Shot)$7.0M2024U.S. Department of Energy

Total equity/PRI funding ≈ $6.09M per public records. Grant funding is non-dilutive.

On The Record

What they said

Our decentralized model - using existing landfill infrastructure and locally sourced waste biomass - can scale rapidly and cost-effectively.

Andrew Jones · CEO, Carba

The team has built a credible, scalable business model to monetize biomass waste to clean landfills for future generations.

Jim McDermott · Rusheen Capital

Their rigor in measurement, permanence, and cost-efficiency turns an environmental liability into long term value.

Sonia Tsao · Partner, CanopyGen
Latest Updates

The last twelve months

Dec 2025

Closed a $6M investment round led by Rusheen Capital Management and CanopyGen.

Dec 2025

Brought its first-of-its-kind biocarbon technology online at the Burnsville, Minnesota facility.

Apr 2025

Announced a five-year agreement to deliver 44,000 tonnes of carbon removal credits to Microsoft.

Early 2025

Secured $2.5M in project financing and program-related investments from Minnesota-based funders.

2024

Selected for a $7M U.S. Department of Energy grant under the Carbon Negative Shot Pilot.

Marginalia

Seven things worth knowing

  • Carba describes its process as "reverse coal mining."
  • Co-founder Paul Dauenhauer is a MacArthur "Genius" Fellow.
  • The two founders met in a U of M lab back in 2005.
  • CEO Andrew Jones sold a prior company to Shimadzu of Japan.
  • Co-founder Nick Halla was employee #1 at Impossible Foods.
  • The biochar can filter PFAS, mercury, and lead as it's buried.
  • The reactor is "autothermal" - it runs on its own heat.
Watch & Read

Go deeper

Interviews & demos: Search "Carba carbon removal" or "Andrew Jones Carba" on YouTube for founder talks and reactor walk-throughs. Carba has not published a single official channel URL we could verify, so we're pointing you to the source rather than guessing a link.

YouTube: Carba carbon removal biochar →

Directory

Find Carba

Quick facts: Carba

Carba is a Minneapolis-area climate-tech company that turns low-value waste biomass - dead trees, yard waste, and other biogenic scraps - into a stable, charcoal-like material called biocarbon (biochar). Using a patent-pending autothermal pyrolysis reactor and an anoxic (oxygen-starved) burial method, Carba locks carbon away for a certified 1,000+ years, most notably inside existing landfills where the material can also filter pollutants. The company sells the resulting permanent carbon-removal credits - including a five-year, 44,000-tonne deal with Microsoft - and aims to remove a billion tons of CO2 by 2035.

Founded
2021
Headquarters
Eden Prairie, Minnesota, United States
Founders
Andrew Jones (CEO & Co-founder), Paul Dauenhauer (Co-founder & Senior Advisor), Nick Halla (Co-founder / Founding Advisor)
Team size
~19 employees
Products
Carba Reactor, Permanent Carbon Removal Credits, Biocarbon for Industry, Landfill Carbon Storage & Remediation
Notable
Signed a five-year, 44,000-tonne carbon removal credit agreement with Microsoft (2025), Awarded a $7 million U.S. Department of Energy grant under the Carbon Negative Shot program, Methodology certified by Isometric for 1,000+ year carbon durability

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