BREAKING  Furno Materials shrinks the cement kiln to fix 8% of global CO2 SEED  $6.5M oversubscribed round led by Energy Capital Ventures GRANT  $20M from the U.S. Department of Energy for Chicago micro-kilns SPEC  ASTM C150 certified - tested at 2x standard strength EFFICIENCY  Furno Brick runs at 80%+ thermal efficiency vs ~30% EMISSIONS  NOx and SOx eliminated; 70%+ less fossil CO2 BREAKING  Furno Materials shrinks the cement kiln to fix 8% of global CO2 SEED  $6.5M oversubscribed round led by Energy Capital Ventures GRANT  $20M from the U.S. Department of Energy for Chicago micro-kilns SPEC  ASTM C150 certified - tested at 2x standard strength EFFICIENCY  Furno Brick runs at 80%+ thermal efficiency vs ~30% EMISSIONS  NOx and SOx eliminated; 70%+ less fossil CO2
Company Profile · Climate · Hardware
Furno Materials logo - a red F

Furno Materials

The company that decided cement's biggest problem was the size of the kiln - and built one small enough to sit on a construction site.

A red "F," cast like something that has been through fire and come out harder. The mark is the whole thesis: heat, made small, made clean.

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The Story

A very hot, very old machine

Cement is the most boring important thing in the world. It is the gray powder that, mixed with water and gravel, becomes concrete, which becomes basically everything - buildings, bridges, sidewalks, the parking garage you are annoyed at. It is the second-most-used substance on earth after water. It is also, and this is the part nobody puts on a billboard, responsible for something like 8% of global carbon dioxide emissions. If cement were a country, it would be one of the top emitters on the planet, which is an awkward thing to be for a product whose main personality trait is "gray."

The reason cement is so dirty is chemistry plus machinery. To make it, you heat limestone to around 1,450 degrees Celsius, which releases CO2 twice: once from burning fuel to generate the heat, and once from the limestone itself, which sheds carbon as it turns into clinker. You do this inside a rotary kiln, which is a horizontal steel tube that can run more than a mile long, rotates slowly, and captures only about 30% of the heat it generates. The other 70% goes, roughly, into the sky. This design is over a century old. It works. It is enormous, expensive, filthy, and it has been the only real option for a very long time.

Furno Materials, founded in 2020 and based in South San Francisco, looked at that mile-long tube and asked the question that founders ask about legacy industries right before they annoy everyone in them: what if it were small? Not a little smaller. Small enough to fit on a construction site. Small enough to build in a factory and ship. Small enough that you could put cement production wherever concrete is actually poured, instead of trucking the powder in from a plant a hundred miles away. The answer they built is called the Furno Brick, and the whole company follows from it.

By the numbers

The math that makes it interesting

8%
of global CO2 comes from cement
80%+
Furno Brick thermal efficiency
70%+
less fossil-fuel emissions
2x
the ASTM strength standard, tested
Infographic

Where the heat goes

A conventional rotary kiln is a leaky bucket for heat. Furno's vertical micro-kiln is built to catch it. Same chemistry, radically different thermodynamics.

Traditional rotary kiln~30% efficient
30%
Furno Brick micro-kiln80%+ efficient
80%+

Gas-based (oxyfuel) combustion also eliminates NOx and SOx entirely - the pollutants behind smog and acid rain - and reaches zero emissions when run on hydrogen.

Products

What Furno actually makes

The core product

Furno Brick

A modular, prefabricated cement plant - billed as the world's first nimble, carbon-neutral one. Instead of a mile-long tube, it uses compact vertical kilns running above 80% thermal efficiency, roughly double a standard plant. You can standardize it, ship it, and scale it up by adding units as demand grows.

The engine

Micro-kiln technology

Novel combustion and kiln design that burns gas-based fuels instead of solid ones. It cuts fossil-fuel emissions at least 70%, eliminates NOx and SOx completely, and can hit zero emissions on hydrogen - fuel-flexible by design, so it bends to a shifting regulatory landscape.

The output

ASTM-certified OPC

Real Ordinary Portland Cement, not a green-but-weaker substitute. Furno's cement earned ASTM C150 certification and tested at up to 2x the industry strength standard - so it drops into existing concrete recipes with no performance trade-off.

We have the ability to produce Ordinary Portland cement now, adapt to a range of gas-based fuels, and meet demand where it exists while still abiding by a shifting regulatory landscape.
- Gurinder Nagra, Founder & CEO
Why it matters

The point is deleting the distance

Here is the thing about cement that makes Furno's small-kiln idea more than a novelty: cement is heavy and cheap, which means moving it is a large and stupid fraction of its cost and its emissions. If you are a concrete producer in Chicago and your cement comes from a plant a hundred miles away, you are paying to truck a very heavy gray powder down a highway, and every mile of that is money and carbon. Furno's pitch is that you should not have to. Put the plant where the demand is. Make the cement on-site, or nearly so, from local limestone and recycled material.

That is what a concrete producer can do with Furno: make its own low-carbon, standards-grade cement at the point of use, instead of buying it and hauling it. The benefits stack in a way that is unusual for climate products, which normally ask you to pay more or accept less. Here you get lower emissions, lower transport cost, a resilient local supply, and cement that meets or beats spec. The company's own framing - "revolutionizing cement, not reinventing risk" - is a tell. It knows that concrete producers are conservative for good reasons, because buildings fall down when materials fail, and it is selling drop-in performance rather than a science experiment.

There is also a bigger, slightly patriotic version of the argument, which is onshoring. Cement is strategic infrastructure, and making it locally instead of importing it is the kind of thing governments have started to care about a great deal. Furno's tagline - "Stronger Cement. Smarter Supply. A Resilient America." - leans into exactly that, and it helps explain why the federal government wrote them a very large check.

The founder

Gurinder Nagra

Founder & CEO

Furno's founder was born in India, raised in rural Australia, and trained in Earth Systems Science at Stanford before deciding that the highest-leverage climate problem was not a slogan but combustion chemistry. He holds a Bachelor of Advanced Science from the University of New South Wales and a Master of Science from Stanford. His argument, roughly, is that you cannot fix cement by tweaking the edges - you have to redesign the kiln, and then make it small enough that the industry can actually adopt it.

Stanford, Earth Systems Science UNSW, Adv. Science Combustion & kiln design Climate hardware
Funding

Who is backing it

The useful tell in Furno's cap table is that both venture capital and the U.S. Department of Energy backed the same hardware bet. When private money and the federal government agree, the technology risk is real and the prize is large.

RoundAmountDateLead / Source
Seed (oversubscribed)$6.5MMar 2024Energy Capital Ventures; O'Shaughnessy Ventures, Cantos, Neotribe, Breakthrough Energy
U.S. DOE grant$20MOct 2024DOE Office of Manufacturing & Energy Supply Chains
Furno had the best team, technology, business model and competitive advantages - it enables a level of decarbonization in a class all of its own.
- Vic Pascucci, Energy Capital Ventures
Partners & deployments

Where it goes to work

Chicago

Ozinga

The DOE-backed flagship: up to eight micro-kilns at Ozinga's Chinatown Yard, replacing ~60,000 tons of cement a year currently trucked in from 100+ miles away. Ozinga plans to power them with biogas plus recycled materials.

Announced Dec 2025

Maschmeyer Concrete

A partnership to pioneer onshored cement production - using Furno's kilns to upcycle roughly 90,000 tons of Maschmeyer's annual waste concrete into new, usable cement. Liability becomes feedstock.

Federal

U.S. Dept. of Energy

The $20M grant is more than money; it is a signal. The DOE emphasized job creation - about 50 construction and 30 permanent roles - particularly for workers displaced by coal-plant closures.

Latest updates

The recent record

December 2025

Maschmeyer Concrete partnership

Deal to pioneer onshored cement and upcycle ~90,000 tons of annual waste concrete into new cement.

October 2024

$20M DOE grant for Chicago micro-kilns

Funding to build up to eight low-carbon micro-kilns at Ozinga's Chinatown Yard, with a Series A signaled for early 2025.

March 2024

$6.5M oversubscribed seed round

Led by Energy Capital Ventures, to scale the Furno Brick and its micro-kiln combustion technology.

Amusements & asides

Five things worth knowing

Cement is the second-most-used substance on earth after water. Furno's whole pitch is making the second one behave like the first - local, and everywhere.

A traditional rotary kiln can run more than a mile long and still waste roughly 70% of its heat. Furno's vertical unit fits far smaller and keeps most of it.

Every metric ton of conventional cement releases about 600 kilograms of CO2 - before you have poured a single slab.

Furno's kilns emit zero NOx and zero SOx. Not less. None - the smog and acid-rain pollutants are designed out, not scrubbed down.

Watch & explore

Interviews & demos

Links open YouTube search results, since Furno maintains no single official channel we could verify.