For every 1,000 kilograms of cement produced worldwide, 600 kilograms of carbon dioxide are released into the atmosphere. If you don't think that's a lot, consider that the world produced about 4.2 billion tons of cement last year. This is large enough to account for about 8% of all carbon pollution.
This is a big question, and one that weighed heavily on Gurinder Nagra's mind when he was a graduate student at Stanford University. That wasn't the focus of his PhD – it's carbon capture and storage – but he couldn't stop thinking about it. He told TechCrunch that of the three energy venture classes he took in two years, “each time they focused on cement.”
Pollution wasn't the only problem bothering Nagra. “Emissions is one aspect. The other is that this is a dirty industry that is overlooked, but in some ways necessary for modern civilization. It's everywhere,” he said. . Doing something with cement could have ramifications far beyond climate change.
“The companies that control the supply of cement behind the scenes pretty much run the world. They have a lot of power, although not as much as the oil industry,” he said. “It costs $1 billion to build a new factory. When a company decides to build a factory in a developing or developing country, it controls the fate of that developing economy's trajectory. can.”
So, after completing his degree in 2020, Nagra founded Furno. The goal was simple and ambitious: to transform the cement industry.
Many developing countries are unable to finance new factories or attract businesses, so they end up importing cement and paying high costs in the process. “We find that many developing countries actually pay more for cement than developed countries, in some cases paying three to four times the market price.”
Furno's answer was to develop a cement kiln that was smaller, more efficient, and more flexible than the giant cement kilns favored by industry today. While each unit may produce less than today's industry standard designs, it promises to be cheaper to manufacture and consume less energy in operation.
Furno's compact kiln bucks the trend in today's cement industry towards larger equipment. Large rotary kills can put pressure on operating costs, but in the process new plants become so large that each plant is essentially a bespoke facility and requires significant labor costs to construct. By building smaller kilns, Furno hopes to reduce capital expenditures through mass production and reduce operating costs through energy efficiency.
Here's how: The most commonly used type, Portland cement, is produced by heating calcium-containing minerals, usually from limestone. These minerals are sent to a kiln, where they are heated to over 1,110 degrees (600 degrees Celsius), almost always using fossil fuels. As is known, the calcination process produces lime (calcium oxide) and carbon dioxide. There are several other steps that take place in a modern cement factory, but this is the most important one. The raw material enters the horizontal kiln at one end and is forced through an intense flame to the other end, where it emerges as clinker.
Current kilns are not very efficient. A Chinese study showed that only about 30% of the heat in the kiln accelerated the firing reaction. The rest was lost. “He can stand 40 feet away from the kiln and feel the heat radiating off the walls of the equipment,” Nagra says.
Furno's kiln, on the other hand, is much more efficient, reducing emissions from fossil fuels by more than 70%. This is achieved by rotating the kiln vertically, filling it with raw material that has been ground to the desired dimensions, infiltrating it with combustible gas (natural gas, biogas, or hydrogen) and igniting it. By varying the amount of gas and oxygen flowing through the column, the Furno controls where the flame starts inside, ensuring more heat is fed into the firing process rather than escaping from the kiln. Less fuel means less pollution, and carbon capture can help reduce emissions even further. The raw material flows continuously into the top of the kiln and the clinker falls from the bottom of the kiln.
Additionally, Nagra said the company has an avenue to use recycled cement from old concrete because it allows for more precise control of the flame front in the kiln. Since recycled cement has already been calcined, it does not use as much fuel in the kiln. Additionally, because Furuno's kilns are small, it may be possible to remanufacture cement directly at the construction site.
This approach helped Furno raise a $6.5 million seed round, TechCrunch has learned exclusively. The round was led by Energy Capital Ventures with participation from Cantos, Neotribe, and O'Shaughnessy Ventures.
Furno has already attracted the attention of ready-mix concrete companies that need to buy cement from vertically integrated companies. “They have to buy cement from competitors, which is not a very fair market.” Modular kilns offer them the opportunity to have some control over their own destiny.
Furno's focus on the kiln and the software that controls it sets it apart from many of its competitors, which instead focus on changing the chemical reactions themselves. By improving the kiln and leaving most of the rest alone, Furno may be able to sell itself more easily to an industry unaccustomed to change.