Tell me about your breakthrough technology.
I’ll start by contrasting it to the way we make cement now in high-temperature kilns that go up to 1,400 degrees Celsius and use limestone, which is 50% CO2 by weight. Our process is an electrochemical route. I am an electrochemist by training. Instead of thermal decomposition, it is chemical decomposition. Because we do this, we can take calcium-bearing materials other than limestone.
We call ourselves true zero rather than net zero. There’s no addition or subtraction of CO2 necessary. We are replacing that Portland cement kiln with another manufacturing process. That will allow us to compete on cost.
What have you produced so far?
We have a pilot plant that produces 250 tons of cement per year. We’ve had our first commercial application of Sublime cement at the Seaport. And with Turner, we poured a foundation using our cement. It was a boring day in construction because everything worked according to plan, but it was a very exciting day for us.
You received $87 million as part of the Department of Energy’s $6 billion in decarbonization grants earlier this year.
It was a huge pot of money, and it could not have been better timed. There’s this cleantech 2.0 wave going on. A lot of technologies didn’t make it through cleantech 1.0. It was understood to be a bit of a failure. The folks at the White House were thinking, there’s been this Cambrian explosion of cleantech 2.0, but how do we make sure this happens differently this time. Especially because industrial cleantech goes through awkward teenage years.
What happens for you now?
Business as usual. This is our one shot to get this right. Many of the other projects [that received DoE funding] were rather normal technologies, like carbon capture and calcined clay. But ours is new. It’s the breakthrough.
What got you interested in cement?
I have always been interested in climate. Growing up, I had a ‘save the endangered species’ coloring book and a ‘save the whales’ t-shirt was my favorite t-shirt. Chemistry is pure and utter magic. It’s a way of solving problems. Many of our problems are caused by chemistry, but they are also solved by chemistry, and as our knowledge of chemistry grows we have more ability to solve our problems.
After my Ph.D., I went to MIT to work with my mentor Yet-Ming Chiang who is a serial entrepreneur. It was his idea to work on cement. We are both battery scientists and electrochemists. The utility sector is the biggest tranche of emissions. It’s largely figured out from the science perspective. Where is science needed? That’s cement and steel, each of which is 8% of global emissions. Assuming you have green energy, how will you use that to create green cement? If you find a 1% improvement in cement, you will have a much bigger impact than in batteries.
Do you intend to work on your own or partner with big cement companies
We will do what it takes. We’re nerds. We like electrochemistry. If you can license the technology and sell the equipment and operate as a service, that is a way you can have swift and massive impact.
I do think it takes a lot of time to build trust in the cement industry. They don’t believe things they see in powerpoints and spreadsheets, and they shouldn’t. That’s why our focus is on scale. The last test is building this demonstration plant in Holyoke [expected to open as early as 2026] and showing people it works and has viable economics. Until then there are always going to be skeptics. And that’s correct: You should be skeptical of startups.
Have you found the big cement companies open to discussion?
Six years ago, they would’ve dismissed this and kicked the can down the road. Now it is much different. We are being taken seriously by the cement companies. If you ask the CEOs of major cement companies, they will say their number one priority is sustainability.
Blended cements are also changing the way people think about cement. When you go to a job site, contractors aren’t talking about the crystal structure. They are talking about performance. That lets you solve the right problem, which is to create a low-cost performance cement, not a Portland cement.
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