Brent Contstantz is moving upstairs.
The founder of Calera, a company that wants to sequester carbon dioxide derived from industrial plants in cement filler, has been replaced as CEO with William Roach. Until recently, Roach was the CEO of UTS Energy, an oil sands company in Canada that Total bought earlier this month.
Contstantz is still a board member, according to the company's web site.
A company spokesperson said that the change occurred in the last few weeks, but to the outside world, it looks sort of sudden. Last week, Constantz presided over a webinar about Calera's technology. Calera has not put out a release on the changes yet. The UTS transaction only concluded October 14. (Constantz is the one with the plaid tie in the picture. He's sitting next to some guy from England.)
Calera is one of most controversial companies in green. The company claims it can take carbon dioxide and seawater and produce calcium carbonate, or limestone, which can then be mixed into cement or other industrial products.
Contstantz in an interview earlier this year ticked off the potential benefits: The world mines 36 billion tons of aggregate and limestone a year and generally, these materials are harvested from surface mining operations. Producing construction filler from CO2 would thus curb this environmental hazard. Likewise, it would take factory emissions that otherwise would contribute to global warming and transform them into an economically valuable commodity. Investor Vinod Khosla is a prominent backer. Some have claimed that it could be the star company in the Khosla Ventures portfolio.
Critics -- and there are many -- have maintained that the transformative process generates more carbon dioxide than it sequesters and consumes an inordinate amount of energy.
The critics, though, don't fully understand calcium carbonate, Constantz argued earlier this year.
"Calcium carbonate is just a chemical formula," he said, denoting a substance that consists of molecules containing calcium, carbon and oxygen atoms in a specific ratio. The key is that different crystalline forms, or polymorphs, of calcium carbonate occur naturally. Textbooks identify around nine forms -- Aragonite, Calcite, etc. -- of calcium carbonate, he said. If you studied Calera's business plans with those forms involved, you could come to the same conclusion to which the critics have jumped, he argued.
But in reality, approximately 30 polymorphs occur in nature. Many of the more exotic forms produced by corals, however, are initially unstable and revert to one of the more familiar nine forms listed in textbooks, he said. Calera manages to exploit these exotic polymorphs in the way it controls the reaction between seawater and carbon dioxide. It does not rely on magic catalysts. Newsweek listed the company's process as one of its top ten green ideas last week.
Constantz has been studying bone mineralization for years. Bone generation and bio-mineralization have been the basis of his previous startups and sixty-something patents. Some of the insights into these polymorphs have come through his work at the Stanford Linear Accelerator.
He's not the first founder to step down as CEO. Earlier this month, Peter Corsell, former CEO of GridPoint, stepped down. Meanwhile, traditional energy execs like Amyris CEO John Melo (BP alum) have crowded into green.
Here is a video of Constantz describing the process in more detail.