Bill Gates visited the startup Modern Hydrogen on Wednesday and had the chance to fill a pothole in the company’s Woodinville, Wash., parking lot with an asphalt that sequesters carbon captured from natural gas. (Gates Ventures Photo)

Bill Gates grabbed a wheelbarrow and shovel on Wednesday to fill a parking lot pothole with a new carbon trapping asphalt.

Gates was visiting Modern Hydrogen, a Seattle-area climate tech startup that has developed a device for cracking natural gas molecules, producing hydrogen for fuel and a product known as solid carbon that has a variety of industrial applications — including as a key ingredient in asphalt.

“Bill was great,” said Tony Pan, Modern Hydrogen’s CEO, of the Microsoft co-founder’s visit. “He was super engaged, hands-on.”

Gates had the chance to check out a demo version of the company’s methane pyrolysis reactor, which takes natural gas from fossil fuels or biogas from sources like manure to make pure hydrogen. The hydrogen fuel burns cleanly, producing water vapor as a byproduct. It can be used for energy production, in industrial processes like steel manufacturing, and in fuel cells.

In the past few months, Modern Hydrogen has deployed demo reactors to two customers: Portland’s NW Natural, which is Oregon’s largest natural gas utility, and an unnamed customer in Miami.

The startup recently moved to a facility in Woodinville and is developing a second-generation, larger version of the reactor that it will be able to manufacture at the new location.

Modern Hydrogen got its start in 2015 at Intellectual Ventures, an innovation hub created by former Microsoft researcher Nathan Myhrvold with backing from Gates. The startup, which was originally called Modern Electron, initially focused on devices that paired with home furnaces and hot water tanks to capture the appliances’ wasted heat and turn it into electricity. It recently pivoted to hydrogen.

Gates was a founding investor and has visited the company over the years. “He likes the technical stuff,” Pan said, adding that “he kind of nerded out” on the technology on this week’s tour.

Gates, who created the climate-focused research and investment organization Breakthrough Energy, has been an enthusiastic supporter of hydrogen fuel. In June 2022, he posted a Gates Notes touting the so-called “Swiss Army knife” of clean energy given its versatile applications.

Bill Gates, right, gets hands-on with Modern Hydrogen’s solid carbon. (Gates Ventures Photo)

The fuel, however, presents some significant challenges. It’s costly to transport, so it makes sense to produce and use it at the same location. Modern Hydrogen’s reactors are small enough — the initial demos are about half the size of a shipping container — so they can be placed where the fuel is needed.

Another benefit of the reactors is they’re self-powered: in optimal conditions, about one-quarter of the hydrogen produced will be recycled back into the system to power the generation of more fuel.

And there’s the question of what to do with the solid carbon. The material can be used in applications such as tires, ink and rubber. The Modern Hydrogen team realized that the solid carbon it was producing was a great match for use in asphalt, no extra processing required. The solid carbon can replace some of the fossil fuel-derived bitumen used to bind the sand and gravel used in asphalt, which cuts the asphalt’s climate impacts, sequesters the carbon, and saves money.

“We found a high value application,” said Pan, who said the asphalt binder market is massive.

The company has raised $100 million in venture capital and has a team of 60 employees.

There are other hydrogen fuel efforts underway in Washington. In October, the Pacific Northwest was selected to become one of seven Regional Clean Hydrogen Hubs (H2Hubs). The U.S. Department of Energy supported hubs are meant to kick-start the nascent hydrogen fuel sector and each will be eligible for roughly $1 billion of federal funding.

Editor’s note: Story updated April 12 to replace references to “carbon black” with “solid carbon.”

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