Episode 55 | CO2 Cycle | Net Power





There are a few conversations that can change the course of your life. My conversation 3 years ago with today’s guest is arguably the reason for Energy Cast and my career turn back to utilities.

Bill Brown is the CEO of Net Power and CEO/Co-Founder of 8 Rivers Capital, both based in Durham, NC. Bill and longtime associate Miles Palmer founded 8 Rivers following the 2008 financial crisis. After serving as a longtime Managing Director at Morgan Stanley, Bill decided he wanted to “build something good for a change,” and all 8 Rivers business ventures are carbon-free. That also includes:


Bill describes 8 Rivers as focusing on “large, capital-intensive innovation.” Both he and Palmer had spent their careers working on “9 Commas (billion dollar) deals,” and these high stakes are part of their foundational keys to their unique business model. As Bill described it, that includes:


Net Power’s technology captures carbon from natural gas combustion, though it was originally conceived as a coal-fueled. As part of the American Recovery and Reinvestment Act of 2009, millions of dollars were made available for coal . However, when Net Power decided to shift to natural gas, those grants did not cover gas carbon capture and the company had to seek alternative funding. Bill says if he were in charge of the prizes, they would include a 10% revenue-sharing agreement whereby successful projects fund future projects.

The project had three additional partners, Exelon, a utility; Toshiba, the combustor and turbine manufacturer; and CB&I (McDermott), the facility contractor. The 50-MW, La Port, Texas test facility is also located at an Air Liquide facility to provide the Oxygen for the oxy-combustion process.

Carbon capture technologies are the family of technologies that aim to remove carbon dioxide from emissions on fossil fuel-burning power plants. You take out the carbon, these plants are as essentially clean from an emissions standpoint as nuclear or renewable energy.

Fossil fuels produce 63% of our power. Renewables excluding hydropower—10%. I have long argued that it would make more sense to cap or retrofit the existing fleet than build more intermittent energy sources.

However, carbon capture is challenging. For one, the exhaust is not pure CO2. It’s closer to 15% at most, and that makes pulling it out selectively challenging and expensive.

When you bolt on capture equipment to a traditional power plant, we call that “post-combustion carbon capture.” NRG, our guest from Episode 31 is doing that. It is proven and it works.

But in the past 10 years, there have been other suggestions for isolating CO2 before it comes out in the flue gas. There was no reason to focus on these technologies because no one really cared about CO2 until the last decade. CO2 isn’t a pollutant like Sulfur Dioxide and Nitrogen Oxides.

That has led to solutions like my guest from Episode 23 at Ohio State, who is using chemical looping to isolate CO2 from the flue gas, in the form of iron pellets.

The chemical looping and process our guest has developed fall into a family of technologies called “Oxy Combustion.” The reason why CO2 is only a fraction of the exhaust gas is because fossil fuels are burned in air, which is mostly nitrogen.

If you burned fossil fuels in only oxygen, you would get almost pure CO2—which would be much easier to capture.

The problem is that if you burned millions of tons of gas or coal with pure oxygen, you would make the air separation companies rich. The power companies—not so much. In addition, Oxygen is lighter than nitrogen, so the replacement would be greater than 1 Nitrogen: 1 Oxygen.

Bill says that the “Eureka” moment came when they suggested using CO2 instead of Nitrogen in the combustion process. Oxygen is still required, but not enough to be unprofitable. The Oxygen is combusted with the fuel—natural gas—creates CO2, which then cycles around with more Oxygen and fuel. It’s called the Allam Cycle, and while the term was first coined in 2012, it might has captured the energy community’s imaginations.

According to Bill, Rodney Allam, a former Air Products executive, had been working on a gas-to-liquids technology. In 2009, after setbacks with coal-based CO2 capture, Bill met with Allam in London, where Allam first suggested using CO2 in the cycle. Allam joined 8 Rivers as a Principal, and along with Jeremy Fetvedt, was able to transform Allam’s suggestions into working designs.

The cost savings are incredible with this process. Because CO2 capture is baked-in to the technology, there is no need for extra capture equipment on the back end. The whole power plant is designed to create pure CO2 as exhaust.

I would argue that this pivot from coal to natural gas was critical. In this country at least, no one cares about new natural gas plants. They will grind a utility to halt over a single coal-fired unit. So not only is Net Power capturing carbon, they’re doing it with a fuel source that has little public opposition. My guess is this technology will proliferate in the U.S. much faster than had it been coal-based, just on its public perception merits alone.

However, Bill was adamant that Net Power will use coal. “We are going to solve the coal problem for the rest of the world that does use coal,” he said. “And unfortunately, we think that the rest of the world look like America and it doesn’t. Our mantra is that we will produce clean electricity at a price that the entire world can afford, not just a bunch of rich people.”

At the time of this episode, Bill says designs for a 300-MW are locked down. I asked if he had any concerns about scale-up issues. He said the most critical piece of the process—the Combustor—will not be scaled up but simply multiplied. All other components are “off the shelf.”

In fact, the original plan called for a blowdown test in Germany. Net Power opted instead for a test at the Houston site. Though the decision resulted in an 18-month “delay,” Bill says the information gathered, using a full-scale Combustor, was worth the time.

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