Zero Emissions from a Fossil Fuel Plant … Really?

The claim of zero emissions from a fossil fuel plant sounds too good to be true. I was skeptical when I first read the headline, “Goodbye Smokestacks: Startup Invents Zero-Emission Fossil Fuel Power,” on the Science website. But on second glance, this does appear to be a big deal in the carbon capture realm.

Oxymoron or Innovation?

Author Robert Service notes: “Zero emissions fossil fuel power sounds like an oxymoron.” And indeed, it does. But the people behind startup NET Power believe its technology makes this possible. The company is backing a 25 MW demonstration plant in the Houston area that will be activated later this year. Basically, the plant will burn natural gas in a pure oxygen combustor. By using mostly pure, high pressure CO, the plant can avoid the phase changes of traditional steam cycles. And instead of driving a steam cycle and losing heat up a smokestack, the NET Power plant retains heat within the system, resulting in less fuel used for a turbine to reach the necessary temperature.

The result, the company claims, is a stream of nearly pure CO that is then piped away and stored underground, or that can be shot into sapped oil reservoirs to recover what oil remains. This latter process is called enhanced oil recovery. In either case, the CO is kept out of the atmosphere. The system is based on work done by Rodney Allam, a retired British engineer, and is called the Allam Cycle. The key to Allam’s idea is the recycling of the CO in a loop.

A Fossil-Fueled Game Changer

NET Power says it can produce emissions-free power at about $0.06/kWh, which is about the same as the cost from a state of the art, natural gas-fired plant. And lower than most renewable energy. If the demonstration meets expectations, the company intends to move to a full-scale, 300 MW version that could be operational in 2021 at a cost of about $300 million. Such a power plant could supply more 200,000 homes. One expert, John Thompson from the Clean Air Task Force, says the breakthrough plant would be “a game-changer if they achieve 100% of their goals.”

We shall see. The NET Power facility could fail to reach its goal; as carbon capture expert Howard Herzog says, “There are only a million things that can go wrong.” But if successful, the zero emissions plant could be a bridge to a cleaner environment, and could drive more aggressive use of renewable sources. So, what’s not to like about this kind of audacious engineering that aims to solve a problem in a practical way? Failure is a possibility, but success is, too.