Natural gas power plant developer NET Power LLC, with partners Baker Hughes, Occidental Petroleum and Constellation Energy, will narrow selection of an EPC contractor by year end to build an estimated $750-million to $950-milloin million utility scale power plant that it claims will be the world's first to burn natural gas with oxygen to generate power and produce pure carbon dioxide as a sellable byproduct with no harmful air emissions.

The project will be built in the Texas Permian Basin at an Occidental hosted site near Odessa.

A 50-MW pilot plant created to test the closed-loop supercritical technology—which was completed in La Porte, Texas near Houston by EPC contractor McDermott in 2021—successfully synchronized the power it produced to the Texas electric grid after operating for more than 1,500 hours.

When completed, the larger Odessa project will combust natural gas and capture an estimated 860,000 tonnes of CO₂ per year, NET Power said

“The technology can get energy out of natural gas with no emissions, no tailpipe, no stack,” firm CEO Ron DeGregorio told ENR. Pure oxygen reduces fuel consumption and increases flame temperatures, with no nitrogen oxides, sulfur oxides or carbon dioxide emitted to the air, he said.

The resulting CO₂ is expanded in the turbine and moves into the heat exchanger where water is removed and remaining CO₂ is either recaptured or compressed, pumped back into high pressure and reheated in the heat exchanger. The process produces “pipeline quality industrial CO₂,” he said, which can be sequestered. 

The plant does not have units to capture air emissions of CO₂ and other harmful substances. Its only air emission is water, DeGregorio added.

The technology is clean, reliable, dispatchable and economical, according to the CEO. “It will be able to compete without subsidies on a levelized cost of electricity and will beat highly efficient combined-cycle plants with carbon capture at the end of the pipe,” he said.

NET Power’s technology was ranked by the Massachusetts Institute of Technology in 2018 as one of its 10 breakthrough technologies.

“The plant puts the carbon dioxide released from burning natural gas under high pressure and heat, using the resulting supercritical CO₂ as the ‘working fluid’ that drives a specially built turbine. “Much of the CO₂ can be continuously recycled; the rest can be captured cheaply,” said MIT Technology Review. “Of all the clean-energy technologies in development, NET Power’s is one of the furthest along to promise more than a marginal advance in cutting carbon emissions.”

Multiple Revenue Streams

The utility-scale project to be built will generate 370 MW of power, with 300 MW going to the grid and 70 MW used to run the plant’s air separator unit. The technology burns pure oxygen, which requires the separation of air. “The cost is figured into the economics,” DeGregorio said.

The plant will have multiple revenue streams related to its power generated as well as to the CO₂, nitrogen and argon byproducts produced.

Pre-front end engineering and design is complete, with final engineering expected to begin in early 2023, after the EPC contractor is selected, DeGregorio said.

There are five shortlisted construction contenders for the project that he declined to name. They will be narrowed to two before a final selection is made.

The contractor will update the cost estimate and design the project in a way to make it more modular, DeGregorio said. Construction is set to begin in 2024 and finish in 2026.

NET Power has five other projects in the works, including two 280-MW plants in the U.S. that are being co-developed with Cayote Energy in Colorado and with Broadwing Energy in Illinois, as well as a 300-MW project in the U.K. with Whitetail Energy. Others are planned with Frog Lake Energy in Canada and with Wilhelmshaven Green Energy in Germany.

The developer also is working with other large utilities that have shown interest in building plants, DeGregorio said, as well as with multiple energy investment funds. “We have a lot going on,” said the executive, who added that NET Power also licenses its technology.  

Energy technology company Baker Hughes joined the Permian Basin group in January and is developing the facility’s supercritical CO₂ turboexpanders and other pumping and compression technology and will provide equipment for other projects.

The pilot plant was built with Toshiba equipment but Baker Hughes will supply it for the scaled-up project.

DeGregorio said NET Power has been quietly developing the technology for 12 years until completion of the demonstration plant. The original idea for the technology came from scientists at low-carbon energy developer 8 Rivers, which worked with air separators and is an early investor in NET Power. 

Early investors also include Constellation. Occidental joined in 2014 and now is its largest investor. McDermott was previously an investor.

Occidental said Nov. 9 that its third-quarter profit rose to $2.5 billion in the three-month period ended Sept. 30, compared to $628 million during the same time last year—with the firm citing higher gas and oil prices due to the Ukraine war. Revenue increased nearly 40% to $19.5 billion, the firm said,  compared to $6.8 billion in the same 2021 period.

The energy firm also noted a continued focus on carbon capture, eyeing development of up to 30 direct air capture plants in Kleberg County, 'texas, in an area it said has access to underground geologic reservoirs that could store captured carbon.

NETPower said it intends to pursue government support, including loans and incentives under the 2021 federal infrastructure law and carbon capture tax credits in the new Inflation Reduction Act.