Emissions-Free Power Plant Prototype Advances

A joint venture of Exelon Generation, McDermott International and 8 Rivers Capital achieved an important milestone when it successfully fired the commercial-scale combustor in Texas.
NET Power’s 50 MWth Demonstration Plant in La Porte, Texas (PRNewsfoto/NET Power, LLC)

In what could be a potential game changer in climate control and carbon capture technology, NET Power LLC has begun operating its low-cost, emissions-free natural gas power system at a test facility in La Porte, Texas.

NET Power, a Durham, N.C.-based company owned by Exelon Generation, McDermott International and 8 Rivers Capital, achieved an important milestone recently when it fired the 50MW commercial-scale combustor developed in partnership with Toshiba Energy Systems & Solutions Corp. for the first time. The first fire validates the operability of the new power system, which is designed to produce cheaper electricity from natural gas while generating near-zero atmospheric emissions, including full CO₂ capture. It will be the model for a 300MW natural gas plant that NET Power plans to license to power generation, oil and gas and industrial companies in the United States and globally.

“Because of the collaborative effort of the extended team, our achievements have fully met our expectations,” Charlie Bowser, NET Power’s president, said in a prepared statement.

“McDermott is a global leader in technology licensing for the energy industry and NET Power is a valuable piece of our current portfolio and our long-term strategy,” added Sean Sexstone, global vice president of power for McDermott. “This partnership in NET Power also gives McDermott the opportunity to build energy products that have the potential to revolutionize how we produce power and capture carbon.”

Built over a two-year period with a $140 million investment in startup costs and design, the 50MW demonstration plant is the world’s only industrial-scale supercritical carbon dioxide-based power plant and CO₂ test facility. Construction began in March of 2016 and gradually each piece of equipment has been brought on line, Walker Dimmig, a NET Power spokesman, told CPE Energy.

 “We have the plant running and doing all the testing we need to do,” he said. “We have one more upcoming milestone. It will be burning gas in the combustor that goes into the turbine and produces the power.”

Dimmig said they expect to be generating power later this year.

The plant is designed to demonstrate NET Power’s Allam Cycle technology, named after Rodney Allam, an internationally renowned chemical engineer who was a lead designer of the system and an 8 Rivers partner. The technology uses a new turbine and combustor created for the process by Toshiba. Using carbon dioxide as a working fluid to drive the combustion turbine, the Allam Cycle eliminates nearly all the emissions from the natural gas power generation without requiring expensive carbon capture equipment, or scrubbing technology, at the back end. The system burns natural gas with oxygen, not air. Instead of using steam, the Allam Cycle uses high-pressure CO₂ to turn the turbine and generate electricity. The carbon dioxide emissions are captured and stored. All other air emissions, including nitrogen oxides, are captured. The NET Power plant produces only electricity, liquid water and pipeline-ready CO₂. It also does not require any water to be used in the air cooled configuration.

The system’s goal is also to generate pipeline-quality carbon dioxide as cheaply as possible, Dimmig said. That can be used for enhanced oil recovery (EOR) or other industrial issues and creates an additional and separate revenue stream.

Dimmig said NET Power’s business model is to be a licensing company and is advancing the development of commercial-scale 300MW natural gas plants which are estimated to cost about $300 million and could generate about 890,000 tons of CO₂ per year. That could happen by 2021, he said.

“We’re getting interest both at home and abroad,” he said. “There a lot of interest in the Middle East and a big market for us will be Southeast Asia.”

Dimmig said the United Kingdom is also projected to be a strong market because of carbon capture regulations.

The technology could be used anywhere in the U.S., he said, particularly the Gulf Coast, West Texas, California and the Mountain West states such as New Mexico, Colorado and Wyoming.

The company also expects the 45Q carbon capture tax credit reform approved by Congress in February to make the plant technology more attractive because it offers more money per ton of carbon dioxide captured and removes a cap on how much the plants could store. The tax credits now range from $35 to $50 per ton of CO₂ and will be available for projects started by 2024. Plant owners then get 12 years of tax credits, Dimmig said.