STEP Demo Supercritical CO2 (sCO2) Brayton Cycle Project Continues to Progress: When Will This Tech Finally Be Operating Commercially Through NET Power’s Allam Cycle Projects and Other sCO2 Power Cycle Projects?

     In my 2022 book, Natural Gas and Decarbonization, I wrote that the first deployment of a 300MW Allam Cycle (a subset of the Brayton Cycle) Natural Gas plant would begin in 2022 and full commercialization was likely in the mid-2020s. We are getting close to the mid-2020s so perhaps we should see where the schedule is now for commercialization. It looks like I “jumped the gun” a bit as according to NET Power’s website, the first announcement of a commercial Allam Cycle plant was in November 2022, and it was expected to be in operation in 2026 – still mid-2020s but only one. However, NET Power recently offered a 12-month cushion due to supply chain issues, so 2027 or even early 2028 are now being considered. Several other projects have been announced. Thus, the tech should grow throughout the late 2020s to full scaling-up commercialization around 2030. Admittedly, this is a few years behind schedule and does not bode very well for decarbonization schedules. Time delays in such projects, perhaps should be mentioned as a reason to continue replacing coal plants with conventional combined-cycle natural gas plants as clearly the best method to decarbonize in the near term. The site for the first plant is near Odesa, Texas, hosted by Occidental Petroleum within their Permian Basin operations. Currently, front-end engineering design (FEED) and engineering, procurement, and construction (EPC) are being implemented. NET Power was capitalized by a SPAC in mid-2023, merging with Rice Acquisition Corporation II. They note that they were very well-capitalized, which allows them to endure these delays without loss of capital. Such loss of capital through time delays has doomed several other first-of-a-kind projects. The NET Power oxyfuel combustion sCO2 natural gas power plant projects are without a doubt one of the most important CCUS project types on the planet.

     The Supercritical Transformational Electric Power (STEP) Demo project in San Antonio is testing several different sCO2 power cycle configurations and developing knowledge about operation and wear-and tear, parts and equipment testing, and developing supply chains for parts and equipment. NET Power has also been developing strategic supplier agreements for equipment. In December 2023 they announced such an agreement with Lummus Technology to design and supply recuperative heat exchangers (HXRs). “The HXR recovers energy from the turboexpander exhaust and air separation unit to reheat recirculated CO2, making it one of the most important equipment components in the NET Power Cycle.” The NET Power Allam Cycle is shown below:

 

 

 

 

The STEP Demo and sCO2 Power Cycles

 

     The STEP Demonstration facility in San Antonio, Texas, for sCO2 power cycle technologies began in 2018 as a collaboration between industry, government, academia, and research institutes. It is a good model for a public-private partnership. One of those partners, Gas Technology Institute (GTI), reported a new milestone in January 2024:  “An industry “first” was achieved with the initial hot-fire closed loop operation of the 10-megawatt (MWe) Supercritical Transformational Electric Power (STEP) Demo test facility in San Antonio, Texas, which fired the 93 MW heater and spun the turbine up to 18,000 rpm for the first time.” “System commissioning tests for the initial 5 MWe Simple Cycle configuration will continue to progress towards full power over the next couple of months by increasing operating temperatures and ramping up turbine speed to 27,000 rpm.”

     Supercritical CO2 (sCO2) power cycles offer increased efficiency over the steam cycles often used in combined cycle plants. They also provide high purity carbon capture, especially with the oxyfuel combustion in Allam Cycle plants which utilizes oxygen. Another benefit is much smaller turbine size and much smaller total plant footprint. Much lower water use compared to traditional fossil fuel plants is also a significant advantage. Turbine exhaust, concentrated solar, biomass firing, geothermal, and nuclear can all be sources of heat for sCO2 power cycles. It can basically use any heat source for heat recovery. It is also being developed for shipboard propulsion. Add in the emissions reductions advantages and the expected competitive costs with traditional fossil plants when full scale-up occurs and you now have a very desirable power plant system type which can have many applications.

STEP Demo: Revolutionizing Future Power Generation on Vimeo

 

 

References:

 

Major Power Industry First Demonstrated by STEP Demo Project. Gas Technology Institute. January 19, 2024. Major Power Industry First Demonstrated by STEP Demo Project • GTI Energy

 

NET Power Announces its First Utility-Scale Clean Energy Power Plant Integrated with CO2 Sequestration. NET Power. November 7, 2022. NET Power Announces its First Utility-Scale Clean Energy Power Plant Integrated with CO2 Sequestration | NET Power

 

NET Power Selects Zachry Group to Build Its First Utility-Scale Clean Power Plant. NET Power. April 11, 2023. NET Power Selects Zachry Group to Build Its First Utility-Scale Clean Power Plant | NET Power

 

NET Power Reports Third Quarter 2023 Results and Provides Business Update. NET Power. November 14, 2023.  NET Power Reports Third Quarter 2023 Results and Provides Business Update | NET Power

 

 NET Power and Lummus Sign Strategic Supplier Agreement for Heat Transfer Equipment. NET Power. December 6, 2023. NET Power and Lummus Sign Strategic Supplier Agreement for Heat Transfer Equipment | NET Power

 

A STEP closer to transformational electric power. STEP Demo. 2024. STEP Demo: High-efficiency power generation pilot program • GTI Energy