Supercritical-Carbon-Dioxide-Based-Power-Plants (2)-compressed.pptx

Supercritical-Carbon-Dioxide-Based-Power-Plants

1. Supercritical Carbon Dioxide Based Power Plants Presented by- Vindhyachal Singh, Assistant Professor, ITM GIDA Gorakhpur INAE- CEEE PROGRAM ENERGY (DOMAIN- 3)

2. What is Supercritical CO2? When carbon dioxide is heated above 31°C and pressurised beyond 7.4 MPa, it enters a remarkable supercritical state— a fluid phase that combines the density of a liquid with the flow characteristics of a gas. This unique thermodynamic state enables highly efficient energy conversion in advanced power cycles, offering performance that significantly surpasses conventional steam- based systems. CO 2 is supercritical if the pressure and temperature are greater than the critical values Critical Point Operation Operates CO ₂ above its critical point at 31°C and 7.4 MPa, creating unique thermophysical properties ideal for power generation. Gas- Liquid Hybrid State Behaves simultaneously like a gas whil e maintaining liquid density, enabling remarkably compact and efficient turbomachinery design.

3. A Supercritical CO₂ Power Cycle Temperature, T Supercritical region T crit P crit Liquid region Gas region Liquid + vapor region Entropy, S A supercritical power cycle is a thermodynamic cycle in which the working fluid operates above its critical temperature and pressure — meaning it is in a supercritical state, where it does not distinctly behave as a liquid or a gas. In a supercritical power cycle, the working fluid (CO₂): Absorbs heat at high temperature and pressure. Expands through a turbine to produce mechanical (and then electrical) power. Rejects heat to a cooler and is recompressed back to high pressure. Because there’s no distinct boiling or condensation process, the cycle runs smoothly and efficiently.

4. Why sCO2 Power Cycles? Superior Efficiency Achieve up to 10% higher thermal efficiency than traditional steam Rankine cycles, translating to significant performance gains. Compact Design Smaller plant footprint and lower capital costs due to remarkably compact equipment and simplified infrastructure. Water Conservation Dramatically reduced water usage with potential for dry cooling and completely water- free operation. Reduced Emissions Lower fuel consumption translates directly to decreased environmental impact and carbon footprint.

5. Simple Indirect- Fired Brayton Cycle Cycle Configuration Working fluid circulates between compressor and turbine. Heat added before expansion; cooling required after turbine. Efficiency Factors Depends on pressure ratio and working fluid properties. CO ₂ achieves 34.5% efficiency at optimal conditions. Power cycles using sCO2 as the working fluid take on two primary configurations relevant to power generation: 1. an indirect-fired closed Brayton cycle that is applicable to advanced fossil fuel combustion, nuclear, and solar applications; and 2. a semi-closed, direct-fired, oxy-fuel Brayton cycle well-suited to fossil fuel oxy-combustion applications with CO2 capture. These cycles are described in greater detail in the following sections. The sCO ₂ Brayton Cycle Configurations

6. Recuperated Brayton Cycle Recuperator reduces heat loss in cooler and increases working fluid throughput. CO ₂ achieves 46.8% efficiency— 12 percentage points higher than simple cycle. Advanced configuration incorporates heat exchanger between expander exhaust and compressor exhaust, dramatically improving efficiency. Key Innovation Design Considerations Lower optimal pressure ratio (4.5 vs 34.9). Increased system complexity with additional heat exchanger.

7. Recompression Brayton Cycle Most advanced indirect configuration optimizes recuperator effectiveness by bypassing cooler for portion of working fluid. Split Flow Design Portion of low- pressure CO ₂ bypasses cooler and low-temperature recuperator section. Thermal Matching Better thermal capacity balance between hot and cold recuperator sides. Peak Performance 52.1% efficiency achieved— 5 % points higher than recuperated cycle.

8. Direct- Fired Oxy- Fuel Cycle T he CO 2 heater is replaced with a pressurized oxy-fuel combustor. Fuel is burned in relatively pure and near stoichiometric oxygen in the combustor, and the resulting stream, which contains mainly CO 2 and H 2 O, is used to drive the turbine. The remaining heat in the stream exiting the turbine is recuperated and the stream is then further cooled to condense the water out, leaving a stream of high concentration CO 2 . A portion of the CO 2 is compressed to the desired pressure. The cooled and compressed CO 2 passes through the recuperator to be preheated and it is then recycled to the combustor as diluent . The remainder of the CO 2 is ready to be compressed for storage. Higher Temperatures 1100- 1500°C turbine inlet achievable Superior Efficiency Significantly exceeds indirect cycles Water Recovery Captures combustion water as liquid

9. Applications Across Energy Sectors sCO2 power cycles can be applied to many heat sources and have a small footprint . Fossil Fuel Plants Coal and natural gas facilities with potential for integrated carbon capture and storage systems. Concentrated Solar Power CSP plants paired with thermal energy storage for continuous clean energy generation. Nuclear Power Next- generation nuclear reactors utilising advanced supercritical cycles for enhanced safety and efficiency. Renewable Integration Biomass, geothermal, waste heat recovery, and marine propulsion applications. Industrial Power On- site power generation and waste heat utilisation for manufacturing facilities. Heat recovery steam generators are replaced by compact sCO ₂ turbomachinery, enabling combined cycle plants with higher efficiency and substantially lower emissions than traditional combined cycle gas turbine (CCGT) systems.

10. STEP Demo: 10 MWe Supercritical CO2 Pilot Power Plant Developed by GIT, SwRI , GE Global Research in San Antonio, Texas.

11. Revolutionary Power Generation Technology Led by Gas Technology Institute (GTI), Southwest Research Institute (SwRI), and General Electric Global Research (GE), the STEP Demo project aims to design, construct, commission, and operate a versatile 10 MWe facility at SwRI's San Antonio, Texas campus. This $119 million initiative— with $84 million from the U.S. Department of Energy— represents one of the largest and most comprehensive sCO2 projects worldwide. The primary goal: advance high- temperature sCO2 power cycle performance from Proof of Concept to System Prototype validated in operational conditions . GTI leads overall project management and systems engineering. SwRI provides the San Antonio host site, facility design, construction, and test operations. GE Global Research delivers turbomachinery technical definition and innovative valve technology. The team integrates decades of combined experience, having completed over two dozen sCO2-related projects. GTI brings proven leadership in large pilot facilities and joint partnerships. SwRI offers on-site technology development and test operations expertise. GE leverages existing 1 MWe turbomachinery hardware from the DOE SunShot program. The 14 MWe (gross) sCO2 turbine represents a significant advancement, designed for 700°C turbine inlet temperature with 100,000-hour casing and rotor life—five times longer than previous designs.

12. Introducing The STEP Demo: World's Largest sCO2 Pilot Plant The Supercritical Transformational Electric Power (STEP) Demo in San Antonio, Texas, is the world's largest pilot plant utilizing supercritical carbon dioxide (sCO2) Brayton cycles. This pioneering facility converts heat energy into electrical power using advanced sCO2 technology, which operates through a highly efficient process of compression, heating, expansion, and cooling. 01 02 Compression Supercritical CO2 (sCO2) is compressed to high pressure, significantly increasing its temperature and density for maximum efficiency. Heating Thermal energy is efficiently added to the sCO2 from a heat source, raising its temperature significantly before expansion. 03 04 Expansion Cooling The high- pressure, high- temperature sCO2 expands through a turbine, After expansion, the sCO2 is cooled back to its initial temperature and generating mechanical power that drives the electrical generator. density, preparing it to return to the compressor for a continuous cycle.

13. The STEP Demo: Implementing a Supercritical CO ₂ Brayton Cycle STEP Demo's Cycle Configuration The STEP Demo facility in San Antonio, Texas, utilizes an advanced closed- loop supercritical CO ₂ (sCO ₂ ) Brayton cycle. In this configuration, sCO ₂ is compressed, then heated by an indirect heat source before expanding through a turbine to generate 10 MWe of power. Following expansion, the sCO ₂ is cooled in a recuperator and cooler before returning to the compressor, completing the cycle. Validating sCO ₂ Brayton Efficiency A primary goal of the STEP Demo is to validate the enhanced efficiency achievable with supercritical CO ₂ . By leveraging the unique thermodynamic properties of sCO ₂ near its critical point, the plant aims to demonstrate high thermal efficiencies, potentially exceeding 50%. This project will provide crucial data on the operational performance and economic viability of sCO ₂ power cycles for future energy systems.

14. Phased Testing Approach The STEP Demo employs a strategic two- phase testing methodology to successively mitigate risks while building operational knowledge and validating performance. Phase 1: Simple Cycle Single compressor, turbine, recuperator, and cooler configuration. sCO2 delivered at ~500°C and 250 bar. Demonstrates controls, operability, and component validation with shortest path to data collection. Phase 2: Recompression Cycle High-efficiency RCBC configuration with second recuperator and bypass compressor. Turbine inlet temperature increased to 715°C. Targets >50% thermodynamic efficiency goals. Simple Cycle Configuration - Initial testing phase with streamlined components Recompression Closed Brayton Cycle - Advanced configuration for maximum efficiency

15. STEP Demo Achieves Major Milestone The $169 million STEP Demo pilot plant in San Antonio, Texas, completed Phase 1 testing in October 2024, demonstrating commercial readiness of sCO2 Brayton cycle technology. Generated 4 MWe of grid- synchronized power Turbine Operation at 27,000 RPM at 500°C and 250 bar Critical Data collected for future commercial deployment Phase 2 starting in 2025 will reconfigure to Recompression Brayton Cycle and increase temperature to 715°C for significant efficiency boost.

16. STEP Demo Builds on Grid Integration Success The STEP Demo continues earlier work to prove that sCO ₂ Brayton cycle plants can be connected to real power grids. In August 2022, Sandia National Laboratories made history by using an sCO ₂ test system to deliver power directly to the Kirtland Air Force Base grid. Advanced Working Fluid STEP Demo utilizes heated supercritical CO 2 instead of steam for high efficiency. High Operating Temperature Designed for temperatures up to 1,319°F (715°C) for optimal energy conversion. Enhanced Efficiency The 10 MWe STEP Demo aims to demonstrate significantly higher efficiency than traditional power generation. Modern Application STEP Demo applies the 19th-century Brayton cycle with modern sCO2 as the working fluid for next- gen power.

17. Industry Momentum for STEP Demo Major industry partnerships are accelerating the commercialization of sCO2 technology, with key contributions aimed at the STEP Demo project. 1 GE Vernova Developing turbomachinery crucial for the successful operation of the STEP Demo plant. 2 Peregrine Turbine Technologies Announced breakthrough biomass solutions in 2023, expanding potential clean power generation applications, including those relevant for future sCO2 integration. 3 International Partnerships Collaborations with entities like CSIRO from Australia and organizations from Thailand are joining development efforts, supporting the broader sCO2 ecosystem that STEP Demo will validate. The STEP Demo is attracting investment across multiple sectors including nuclear, solar thermal, geothermal, and fossil fuel with carbon capture, showcasing the technology's versatility. Market projections show the STEP Demo paving the way for widespread sCO2 deployment by the 2030s.

18. Technical Challenges in sCO2 Power Plants Developing supercritical CO2 power systems requires overcoming significant engineering obstacles across multiple domains. 01 Turbomachinery Design Engineering turbines and compressors capable of handling extreme density variations and pressure fluctuations inherent to supercritical fluids. 02 Recuperator Development Creating highly durable heat exchangers for efficient heat recovery that maintain performance over extended operational periods. 03 Materials Science Identifying and testing materials resistant to corrosion, creep, and fatigue under sustained high temperatures and pressures. 04 Operational Control Managing complex startup procedures, load following capabilities, and transient operations smoothly and safely.

19. Environmental and Economic Impact 2- 4% Efficiency Gain In fossil plants, reducing CO 2 emissions equivalent to removing 14 million cars from the road annually. 30% Cost Reduction Smaller, modular plants significantly reduce construction time and capital expenditure. 90% Water Savings Lower water consumption critical for arid regions and sustainable operation in water- stressed areas. These combined benefits position sCO 2 technology as a cornerstone for sustainable energy infrastructure development worldwide.

20. References GTI, SwRI , and GEGR, “STEP Project: Detailed Description,” U.S. Department of Energy, Dec. 2018. U.S. DOE (2016), Supercritical Carbon Dioxide Brayton Cycle Report. Argonne National Laboratory, Technical Publications on sCO ₂. MDPI & Elsevier Journals on Supercritical CO₂ Power Systems. Thermal Science (2020) – Thermodynamic Analysis of sCO ₂ cycles.