Supercritical Coal Boiler Technology Landscape 2026
Supercritical Coal Boiler Technology Landscape 2026
Supercritical and ultra-supercritical coal boiler patents span two competing paradigms: established SC/USC steam Rankine cycles and rapidly developing sCO₂ Brayton cycle systems. China holds 82% of filings, with Xi’an Thermal Power RI commanding 11 of 17 retrieved patents.
Two Working-Fluid Paradigms Define Supercritical Coal Boiler Innovation
Supercritical and ultra-supercritical (SC/USC) steam Rankine cycles operate at pressures of 25–30 MPa and temperatures of 560–625°C in current commercial designs, with advanced ultra-supercritical (A-USC) targeting 700°C and 350 bar using nickel-based superalloys. A reference 700 MW A-USC plant achieves 47.6% net efficiency and 700 kgCO₂/MWh, approximately 8 percentage points above subcritical units.
Supercritical CO₂ (sCO₂) Brayton cycle coal boilers represent the most patent-active cluster in the dataset, dominated by Xi’an Thermal Power Research Institute Co., Ltd. CO₂ enters the boiler at temperatures typically exceeding 500°C, creating unique heat surface arrangement challenges absent in conventional steam boilers. Literature confirms sCO₂ cycles achieve equivalent efficiency to 700°C steam cycles at only 620°C, bypassing the nickel superalloy material constraint.
A 660 MW supercritical unit analyzed in the dataset demonstrated a steam generator efficiency benchmark of approximately 86% and confirmed the boiler as the primary source of exergy destruction at 51% exergetic efficiency. Net efficiencies of up to 49.2% at 780°C turbine inlet temperature have been confirmed for coal-fired sCO₂ plants in literature, while combined coal-sCO₂-CCS configurations project 44.5% at 700°C.
The dataset of 17 patent records spans 2008 to 2023 across three innovation phases: foundational SC/USC optimization (2008–2013), rapid sCO₂ architecture diversification (2014–2019), and maturation with hybridization into lignite pre-drying, nuclear-fossil hybrids, and safety-oriented sCO₂ control systems (2020–2023). China accounts for 82% of filings, with no EU, Japanese, or South Korean patents in this dataset.
sCO₂ Brayton Cycle Patents Dominate the 2016–2023 Filing Wave
The dataset reveals a concentrated filing surge from 2016–2019 driven entirely by Xi’an Thermal Power Research Institute Co., Ltd., with the sCO₂ Brayton cycle cluster accounting for the majority of all patents. Efficiency benchmarks across steam and sCO₂ architectures span from 44.5% for CCS-integrated configurations to 49.2% for pure sCO₂ at 780°C.
Patent Filings by Technology Cluster — Supercritical Coal Boiler Dataset (2008–2023)
sCO₂ Brayton cycle patents account for the largest single cluster, with USC steam Rankine and combustion/hybrid patents forming the remaining shares.
↗ Click bars to exploreNet Efficiency by Technology Configuration — Supercritical Coal Boiler Systems
sCO₂ at 780°C turbine inlet achieves 49.2% net efficiency, surpassing current USC steam designs at 47.6% and exceeding CCS-integrated sCO₂ configurations at 44.5%.
↗ Click bars to exploreKey Deployment Contexts for Supercritical Coal Boiler Technology
The 17-patent dataset maps supercritical coal boiler technology across four distinct application contexts, from large-scale Chinese grid power to oil-sector steam generation and emerging nuclear-coal hybrid configurations.
Utility-Scale Grid Power, China
Multiple patents from Xi’an Thermal Power RI (2016–2023) and Huaneng International Power (2016) explicitly state coal-fired generation will remain the backbone of China’s electricity system for decades. The 2019 Coal-Fired sCO₂ Brayton Cycle Power Generation System and the 2019 Coal-Based sCO₂ Brayton Cycle Power Generation System and Method are both explicitly designed for large-scale grid-connected deployment in China. China accounts for 14 of 17 filings (82%) in this dataset.
Utility Power GenerationLignite Brown Coal Power Generation
The Lignite Pre-Drying sCO₂ Power Generation System Integrating Compression Heat Pump (Xi’an Thermal Power RI, 2021, CN) targets China’s 130 billion-ton proven lignite reserves, addressing low calorific value and high moisture content. An oxy-fuel 600 MW supercritical plant analyzed in literature (2013) burns lignite with 42.5% moisture content in a circulating fluidized bed boiler. Only one patent in the dataset directly addresses lignite pre-drying for sCO₂ systems, representing a white space opportunity.
Lignite Power GenerationOil and Gas Industrial Steam
Saudi Arabian Oil Company filed three US patents (2019, 2020, 2021) covering dual-boiler configurations for producing supercritical steam in petroleum-based power plants, where conventional oil-fired boilers are limited to sub-supercritical temperatures. These are the only non-Chinese multi-filing patents in the dataset and represent a distinct application of supercritical steam technology in the oil and gas sector. Saudi Arabian Oil Company accounts for all 3 US jurisdiction filings in this dataset.
Oil and Gas SectorNuclear-Coal Hybrid Power Plants
The 2023 CN patent on Fossil Fuel Boiler–High-Temperature Gas-Cooled Reactor Combined Power Generation System (Xi’an Thermal Power RI, 2023) targets applications where nuclear heat supplements coal combustion to push working fluid temperatures and efficiencies beyond current USC steam ceilings. The concept seeks net efficiency beyond the 46.3% ceiling of current USC steam technology while reducing per-unit CO₂ emissions. An Indian patent from Lovely Professional University (2023, IN) on a 660 MW supercritical unit energy-exergy analysis reflects geographic expansion of supercritical coal technology filing activity.
Nuclear-Fossil HybridXi’an Thermal Power RI Commands 65% of Dataset Filings
Among 9 named assignees in the 17-patent dataset, Xi’an Thermal Power Research Institute Co., Ltd. holds 11 patents spanning every sCO₂ architecture sub-category, reflecting a deliberate national technology development strategy. Saudi Arabian Oil Company is the only non-Chinese assignee with multiple filings.
Top Assignees by Filing Count — Supercritical Coal Boiler Patent Dataset
↗ Click bars to exploreXi’an Thermal Power Research Institute
Xi’an Thermal Power Research Institute Co., Ltd. (CN) holds 11 of 17 patents in this dataset, filed between 2016 and 2023, covering the full spectrum of coal-fired sCO₂ Brayton cycle architectures: dual-split-flow recompression, single-stage split flow, double sCO₂ combined cycle, sCO₂ + ORC hybrid, boiler apparatus design, lignite pre-drying integration (2021), and fossil-nuclear hybrid systems (2023). The 2023 filing Coal-Based sCO₂ Brayton Cycle Power Generation System and Method introduces dual-function flue gas cooler streams serving both normal heat recovery and emergency over-temperature quench injection, signaling maturation from efficiency optimization toward safety engineering. All filings are in CN jurisdiction.
China — CNSaudi Arabian Oil Company
Saudi Arabian Oil Company holds 3 US patents filed in 2019, 2020, and 2021 covering dual-boiler configurations for producing supercritical steam in petroleum-based power plants, where conventional oil-fired boilers are limited to sub-supercritical temperatures. These are the only US-jurisdiction filings in the dataset and the only non-Chinese multi-patent position, focused on a distinct application in oil and gas sector steam generation rather than coal boilers directly. All three filings represent continuation and related patents of the System and Method for Providing Supercritical Steam family.
United States — USFive Innovation Signals from 2021–2023 Filings and Literature
The most recent filings (2021–2023) signal a transition from pure efficiency optimization toward operational safety, waste heat recovery, nuclear hybridization, and multi-objective environmental-economic optimization, indicating the field is approaching industrial deployment readiness.
Nuclear-Fossil Boiler Hybridization (2023)
The Fossil Fuel Boiler–HTGR Combined Power Generation System patent (Xi’an Thermal Power RI, 2023, CN) combines high-temperature gas-cooled reactor heat with fossil fuel boiler cycles, targeting net efficiency beyond the 46.3% ceiling of current USC steam technology. This approach avoids high-temperature alloy availability constraints while reducing per-unit CO₂ emissions. It is described as a nascent but strategically significant direction in the dataset.
Waste Heat Recovery via Compression Heat Pump (2021)
The Lignite Pre-Drying sCO₂ System with Compression Heat Pump (Xi’an Thermal Power RI, 2021, CN) introduces cold-end waste heat recovery through a compression heat pump that simultaneously dries lignite fuel and recovers sCO₂ cycle cold-end losses. This systems integration concept targeting China’s 130 billion-ton lignite reserves was not present in any earlier filings. The dataset identifies lignite sCO₂ integration as a white space with only one filing addressing it.
USC Steam Rankine Cycle vs. Coal-Fired sCO₂ Brayton Cycle
Click any row to explore further.
| Dimension | USC Steam Rankine Cycle | Coal-Fired sCO₂ Brayton Cycle |
|---|---|---|
| Working Fluid | Water / Steam | Supercritical CO₂ |
| Operating Pressure | 25–30+ MPa (A-USC: 350 bar) | Above CO₂ critical point; high inlet temperatures above 500°C |
| Operating Temperature | 560–625°C (USC); 700°C (A-USC target) | Turbine inlet up to 780°C; equivalent to 700°C steam at only 620°C |
| Net Efficiency | 45–47.6% (USC/A-USC); projected >50% for A-USC | Up to 49.2% at 780°C TIT; 44.5% with CCS at 700°C |
| CO₂ Emissions | ~700 kgCO₂/MWh (A-USC at 47.6%) | Reduced per MWh vs. subcritical; exact value not stated in dataset |
| Material Constraint | Nickel-based superalloys required at 700°C; limiting commercialization | Achieves 700°C steam-equivalent efficiency at 620°C, bypassing nickel superalloy barrier |
| Patent Filing Volume (Dataset) | 3 patents in this dataset (2008–2023) | 10+ patents in this dataset; dominant cluster (2016–2023) |
| Lead Assignee | Shanghai Power Equipment RI; North China Electric Power University | Xi’an Thermal Power Research Institute Co., Ltd. (11 patents) |
| Commercial Status | Incumbent commercial standard; large installed base | Rapidly developing; moving toward operational safety and deployment readiness (2023 filings) |
| Boiler Inlet Challenge | Conventional economizer arrangement applicable | CO₂ enters boiler above 500°C; requires redesigned heat surface arrangements |
Frequently Asked Questions: Supercritical Coal Boiler Technology
Supercritical (SC) coal boilers operate at steam pressures and temperatures above the thermodynamic critical point of water. Ultra-supercritical (USC) designs operate at pressures of 25–30 MPa and temperatures of 560–625°C, achieving net efficiencies of 45–47.6%. Advanced ultra-supercritical (A-USC) targets 700°C and 350 bar using nickel-based superalloys, with a projected efficiency of greater than 50%, approximately 8 percentage points above subcritical units.
sCO₂ Brayton cycle coal boilers can achieve efficiency equivalent to 700°C steam cycles at only 620°C, circumventing the nickel superalloy material barrier that constrains advanced ultra-supercritical steam technology commercialization. Literature in the dataset confirms net efficiencies of up to 49.2% at 780°C turbine inlet temperature for coal-fired sCO₂ plants, compared to 47.6% for A-USC steam designs.
Xi’an Thermal Power Research Institute Co., Ltd. (China) holds 11 of 17 patents in this dataset, filed between 2016 and 2023. This covers the full spectrum from boiler apparatus design to complete sCO₂ system architectures including dual-split flow, single-stage split flow, double sCO₂ combined cycle, sCO₂ + ORC hybrid systems, lignite pre-drying integration, and fossil-nuclear hybrid configurations.
The core challenge is that CO₂ enters the sCO₂ boiler at temperatures typically exceeding 500°C — far higher than equivalent steam boiler inlets — causing prohibitively high flue gas temperatures after the economizer with conventional heat surface arrangements. Solutions in the dataset include redesigned economizer placements, flue gas coolers with dual-function emergency quench injection capability, and compression heat pump integration for cold-end waste heat recovery.
Among 17 retrieved patent records, China (CN) accounts for 14 filings (82%), the United States (US) accounts for 3 filings (18%) — all held by Saudi Arabian Oil Company — and India (IN) accounts for 1 filing. No patent filings from the European Union, Japan, or South Korea appear in this dataset, though literature contributions from those regions are present.
Based on 2021–2023 filings in this dataset, five directions emerge: nuclear-fossil boiler hybridization combining HTGR heat with coal cycles (Xi’an Thermal Power RI, 2023); lignite pre-drying sCO₂ integration with compression heat pumps (Xi’an Thermal Power RI, 2021); sCO₂ cycle safety and emergency over-temperature control engineering (Xi’an Thermal Power RI, 2023); incremental A-USC steam double-reheat improvements (Shanghai Power Equipment RI, 2023); and multi-objective environmental-economic optimization applying MIDACO and genetic algorithms to sCO₂ layouts (literature, 2022–2023).
Data and insights on this page are based on a limited patent and literature dataset and are for reference only. Figures may not represent the complete technology landscape.