CO2 Circulating Combustor Cycle for High-Efficiency Carbon Capture

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Solution Overview

Problem

Current power generation methods from fossil fuels face challenges such as rising energy costs, increasing carbon dioxide emissions, and low thermal efficiencies in CO2 capture, making it difficult and costly to reduce CO2 emissions effectively.

Innovation Solution

A high efficiency power generation system using a transpiration cooled combustor with a CO2 circulating fluid, which introduces CO2 along with fuel and oxidant for combustion, producing a high pressure, high temperature fluid stream that expands through a turbine to generate power, with a heat exchange unit to transfer heat to the CO2 stream and compressors to recycle and pressurize the CO2 for sequestration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-generated harmful factors

If conventional CO2 capture technology is used, then CO2 can be captured for delivery to sequestration sites, but thermal efficiency is very low and capital costs are high

Engineering Contradiction:
ImproveCO2 emissionVSAvoidthermal efficiency
Core Design Contradiction:
Object-generated harmful factorsVSLoss of energy

Solution Approach 1:

The patent changes the operating parameters of the power generation system by using supercritical CO2 as the working fluid and operating the turbine at high pressures (above 7.38 MPa). This parameter change enables the system to achieve both CO2 capture and high thermal efficiency (50% or greater), resolving the contradiction between CO2 capture and energy loss.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system performs multiple functions simultaneously: it generates electricity, captures CO2, and delivers the captured CO2 at pipeline pressure for sequestration. The CO2 circulating fluid serves both as the working fluid for power generation and as the captured CO2 product, eliminating the need for separate capture and compression systems.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Object-generated harmful factors

If conventional CO2 capture technology is used, then CO2 can be captured, but capital costs are high resulting in significantly higher electricity costs

Engineering Contradiction:
ImproveCO2 emissionVSAvoidcapital cost
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The system performs multiple functions simultaneously: it generates electricity, captures CO2, and delivers the captured CO2 at pipeline pressure for sequestration. The CO2 circulating fluid serves both as the working fluid for power generation and as the captured CO2 product, eliminating the need for separate capture and compression systems.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

Instead of discarding CO2 as a waste product requiring separate capture and compression infrastructure, the system recovers CO2 as a valuable byproduct of the power generation process itself. The CO2 is captured at high pressure during the power generation cycle and directly delivered to sequestration sites, turning a cost center into a cost-neutral or beneficial process.

Inventive Principle:
Principle #34Discarding and recovering

3Stress or pressure

If high pressure is used in the turbine to maintain CO2 in gaseous phase, then CO2 can be delivered for sequestration, but the pressure ratio across the turbine must be limited

Engineering Contradiction:
ImproveCO2 pressureVSAvoidpower generation efficiency
Core Design Contradiction:
Stress or pressureVSProductivity

Solution Approach 1:

The patent changes the operating parameters of the power generation system by using supercritical CO2 as the working fluid and operating the turbine at high pressures (above 7.38 MPa). This parameter change enables the system to achieve both CO2 capture and high thermal efficiency (50% or greater), resolving the contradiction between CO2 capture and energy loss.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The system achieves high efficiency power generation with reduced capital costs, capable of producing substantially pure CO2 at pipeline pressure for sequestration, exceeding the efficiency of current coal-fired power stations, and significantly reducing physical and capital costs while recovering nearly 100% of CO2.

Implementation Method 1

combustion of a fuel, and any circulating fluid introduced into the combustor

Methodology Applied
Scientific EffectCombustion: Combustion

Implementation Method 2

The fluid stream is introduced into a power generation device, such as a turbine. Advantageously, the fluid stream is maintained at a relatively high pressure during expansion in the turbine

Methodology Applied
Scientific EffectExpansion:

Implementation Method 3

a primary heat exchange unit in fluid communication with the primary turbine for receiving the turbine discharge stream and transferring heat there from to the C02 circulating fluid stream

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Implementation Method 4

at least one compressor in fluid communication with the at least one heat exchanger for pressurizing the C02 circulating fluid stream

Methodology Applied
Scientific EffectCompression: Compression

Data Source

PatentEP2840312B1System for high efficiency power generation using a carbon dioxide circulating working fluid
Publication Date: 2018.11.21 8 RIVERS CAPITAL LLC
  • EP2840312B1 patent drawingFigure 1
  • EP2840312B1 patent drawingFigure 2
  • EP2840312B1 patent drawingFigure 3A~3B

AI summary

The present invention provides methods and system for power generation using a high efficiency combustor (220) in combination with a CO2 circulating fluid (236). The methods and systems advantageously can make use of a low pressure ratio power turbine (320) and an economizer heat exchanger (420) and additional low grade heat from an external source (Q) can be used to provide part of an amount of heat needed for heating the recycle CO2 circulating fluid. Fuel derived CO2 can be captured and delivered at pipeline pressure while other impurities can be captured.