Aqueous Ammonia Ejector CO2 Capture Without Refrigeration

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Solution Overview

Problem

Existing CO2 removal systems, such as the chilled ammonia process, require special refrigeration systems and equipment like fans and blowers, and generate a slurry that necessitates specialized piping and pumping, increasing energy consumption and complexity.

Innovation Solution

The use of a high-pressure aqueous ammonia solvent and liquid driven ejectors to absorb CO2, eliminating the need for refrigeration systems and specialized equipment by regenerating the solvent at high pressure, thereby utilizing the ejectors' discharge pressure to handle flue gas and requiring only regular piping and pumping.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a chilled ammonia process is used to remove CO2 from flue gas, then CO2 absorption efficiency is improved, but energy consumption increases due to refrigeration systems and fans/blowers

Engineering Contradiction:
ImproveCO2 absorption efficiencyVSAvoidenergy consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent changes the temperature parameter from low temperature (0-20°C) in conventional chilled ammonia processes to ambient temperature operation, eliminating the need for refrigeration systems. The ammonia solvent is contacted with flue gas at or near ambient temperature, fundamentally changing the thermal conditions of the absorption process to reduce energy consumption.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent extracts and eliminates the refrigeration system and fan/blower components from the conventional chilled ammonia process. By removing these energy-intensive components, the system achieves CO2 absorption without requiring artificial cooling or high-velocity gas movement, thereby reducing energy consumption while maintaining absorption efficiency.

Inventive Principle:
Principle #2Taking out (Extraction)

2Productivity

If a chilled ammonia process is used to remove CO2 from flue gas, then CO2 removal capability is improved, but device complexity increases due to special refrigeration systems and piping

Engineering Contradiction:
ImproveCO2 removal capabilityVSAvoidequipment complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent removes the refrigeration system, special low-temperature piping, and associated control equipment from the conventional chilled ammonia process. By extracting these complex components, the system achieves CO2 removal using only standard ambient temperature equipment, significantly reducing device complexity while maintaining removal capability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent makes the ammonia solvent contactor serve multiple functions: CO2 absorption, temperature control (through ambient conditions), and gas mixing, all in a single unit operating at ambient temperature. This eliminates the need for separate refrigeration systems and specialized piping, reducing overall equipment complexity while maintaining CO2 removal capability.

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

3Use of energy by moving object

If high-pressure ammonia solvent regeneration is used, then compression energy is saved, but pressure requirements increase

Engineering Contradiction:
Improvecompression energyVSAvoidpressure requirements
Core Design Contradiction:
Use of energy by moving objectVSStress or pressure

Solution Approach 1:

The patent employs the high-pressure ammonia solvent to self-compress the flue gas through liquid-driven ejectors. The expanding high-pressure ammonia from the regenerator provides the driving force to compress and move the flue gas through the absorption columns, eliminating the need for external compression equipment and reducing overall compression energy requirements despite the high pressure of the ammonia solvent.

Inventive Principle:
Principle #25Self-service

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

This approach enhances CO2 absorption efficiency while reducing energy consumption and equipment complexity, achieving over 99% CO2 recovery with minimal electric power requirements and eliminating the need for multiple compression stages.

Implementation Method 1

using a high-pressure aqueous ammonia (NH3) solvent and a plurality of liquid driven ejectors to absorb and remove CO2

Methodology Applied
Scientific EffectChemical absorption: Absorption (physical)

Implementation Method 2

the NH3 solvent is regenerated at a high pressure to save potential compression energy required for the absorption and removal of CO2

Methodology Applied
Scientific EffectPressure-driven flow: Pressure Gradient

Data Source

PatentEP4351763B1Systems and methods for removing carbon dioxide from a combustion flue gas and/or air
Publication Date: 2025.12.31 BECHTEL ENERGY TECHNOLOGIES & SOLUTIONS INC
  • EP4351763B1 patent drawingFigure 1
  • EP4351763B1 patent drawingFigure 2
  • EP4351763B1 patent drawingFigure 3

AI summary

Systems and methods for removing carbon dioxide from a combustion flue gas and/or air by using a high-pressure aqueous ammonia solvent and a plurality of liquid driven ejectors to absorb and remove the carbon dioxide for carbon capture utilization or storage. The aqueous ammonia solvent is regenerated at a high pressure to save potential compression energy required for the absorption and removal of carbon dioxide.