Potassium Carbonate CO2 Separation in Gas Turbine Recycle Loops

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Solution Overview

Problem

Current methods for low emission power generation and CO2 capture are inefficient and costly, particularly in gas turbine power plants, due to high CO2 concentration in exhaust gases and the presence of volatiles which can lead to corrosion and safety hazards when used for enhanced oil recovery or sequestration.

Innovation Solution

A low emission power generation system incorporating an exhaust gas recycle loop and potassium carbonate (K2CO3) separation system, which recycles exhaust gases to separate and recover CO2, and removes volatile components before regeneration, producing high purity CO2 with minimal contaminants.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If amine solvent absorption is used to capture CO2, then CO2 capture capability is improved, but the presence of oxygen, sulfur oxides, and nitrogen oxide causes solvent degradation and operational problems

Engineering Contradiction:

ImproveCO2 capture reliabilityVSAvoidsolvent degradation from oxygen, SOX, and NOX

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent employs potassium carbonate solvent which can be continuously regenerated and reused, effectively treating it as a durable capture medium that withstands harsh exhaust conditions without degrading like amine solvents would

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent changes the chemical parameters of the absorption system by using potassium carbonate instead of amine solvents, and operates at elevated temperatures and pressures to maintain solvent stability in the presence of oxygen, sulfur oxides, and nitrogen oxide

Inventive Principle:

Principle #35Parameter changes

2Quantity of substance

If CO2 is captured from low concentration exhaust streams, then CO2 recovery is achieved, but large volume of gas must be treated at low pressure resulting in high capture costs

Engineering Contradiction:

ImproveCO2 recovery quantityVSAvoidCO2 capture cost

Core Design Contradiction:

Quantity of substanceVSEase of manufacture

Solution Approach 1:

The patent applies preliminary compression to increase the pressure of the exhaust gas stream before CO2 capture, and uses heat exchangers to pre-condition the gas, thereby reducing the overall energy and cost requirements for CO2 separation and purification

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent employs compression and pressure manipulation techniques to concentrate the CO2 stream, using pneumatic systems to increase pressure and reduce volume, making the subsequent separation and capture processes more economically viable

Inventive Principle:

Principle #29Pneumatics and hydraulics

3Productivity

If volatile components are present in recovered CO2, then CO2 recovery efficiency is maintained, but corrosion rates increase and safety hazards arise for EOR and sequestration applications

Engineering Contradiction:

ImproveCO2 recovery efficiencyVSAvoidcorrosion and safety hazards from volatiles

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent extracts and removes volatile components from the recovered CO2 stream through selective separation processes, isolating the harmful volatiles from the CO2 to prevent corrosion and safety issues while maintaining CO2 recovery efficiency

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent may employ porous materials or adsorbents that selectively trap volatile components while allowing CO2 to pass through, thereby purifying the CO2 stream without sacrificing recovery efficiency

Inventive Principle:

Principle #31Porous materials

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 power generation efficiency, reduces costs, and produces high purity CO2 suitable for enhanced oil recovery and sequestration by utilizing a potassium carbonate-based system to capture and purify CO2 while minimizing volatile contaminants.

Implementation Method 1

a first separation system that employs a potassium carbonate-based solvent to absorb and recover CO2

Methodology Applied

Scientific EffectChemical absorption: Absorption (physical)

Implementation Method 2

a stripping section that removes volatile components from the bicarbonate solvent solution

Methodology Applied

Scientific EffectVapor stripping: Distillation

Implementation Method 3

a regeneration section that releases CO2 from the bicarbonate solvent

Methodology Applied

Scientific EffectThermal decomposition: Decomposition (biological)

Data Source

PatentUS9463417B2Low emission power generation systems and methods incorporating carbon dioxide separation

Publication Date: 2016.10.11 EXXONMOBIL UPSTREAM RESEARCH COMPANY(US)

AI summary

Methods and systems for CO2 separation in low emission power plants are provided. One system includes a gas turbine system that combusts a fuel and an oxidant in the presence of a compressed recycle stream to provide mechanical power and a gaseous exhaust. A purge stream is taken from the compressed recycle stream and directed to a CO2 separator configured to absorb CO2 from the purge stream using a potassium carbonate solvent. Volatiles are removed from the rich solvent by stripping or by flashing to an intermediate pressure before the rich solvent is regenerated and CO2 is removed.