CO2 Recovery Tower Segmentation to Limit Absorbent Thermal Degradation

Solution Overview

Problem

In CO2 recovery devices, the CO2 absorption liquid in the regeneration tower is prone to thermal deterioration due to prolonged residence time, which affects the stability of the regeneration process.

Innovation Solution

A CO2 recovery device with a CO2 absorption tower and a regeneration tower that includes a first storage part and a second storage part with a smaller capacity, equipped with a liquid level measuring device and a control system to manage the liquid surface level, reducing the liquid volume and residence time of the CO2 absorption liquid, thereby minimizing thermal degradation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a large volume of CO2 absorption liquid is stored in the regeneration tower to ensure stable feeding, then the pump cavitation is prevented, but the thermal deterioration of the CO2 absorption liquid increases

Engineering Contradiction:

Improvestable feeding of CO2 absorption liquidVSAvoidthermal deterioration of CO2 absorption liquid

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The storage space in the regeneration tower is divided into two distinct parts: a first storage part for temporary storage and a second storage part with smaller capacity positioned downward from the first storage part. This segmentation allows the system to maintain sufficient liquid volume for stable pumping while reducing the overall residence time of the CO2 absorption liquid in the heated zone, thereby minimizing thermal deterioration.

Inventive Principle:

Principle #1Segmentation

2Object-affected harmful factors

If the liquid volume of CO2 absorption liquid is reduced to minimize thermal degradation, then the residence time is shortened, but the risk of gas entrainment and pump cavitation increases

Engineering Contradiction:

Improvethermal degradation of CO2 absorption liquidVSAvoidstable feeding of CO2 absorption liquid

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The storage space in the regeneration tower is divided into two distinct parts: a first storage part for temporary storage and a second storage part with smaller capacity positioned downward from the first storage part. This segmentation allows the system to maintain sufficient liquid volume for stable pumping while reducing the overall residence time of the CO2 absorption liquid in the heated zone, thereby minimizing thermal deterioration.

Inventive Principle:

Principle #1Segmentation

3Stability of the object's composition

If the CO2 absorption liquid residence time in the regeneration tower is extended to ensure stable operation, then the feeding stability is improved, but the thermal degradation of the absorption liquid increases

Engineering Contradiction:

Improvefeeding stabilityVSAvoidresidence time of CO2 absorption liquid

Core Design Contradiction:

Stability of the object's compositionVSDuration of action of stationary object

Solution Approach 1:

The storage space in the regeneration tower is divided into two distinct parts: a first storage part for temporary storage and a second storage part with smaller capacity positioned downward from the first storage part. This segmentation allows the system to maintain sufficient liquid volume for stable pumping while reducing the overall residence time of the CO2 absorption liquid in the heated zone, thereby minimizing thermal deterioration.

Inventive Principle:

Principle #1Segmentation

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 configuration reduces the thermal degradation of the CO2 absorption liquid during regeneration, stabilizes the liquid feed, and prevents gas entrainment, enhancing the overall efficiency of the CO2 recovery process.

Implementation Method 1

CO2 contained in a gas to be treated is absorbed by a CO2 absorption liquid by bringing the gas to be treated into contact with the CO2 absorption liquid

Methodology Applied

Scientific EffectAbsorption: Absorption (physical)

Implementation Method 2

a CO2 absorption liquid regeneration tower that heats the CO2 absorption liquid, which has absorbed CO2, to release CO2 from the CO2 absorption liquid to regenerate the CO2 absorption liquid

Methodology Applied

Scientific EffectHeating: Heating

Implementation Method 3

a liquid level measuring device that is disposed at the second storage part and that measures the liquid surface level of the CO2 absorption liquid

Methodology Applied

Scientific EffectLiquid level measurement:

Data Source

PatentUS10213727B2CO<sub>2 </sub>recovery device and CO<sub>2 </sub>recovery method

Publication Date: 2019.02.26 MITSUBISHI HEAVY IND LTD

AI summary

A CO2 recovery device includes: a CO2 absorption tower in which CO2 included in an exhaust gas is absorbed by a CO2 absorption liquid; and a CO2 absorption liquid regeneration tower that heats and regenerates the CO2 absorption liquid that has absorbed CO2. The CO2 absorption liquid regeneration tower includes: a main body part in which the CO2 absorption liquid is temporarily stored; a boot part provided downward from a tank end of the main body part, having a relatively smaller capacity than the main body part; a flowmeter provided to the boot part, and measuring the liquid surface level of the CO2 absorption liquid that changes between the main body part and the boot part; and a control device controlling the liquid surface level of the CO2 absorption liquid between the main body part and the boot part on the basis of the measurement result of the flowmeter.