Reflux Water Drum Cleaning for Low-Contamination CO2 Recovery

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Solution Overview

Problem

Existing CO2 recovery systems face challenges in maintaining the concentration of CO2 absorption agent within the system, leading to potential leakage and suboptimal product CO2 quality due to residual absorption agent in the gas phase.

Innovation Solution

Incorporation of a cleaning part in the reflux water drum or CO2 flow passage using a cleaning liquid with lower CO2 absorption agent concentration to remove residual agent from the gas phase, combined with circulation and reuse of cleaning liquids to enhance effectiveness and space efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional CO2 recovery system uses a reflux water drum to separate released gas into CO2 gas and condensed water, then the system can regenerate CO2 absorption liquid, but CO2 absorption agent leaks outside the system due to residual agent in the gas phase

Engineering Contradiction:

ImproveCO2 absorption liquid regeneration effectivenessVSAvoidCO2 absorption agent leakage

Core Design Contradiction:

ReliabilityVSLoss of substance

Solution Approach 1:

A cleaning liquid is introduced as an intermediary substance between the released gas and the environment. This cleaning liquid absorbs the CO2 absorption agent from the gas phase in the reflux water drum, preventing its leakage outside the system while maintaining the regeneration process effectiveness.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The system is segmented into distinct functional zones: the reflux water drum for initial separation, a cleaning liquid introduction point for removing residual absorption agent, and a CO2 gas outlet. This segmentation allows targeted treatment of the gas phase to eliminate absorption agent leakage.

Inventive Principle:

Principle #1Segmentation

2Productivity

If the CO2 absorption liquid is heated by steam in the regeneration tower, then the CO2 absorption liquid is regenerated effectively, but an extremely small amount of CO2 absorption agent remains in the gas phase at the downstream of the reflux water drum

Engineering Contradiction:

ImproveCO2 absorption liquid regeneration efficiencyVSAvoidCO2 absorption agent concentration control

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The mechanical heating process in the regeneration tower is supplemented by a chemical absorption process using cleaning liquid. This substitution approach replaces reliance solely on thermal separation with a chemical absorption mechanism to achieve precise control over CO2 absorption agent concentration in the final CO2 gas product.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Manufacturing precision

If the CO2 absorption agent concentration in product CO2 is reduced to meet standards, then product quality improves, but the system complexity increases due to additional cleaning mechanisms

Engineering Contradiction:

ImproveProduct CO2 qualityVSAvoidSystem structure

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The cleaning liquid introduction mechanism is merged with the existing reflux water drum structure. The cleaning liquid is introduced into the gas-phase section where it naturally contacts and absorbs residual CO2 absorption agent, combining the cleaning function with the existing separation vessel without requiring entirely separate equipment.

Inventive Principle:

Principle #5Merging (Combining)

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

Effectively suppresses CO2 absorption agent leakage and reduces the concentration of residual agent in the final product CO2, ensuring compliance with strict quality standards.

Implementation Method 1

a cleaning part installed in a gas-phase part of the reflux water drum or in a CO2 flow passage... configured to remove a CO2 absorption agent contained in the CO2 gas by using a cleaning liquid

Methodology Applied

Scientific EffectAbsorption: Absorption (physical)

Implementation Method 2

a reflux water drum configured to separate released gas from the regeneration tower into CO2 gas and condensed water

Methodology Applied

Scientific EffectCondensation: Condensation

Data Source

PatentEP3838379B1Absorption liquid regeneration device, co2 recovery device provided therewith, and absorption liquid regeneration method

Publication Date: 2026.02.25 MITSUBISHI HEAVY IND LTD

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AI summary

This absorption liquid regeneration device is characterized by comprising: a regeneration tower for regenerating a CO2 absorption liquid; a return flow water drum that is structured so as to separate an emitted gas from the regeneration tower into a CO2 gas and condensed water and cause the condensed water to flow back to the regeneration tower; and a cleaning section that is provided within a gas phase section of the return flow water drum, or on a CO2 flow path along which the CO2 gas that has flowed out from the gas phase section flows, and is structured so as to use a cleaning liquid to remove a CO2 absorption agent included in the CO2 gas, wherein the cleaning liquid has a lower concentration of the CO2 absorption agent compared to the condensed water that has accumulated in a liquid phase section of the return flow water drum.