Ammonia Water CO2 Absorption with Circulation Cooler
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Solution Overview
Problem
Existing methods for recovering carbon dioxide from flue gas using ammonia water face issues such as ammonia volatilization due to absorptive heat generation, leading to decreased absorption efficiency and line clogging from ammonia salt formation.
Innovation Solution
An apparatus and method that incorporates a circulation cooler to dissipate absorptive heat and integrates washing and purification sections with the absorption and regeneration columns to prevent ammonia volatilization and salt formation, respectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If ammonia water is used as absorbent to recover carbon dioxide from flue gas, then treatment cost is reduced and corrosion problem is mitigated, but absorptive heat generation causes temperature increase leading to ammonia volatilization and decreased absorption efficiency
Solution Approach 1:
The absorption column is divided into multiple sections with different functions: a lower absorption section for carbon dioxide absorption and an upper washing section for ammonia removal. This segmentation allows the system to address both absorption efficiency and ammonia volatilization issues simultaneously by separating the functions spatially.
Solution Approach 2:
Water is introduced as an intermediary substance in the washing section to remove ammonia from the absorbent. The water acts as a mediator that selectively removes ammonia while allowing the absorbed carbon dioxide to remain, thus preventing ammonia volatilization without compromising absorption efficiency.
2Productivity
If high-concentration ammonia water is used to increase absorption capacity, then carbon dioxide absorption rate is improved, but ammonia volatilization increases due to high volatility and temperature rise
Solution Approach 1:
The system changes the concentration parameter of ammonia water from high concentration to low concentration (5-15 wt%). This parameter change reduces ammonia volatility and volatilization losses while maintaining sufficient absorption capacity through the multi-section design that optimizes contact time and mass transfer efficiency.
Solution Approach 2:
The washing section extracts ammonia from the absorbent stream using water. By removing ammonia from the circulation system, the system prevents re-volatilization and loss, allowing the use of lower-concentration ammonia water without compromising overall absorption performance.
3Device complexity
If conventional absorption process is used without additional washing sections, then device complexity is reduced, but ammonia salt formation causes line clogging in absorption and regeneration columns
Solution Approach 1:
The washing section is merged with the absorption column structure, integrating ammonia removal functionality into the existing absorption system. This combination allows the system to prevent ammonia salt formation and line clogging without requiring completely separate additional columns, thus balancing complexity reduction with reliability improvement.
4Productivity
If reboiling process is performed in regeneration column to remove carbon dioxide, then absorbent regeneration is achieved, but energy consumption increases due to high temperature requirements
Solution Approach 1:
The washing section performs preliminary ammonia removal from the absorbent before it enters the regeneration column. This preliminary action reduces the load on the regeneration column, allowing for more efficient carbon dioxide stripping at lower temperatures and reduced energy consumption.
Solution Approach 2:
The system changes the operational parameters of the regeneration column by reducing the temperature requirement through preliminary washing. This parameter change allows for energy-efficient regeneration without compromising the ability to strip carbon dioxide from the absorbent.
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 significantly increases carbon dioxide absorption efficiency and prevents line clogging, allowing for effective recovery of carbon dioxide even with low-concentration ammonia water, while maintaining ammonia concentration and reducing energy consumption.
Implementation Method 1
a process of absorbing and recovering carbon dioxide from flue gas using an absorbent
Implementation Method 2
ammonia partially reacts with carbon dioxide to thus produce ammonia salt at low temperatures
Implementation Method 3
absorptive heat, generated in the course of recovering carbon dioxide from flue gas using ammonia water, is effectively dissipated
Implementation Method 4
a high-temperature absorbent is circulated out of an absorption column and is cooled by a circulation cooler connected to the absorption column so that the temperature of the absorbent is decreased
Implementation Method 5
ammonia contained in flue gas from which carbon dioxide is removed by the absorbent is washed and recovered
Implementation Method 6
ammonia contained in the removed carbon dioxide is purified and recovered
Implementation Method 7
a concentration column for concentrating and recovering ammonia from wash fluid and purification fluid
Data Source
AI summary
An apparatus and method for absorbing and recovering carbon dioxide from flue gas using ammonia water as an absorbent, including an absorption column and a circulation cooler connected to the absorption column so that a high-temperature absorbent is recovered from the absorption column, cooled to a preset temperature, and then supplied again into the absorption column, in order to dissipate absorptive heat generated when carbon dioxide is absorbed from the flue gas.