Dual-Stage Amine Capture System for CO2 Exhaust
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Solution Overview
Problem
Carbon dioxide capture systems face challenges in efficiently reducing the release of amine into the air with decarbonated combustion exhaust gas, leading to reduced cleaning performance and increased energy consumption due to inefficient amine capture and regeneration processes.
Innovation Solution
The system incorporates a dual cleaning unit configuration with temperature-controlled cleaning liquids, where the first cleaning unit operates at a higher temperature than the second, utilizing waste heat and condensation effects to enhance amine capture, and includes demisters to capture mist, thereby reducing amine release and energy usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If a conventional absorber configuration is used to capture carbon dioxide, then carbon dioxide separation is achieved, but a large amount of amine is released into the air with the decarbonated combustion exhaust gas
Solution Approach 1:
The absorber is divided into multiple absorption sections (first, second, and third absorption sections) with different operating characteristics. The first section operates at higher amine concentration for efficient CO2 capture, while the second and third sections are optimized for amine recovery with lower operating temperatures and different liquid flow rates, allowing simultaneous achievement of high CO2 capture efficiency and reduced amine release
Solution Approach 2:
Different absorption sections are assigned different local qualities including varying amine concentrations, temperatures, and liquid flow rates. The first absorption section uses higher temperature and amine concentration for CO2 capture, while the second section uses lower temperature and optimized liquid flow to maximize amine absorption from the decarbonated gas, thereby reducing overall amine release
2Productivity
If the amine concentration in the absorbing liquid is increased to improve carbon dioxide capture efficiency, then more amine is available for absorption, but the amount of amine released into the air increases
Solution Approach 1:
The absorbing liquid is segmented into different sections with different amine concentrations. The first absorption section operates with higher amine concentration (0.2-0.5 mass%) to ensure efficient CO2 capture, while the second absorption section operates with lower amine concentration (0.05-0.2 mass%) specifically designed to absorb amine from the decarbonated gas, thus preventing excessive amine release
Solution Approach 2:
The system changes operating parameters including amine concentration, temperature, and liquid flow rate across different absorption sections. The first section uses higher temperature and amine concentration for CO2 capture, while the second section uses lower temperature and optimized liquid flow rate to maximize amine recovery, thereby decoupling CO2 capture efficiency from amine release
3Speed
If the absorber operates at higher temperature to improve carbon dioxide absorption rate, then absorption kinetics are enhanced, but amine release into the air increases
Solution Approach 1:
The absorber is segmented into temperature zones: the first absorption section operates at higher temperature (30-50°C) to enhance CO2 absorption kinetics, while the second absorption section operates at lower temperature (10-30°C) to minimize amine release and maximize amine recovery from the decarbonated gas
Solution Approach 2:
The system employs different temperature parameters in different sections: higher temperature in the first section for fast CO2 absorption kinetics, and lower temperature in the second section for efficient amine recovery. This parameter differentiation allows the system to achieve both high absorption rate and low amine release
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 configuration effectively captures amine from decarbonated combustion exhaust gas, reducing amine release into the air and optimizing energy efficiency by utilizing waste heat and condensation, thereby improving the overall performance of the carbon dioxide capture system.
Implementation Method 1
a first cleaning unit configured to use first cleaning liquid to clean combustion exhaust gas discharged from the carbon dioxide capturer and capture amine flowing together with the combustion exhaust gas
Implementation Method 2
a second cleaning unit configured to use second cleaning liquid to clean combustion exhaust gas discharged from the first cleaning unit and capture amine flowing together with the combustion exhaust gas
Implementation Method 3
The heater heats the first cleaning liquid to a higher temperature than the temperature of an upper portion of the carbon dioxide capturer and of the second cleaning liquid
Implementation Method 4
an absorber having a carbon dioxide capturer configured to cause carbon dioxide contained in combustion exhaust gas to be absorbed in an absorbing liquid containing amine
Implementation Method 5
a stripper configured to cause the carbon dioxide to be released from the absorbing liquid containing the absorbed carbon dioxide and supplied from the absorber
Data Source
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AI summary
A carbon dioxide capture system according to an embodiment includes an absorber, a stripper, and a heater. The absorber includes a first cleaning unit and a second cleaning unit. The first cleaning unit uses first cleaning liquid to clean combustion exhaust gas discharged from a carbon dioxide capturer and captures amine flowing together with the combustion exhaust gas. The second cleaning unit uses second cleaning liquid to clean the combustion exhaust gas discharged from the first cleaning unit and captures amine flowing together with the combustion exhaust gas. The heater heats the first cleaning liquid to a temperature higher than the temperature of an upper portion of the carbon dioxide capturer and of the second cleaning liquid.