Amine Wash Solution Regeneration via Multi-Stage Expansion
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Solution Overview
Problem
Existing methods for regenerating amine-containing scrubbing solutions that chemically bind CO2 and sulfur compounds require high operating pressures and temperatures, leading to solution losses and decomposition risks, while also leaving impurities that negatively affect reuse.
Innovation Solution
A multi-stage pressure- and temperature-controlled expansion process that separates CO2 and sulfur compounds at lower pressures and temperatures, utilizing flash relaxation stages with heat recovery and recirculation to achieve high purity and reduce energy consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If high pressure and high temperature are used to regenerate the scrubbing solution, then CO2 and sulfur compounds are effectively removed, but solution losses and decomposition risks increase
Solution Approach 1:
The regeneration process is divided into multiple expansion stages (first expansion stage, second expansion stage, third expansion stage) with progressively decreasing pressures. This segmented approach allows CO2 and sulfur compounds to be removed in steps rather than requiring a single high-pressure treatment, thereby reducing solution losses while maintaining separation efficiency.
Solution Approach 2:
The process utilizes systematic changes in pressure and temperature parameters across different expansion stages. By gradually reducing pressure from the absorption pressure to lower expansion pressures and controlling temperature at each stage, the method achieves effective separation without subjecting the scrubbing solution to extreme conditions that would cause decomposition.
2Manufacturing precision
If high temperature is used to remove CO2 from the scrubbing solution, then separation efficiency improves, but energy consumption increases
Solution Approach 1:
The process employs heat exchangers that utilize the thermal energy from the hot scrubbing solution exiting the expansion stages to preheat the incoming scrubbing solution. This self-service heat recovery system reduces the external energy input required for heating while maintaining the temperature conditions necessary for CO2 removal efficiency.
Solution Approach 2:
The method exploits the phase transition of CO2 from dissolved state to gas phase during the expansion and depressurization stages. By controlling pressure and temperature to facilitate this phase transition, CO2 is removed efficiently without requiring excessive thermal energy input.
3Stability of the object's composition
If high pressure is used to maintain scrubbing solution circulation, then CO2 remains bound, but solution decomposition risk increases
Solution Approach 1:
The pressure management is segmented into distinct stages: high pressure during absorption to maintain CO2 binding, followed by controlled progressive pressure reduction during three expansion stages for CO2 removal. This segmentation allows the solution to experience high pressure only when necessary for binding, reducing cumulative exposure to decomposition risks.
Solution Approach 2:
The process dynamically adjusts pressure conditions based on the operational phase. During absorption, high pressure maintains CO2 binding stability. During regeneration, pressure is dynamically reduced through multiple expansion stages to remove CO2 while monitoring and controlling conditions to prevent solution decomposition, thus maintaining reliability.
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 process regenerates a highly pure scrubbing solution with reduced energy input, maintaining water content and achieving high separation efficiency, allowing for efficient reuse with lower detergent amounts and minimized methane losses.
Implementation Method 1
chemical scrubbing preferably being carried out using a scrubbing solution containing amines, in which the separated CO2 and sulfur compounds are chemically bound
Implementation Method 2
the expansion preferably takes place as a flash relaxation
Implementation Method 3
expanded in a first expansion stage, preferably to a pressure of 1 to 8 bar, the predominant proportion of CO2 and sulfur compounds being separated off from the scrubbing solution as a gas stream
Implementation Method 4
The contaminated scrubbing solution is heated to a temperature of at least 110 °C, optionally up to 135 °C
Implementation Method 5
The proportion of water contained in the scrubbing solution is retained, since the evaporated water removed by means of the vapors is returned to the cleaned scrubbing solution after condensation has taken place
Data Source
AI summary
The invention relates to a method for regenerating an amine-containing wash solution which is obtained during gas purification and in which CO2 and sulfur compounds are chemically bonded as well as a system that is suitable for carrying out said method. According to the invention, a) the contaminated wash solution is heated, compressed, and expanded in several stages such that CO2 and sulfur compounds are separated, and b) the expanded wash solution is subdivided into two partial streams, and one partial stream is recirculated into the process.