MEG Reclamation via High-Pressure Flash Vaporization
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Solution Overview
Problem
Conventional MEG reclamation processes face issues with MEG degradation due to long residence times at elevated temperatures, requiring operation at sub-atmospheric pressures to prevent degradation, which leads to significant MEG losses and environmental concerns.
Innovation Solution
Operating a flash separator vessel at higher pressures (above 0.3 barA) with reduced residence times (1 second to 10 minutes) and elevated temperatures (110° C. to 250° C.) minimizes MEG degradation, allowing for complete vaporization without prolonged exposure to high temperatures, and eliminates the need for vacuum systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If conventional flash vaporization processes operate at sub-atmospheric pressures with long residence times to prevent MEG degradation, then MEG stability is improved, but equipment size increases and vacuum systems are required
Solution Approach 1:
The patent changes the operating parameters from sub-atmospheric pressure with long residence times to super-atmospheric pressure (above 0.3 barA) with short residence times (1 second to 10 minutes). This parameter inversion allows the system to eliminate vacuum equipment while preventing MEG degradation through rapid processing at elevated pressures and temperatures (110°C to 250°C).
Solution Approach 2:
The patent applies the 'rushing through' principle by minimizing the residence time of MEG in the flash separator to 1 second to 10 minutes. This rapid processing allows the system to complete vaporization and separation before significant degradation can occur, eliminating the need for vacuum systems and reducing equipment complexity.
2Productivity
If conventional processes use long residence times at elevated temperatures for complete vaporization, then vaporization completeness is improved, but MEG degradation increases
Solution Approach 1:
The patent changes the temperature-pressure-time parameters simultaneously: operating at super-atmospheric pressures (above 0.3 barA) enables elevated temperatures (110°C to 250°C) to be applied without causing excessive degradation, while maintaining short residence times (1 second to 10 minutes) to ensure complete vaporization occurs rapidly before degradation can significantl y progress.
3Productivity
If MEG is exposed to elevated temperatures for prolonged periods to ensure complete vaporization, then vaporization efficiency is improved, but corrosion rates increase due to MEG degradation
Solution Approach 1:
The patent minimizes the exposure time of MEG to elevated temperatures by reducing residence time to 1 second to 10 minutes. This rapid processing achieves complete vaporization efficiency while limiting the time available for thermal degradation reactions that produce carboxylic acids and increase corrosion rates.
Solution Approach 2:
The patent changes the operating pressure to super-atmospheric levels (above 0.3 barA), which allows elevated temperatures (110°C to 250°C) to be used for efficient vaporization while the short residence time prevents excessive degradation and corrosion.
4Stability of the object's composition
If conventional processes operate at reduced pressure to prevent MEG degradation, then MEG stability is improved, but equipment size increases
Solution Approach 1:
The patent inverts the pressure parameter from sub-atmospheric to super-atmospheric (above 0.3 barA), which allows for compact equipment design. The short residence time (1 second to 10 minutes) at these elevated pressures enables complete vaporization in a smaller volume while maintaining MEG stability through rapid processing.
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 reduces equipment size, eliminates the need for vacuum systems, minimizes oxygen ingress, and decreases corrosion rates, resulting in cost savings and reduced environmental impact by preventing MEG degradation and associated losses.
Implementation Method 1
flash vaporization process in which a heated recycle liquid provides heat to vaporise an aqueous stream of glycol
Implementation Method 2
the temperature is in the range of 110° C. to about 250° C.; alternatively above 150° C. to about 220° C.
Implementation Method 3
the volatile components of the feed are fully vaporized and the dissolved salt components of the feed are precipitated and removed from the heat transfer fluid
Data Source
AI summary
Monoethylene glycol (MEG) may be reclaimed by a process that includes contacting a MEG-water-salt stream with a heat transfer fluid and then flash separating the MEG and water in the flash separator vessel where the pressure is higher than 0.3 barA (0.03 MPa), the temperature is in the range of above 120° C. to about 250° C., and the residence time of the MEG and water ranges from about 1 second to about 10 minutes, and then removing the MEG and water in an overhead of the flash separator vessel and removing the salt from the flash separator vessel. In some embodiments it is expected that the temperature of the process may range from above 165° C. to about 250° C. and/or that the pressure may be atmospheric.