CO2 Partial Condensation and Membrane Separation Above Triple Point
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Solution Overview
Problem
The separation of high-carbon dioxide gases by partial condensation and permeation faces challenges due to excessive temperature drops, which can lead to CO2 solidification and degradation of membrane performance, and inefficient heat valorization in existing systems.
Innovation Solution
The method involves controlling the temperature drop by heating the membrane system to maintain temperatures above the CO2 triple point, using heat exchangers to optimize heat recovery, and reheating gases in multiple stages to prevent excessive cooling, thereby minimizing exergy losses and ensuring efficient CO2 separation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the gas is cooled to near the triple point of CO2 for efficient partial condensation separation, then the CO2 capture efficiency is improved, but the temperature drop causes CO2 solidification and membrane performance degradation
Solution Approach 1:
The patent modifies the temperature parameter by heating the pot head to maintain the temperature above the CO2 triple point, preventing solidification while preserving separation efficiency. This parameter change resolves the contradiction between achieving efficient CO2 capture through cooling and avoiding harmful CO2 solidification.
Solution Approach 2:
The patent applies preliminary heating to the pot head before the CO2 can solidify, creating a preventive counter-action against the harmful effect. By maintaining the temperature above the triple point through proactive heating, the system prevents CO2 solidification while still enabling efficient partial condensation separation.
2Productivity
If the membrane operates at lower temperatures for optimized separation performance, then the CO2 permeation efficiency is improved, but the temperature drop increases exergy losses and complicates heat valorization
Solution Approach 1:
The patent changes the temperature parameter by implementing heating of the pot head and intermediate reheating stages, maintaining temperatures that optimize membrane performance while minimizing exergy losses. This allows the system to achieve efficient CO2 permeation without excessive temperature drops that would increase energy losses.
Solution Approach 2:
The patent divides the permeation process into multiple stages with intermediate reheating, segmenting the temperature control to optimize both separation performance and energy efficiency at each stage while minimizing overall exergy losses.
3Productivity
If the temperature is minimized for optimized membrane separation performance, then the CO2 capture productivity is improved, but the CO2 risks solidification and membrane integrity is threatened
Solution Approach 1:
The patent modifies the temperature parameter by heating the pot head to maintain temperatures above the CO2 triple point, preventing solidification and protecting membrane integrity while still achieving optimized separation performance. This parameter adjustment resolves the contradiction between maximizing productivity and ensuring reliability.
Solution Approach 2:
The patent applies beforehand cushioning by pre-heating the pot head and implementing intermediate reheating stages, creating a protective thermal buffer that prevents CO2 solidification and protects the membrane from damage while maintaining optimal separation conditions.
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 prevents CO2 solidification, optimizes membrane performance, and enhances the valorization of cold fluids, resulting in improved efficiency and reduced exergy losses during the separation process.
Implementation Method 1
Membranes in which the CO2 will permeate preferentially compared to the other compounds will be chosen in order to capture the CO2 in the permeate of the membranes
Implementation Method 2
the gas rich in carbon dioxide is cooled at least in a first heat exchanger
Implementation Method 3
the gas rich in carbon dioxide cooled in the first heat exchanger or a fluid derived from this gas enters a first phase separator at a first temperature between -50°C and -53°C, a liquid enriched in carbon dioxide is withdrawn from the first phase separator
Data Source
Figure 1~2
Figure 3
AI summary
The invention relates to a separation method in which a carbon dioxide-rich gas is cooled in a first heat exchanger (5); the carbon dioxide-rich gas cooled in the first heat exchanger enters a first phase separator (9) at a first temperature between -50 °C and -53 °C; a carbon dioxide-enriched liquid (13) is drawn from the first phase separator and acts as product; a carbon dioxide-depleted gas (11) from the first separator is reheated in the first exchanger to a second temperature between -35 °C and -45 °C, without having been expanded downstream from the first phase separator and enters a permeation unit (17) at the second temperature; the reheated gas is subjected to at least one permeation step in the permeation unit in order to produce at least two fluids (19, 21) which are then reheated in the first exchanger, the fluid from the permeation unit, reheated in the exchanger, which exits the permeation unit at the lowest temperature, being at a temperature of more than -54 °C.