CO2 Stream Drying With Antifreeze-Assisted Compression
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Solution Overview
Problem
The existing processes for compressing CO2-rich streams require expensive stainless steel or noble materials to prevent corrosion, and involve costly drying and purification steps, especially due to water condensation issues during compression and cooling.
Innovation Solution
Incorporating an antifreeze, such as methanol, into the CO2-rich stream to lower the freezing point of water, allowing for cooling without condensation and using carbon steel or low-alloy steel compressors, which reduces equipment costs and energy consumption by avoiding the need for expensive corrosion-resistant materials and costly drying units.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If stainless steel or noble materials are used for the compressor to prevent corrosion, then corrosion resistance is improved, but equipment cost increases
Solution Approach 1:
The invention extracts water from the CO2-rich stream through a drying unit positioned upstream of the compressor. By removing water before compression, the corrosive environment is eliminated, allowing the use of cheaper carbon steel or low-alloy steel materials in the compressor while maintaining corrosion resistance through preventive water removal rather than relying on expensive corrosion-resistant materials
Solution Approach 2:
The drying unit performs preliminary water removal before the gas enters the compressor. This preliminary action prevents water condensation during compression and cooling, thereby preventing corrosion in advance and enabling the use of less expensive materials that would otherwise be susceptible to corrosion from wet CO2 streams
2Reliability
If drying units and purification steps are added to remove water, then corrosion protection is improved, but process complexity and cost increase
Solution Approach 1:
The invention introduces an intermediary substance (glycol or other antifreeze agent) that is injected into the CO2-rich stream to lower the freezing point of water. This intermediary prevents water condensation during compression and cooling by maintaining water in a liquid state at lower temperatures, thereby providing corrosion protection without requiring complex drying units or multiple purification steps
Solution Approach 2:
The invention changes the freezing point parameter of water by adding glycol or other antifreeze agents to the CO2-rich stream. This parameter change allows the system to operate at lower temperatures without water condensation, simplifying the overall process by eliminating or reducing the need for complex drying and purification equipment while maintaining reliable corrosion protection
3Quantity of substance
If water is removed by adsorption drying, then water content is reduced, but energy consumption and operational cost increase
Solution Approach 1:
The invention uses glycol or other antifreeze agents as intermediaries that lower the freezing point of water, preventing condensation during compression and cooling. This approach reduces water content and prevents corrosion without requiring energy-intensive adsorption drying processes, thereby lowering operational costs while maintaining low water content in the compressed CO2 stream
Solution Approach 2:
By changing the freezing point parameter through additive injection, the system prevents water condensation at lower temperatures without requiring energy-intensive drying processes. This parameter modification allows the compression process to proceed with lower energy consumption while still achieving the necessary water content reduction for corrosion prevention
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 reduces the cost of compression and purification units, stabilizes suction temperatures, decreases compression power, and eliminates the need for costly adsorption-drying equipment, while maintaining efficient operation and low residual water content.
Implementation Method 1
Incorporating an antifreeze, such as methanol, into the CO2-rich stream to lower the freezing point of water
Implementation Method 2
cooling of the CO2-rich stream to a temperature below the dew point of the stream
Implementation Method 3
compression of the CO2-rich stream
Data Source
AI summary
A process for compressing a CO2-rich fluid containing water. The CO2-rich fluid is compressed in a compressor; upstream of the compression step, an antifreeze is mixed with the CO2-rich fluid containing water. The CO2-rich fluid containing antifreeze is cooled, water is separated from the cooled fluid and the water-depleted cooled fluid is compressed in the compressor, wherein the CO2-rich fluid containing water is sent to a scrubbing column fed, preferably at the top, with a water/antifreeze mixture, where it cools and is separated from the water, the water-depleted cooled fluid is extracted from the top of the column; a water/antifreeze mixture in the column is extracted at a level below the top; the mixture is cooled using the refrigeration from an apparatus for cooling and/or purifying the cooled fluid compressed in the compressor and the fluid is returned to the top of the column.