Contact and Separation Column with Swirler for Gas Treating
Solution Overview
Problem
Existing gas/liquid mass transfer columns, particularly those used in offshore gas mining, face limitations in mass transfer efficiency due to sea motion-induced sloshing and waving, which reduces their effectiveness, and they have limited capacity for high partial pressures of impurities like CO2.
Innovation Solution
A contact and separation column design featuring a stack of cells with a larger cross-sectional area in the contact zone compared to the separation zone, where the swirler is located at 50-90% of the contact and separation zone length, allowing for increased mean residence time and volumetric mass transfer rates, and enabling liquid recycle for flexible operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the swirler is located close to the gas inlet to maximize centrifugal separation, then separation efficiency improves, but the contact time between gas and liquid decreases reducing mass transfer efficiency
Solution Approach 1:
The contact and separation unit is divided into two distinct zones: an upstream contact zone where gas and liquid are intensively mixed for mass transfer, and a downstream separation zone where centrifugal separation occurs. This segmentation allows both contact time and separation efficiency to be optimized independently in their respective zones.
Solution Approach 2:
The swirler is positioned at a distance from the gas inlet (50-90% of the total length) rather than immediately adjacent, utilizing the longitudinal dimension of the unit to provide both contact and separation functions at different locations along the flow path.
2Productivity
If the cross-sectional area of the contact zone is increased to improve mass transfer, then volumetric mass transfer rate increases, but the overall column size and complexity increase
Solution Approach 1:
The contact zone is designed with a larger cross-sectional area specifically where mass transfer is needed, while the separation zone can have a different cross-sectional area optimized for centrifugal separation. This local optimization allows high volumetric mass transfer rates without unnecessarily increasing overall column size.
3Productivity
If gas flow velocity is increased to improve throughput capacity, then productivity increases, but pressure drop increases and mass transfer efficiency decreases
Solution Approach 1:
By separating the contact and separation functions into distinct zones, the system can optimize gas flow velocity for mass transfer in the contact zone (lower velocity for higher efficiency) while allowing higher velocities in the separation zone for improved throughput, thereby managing pressure drop across the entire unit.
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 design enhances mass transfer rates by maintaining lower gas flow velocities in the contact zone and higher velocities in the separation zone, improving separation efficiency and reducing pressure drops, making it suitable for floating applications and effective in removing contaminants like CO2 and H2S from natural gas.
Implementation Method 1
the liquid-gas flow is subjected to a rotary motion thereby creating an upwardly moving rotating liquid film
Implementation Method 2
separated with a cyclonic gas/liquid device can be made significantly more compact than a regular tray where the separation between gas and liquid is by gravitational forces instead of centrifugal forces
Data Source
AI summary
A contact and separation column (1) encasing a stack of one or more contact and separation cells (3). Each cell comprises: —a tray (4) with gas flow openings (6) opening into contact and separation units (7); —a downcomer (16) defining a liquid discharge; and —a liquid supply (17). Each contact and separation unit (7) comprises an upstream contact zone (8, 9) with liquid inlets (12), and one or more downstream separation zones (10) provided with a swirler (13) and a top end with a gas outlet (14). The swirler (13) is located at a distance from the gas inlet of from 50 to 90 % of the total length of the contact and separation zone. Process for treating a gas with such a column.