Multi-Stage Gas Separation by Sequential Cooling and CO2 Desublimation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for separating gases in natural gas production are often energy inefficient, have limited extraction capacity, and are not feasible in remote locations, necessitating the need for energy-efficient and cost-effective purification techniques.
Innovation Solution
A multi-stage process involving cooling and condensation in sequential vessels to separate methane, water, carbon dioxide, and Natural Gas Liquids (NGLs), where water, NGLs, and carbon dioxide are progressively condensed or desublimated, reducing impurities and energy consumption while integrating gas sweetening, drying, and NGLs recovery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional gas separation methods are used, then extraction capacity is achieved, but energy consumption increases
Solution Approach 1:
The gas separation process is divided into multiple sequential stages, each targeting specific components at different temperature levels. The first stage removes water and heavy NGLs, the second stage removes additional NGLs, and the third stage removes methane and CO2. This segmentation allows each stage to operate optimally for its specific separation task, improving overall energy efficiency while maintaining high extraction capacity.
Solution Approach 2:
The process utilizes temperature as a key parameter to control component condensation. By progressively lowering the temperature through each stage (from initial cooling to final deep cooling), the process selectively condenses different gas components based on their dew points. This parameter change approach enables efficient separation without requiring high-energy compression or chemical treatment.
2Reliability
If conventional purification processes are implemented, then gas separation is achieved, but device complexity and capital costs increase
Solution Approach 1:
The process combines multiple separation functions (water removal, NGLs recovery, methane condensation, and CO2 removal) into a single integrated cooling train. Instead of using separate units for each separation task, all functions are achieved through sequential cooling stages using the same equipment train, thereby reducing device complexity and capital costs while maintaining purification effectiveness.
Solution Approach 2:
The cooling vessels and heat exchangers serve multiple purposes across different stages. For example, the first cooling vessel removes water and heavy NGLs, while subsequent stages use the same equipment to remove additional components. This multi-functionality reduces the number of dedicated units needed, simplifying the overall process design and reducing capital investment.
3Reliability
If traditional gas treatment methods are used, then contaminants are removed, but equipment size and installation footprint increase
Solution Approach 1:
The separation process is segmented into compact sequential stages within a unified equipment train. Each stage targets specific contaminants and is integrated into the same physical footprint, avoiding the need for large separate units for water removal, NGLs recovery, and CO2 removal. This segmentation enables effective contaminant removal in a compact configuration suitable for remote locations.
4Productivity
If pressure reduction is applied for gas treatment, then separation efficiency improves, but additional equipment and energy requirements increase
Solution Approach 1:
The process achieves separation efficiency through temperature changes rather than pressure reduction. By controlling the cooling temperature at each stage, the process selectively condenses different gas components based on their vapor-liquid equilibrium characteristics at those temperatures. This approach maintains separation efficiency without requiring pressure reduction equipment or the associated energy consumption for compression and decompression.
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 energy consumption, capital costs, and equipment size, enabling effective treatment of high-carbon dioxide natural gas streams while minimizing chemical hazards and environmental impacts, and allows for the treatment of natural gas at typical plant pressures without pressure reduction.
Implementation Method 1
A portion of the water condenses to form a primary liquid stream
Implementation Method 2
A first portion of the NGLs condense to form a secondary liquid stream
Implementation Method 3
A first portion of the methane condenses to form a liquid methane stream
Implementation Method 4
a first portion of the carbon dioxide condenses, desublimates, or condenses and desublimates
Implementation Method 5
a first portion of the carbon dioxide condenses, desublimates, or condenses and desublimates
Data Source
AI summary
The disclosure provides a method for separating components of a gas. A feed gas stream is cooled in a first vessel. The feed gas stream includes methane, water, carbon dioxide, and Natural Gas Liquids. The feed gas stream is cooled in a first vessel. A portion of the water condenses to form a primary liquid stream, resulting in a first depleted gas stream, which is cooled in a second vessel. A portion of the NGLs condense to form a secondary liquid stream, resulting in a second depleted gas stream, which is cooled in a condensing exchanger. A first portion of the methane condenses to form a liquid methane stream, resulting in a third depleted gas stream, which is cooled in a third vessel. A portion of the carbon dioxide condenses, desublimates, or condenses and desublimates as a final product stream, also resulting in a fourth depleted gas stream.