Combined cryogenic distillation and PSA for argon production
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Solution Overview
Problem
Current methods for producing high purity argon, such as the deoxo process and cryogenic distillation, are energy intensive and impractical in regions with limited hydrogen availability, and can destabilize cryogenic distillation columns due to nitrogen accumulation, leading to inefficiencies and contamination.
Innovation Solution
A method involving a cryogenic rectification column combined with a pressure swing adsorption system, using carbon molecular sieve and zeolite adsorbents to selectively remove oxygen and nitrogen from an argon stream, and regulating the flow of depressurization gas to maintain stability and efficiency in the distillation process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a large or superstaged argon column is used for cryogenic distillation to produce high purity argon, then argon purity is improved, but device complexity and energy consumption increase
Solution Approach 1:
The system divides argon purification into two separate functional stages: a crude argon column for initial separation and a VPSA unit for final purification. This segmentation allows each unit to be optimized for its specific function, reducing the need for a single large superstaged column while achieving the same purity level.
Solution Approach 2:
The invention changes the operating parameters by introducing pressure swing adsorption with cyclic pressure variations. The VPSA unit operates at high pressure during adsorption and low pressure during desorption, enabling efficient contaminant removal without requiring a large distillation column.
2Manufacturing precision
If the deoxo method is used to purify crude argon stream, then oxygen removal is improved, but energy consumption increases due to heating and cooling requirements
Solution Approach 1:
The VPSA process uses pressure as the controlling parameter instead of temperature. By cycling between high pressure (for adsorption) and low pressure (for desorption), the system achieves oxygen removal without the heating and cooling steps required by the deoxo method, significantly reducing energy consumption.
Solution Approach 2:
The invention replaces the thermal field (heating/cooling) used in the deoxo method with a mechanical field (pressure cycling). The VPSA unit uses pressure swing to drive the adsorption and desorption processes, substituting thermal energy with mechanical work.
3Device complexity
If depressurization gas is not regulated before returning to the distillation column, then process simplicity is maintained, but nitrogen accumulation occurs causing column instability
Solution Approach 1:
The system implements feedback control by monitoring the composition and flow of depressurization gas returning to the distillation column. Flow control valves and composition analyzers provide continuous feedback to adjust operating parameters, preventing nitrogen accumulation and maintaining column stability.
Solution Approach 2:
The invention changes the flow rate and pressure parameters of the depressurization gas using control valves and regulators. By adjusting these parameters, the system prevents nitrogen buildup in the distillation column while maintaining overall process simplicity.
4Productivity
If VPSA is used for argon purification, then argon recovery is improved, but device complexity increases due to multiple adsorption beds
Solution Approach 1:
The invention merges the VPSA unit with the existing distillation system, integrating the adsorption beds into the overall argon production flow. The VPSA unit processes the crude argon stream from the distillation column and returns purified argon, creating a unified system that improves recovery without requiring completely separate equipment.
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 effectively produces high purity argon (>99.999%) with reduced energy consumption and nitrogen contamination, while maintaining stability in the cryogenic distillation column, enhancing argon recovery and process efficiency.
Implementation Method 1
using carbon molecular sieve and zeolite adsorbents to selectively remove oxygen and nitrogen from an argon stream
Implementation Method 2
using carbon molecular sieve and zeolite adsorbents to selectively remove oxygen and nitrogen from an argon stream
Implementation Method 3
a pressure swing adsorption system, using carbon molecular sieve and zeolite adsorbents to selectively remove oxygen and nitrogen from an argon stream
Data Source
Figure 1
AI summary
A method and apparatus for producing high purity argon by combined cryogenic distillation and adsorption technologies is disclosed. Crude argon from a distillation column or a so-called argon column is passed to a system of adsorption vessels for further purification. Depressurization gas from adsorption is introduced back, in a controlled manner, to the distillation column and/or a compressor or other means for increasing pressure. Particulate filtration and getter purification may optionally be used.