Noble Gas Recovery Using Chemical Looping Purification
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Solution Overview
Problem
Current systems for recovering noble gases like argon from gas mixtures containing oxidizable impurities are inefficient and costly, particularly due to the need for cryogenic separation and excessive oxygen injection, which limits their appeal for local, point-of-use recovery and recycling.
Innovation Solution
A method utilizing Chemical Looping Combustion (CLC) with a solid state oxygen carrier, such as a metal oxide, to oxidize combustible species to CO2 and H2O without injecting oxygen into the gas stream, allowing for efficient removal of impurities and regeneration of the oxygen carrier, thereby simplifying the recovery process and reducing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional catalytic combustion with excess oxygen injection is used, then combustible impurities are converted to CO2 and H2O, but the system requires complex oxygen removal and frequent metal bed regeneration
Solution Approach 1:
The patent extracts the oxygen supply function from the gas stream and implements it through a separate solid state oxygen carrier bed. This removes the need for oxygen injection and subsequent oxygen removal steps, simplifying the overall system while maintaining effective combustion of combustible impurities.
Solution Approach 2:
The solid state oxygen carrier acts as an intermediary that provides oxygen for combustion without requiring direct oxygen injection into the gas stream. The oxygen carrier material (such as metal oxides) releases oxygen in situ, enabling impurity conversion while avoiding the complexity of oxygen management in the gas phase.
2Manufacturing precision
If cryogenic separation is used for noble gas recovery, then high purity noble gas is obtained, but the cost and energy consumption become prohibitive for all but largest installations
Solution Approach 1:
The patent changes the operating parameters from cryogenic temperatures to moderate temperatures using solid state oxygen carriers. This parameter change enables noble gas recovery at lower costs and energy consumption while maintaining the ability to achieve high purity through selective oxidation of impurities rather than through cryogenic separation.
3Quantity of substance
If metal bed is used for oxygen removal, then excess oxygen is removed from the gas stream, but the metal bed has limited capacity and requires frequent regeneration
Solution Approach 1:
Instead of removing oxygen after combustion, the patent inverts the approach by using a solid state oxygen carrier that provides oxygen during combustion. This eliminates the need for a separate oxygen removal step and the associated frequent regeneration requirements.
Solution Approach 2:
The solid state oxygen carrier bed is designed to be regenerated in situ during normal operation by exposure to the gas stream, allowing continuous operation without frequent offline regeneration. The system essentially serves itself by using the process gas to regenerate the oxygen carrier.
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 enables the recovery of noble gases at high purity (99.9999%) while eliminating the need for cryogenic separation and reducing operational complexity, making it more economically viable for smaller-scale applications.
Implementation Method 1
A method utilizing Chemical Looping Combustion (CLC) with a solid state oxygen carrier, such as a metal oxide, to oxidize combustible species to CO2 and H2O
Implementation Method 2
oxidize combustible species to CO2 and H2O without injecting oxygen into the gas stream
Implementation Method 3
The gas is then passed through a molecular sieve to remove CO2 and H2O
Data Source
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AI summary
The method of recovery and recycling of inert gases, especially noble gases, from processes such as vacuum furnaces and other applications. A first gas stream comprising the inert gas and oxidisable impurities, is supplied to an oxidation column comprising a metal oxide. The impurities in the first gas stream are oxidised in the column in the presence of the metal oxide to form a second gas stream containing carbon dioxide and water, the second gas stream is supplied to a regenerable carbon dioxide removal column; the carbon dioxide is removed from the second gas stream in the column to form a third gas stream. Water is removed from the third gas stream in an absorption column, and the exhausted, purified inert gas is collected from the absorption column for conveying to a process utilising the inert gas. The recovered gas stream is of around 6N purity (99.9999% pure) i.e. having lppm total contaminants.