Cryogenic Air Purification Adsorbent Layout for Smaller TSA Columns
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Solution Overview
Problem
Conventional cryogenic air separation systems face challenges in downsizing due to large adsorption column diameters, which lead to issues with gas dispersion and increased installation areas, and struggle to efficiently remove nitrogen oxide and hydrocarbons simultaneously with carbon dioxide using existing adsorbents.
Innovation Solution
The method involves using a carbon dioxide adsorbent with a specific overall mass transfer coefficient range (2 to 8 s^-1) and a NaX zeolite with a particle diameter of 2.2 to 4.5 mm, packed in a way that the entire adsorbent layer acts as a mass transfer zone, allowing for efficient removal of carbon dioxide, nitrogen oxide, and hydrocarbons like C2H4, while reducing the adsorbent amount and column size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the flow rate of feed air is increased to increase production, then productivity is improved, but the column diameter must be increased leading to larger installation area
Solution Approach 1:
The patent changes the operating parameters by increasing the air velocity at the entrance of the adsorbent layer to 0.5 m/s or more, which allows the column diameter to be reduced while maintaining the required flow rate for high productivity
Solution Approach 2:
The patent transitions from conventional low-velocity adsorption to high-velocity adsorption, effectively changing the velocity dimension parameter to enable column downsizing while maintaining throughput
2Productivity
If the column diameter is increased to handle higher flow rates, then productivity is improved, but gas dispersion becomes difficult and uniform flow through adsorbent layer is compromised
Solution Approach 1:
By changing the air velocity parameter to 0.5 m/s or more, the patent achieves better gas distribution and uniform flow through the adsorbent layer, preventing the dispersion problems that occur in large-diameter columns with conventional low-velocity operation
3Quantity of substance
If an adsorbent with increased adsorption capacity is used to reduce adsorbent amount, then the adsorption column can be downsized, but simultaneous removal of nitrogen oxide and hydrocarbon becomes challenging
Solution Approach 1:
The patent employs a multi-functional adsorbent system where NaX zeolite serves multiple purposes: it adsorbs carbon dioxide, nitrogen oxide, and hydrocarbons simultaneously, enabling a single column to handle multiple impurities with reduced adsorbent quantity
Solution Approach 2:
The patent uses a composite adsorbent system combining NaX zeolite with specific particle diameters (2.2 to 4.5 mm) to achieve enhanced multi-component adsorption performance, allowing simultaneous removal of various impurities
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 results in a purification apparatus with low pressure loss, reduced installation area, and efficient removal of impurities, maintaining economical efficiency and enabling simultaneous removal of nitrogen oxide and hydrocarbons with carbon dioxide, thus addressing the limitations of conventional systems.
Implementation Method 1
a carbon dioxide adsorbent with a specific overall mass transfer coefficient range (2 to 8 s^-1)... packed in a way that the entire adsorbent layer acts as a mass transfer zone, allowing for efficient removal of carbon dioxide, nitrogen oxide, and hydrocarbons
Implementation Method 2
a NaX zeolite with a particle diameter of 2.2 to 4.5 mm, packed in a way that the entire adsorbent layer acts as a mass transfer zone, allowing for efficient removal of carbon dioxide, nitrogen oxide, and hydrocarbons like C2H4
Data Source
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AI summary
A purification method for feed air in cryogenic air separation of the present invention includes purifying the feed air for the cryogenic air separation by using a temperature swing adsorption method, wherein the whole region of a carbon dioxide adsorbent layer packed in an adsorption column is used as a mass transfer zone of a carbon dioxide. Also, a purification apparatus for feed air in cryogenic air separation of the present invention includes at least two adsorption columns; and a moisture adsorbent and a carbon dioxide adsorbent being laminated and packed in the adsorption columns, wherein the packed amount of the carbon dioxide adsorbent is the same as the amount of the carbon dioxide adsorbent in the region of the carbon dioxide adsorbent which a mass transfer zone of a carbon dioxide occupies at the end of an adsorption step, and a temperature swing adsorption method is used.