Air Separation Bypass Compression for Variable Product Pressure
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Solution Overview
Problem
Conventional air separation plants face high operational costs due to the constant need for electricity to compress air, and varying product pressures to adjust production rates are inefficient, leading to minimal power savings when reducing pressures.
Innovation Solution
A method and system that allows for the diversion of compressed air into a bypass system to adjust production rates and pressures by selectively introducing it into a booster compressor circuit or a bypass circuit, enabling greater control over pressurized product streams and reducing energy consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If compressed air is continuously fed through the booster compressor to maintain liquid product production, then liquid product output is maintained, but energy consumption increases
Solution Approach 1:
The system dynamically adjusts the booster compressor operation based on real-time liquid demand signals. When liquid demand is low, the compressor is bypassed or reduced; when demand is high, it is activated. This dynamic control allows the system to match energy consumption with actual production needs rather than operating at constant capacity.
Solution Approach 2:
The bypass system serves multiple functions: it can completely bypass the booster compressor, partially bypass it, or route all flow through it. This multi-functional bypass arrangement allows the same system component to adapt to varying production requirements and energy conditions, providing flexibility in managing both productivity and energy consumption.
2Use of energy by moving object
If the booster compressor is bypassed to reduce energy consumption, then energy cost decreases, but liquid product production rate decreases
Solution Approach 1:
The system uses dynamic control to adjust booster compressor operation based on liquid demand. The control system receives signals about liquid demand and automatically adjusts whether to bypass or activate the compressor, enabling the system to optimize energy cost while maintaining appropriate production rates for current demand conditions.
Solution Approach 2:
The system incorporates feedback control where liquid demand information is continuously monitored and fed back to the bypass control mechanism. This feedback loop enables automatic adjustment of compressor operation to match actual production needs, ensuring energy costs are optimized without compromising production when demand requires it.
3Stress or pressure
If compressed air is diverted to the bypass circuit to reduce pressure, then product pressure is reduced, but the ability to respond to varying demand efficiently is limited
Solution Approach 1:
The bypass system provides dynamic pressure control by allowing compressed air to be diverted to different paths based on demand conditions. The system can adjust the degree of bypassing in real-time, enabling flexible response to varying demand scenarios and optimizing both product pressure and adaptability.
Solution Approach 2:
The air flow path is segmented into multiple routes: through the booster compressor and through the bypass circuit. This segmentation allows independent control of different flow paths, enabling the system to optimize pressure and flow distribution according to specific demand requirements for different product streams.
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 allows for more efficient variation of production rates and pressures, resulting in significant cost savings by optimizing energy use and maintaining efficient operation across different demand scenarios.
Implementation Method 1
expanding the compressed air stream in a turbo-expander to produce an exhaust stream
Implementation Method 2
liquid and vapor that can be composed of nitrogen-rich and oxygen-rich liquid and vapor are introduced into a main heat exchanger and passed in indirect heat exchange with the incoming air to help cool the air
Implementation Method 3
The condenser reboiler condenses a stream of the of the nitrogen-rich vapor column overhead through indirect heat exchange with the oxygen-rich liquid column bottoms to produce liquid nitrogen reflux
Implementation Method 4
Air is separated in air separation plants that employ cryogenic rectification to separate the air into products that include nitrogen, oxygen and argon
Data Source
AI summary
A system and method for separating air in an air separation plant is provided. The disclosed systems and methods divert a portion of the compressed, purified air stream to a bypass system configured to selectively produce a higher pressure compressed output stream or a lower pressure compressed output stream. The higher pressure and/or lower pressure compressed output streams are cooled in a main heat exchanger by indirect heat transfer with a plurality of product streams from the air separation plant and then rectified in the distillation column system. A second portion of the compressed, purified air stream is partially cooled in the main heat exchanger and expanding in a turbo-expander to produce power and an exhaust stream which is directed to the distillation column system of the air separation plant where it imparts additional refrigeration generated by the expansion of the compressed air stream in the turbo-expander.