Single-PSA Syngas Separation with Cryogenic and Shift Integration
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Solution Overview
Problem
Existing methods for producing carbon monoxide and hydrogen require multiple PSA units, increasing costs and are dependent on MeOH synthesis demands, which is not economically viable in all scenarios.
Innovation Solution
A process utilizing a single pressure swing adsorption unit to separate carbon monoxide and hydrogen streams, incorporating a compressor to regenerate temperature swing adsorption units and employing gaseous nitrogen for regeneration, thereby reducing the need for multiple PSA units.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multiple PSA units are used to separate carbon monoxide and hydrogen streams, then separation efficiency is improved, but investment costs increase
Solution Approach 1:
The patent combines two separate PSA units into a single PSA unit by integrating the separation of carbon monoxide and hydrogen streams into one device. The single PSA unit performs both separations simultaneously through staged pressure swing adsorption, eliminating the need for multiple separate units while maintaining separation efficiency.
Solution Approach 2:
The single PSA unit is designed to perform multiple functions: separating both carbon monoxide and hydrogen from the synthesis gas stream. By incorporating multiple adsorption beds with different adsorbents and implementing staged pressure swing cycles, the unit achieves universal separation capability that previously required dedicated units for each gas component.
2Device complexity
If a single PSA unit is used to reduce investment costs, then device complexity is reduced, but separation efficiency may deteriorate
Solution Approach 1:
The single PSA unit is divided into multiple adsorption beds (typically three or more) that operate in sequence. Each bed is segmented to handle specific separation tasks at different stages of the pressure swing cycle, allowing the unit to achieve complex multi-component separation through coordinated operation of divided sections.
Solution Approach 2:
The PSA unit employs periodic pressure swing cycles with multiple stages, where beds are cycled through adsorption, depressorption, and regeneration phases in sequence. This periodic action with varying pressure levels enables the single unit to achieve separation efficiency comparable to multiple continuous units by exploiting temporal separation of gas components.
3Productivity
If temperature swing adsorption units are regenerated using existing processes, then operational continuity is maintained, but energy consumption increases
Solution Approach 1:
The system uses its own produced gases (carbon monoxide and hydrogen) to regenerate the temperature swing adsorption units. The purified gas streams from the PSA unit are directed back through the TSA units, using their thermal energy and flow to desorb and regenerate the adsorbents, thereby making the system self-sufficient for regeneration without external energy inputs.
Solution Approach 2:
The patent converts the thermal energy that would otherwise be wasted during gas cooling and compression processes into a useful resource for regenerating the TSA units. By routing the PSA off-gas through the TSA beds, the system transforms potential energy losses into beneficial regeneration heat, reducing overall energy consumption while maintaining operational continuity.
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
Reduces overall investment costs by using a single PSA unit while maintaining efficient separation of carbon monoxide and hydrogen, independent of MeOH market demands.
Implementation Method 1
a single pressure swing adsorption unit to separate carbon monoxide and hydrogen streams
Implementation Method 2
two temperature swing adsorption units, in series, for the separation of acid gases from the synthesis gas
Implementation Method 3
a compressor to compress the synthesis gas and/or the gas streams produced by the pressure swing adsorption unit and/or the temperature swing adsorption units
Implementation Method 4
employing gaseous nitrogen for regeneration
Data Source
Figure 1
Figure 2
AI summary
A process for separating two gaseous streams each containing at least one acid gas, carbon monoxide and hydrogen to remove carbon monoxide and hydrogen, the first gaseous stream (5) is purified in a first acid gas removal absorber (AGR1A) to remove at least one acid gas, purified in a TSA unit (TSA1) to remove at least carbon and then separated at a cryogenic temperature in a separation unit (CB) to produce a stream of fluid enriched in hydrogen (11), the second gaseous stream (7) is sent to a shift reaction unit (14), the shifted second stream (15) is purified in a second acid gas removal absorber (AGR2A) to remove carbon dioxide and the purified second stream (17, 19) is sent as a feed stream to a PSA unit (PSA) to produce a hydrogen enriched stream (21) and at least part of the stream enriched in hydrogen (11) from the separation unit (CB) is sent as a feed stream to the PSA unit to produce the hydrogen-enriched stream (21).