Pressure Swing Adsorption Elution Gas Fraction Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
PSA units operating under reduced feed rates or demand conditions become oversized, leading to increased specific costs and reduced hydrogen production efficiency, as they are not optimized to handle variations in feed gas flow and composition effectively.
Innovation Solution
A pressure modulated adsorption process that adjusts the fraction of gas flow enriched in compounds like hydrogen or CO2 during the elution phase, using a combination of co-current depressurization and production-derived elution gas, to optimize extraction yield and maintain purity by adjusting phase times based on operating conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If PSA units operate under reduced feed rates, then hydrogen production decreases, but specific costs increase due to oversizing
Solution Approach 1:
The patent applies dynamics by making the elution gas composition adjustable rather than fixed. The system dynamically adapts the fraction of gas stream enriched in compound X in the elution gas according to operating conditions (feed flow rate, purity requirements, extraction yield targets), allowing the PSA unit to optimize performance across different production rates and avoid the penalty of oversizing.
Solution Approach 2:
The patent changes the parameter of elution gas composition by adjusting the fraction of gas stream enriched in compound X. This parameter adjustment allows the system to maintain optimal extraction yield and purity across varying feed rates, effectively resolving the contradiction between reduced productivity and increased specific costs.
2Productivity
If the fraction of gas stream enriched in compound X is increased in elution gas, then extraction yield improves, but purity control becomes more difficult
Solution Approach 1:
The patent implements feedback control by adjusting the fraction of gas stream enriched in compound X in the elution gas based on operating conditions and performance targets. This feedback mechanism allows the system to simultaneously optimize extraction yield and maintain purity control, as the composition is continuously adapted to achieve both objectives.
Solution Approach 2:
The system dynamically adjusts the elution gas composition to balance extraction yield and purity control. By making the fraction of enriched gas stream adjustable, the system can respond to changing conditions and maintain optimal performance for both productivity and purity.
3Stability of the object's composition
If phase time is extended to maintain purity at reduced feed rates, then purity is maintained, but hydrogen production efficiency decreases
Solution Approach 1:
Instead of solely extending phase time to maintain purity, the patent changes the parameter of elution gas composition by adjusting the fraction of gas stream enriched in compound X. This alternative parameter adjustment allows purity to be maintained while avoiding the productivity loss associated with extended phase times.
Solution Approach 2:
The system dynamically adjusts the elution gas composition to maintain purity at reduced feed rates without requiring extended phase times. This dynamic parameter adjustment resolves the contradiction between purity stability and production efficiency.
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 enhances hydrogen production yield and reduces the quantity of feed gas required, thereby lowering operational costs and improving economic efficiency by leveraging the oversizing of PSA units.
Implementation Method 1
a) Adsorption at the high pressure of the cycle with production of the gas stream enriched in compound X
Implementation Method 2
b) Depressurization to the low pressure of the cycle
Implementation Method 3
c) Elution at the low pressure using an elution gas
Implementation Method 4
d) Repressurization to the high pressure
Data Source
Figure 1
AI summary
The invention relates to a pressure swing adsorption method (PSA) for producing a gas stream enriched with a compound X from a gaseous input stream, using at least two adsorbers, each adsorber being subjected to a pressure cycle having a high pressure and a low pressure and including the following consecutive steps: a) adsorption at the high pressure of the cycle with production of the gaseous stream enriched with the compound X; b) depressurisation down to the low pressure of the cycle; c) elution at the low pressure by means of an elution gas; d) repressurisation up to the high pressure, characterised in that: the elution gas includes a fraction of a gaseous stream from the depressurisation of an adsorber and a fraction of the gaseous stream enriched with the compound X; said fraction of the gaseous stream enriched with the compound X can be adjusted using adjustment means; and the pressure cycle has a phase time corresponding to the duration of a pressure cycle divided by the number of adsorbers and the fraction of the gaseous stream enriched with the compound X is determined in accordance with the phase time.