Online PSA Gas Analysis for Biomethane Saturation Control
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Solution Overview
Problem
Conventional RNG facilities face challenges with operability and reliability due to over or under saturation of PSA media, leading to product/target gas loss or increased plant product gas yield or BTU value.
Innovation Solution
The implementation of online gas analytical pressure-swing adsorption (PSA) control systems that capture and analyze gas streams in real-time to detect targeted products, allowing for adjustments in adsorption time and flow redirection between PSA vessels to prevent saturation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional PSA control is used without online gas analysis, then the system is simpler to operate, but the PSA media becomes over or under saturated leading to product gas loss
Solution Approach 1:
The patent implements online gas analytical control that continuously monitors the gas stream composition and provides real-time feedback to adjust PSA operation parameters. Gas analyzers detect the presence and concentration of target products, and this information feeds back to control the adsorption/desorption cycles, preventing over or under saturation of PSA media while maximizing methane recovery efficiency.
Solution Approach 2:
The patent replaces conventional mechanical/timing-based PSA control with an analytical control system that uses online gas analysis. Instead of relying on fixed time cycles or pressure differentials alone, the system uses real-time gas composition data from analyzers to dynamically control the PSA process, substituting mechanical control with intelligent analytical monitoring and adjustment.
2Manufacturing precision
If PSA media is over saturated, then more contaminants are removed, but product/target gas is lost
Solution Approach 1:
Online gas analyzers continuously monitor the effluent gas composition from the PSA vessels. When the analyzer detects that the target product concentration reaches a predetermined threshold, it provides feedback signal to stop the adsorption process and initiate desorption, preventing over-saturation that would cause methane loss while ensuring sufficient contaminant removal for high biomethane purity.
Solution Approach 2:
The patent implements dynamic adjustment of PSA operation parameters based on real-time gas composition analysis. The adsorption time, pressure swing magnitude, and flow rates are dynamically optimized according to the actual contaminant load and product concentration, allowing the system to adapt to varying feed gas conditions and maintain optimal separation efficiency without fixed, static parameters.
3Loss of substance
If PSA media is under saturated, then product gas is preserved, but biomethane yield decreases
Solution Approach 1:
The online analytical system provides continuous monitoring of gas stream composition, enabling the control system to determine the optimal moment to switch between adsorption and desorption modes. This feedback control ensures that the PSA media is utilized to its full capacity without exceeding saturation point, maximizing methane capture and biomethane production yield while preventing premature termination that would reduce productivity.
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 methane recovery efficiency by preventing over or under saturation of PSA media, thereby improving the quality and yield of biomethane production.
Implementation Method 1
separating a majority of trace contaminants from the gas stream in a first pressure swing adsorption (PSA) vessel through preferential adsorption of the trace contaminants
Implementation Method 2
separating nitrogen and oxygen from the gas stream in a second pressure swing adsorption (PSA) vessel through preferential adsorption of methane
Implementation Method 3
Adsorbed methane can be released through depressurization
Data Source
AI summary
A system and method for recovering high-quality biomethane (RNG) from biogas sources are provided. The system and method improve upon conventional practices and yield a biomethane product which meets strict gas pipeline quality specifications. An online sample is captured of a gas stream in near real-time at a pressure swing adsorption vessel, and the online sample is analyzed to detect the presence of one or more targeted products such as CH4, CO2 or N2. The system and method are an improvement to the overall methane recovery efficiency for biogas processing facilities, specifically with regard to PSA control to prevent over or under saturation of the PSA media.