Single Compressor for CO2 Membrane Separation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional gas separation membrane-based systems for removing CO2 from CO2/hydrocarbon mixtures face economic challenges due to the need for expensive two-stage compression systems when CO2 partial pressures exceed membrane design limits.
Innovation Solution
A three-stage gas separation membrane-based system using a single multi-stage compression unit, where each stage's permeate and residue streams are compressed differently, avoiding membrane plasticization and reducing costs by integrating compression duties within a single compressor system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single compressor is used to compress both first stage permeate and second stage residue, then device complexity and cost are reduced, but it becomes difficult to independently control the pressure of each stream to meet membrane design limits and product requirements
Solution Approach 1:
The compression system is segmented into multiple independent compression units, each dedicated to compressing specific streams (first stage permeate and second stage residue) to different pressure levels. This segmentation allows independent pressure control for each stream while maintaining overall system simplicity.
Solution Approach 2:
The compression system is designed with multi-functionality where compression units can serve multiple purposes: compressing permeate streams to feed downstream membranes, compressing residue streams for recycling, and maintaining pressures within membrane design limits. This universal approach reduces overall device complexity.
2Ease of operation
If excess pressure is provided in the second residue stream to enable blending with treated natural gas, then ease of operation is improved, but CO2 partial pressure may exceed membrane design limits causing plasticization
Solution Approach 1:
The system dynamically adjusts pressure parameters of different streams using independent compression units. The second residue stream pressure is controlled to be sufficient for blending with treated natural gas but not excessive enough to cause CO2 partial pressure to exceed membrane design limits, thus preventing plasticization while maintaining ease of operation.
Solution Approach 2:
The compression system incorporates feedback control mechanisms that monitor CO2 partial pressure and stream composition, adjusting compression ratios to maintain pressure levels that enable easy blending while staying within membrane design limits to prevent plasticization.
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 effectively removes CO2 from CO2/hydrocarbon mixtures while maintaining methane enrichment, reducing hydrocarbon losses, and avoiding membrane plasticization, thus being more economical than conventional methods.
Implementation Method 1
Gas separation membranes are used to separate mixtures of carbon dioxide (CO2) and hydrocarbons
Implementation Method 2
membranes arranged in parallel or in series that are selective for CO2 over methane
Implementation Method 3
compressing the first permeate in one or more compressors of a multi-stage compression unit
Data Source
AI summary
A single compressor is used to separately compress permeate from cascaded first and second gas separation membrane-based separation units and residue from a fourth gas separation membrane-based separation unit in order to avoid too high a CO2 partial pressure in the compressed permeate. After the permeates from the first and second stages are compressed, the compressed stream is fed to a third gas separation membrane-based separation unit.