Multiple Membrane Stages for High-Yield Carbon Dioxide Separation
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Solution Overview
Problem
Existing gas separation membranes require high energy for operation and have low yield in separating carbon dioxide from combustion gases, necessitating a method to reduce energy consumption while increasing the yield of the separation process.
Innovation Solution
A method involving multiple gas separation membrane units connected in series, with controlled volumetric flow rates and stage cuts, and additional compressors to optimize gas flow and pressure, reducing the area of the membrane required and enhancing the yield of carbon dioxide separation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a gas separation membrane is used to separate carbon dioxide from combustion gas, then the separation process avoids phase change energy consumption, but the operating energy remains high and yield is low
Solution Approach 1:
The gas separation membrane system is divided into multiple stages (first gas separation membrane unit, second gas separation membrane unit, third gas separation membrane unit) connected in series. Each stage performs partial separation, with the permeate from one stage becoming the feed for the next stage. This segmented approach increases overall carbon dioxide yield while allowing each membrane unit to operate at optimized conditions, reducing total energy consumption compared to a single large-scale unit.
2Area of stationary object
If the area of the gas separation membrane is reduced to lower equipment cost, then the investment cost decreases, but the separation yield and energy efficiency worsen
Solution Approach 1:
Instead of using one large membrane area, the system employs multiple smaller membrane units in series. The first unit processes the entire feed stream at a controlled stage cut ratio (V1P/V1F < 0.2), the second unit processes the permeate from the first, and the third unit processes the permeate from the second. This segmentation allows each membrane to operate at optimal flux conditions, achieving high overall yield with smaller individual membrane areas, thus reducing total membrane material required.
Solution Approach 2:
The first gas separation membrane unit performs preliminary separation of carbon dioxide from the combustion gas feed, producing a permeate stream with elevated CO2 concentration. This pre-concentrated stream is then fed to the second and third units, which require smaller membrane areas to achieve the same overall yield because they are processing already-enriched gas rather than dilute feed gas.
3Productivity
If the volumetric flow rate ratio (V1P/V1F) is controlled to less than 0.2 in the first gas separation membrane unit, then the yield of carbon dioxide separation increases, but the energy consumption per unit area increases
Solution Approach 1:
The system segments the separation process so that the first membrane unit operates at low stage cut (V1P/V1F < 0.2) to maximize carbon dioxide recovery yield, accepting higher energy consumption per unit area. However, because the permeate from this first unit is fed to a second membrane unit (which also operates at low stage cut), and its permeate to a third unit, the overall system achieves high total yield. The energy penalty of the first unit is offset by the fact that subsequent units process smaller flow rates of already-concentrated gas, reducing their energy requirements.
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
The method achieves a higher yield of carbon dioxide separation with reduced energy consumption by optimizing gas flow and pressure across multiple membrane units, resulting in a more efficient and cost-effective separation process.
Implementation Method 1
The membrane separation method is a method of separating a permeable component and an impermeable component among components consisting of the mixture through a separation membrane. In particular, carbon dioxide and the like are absorbed or dissolved in the separation membrane and then move within the separation membrane to permeate through the separation membrane.
Data Source
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AI summary
The present disclosure relates to a method for separating a mixed gas. Specifically, the present disclosure can separate a large amount of target product from a mixed gas.