Two-Stage Acidic Gas Separation Using Ceramic and Polymer Membranes

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Solution Overview

Problem

The performance of organic polymer separation membranes deteriorates rapidly when carbon dioxide concentration exceeds 20% in the gas to be treated, making it unprofitable for high carbon dioxide concentrations in oil and gas field gases, and recent advancements in resource development are expected to further increase these concentrations.

Innovation Solution

A two-stage acidic gas separation device using an inorganic separation membrane followed by an organic polymer separation membrane to reduce acidic gas concentration in a gaseous hydrocarbon fluid, with the inorganic membrane initially reducing the concentration to prevent membrane deterioration and the organic polymer membrane further reducing it, allowing for extended membrane lifespan and reduced replacement frequency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If an organic polymer separation membrane is used to separate acidic gas from gaseous hydrocarbon fluid, then separation performance per weight and volume is very high, but the membrane performance deteriorates rapidly when carbon dioxide concentration exceeds 20%

Engineering Contradiction:

Improveseparation performanceVSAvoidmembrane durability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The separation process is divided into two stages: first stage uses inorganic separation membrane (such as ceramic membrane) to remove a portion of acidic gas and reduce carbon dioxide concentration to 20% or less, second stage uses organic polymer separation membrane to further separate acidic gas from the pre-treated gas. This segmentation protects the organic polymer membrane from rapid deterioration while maintaining high separation performance.

Inventive Principle:

Principle #1Segmentation

2Productivity

If multiple organic polymer separation membrane modules are connected in series to achieve high acidic gas separation ratio, then separation efficiency increases, but the cost increases and membrane replacement frequency increases due to rapid deterioration

Engineering Contradiction:

Improveseparation efficiencyVSAvoidmembrane lifespan

Core Design Contradiction:

ProductivityVSDuration of action of stationary object

Solution Approach 1:

The system is segmented into two functional units: first separation unit with inorganic membrane handles the harsh high-concentration CO2 environment, second separation unit with organic polymer membrane handles the milder pre-separated gas. This extends the lifespan of organic polymer membranes while maintaining high separation efficiency.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The inorganic separation membrane acts as a protective buffer before the organic polymer membrane, pre-reducing carbon dioxide concentration to protect the organic polymer membrane from rapid deterioration. This beforehand cushioning extends membrane lifespan and reduces replacement frequency.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Productivity

If organic polymer separation membrane is used for high carbon dioxide concentration gas, then separation is achieved, but profitability decreases due to frequent membrane replacement

Engineering Contradiction:

Improveseparation capabilityVSAvoidoperational profitability

Core Design Contradiction:

ProductivityVSEase of manufacture

Solution Approach 1:

Dividing the separation system into two stages with different membrane types reduces the replacement frequency of expensive organic polymer membranes, thereby improving operational profitability while maintaining separation capability for high CO2 concentration gases.

Inventive Principle:

Principle #1Segmentation

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 extends the operational life of organic polymer separation membranes, reduces replacement costs, and improves the profitability of acidic gas separation by maintaining high energy efficiency and compact size while minimizing the depreciation burden of the facility.

Implementation Method 1

a first separation device which has an inorganic separation membrane and is configured to separate a gaseous hydrocarbon fluid containing an acidic gas into a first gaseous fluid having a large acidic gas content and a second gaseous fluid having a smaller acidic gas content than the first gaseous fluid by the inorganic separation membrane

Methodology Applied

Scientific EffectMembrane separation: Semipermeable Membrane

Implementation Method 2

organic polymer separation membranes that have different permeability (selective permeability) between methane and carbon dioxide have been proposed

Methodology Applied

Scientific EffectSelective permeability: Semipermeable Membrane

Data Source

PatentUS11458435B2Acidic gas separation device and acidic gas separation method

Publication Date: 2022.10.04 JAPAN OIL GAS & METALS NAT CORP

AI summary

An acidic gas separation device includes: a first separation device which has an inorganic separation membrane and is configured to separate a gaseous hydrocarbon fluid containing an acidic gas into a first gaseous fluid having a large acidic gas content and a second gaseous fluid having a smaller acidic gas content than the first gaseous fluid by the inorganic separation membrane; and a second separation device which has an organic polymer separation membrane and is configured to separate the second gaseous fluid into a third gaseous fluid having a large acidic gas content and a fourth gaseous fluid having a smaller acidic gas content than the third gaseous fluid by the organic polymer separation membrane.