Organic-Liquid Membrane Separation for Ethylene Recovery

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Solution Overview

Problem

Existing ethylene oxide and ethylene glycol production processes face inefficiencies in ethylene recovery due to the need for significant purging to remove argon and carbon dioxide, leading to energy inefficiency and ethylene loss, despite the use of ethylene recovery units (ERU).

Innovation Solution

A membrane unit is used to separate a gas mixture by soaking a membrane element in an organic liquid, such as propylene oxide or ethylene oxide, to enhance the separation of ethylene, carbon dioxide, and argon, allowing for reduced purging and improved ethylene recovery.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If purging is performed to remove argon and carbon dioxide, then gas composition is improved, but ethylene is lost

Engineering Contradiction:

Improvegas compositionVSAvoidethylene loss

Core Design Contradiction:

ReliabilityVSLoss of substance

Solution Approach 1:

The patent changes the physical-chemical parameters of the membrane by soaking it in organic liquid to modify its permeability characteristics. This allows selective separation of carbon dioxide and argon from ethylene based on their different permeation rates through the modified membrane, enabling removal of unwanted gases without losing ethylene

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The membrane is treated with organic liquid to create localized regions with different permeability properties. The soaked membrane has enhanced selectivity for certain gas components, allowing differential permeation where carbon dioxide and argon are preferentially removed while ethylene is retained

Inventive Principle:

Principle #3Local quality

2Loss of substance

If ethylene recovery unit is installed, then ethylene recovery is improved, but energy consumption increases

Engineering Contradiction:

Improveethylene recoveryVSAvoidenergy consumption

Core Design Contradiction:

Loss of substanceVSUse of energy by moving object

Solution Approach 1:

The patent replaces the mechanical compression system of traditional ethylene recovery units with a membrane separation system. The membrane unit operates at lower pressures and uses the inherent permeability differences of gases to achieve separation, eliminating the need for high-energy compression equipment

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The membrane's permeability parameters are modified by organic liquid soaking, creating a separation mechanism that operates efficiently at reduced pressures. This parameter modification allows the system to achieve high ethylene recovery rates without requiring the high energy input needed by conventional compression-based recovery units

Inventive Principle:

Principle #35Parameter changes

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 membrane separation method increases ethylene recovery and reduces the gas purge rate, enhancing process efficiency and selectivity in ethylene oxide/ethylene glycol production while minimizing ethylene loss.

Implementation Method 1

a membrane element at least partially coated with an organic liquid... separating the gas mixture in the membrane unit

Methodology Applied

Scientific EffectPermeation: Permeation

Data Source

PatentUS20260042052A1Systems and methods for separating a gas mixture that includes organic and inorganic compounds

Publication Date: 2026.02.12 SABIC GLOBAL TECHNOLOGIES BV

AI summary

Systems and methods for separating a gas mixture of organic gaseous compounds and inorganic gaseous compounds are disclosed. The systems include a membrane unit with a membrane element that is at least partially coated with an organic liquid. The methods include using a membrane unit with the membrane element at least partially coated with an organic liquid to separate a gas mixture of organic gaseous compounds and inorganic gaseous compounds.