Variable-Diameter Oligomerization Reactor for Ethylene Dissolution

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Solution Overview

Problem

Existing gas/liquid reactors for ethylene oligomerization face inefficiencies due to significant ethylene loss through the headspace, leading to reduced productivity and selectivity, particularly when managing high amounts of undissolved ethylene.

Innovation Solution

A reactor design with consecutive zones of decreasing diameter from the bottom to the top, increasing the height of the liquid phase without changing the volume, enhances ethylene dissolution and limits the 'piercing' phenomenon by extending the residence time of ethylene in the liquid phase.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the reactor volume is increased to improve ethylene dissolution, then the productivity improves, but the device complexity and cost increase

Engineering Contradiction:
Improveethylene conversionVSAvoidreactor volume
Core Design Contradiction:
ProductivityVSVolume of stationary object

Solution Approach 1:

The patent transitions from a conventional horizontal reactor configuration to a vertical reactor configuration. This dimensional change allows the liquid phase to occupy a greater height within the same reactor footprint, increasing the liquid-gas contact area and improving ethylene dissolution without requiring a larger reactor volume. The vertical arrangement maximizes the use of vertical space to enhance mass transfer efficiency.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent introduces a vortex flow regime in specific zones of the reactor to enhance local mass transfer. By creating rotational flow patterns, the liquid-gas interface is intensified, increasing the contact area and transfer rate of ethylene from the gas phase to the liquid phase. This localized enhancement of flow characteristics improves dissolution efficiency without requiring a larger reactor volume.

Inventive Principle:
Principle #3Local quality

2Productivity

If the liquid phase height is increased to improve ethylene dissolution, then the productivity improves, but the reactor volume increases

Engineering Contradiction:
Improveethylene conversionVSAvoidreactor volume
Core Design Contradiction:
ProductivityVSVolume of stationary object

Solution Approach 1:

The patent adopts a vertical reactor configuration that prioritizes height utilization over horizontal expansion. By arranging the reactor vertically and optimizing the liquid phase height within the vertical dimension, the design increases the residence time and contact area for ethylene dissolution without proportionally increasing the overall reactor volume. This dimensional strategy allows higher liquid phase height while maintaining compact reactor footprint.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Productivity

If the reactor is purged to remove gaseous compounds, then the selectivity improves, but ethylene loss increases

Engineering Contradiction:
Improveethylene conversionVSAvoidethylene loss
Core Design Contradiction:
ProductivityVSLoss of substance

Solution Approach 1:

The patent enhances ethylene dissolution in the liquid phase before significant piercing can occur. By optimizing the liquid-gas contact conditions and increasing the dissolution rate through vortex flow and vertical configuration, ethylene is transferred to the liquid phase in advance, reducing the amount of undissolved gas that would otherwise pierce through to the headspace and require purging.

Inventive Principle:
Principle #10Preliminary action

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 design improves ethylene conversion and selectivity to desired linear alpha-olefins by increasing the height of the liquid phase, thereby reducing ethylene loss and maintaining high saturation levels.

Implementation Method 1

improve the dissolution of gaseous ethylene and therefore limiting the piercing phenomenon for a given volume of liquid phase

Methodology Applied
Scientific EffectMass transfer: Diffusion

Data Source

PatentEP4076723B1Gas/liquid oligomerization reactor having successive zones with variable diameters
Publication Date: 2026.02.11 IFP ENERGIES NOUVELLES
  • EP4076723B1 patent drawingFigure 1
  • EP4076723B1 patent drawingFigure 2
  • EP4076723B1 patent drawingFigure 3

AI summary

The invention relates to a gas/liquid oligomerization reactor having successive zones with variable diameters. The invention also relates to a process for the oligomerization of ethylene using a gas/liquid oligomerization reactor having successive zones with variable diameters.