Antifouling Co-Catalyst for Ethylene Dimerization

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Solution Overview

Problem

Current ethylene oligomerization processes face issues with polymer fouling, leading to frequent process shutdowns, increased maintenance costs, and reduced heat transfer efficiency due to the formation of polyethylene-based residues and 'hot spots' caused by chronic fouling and poor heat removal in reactor systems.

Innovation Solution

An antifouling catalyst system is introduced, comprising a combination of antifouling agents and aluminum alkyl compounds, which form an antifouling co-catalyst when mixed with a titanate compound, reducing polymer fouling by adjusting the molar ratio in real-time via an inline mixer to maintain optimal reactor conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional oligomerization catalyst systems are used, then ethylene dimerization to form 1-butene is achieved, but polymer fouling occurs on reactor walls and tubes leading to frequent shutdowns and increased maintenance costs

Engineering Contradiction:
Improveethylene dimerization rateVSAvoidreactor operation continuity
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

An antifouling agent is introduced as an intermediary substance that modifies the catalyst system to prevent polymer fouling. The antifouling agent interacts with the catalyst and polymer residues to reduce adhesion and facilitate removal, thereby maintaining reactor reliability without sacrificing productivity

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention changes the chemical parameters of the catalyst system by incorporating an antifouling agent and adjusting the molar ratio of aluminum alkyl compound to antifouling agent in real-time. This parameter modification reduces polymer fouling while maintaining desired oligomerization rates

Inventive Principle:
Principle #35Parameter changes

2Productivity

If conventional catalyst systems are used, then oligomerization reactions proceed, but heat removal becomes ineffective leading to hot spots and runaway polymerization

Engineering Contradiction:
Improveoligomerization reaction rateVSAvoidreactor temperature control
Core Design Contradiction:
ProductivityVSTemperature

Solution Approach 1:

The invention modifies the thermal parameters of the reaction system by introducing an antifouling agent that reduces polymer deposition on reactor walls. This prevents the formation of insulating polymer layers that would otherwise impede heat removal and cause hot spots

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system implements real-time control by adjusting the molar ratio of aluminum alkyl compound to antifouling agent based on process conditions. This feedback mechanism ensures optimal temperature control and prevents runaway polymerization while maintaining productivity

Inventive Principle:
Principle #23Feedback

3Loss of energy

If polymer residues accumulate on reactor walls, then heat transfer efficiency decreases, but increasing cleaning frequency increases maintenance costs and shutdown time

Engineering Contradiction:
Improveheat transfer efficiencyVSAvoidmaintenance shutdown time
Core Design Contradiction:
Loss of energyVSLoss of time

Solution Approach 1:

The antifouling agent enables the reactor system to resist polymer adhesion autonomously during operation. By modifying the catalyst system to include the antifouling agent, the reactor maintains heat transfer efficiency without requiring frequent manual cleaning interventions

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The antifouling agent acts as a mediator between the catalyst system and polymer residues, reducing the adhesion of polymer deposits to reactor walls. This intermediary function maintains heat transfer efficiency and reduces the frequency of maintenance shutdowns

Inventive Principle:
Principle #24Intermediary (Mediator)

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 antifouling catalyst system effectively reduces polymer fouling, making it easier to remove formed polymers and maintaining desired oligomerization rates and selectivity, thereby minimizing process shutdowns and maintenance costs while preventing 'hot spots' and maintaining heat transfer efficiency.

Implementation Method 1

bringing the at least one antifouling agent into contact with the at least one aluminum alkyl compound forms at least one antifouling compound including a central aluminum molecule bound to an R1 group, bound to an R2 group, and bound to an R3 group

Methodology Applied
Scientific EffectChemical reaction: Chemical Bonding

Implementation Method 2

feeding the antifouling feed stream, a catalyst comprising at least one titanate compound, and ethylene into a reactor to dimerize ethylene

Methodology Applied
Scientific EffectCatalysis: Catalysis

Implementation Method 3

Long residence times and poor heat removal from the highly exothermic reactions lead to the formation of polyethylene-based residues

Methodology Applied
Scientific EffectExothermic reaction: Exothermic Reaction

Data Source

PatentEP3684745B1Inline process to make antifouling agent co-catalyst for ethylene oligomerization
Publication Date: 2023.07.19 SAUDI ARABIAN OIL CO
  • EP3684745B1 patent drawingFigure 1
  • EP3684745B1 patent drawingFigure 2
  • EP3684745B1 patent drawing

AI summary

A process for selectively producing 1-butene comprises combining at least one antifouling agent and at least one aluminum alkyl compound to form an antifouling feed stream, wherein bringing the antifouling agent into contact with the aluminum alkyl compound forms at least one antifouling agent co-catalyst in a first step. The antifouling agent co-catalyst may comprise a structure comprising a central aluminum molecule bound to an R1 group, an R2 group, and an R3 group. The process further comprises feeding the antifouling feed stream, a catalyst comprising at least one titanate compound, and ethylene into a reactor to dimerize ethylene in a second step. The catalyst is fed as a stream separated from the antifouling feed stream. The feeds may be varied in real-time to adjust a ratio of the formed antifouling agent co-catalyst and residual aluminum alkyl compound or antifouling agent in the antifouling feed stream.