Polymer Particle Temperature Control in Reactor Fouling Prevention

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In polymerization reactor systems, maintaining optimal temperature conditions is challenging due to the risk of fouling and heat transfer inefficiencies, which can lead to reactor fouling, plugging, and adverse effects on polymer properties.

Innovation Solution

A process that involves detecting the bulk fluid temperature and calculating the average temperature of olefin polymer particles using specific heat transfer equations, comparing it to an operating threshold, and adjusting operating parameters such as cooling fluid temperature or flowrate to maintain the particle temperature below the fouling threshold, thereby controlling heat transfer and preventing fouling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the polymerization reaction temperature is increased to improve reaction rate and productivity, then the polymer particles may adhere to the reactor interior surface causing fouling, which reduces reliability and requires shutdown for cleaning

Engineering Contradiction:
Improvepolymerization reaction rateVSAvoidreactor fouling prevention
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system continuously monitors bulk fluid temperature and particle temperature in real-time, comparing actual temperatures against the dynamically calculated fouling temperature threshold. When the particle temperature approaches the fouling threshold, the system automatically adjusts operating parameters (cooling fluid flowrate, jacket temperature) to maintain temperature below the threshold, preventing fouling while maximizing productivity

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically adjusts cooling fluid flowrate and jacket temperature based on real-time particle temperature measurements and calculated fouling thresholds. By continuously modifying these thermal parameters, the system maintains particle temperatures optimally below the fouling temperature, enabling high-rate polymerization without fouling

Inventive Principle:
Principle #35Parameter changes

2Reliability

If cooling fluid flowrate is increased to remove heat and prevent fouling, then particle temperature is maintained below fouling threshold, but energy consumption increases

Engineering Contradiction:
Improvefouling preventionVSAvoidcooling fluid energy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The cooling fluid flowrate and jacket temperature are dynamically adjusted in real-time based on actual particle temperature measurements and calculated fouling thresholds. Rather than maintaining constant high cooling rates, the system varies cooling intensity to match actual thermal conditions, minimizing energy consumption while ensuring particle temperatures remain below the fouling threshold

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system uses real-time temperature feedback to modulate cooling fluid flowrate and jacket temperature. When particle temperatures are well below the fouling threshold, cooling intensity is reduced; when temperatures approach the threshold, cooling is intensified. This feedback-based dynamic control optimizes energy usage while preventing fouling

Inventive Principle:
Principle #23Feedback

3Productivity

If particle temperature is maintained close to fouling temperature to maximize reaction rate, then productivity is improved, but the risk of fouling increases requiring precise temperature control

Engineering Contradiction:
Improvepolymerization reaction rateVSAvoidtemperature control system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The system employs continuous real-time monitoring of both bulk fluid temperature and particle temperature, with automatic feedback control that adjusts cooling parameters when particle temperature approaches the fouling threshold. This automated feedback mechanism enables operation close to the fouling temperature (maximizing productivity) without requiring complex manual control procedures

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system replaces complex manual temperature control procedures with automated computational calculations and electronic control. The processor automatically calculates the fouling temperature threshold based on particle properties and reaction conditions, then electronically controls the cooling system, substituting complex mechanical/manual control with automated computational control

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 effectively maintains polymer particle temperatures below the fouling point, reducing the risk of reactor fouling and ensuring consistent polymer properties by optimizing heat transfer within the reactor.

Implementation Method 1

a cooling fluid may provide a cooling source on at least a portion of the exterior of the polymerization reactor

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 2

ql is the thermal conductivity of the bulk fluid

Methodology Applied
Scientific EffectConduction (thermal): Conduction (thermal)

Implementation Method 3

the heat released within the particle... the slurry film coefficient... thermal conductivity of the bulk fluid

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 4

the slurry film coefficient, which relates the heat released within the particle to the average temperature of the particle

Methodology Applied
Scientific EffectConduction (thermal): Conduction (thermal)

Data Source

PatentEP3250317B1Temperature control for polymerizing particulate polyolefin
Publication Date: 2020.09.09 CHEVRON PHILLIPS CHEMICAL COMPANY LP
  • EP3250317B1 patent drawingFigure 1
  • EP3250317B1 patent drawingFigure 2
  • EP3250317B1 patent drawingFigure 3

AI summary

A method is described that includes contacting an olefin with a catalyst in a polymerization reactor, polymerizing at least a portion of the olefin to form an alpha olefin reaction product, detecting a condition within the polymerization reactor, determining an average temperature of at least one olefin product particle based on the condition, determining an operating particle temperature threshold using a foul curve, comparing the average temperature of the polymer particle to the operating particle temperature threshold, changing one or more operating parameters in response to the comparing, and maintaining the average temperature of the olefin polymer particle at or below the operating particle temperature threshold in response to changing the one or more operating parameters. The alpha olefin reaction product includes a plurality of olefin polymer particles, and the polymerization reactor includes a reaction mixture that includes the olefin, the catalyst, a diluent, and the alpha olefin reaction product.