Spouted Bed Olefin Polymerization Reactor Design

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Solution Overview

Problem

Existing olefin polymerization reactors face challenges with poor structural uniformity of polyolefin particles, high catalyst costs, increased defects, and difficulties in changing production conditions due to complete mixing and residence time distribution issues, leading to off-specification products.

Innovation Solution

A spouted bed olefin polymerization reactor with a vertically extending cylinder and decreasing diameter member, featuring a gas inlet orifice at the bottom and a deflector above, which creates a spouted bed with circulatory particle movement, approximating plug flow and reducing residence time distribution, while allowing for efficient particle transfer and heat removal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single vessel reactor with complete mixing is used, then the construction is simple, but the residence time distribution is wide leading to poor structural uniformity

Engineering Contradiction:

Improvereactor constructionVSAvoidstructural uniformity of polyolefin particles

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The reactor is divided into multiple zones (reaction zone, separation zone, circulation zone) within a single vessel, creating distinct functional regions that enable plug flow characteristics while maintaining simple construction. The spouted bed structure segments the particle flow path to achieve narrow residence time distribution.

Inventive Principle:

Principle #1Segmentation

2Manufacturing precision

If multiple reactors are connected in series to achieve plug flow, then the residence time distribution is narrow, but the equipment cost increases

Engineering Contradiction:

Improveresidence time distributionVSAvoidequipment cost

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

Multiple functional zones that would traditionally require separate reactors are merged into a single integrated vessel. The spouted bed reactor combines reaction, separation, and circulation functions in one unit, achieving plug flow characteristics without the need for multiple connected reactors, thereby reducing equipment cost while maintaining narrow residence time distribution.

Inventive Principle:

Principle #5Merging (Combining)

3Manufacturing precision

If stirring paddles are added to create multiple zones, then the residence time distribution improves, but the device complexity and energy consumption increase

Engineering Contradiction:

Improveresidence time distributionVSAvoidconstruction complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

Mechanical stirring paddles are replaced with a gas-driven spouted bed system. Gas flow through the particle bed creates the spouting effect and circulatory motion, eliminating the need for mechanical agitation devices. This substitution reduces construction complexity while achieving the desired residence time distribution through fluid dynamic control.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

4Manufacturing precision

If a spouted bed is formed with gas flow, then the residence time distribution is narrow, but the gas consumption and energy use increase

Engineering Contradiction:

Improveresidence time distributionVSAvoidgas consumption

Core Design Contradiction:

Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

Gas flow is concentrated in specific regions where it is most effective for creating spouted bed conditions. The gas inlet is positioned to create localized high-velocity jets that initiate spouting, while other regions utilize the circulatory flow pattern. This localized gas application achieves narrow residence time distribution with reduced overall gas consumption compared to uniform gas distribution.

Inventive Principle:

Principle #3Local quality

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 spouted bed reactor achieves narrower residence time distribution, improved structural uniformity of polyolefin particles, reduced catalyst costs, and easier product replacement with changing conditions, enhancing overall reactor efficiency and product quality.

Implementation Method 1

A spouted bed is formed inside a reaction zone enclosed by an inside surface of the decreasing diameter member and an inside surface of the cylinder above the decreasing diameter member

Methodology Applied

Scientific EffectSpouted bed: Fluidisation

Implementation Method 2

a decreasing diameter member which is formed on the cylinder, has an inside diameter that decreases progressively downward, and has a gas inlet orifice at a bottom end thereof

Methodology Applied

Scientific EffectVenturi effect: Venturi Effect

Data Source

PatentUS7993593B2Olefin polymerization reactor, polyolefin production system, and polyolefin production process

Publication Date: 2011.08.09 SUMITOMO CHEM CO LTD

AI summary

An olefin polymerization reactor of the present invention includes a cylinder which extends vertically, and a decreasing diameter member which is formed on the cylinder, has an inside diameter that decreases progressively downward and has a gas inlet orifice at a bottom end thereof. A spouted bed is formed inside a reaction zone enclosed by an inside surface of the decreasing diameter member and an inside surface of the cylinder above the decreasing diameter member.