Diene Production via Dual Catalyst Segmentation and Reactive Distillation

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Solution Overview

Problem

Conventional methods using metal oxide catalysts face challenges in producing diene from raw materials containing branched and straight chain olefins, resulting in low yields due to unwanted byproducts and catalyst deactivation.

Innovation Solution

A method involving the removal of branched olefins to obtain straight chain internal olefins, followed by oxidative dehydrogenation using a first catalyst with a complex oxide including bismuth, molybdenum, and oxygen, and a second catalyst with silica or alumina, which isomerizes internal olefins to terminal olefins for enhanced diene production.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional metal oxide catalysts are used for oxidative dehydrogenation of raw materials containing branched and straight chain olefins, then the process is simple, but diene yield is low due to byproduct formation and catalyst deactivation

Engineering Contradiction:
Improvediene yieldVSAvoidbyproduct formation and catalyst deactivation
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The catalyst system is segmented into two distinct components: a first catalyst (metal oxide such as bismuth molybdate) for oxidative dehydrogenation and a second catalyst (silica-alumina) for isomerization. This segmentation allows each catalyst to perform its specific function optimally, preventing byproduct formation and catalyst deactivation that occur when using a single conventional metal oxide catalyst

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The second catalyst (silica-alumina) acts as an intermediary that isomerizes straight chain terminal olefins to internal olefins before they enter the oxidative dehydrogenation step. This intermediary transformation prevents the formation of unwanted byproducts and protects the first catalyst from deactivation, thereby improving overall diene yield

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If reactive distillation is used to remove branched olefins and isomerize terminal olefins, then internal olefin purity is improved, but process complexity increases

Engineering Contradiction:
Improveinternal olefin purityVSAvoidprocess complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The reactive distillation process merges separation and isomerization operations into a single unit operation. The distillation column simultaneously separates branched olefins from straight chain olefins and performs isomerization of terminal olefins to internal olefins using a catalyst packed within the column, thereby achieving high internal olefin purity without proportionally increasing process complexity

Inventive Principle:
Principle #5Merging (Combining)

3Productivity

If dual catalyst system is used for oxidative dehydrogenation, then diene yield increases, but catalyst complexity increases

Engineering Contradiction:
Improvediene yieldVSAvoidcatalyst complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The second catalyst (silica-alumina) serves multiple functions: it isomerizes terminal olefins to internal olefins, protects the first catalyst from deactivation, and prevents byproduct formation. This multi-functionality justifies the added catalyst complexity by delivering significant improvements in diene yield and process efficiency

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 significantly improves diene yield by suppressing byproduct formation and catalyst deactivation, allowing for high-yield production of diene even from raw materials with branched olefins.

Implementation Method 1

producing diene from the internal olefin by oxidative dehydrogenation using a first catalyst and a second catalyst, wherein the first catalyst has a complex oxide including bismuth, molybdenum and oxygen

Methodology Applied
Scientific EffectOxidative dehydrogenation:

Implementation Method 2

the second catalyst includes at least one selected from the group consisting of silica and alumina

Methodology Applied
Scientific EffectIsomerization: Catalysis

Implementation Method 3

in the step 1, reactive distillation may be performed to remove the branched olefin from the raw material

Methodology Applied
Scientific EffectDistillation: Distillation

Data Source

PatentUS10407362B2Diene production method
Publication Date: 2019.09.10 ENEOS CORP

AI summary

A method for producing diene comprises a step 1 of obtaining a straight chain internal olefin by removing a branched olefin from a raw material including at least the branched olefin and a straight chain olefin; and a step 2 of producing diene from the internal olefin by oxidative dehydrogenation using a first catalyst and a second catalyst, and the first catalyst has a complex oxide including bismuth, molybdenum and oxygen, and the second catalyst includes at least one selected from the group consisting of silica and alumina.