Epoxidation Catalyst Deposit Prevention via Feed Filtration

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Solution Overview

Problem

During extended operation of continuous olefin epoxidation using an aqueous hydrogen peroxide solution from an anthraquinone process, deposits form on the catalyst, reducing activity and causing liquid maldistribution and uneven temperature profiles, which impairs selectivity, and these deposits can block orifices in tube bundle reactors.

Innovation Solution

Mixing the hydrogen peroxide solution with methanol and filtering the resulting mixture before contacting it with the fixed bed epoxidation catalyst, comprising a titanium zeolite, to prevent deposit formation and maintain catalyst activity and even liquid distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If an aqueous hydrogen peroxide solution from an anthraquinone process is used for continuous epoxidation, then the epoxidation reaction can be carried out continuously with high productivity, but deposits form on the catalyst reducing activity and causing liquid maldistribution

Engineering Contradiction:
Improvecontinuous epoxidation rateVSAvoidcatalyst activity stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The invention applies preliminary action by filtering the aqueous hydrogen peroxide solution before it contacts the catalyst. The filter removes deposits that would otherwise accumulate on the catalyst during extended operation. This preliminary removal action prevents the subsequent worsening of catalyst activity and liquid distribution, allowing continuous high-productivity operation without the harmful deposit formation that would otherwise occur.

Inventive Principle:
Principle #10Preliminary action

2Quantity of substance

If deposits form on the catalyst, then catalyst activity is reduced and liquid maldistribution occurs, but the basic epoxidation process remains the same

Engineering Contradiction:
Improvehydrogen peroxide concentrationVSAvoiddeposit formation on catalyst
Core Design Contradiction:
Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The invention applies the taking out principle by extracting and removing the harmful deposits from the hydrogen peroxide solution before it reaches the catalyst. A filter is introduced that selectively removes the deposit-forming substances from the aqueous hydrogen peroxide solution while allowing the hydrogen peroxide and water to pass through. This separation action prevents the deposits from accumulating on the catalyst, maintaining both catalyst activity and proper liquid distribution while preserving the full hydrogen peroxide concentration needed for the epoxidation reaction.

Inventive Principle:
Principle #2Taking out (Extraction)

3Ease of operation

If deposits accumulate at the orifices of the liquid distributor, then orifice blocking occurs leading to maldistribution of liquid to individual tubes, but the reactor structure remains unchanged

Engineering Contradiction:
Improveliquid distribution uniformityVSAvoidfiltering system addition
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The invention applies preliminary action by placing a filter in the liquid distribution system that removes deposits before they can reach and block the orifices. This preliminary filtration action prevents the subsequent problem of orifice blocking and liquid maldistribution. The filter is positioned upstream in the flow path, capturing harmful particles before they can accumulate at the critical orifice locations, thereby maintaining uniform liquid distribution to all reactor tubes.

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 process effectively reduces deposit formation, maintains catalyst activity, and prevents liquid maldistribution, ensuring high selectivity and continuous operation of the epoxidation reaction by filtering the hydrogen peroxide-methanol mixture before use.

Implementation Method 1

The liquid phase epoxidation of olefins with hydrogen peroxide catalyzed by a fixed bed titanium silicalite catalyst

Methodology Applied
Scientific EffectCatalysis: Catalysis

Implementation Method 2

the aqueous hydrogen peroxide solution is mixed with methanol to give a feed mixture and this feed mixture is filtered before being contacted with the fixed bed epoxidation catalyst

Methodology Applied
Scientific EffectFiltration: Filter (physical)

Data Source

PatentEP3380459B1Process for the epoxidation of an olefin
Publication Date: 2020.01.01 THYSSENKRUPP UHDE GMBH

AI summary

In aprocess for the epoxidation ofan olefin by continuously reacting the olefinwith hydrogen peroxidein a methanol solvent on a fixed bed epoxidation catalyst comprising a titanium zeolite, the hydrogen peroxide is used as an aqueous hydrogen peroxide solution made by an anthraquinone process, the aqueous hydrogen peroxide solution is mixed with methanol to give a feed mixture and this feed mixture is filtered before being contacted with the fixed bed epoxidation catalyst.