Alkene Glycol Synthesis via Integrated Absorber Column

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Solution Overview

Problem

Current processes for producing alkylene glycol from alkenes are complex and energy-intensive, requiring multiple equipment vessels and steps, which increases costs and reduces selectivity.

Innovation Solution

A process involving reacting alkenes with oxygen in the presence of a catalyst to produce a gas composition, followed by absorption and conversion in an alkylene oxide absorber with vertically stacked trays or a packed column, where carboxylation and hydrolysis occur, reducing the need for separate reactors and enhancing conversion and selectivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple separate reactors and equipment vessels are used for alkylene glycol production, then the process can achieve complete conversion, but the device complexity and energy consumption increase significantly

Engineering Contradiction:
Improveconversion efficiencyVSAvoidequipment requirements
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent combines multiple separate reactors (carboxylation reactor, hydrolysis reactor, finishing reactor) into a single integrated alkylene oxide absorber column. This merging of functions achieves complete conversion of alkylene oxide to alkylene glycol while significantly reducing device complexity and energy consumption by eliminating the need for multiple separate equipment vessels.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The alkylene oxide absorber column is designed to perform multiple functions simultaneously: absorption of alkylene oxide from the gas stream, carboxylation to form alkylene carbonate, hydrolysis of alkylene carbonate to alkylene glycol, and finishing reactions. This multi-functionality resolves the contradiction by achieving complete conversion in a single piece of equipment.

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

2Productivity

If traditional multi-step processing is used, then conversion can be achieved, but energy consumption and process costs increase

Engineering Contradiction:
Improveconversion rateVSAvoidenergy consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

By merging carboxylation, hydrolysis, and finishing reactions into a single integrated absorber column, the patent eliminates the energy consumption associated with heating and cooling multiple separate reactors, as well as the energy required for inter-stage transfers and additional separation processes.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent implements continuous conversion of alkylene oxide to alkylene glycol within the absorber column, where alkylene oxide is continuously absorbed, carboxylated, and hydrolyzed in a single stream. This continuous action eliminates the energy losses associated with batch processing and multiple discrete reaction stages.

Inventive Principle:
Principle #20Continuity of useful action

3Device complexity

If simple absorption without reaction is used, then equipment complexity is reduced, but conversion of alkylene oxide is insufficient

Engineering Contradiction:
Improveequipment requirementsVSAvoidconversion rate
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The absorber column is designed as a multi-functional unit that simultaneously performs physical absorption of alkylene oxide and chemical reactions (carboxylation and hydrolysis). This allows sufficient conversion to occur while maintaining simple equipment requirements, as all reactions happen within the single absorber column rather than requiring separate reaction vessels.

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

Solution Approach 2:

The patent employs porous catalytic materials packed within the absorber column to facilitate the carboxylation and hydrolysis reactions. The porous structure provides high surface area for catalytic activity, enabling sufficient conversion of alkylene oxide while maintaining a simple single-column equipment configuration.

Inventive Principle:
Principle #31Porous materials

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 achieves high conversion and selectivity of alkylene oxide to alkylene glycol while minimizing equipment requirements, thereby reducing costs and complexity compared to existing methods.

Implementation Method 1

contacting the gas composition with lean absorbent in the alkylene oxide absorber

Methodology Applied
Scientific EffectAbsorption: Absorption (physical)

Implementation Method 2

one or more catalysts that promote carboxylation and hydrolysis

Methodology Applied
Scientific EffectCarboxylation: Chemical Bonding

Implementation Method 3

one or more catalysts that promote carboxylation and hydrolysis

Methodology Applied
Scientific EffectHydrolysis: Hydrolysis

Data Source

PatentEP2178815B1Process for the preparation of alkylene glycol
Publication Date: 2017.07.19 SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ BV
  • EP2178815B1 patent drawingFigure 1
  • EP2178815B1 patent drawingFigure 2
  • EP2178815B1 patent drawingFigure 3

AI summary

The invention provides a process for the preparation of an alkylene glycol from an alkene. A gas composition from an alkylene oxide reactor is supplied to an alkylene oxide absorber comprising a column of vertically stacked trays or comprising a packed column. Lean absorbent comprising at least 20wt% water is supplied to the alkylene oxide absorber and is contacted with the gas composition in the presence of one or more catalysts that promote carboxylation and hydrolysis. At least 50% of the alkylene oxide entering the alkylene oxide absorber is converted in the alkylene oxide absorber. Fat absorbent is withdrawn from the absorber, is optionally supplied to finishing reactors and/or a flash vessel or light ends stripper, and is subsequently subjected to dehydration and purification to provide a purified alkylene glycol product stream.