Glycerol Ether Production via Reactive Distillation and TBA Recycling

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Solution Overview

Problem

Current methods for producing glycerol ethers and isooctane precursors are inefficient, as they require multiple steps and struggle to achieve optimal yields and selectivity, limiting their use as effective diesel and gasoline additives.

Innovation Solution

A method involving the reaction of glycerol and tertiary butanol (TBA) in the presence of an acidic catalyst, followed by oligomerization, to produce mono-, di-, and tri-tert butyl glycerol ethers and branched olefins, which are then separated and hydrogenated to form isooctane, utilizing a reactive distillation column and recycling of isobutylene to enhance yield and selectivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple separate steps are used to produce glycerol ethers and isooctane precursors, then the production process can be controlled step-by-step, but the overall efficiency and productivity are reduced due to multiple operations

Engineering Contradiction:
Improveprocess controlVSAvoidproduction efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent combines the production of glycerol ethers and isooctane precursors into a single integrated process. The reactive distillation column performs etherification of glycerol with TBA while simultaneously oligomerizing isobutylene to form isooctane precursors. This merging of multiple production steps into one unified process dramatically improves productivity while maintaining reliable control through the integrated design of the reactor system.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The reactive distillation column serves multiple functions simultaneously: it acts as a reactor for etherification, an oligomerization reactor for isobutylene, and a separation unit for product purification. This multi-functionality eliminates the need for separate equipment for each step, thereby improving overall production efficiency while maintaining process control through a single integrated system.

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

2Ease of manufacture

If conventional methods are used to produce glycerol ethers, then the process is simpler, but the yield and selectivity of the desired products are insufficient

Engineering Contradiction:
Improveprocess simplicityVSAvoidproduct yield and selectivity
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent employs parameter changes to optimize the etherification and oligomerization reactions. The reactive distillation column operates at specific temperature gradients, pressure conditions, and catalyst loadings that enhance both yield and selectivity. By carefully controlling parameters such as the molar ratio of glycerol to TBA, temperature profiles within the column, and catalyst distribution, the process achieves high manufacturing precision while maintaining relative process simplicity.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses an acidic catalyst as an intermediary to facilitate both the etherification of glycerol with TBA and the oligomerization of isobutylene. The catalyst enables these reactions to proceed efficiently under milder conditions, improving both yield and selectivity without requiring overly complex process conditions. The catalyst acts as a mediator that enhances reaction efficiency while keeping the overall process manageable.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If TBA is used in excess to improve glycerol ether production, then the yield of glycerol ethers increases, but the separation and purification processes become more complex

Engineering Contradiction:
Improveglycerol ether yieldVSAvoidseparation process complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent merges the reaction and separation functions within the reactive distillation column. By operating with excess TBA to maximize glycerol ether yield, the system simultaneously uses the distillation section of the column to separate unreacted TBA from the product mixture. This integration eliminates the need for separate purification steps, thereby maintaining high productivity while avoiding increased separation process complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The reactive distillation column performs self-service by automatically separating unreacted TBA from the glycerol ether products through distillation. The excess TBA that is not consumed in the reaction is readily separated due to its volatility differences, and this separation occurs within the same equipment used for reaction. This self-service capability allows the system to handle excess TBA without requiring additional complex separation equipment.

Inventive Principle:
Principle #25Self-service

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 increases the selectivity and yield of glycerol ethers and isooctane, making them suitable as diesel and gasoline additives, respectively, while simplifying the production process and improving fuel performance.

Implementation Method 1

introducing glycerol and TBA into a reactor comprising an acidic catalyst effective to catalyze the reaction of glycerol and isobutylene to produce one or more glycerol ethers

Methodology Applied
Scientific EffectCatalysis: Catalysis

Implementation Method 2

an oligomerization catalyst effective to catalyze the oligomerization of isobutylene to provide one or more branched olefins

Methodology Applied
Scientific EffectOligomerization: Chemical Bonding

Implementation Method 3

separating the isobutylene oligomers, isobutylene, or both from the one or more glycerol ethers

Methodology Applied
Scientific EffectDistillation: Distillation

Implementation Method 4

hydrogenating at least a portion of the isobutylene oligomers to produce isooctane

Methodology Applied
Scientific EffectHydrogenation: Hydrogenation

Data Source

PatentEP3814314B1Process for the production of diesel and gasoline additives from glycerol
Publication Date: 2023.08.02 LYONDELL CHEMICAL TECHNOLOGY LP
  • EP3814314B1 patent drawingFigure 1
  • EP3814314B1 patent drawingFigure 2

AI summary

A method of producing one or more glycerol ethers, the method comprising contacting glycerol and tertiary butanol (TBA) in the presence of an acidic catalyst to produce one or more glycerol ethers selected from mono-tert butyl glycerol ethers, di-tert butyl glycerol ethers, tri-tert butyl glycerol ethers, or a combination thereof; separating water and a stream comprising isobutylene, unreacted TBA, or a combination thereof from the one or more glycerol ethers; and recycling at least a portion of the stream comprising isobutylene, unreacted TBA, or a combination thereof to the contacting. Also disclosed is a process of co-producing isooctene, wherein the process involves contacting glycerol and tertiary butanol in the presence of a dehydrating catalyst and dimerizing/oligomerizing the dehydrated products in the presence of an oligomerizing catalyst to form isooctene, a precursor of isooctane and isomers thereof.