Crude Ester Catalyst Residue Agglomeration Filtration

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Solution Overview

Problem

Existing processes for working up crude esters containing metal-containing esterification catalyst residues face challenges such as long filtration times, reduced yield, and filter cake retention due to the slimy consistency of catalyst residues, which complicates the separation and leads to process inefficiencies and equipment blockages.

Innovation Solution

A process involving the addition of 1 to 10% water to the crude ester to form a suspo-emulsion, followed by conversion to a water-undersaturated state to facilitate the formation of stable agglomerates that can be easily filtered, utilizing emulsification and agglomeration steps to separate the catalyst residues.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If filtration is performed on crude ester containing catalyst residues in slimy gel-like form, then catalyst residues can be removed, but filtration time becomes excessively long and ester yield is reduced due to large product retention in filter cake

Engineering Contradiction:
Improvecatalyst residue removalVSAvoidfiltration time
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent changes the physical state of catalyst residues from slimy gel-like form to free-flowing granular form by controlling water content and temperature parameters. By maintaining water content below the solubility limit and operating at temperatures above 100°C, the catalyst residues transform into easily filterable granules, resolving the contradiction between effective removal and fast filtration.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent utilizes phase transition of water from liquid to vapor by operating at temperatures above 100°C under pressure. This prevents water from forming a continuous phase that would cause slimy consistency, instead allowing catalyst residues to form discrete granular particles that filter rapidly while maintaining high yield.

Inventive Principle:
Principle #36Phase transitions

2Reliability

If water is added to crude ester to neutralize acid, then neutralization occurs, but water evaporates immediately causing solid NaOH to precipitate and react more slowly

Engineering Contradiction:
ImproveneutralizationVSAvoidreaction speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent performs preliminary action by adding water under pressure at temperatures above 100°C before neutralization begins. This pre-conditioning ensures water remains in liquid phase during base addition, allowing rapid dissolution and reaction. The pressure maintenance prevents premature evaporation, enabling fast neutralization kinetics.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If aqueous base is added at high temperature to neutralize crude ester, then neutralization is effective, but water evaporates causing solid hydroxide precipitation and deposits on pipes and containers

Engineering Contradiction:
Improveneutralization effectivenessVSAvoiddeposits on equipment
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent applies preliminary action by establishing pressure conditions above water vapor pressure before and during base addition. This pre-prevents water evaporation and subsequent hydroxide precipitation, eliminating deposit formation on equipment while maintaining effective neutralization at elevated temperatures.

Inventive Principle:
Principle #10Preliminary action

4Reliability

If large excess of base is used to compensate for slow reaction, then complete neutralization is achieved, but process efficiency is reduced

Engineering Contradiction:
Improvecomplete neutralizationVSAvoidbase consumption
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent changes temperature and pressure parameters to maintain water in liquid phase during neutralization. This enables rapid reaction kinetics with stoichiometric or near-stoichiometric base amounts, achieving complete neutralization without requiring large excesses, thus improving process efficiency and reducing base consumption.

Inventive Principle:
Principle #35Parameter changes

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 method enables rapid and efficient agglomeration of catalyst residues into easily filterable particles, reducing process time and preventing filter clogging, thereby improving throughput and product purity with a low acid number.

Implementation Method 1

the crude ester is mixed with 1 to 10 wt% water in an emulsifying vessel and the water is emulsified in the crude ester to form a suspo emulsion

Methodology Applied
Scientific EffectEmulsification: Emulsion

Implementation Method 2

the water content in the mixture of the suspo emulsion and the pre-filled crude ester is below the solubility limit of water in the crude ester, causing the suspended particulate esterification catalyst hydrolysis products to form stable agglomerates

Methodology Applied
Scientific EffectAgglomeration: Coagulation

Implementation Method 3

the agglomerates formed are filtered off

Methodology Applied
Scientific EffectFiltration: Filter (physical)

Data Source

PatentEP3174845B1Method for the processing of a raw ester containing the esterification catalyst hydrolysis product in suspended particulate form
Publication Date: 2020.04.29 BASF SE
  • EP3174845B1 patent drawingFigure 1A~1B
  • EP3174845B1 patent drawingFigure 2
  • EP3174845B1 patent drawing

AI summary

In a process for workup of a crude ester comprising esterification catalyst hydrolysis product in suspended particulate form, a) the crude ester is admixed in an emulsifying tank with 1% to 10% by weight of water and the water is emulsified in the crude ester to obtain a suspoemulsion, b) the suspoemulsion from the emulsifying tank is transferred to an agglomerating tank containing an initial charge of water-undersaturated crude ester, such that a water content below the solubility limit of water in the crude ester is established in the mixture of the suspoemulsion and the initial charge of crude ester, as a result of which the suspended particulate esterification catalyst hydrolysis products form stable agglomerates, and c) the agglomerates formed are filtered off.