Dicarboxylate Composition Production with Two-Stage Alcohol Recovery

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Solution Overview

Problem

Existing methods for producing diester-based plasticizers face inefficiencies in energy consumption and productivity due to limitations in reflux processes, particularly in batch processes and continuous processes that do not effectively manage the condensation of unreacted alcohol and water, leading to reduced overall process efficiency and economic feasibility.

Innovation Solution

A method involving a two-stage condensation process using a pre-condenser and a condenser in a reflux unit, combined with a gas-liquid separation device and layer separator, to selectively recover and reuse unreacted alcohol, reducing energy consumption and improving efficiency by sharing reflux means across multiple reactors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a single condenser is used to condense all mixed gas from the reactor, then the process is simple, but energy consumption is high and alcohol recovery efficiency is reduced

Engineering Contradiction:
Improveprocess simplicityVSAvoidenergy consumption
Core Design Contradiction:
Ease of manufactureVSUse of energy by moving object

Solution Approach 1:

The condensation process is divided into two separate stages: a first condenser that condenses part of the mixed gas to recover alcohol, and a second condenser that condenses the remaining gas. This segmentation allows optimized energy usage at each stage rather than using a single high-energy condenser for all condensation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A gas-liquid separation device is introduced as an intermediary between the two condensers. This device separates the condensed alcohol from the mixed gas, allowing the second condenser to process only the remaining gas without the interference of liquid alcohol, thereby improving overall energy efficiency.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of manufacture

If all mixed gas is condensed in one stage, then the process is simple, but alcohol recovery completeness is reduced

Engineering Contradiction:
Improveprocess simplicityVSAvoidalcohol recovery completeness
Core Design Contradiction:
Ease of manufactureVSLoss of substance

Solution Approach 1:

The condensation process is divided into two sequential stages with a gas-liquid separation device in between. The first condenser recovers the majority of alcohol, the separation device removes it from the gas stream, and the second condenser recovers remaining alcohol. This ensures more complete alcohol recovery while maintaining reasonable process complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The two-stage condensation with intermediate separation ensures continuous and complete alcohol recovery. By removing condensed alcohol after the first condenser, the system prevents alcohol loss that would occur in a single-stage system, maintaining continuous efficient operation.

Inventive Principle:
Principle #20Continuity of useful action

3Reliability

If cooling water is used for condensing all mixed gas, then condensation is effective, but water consumption increases unnecessarily

Engineering Contradiction:
Improvecondensation effectivenessVSAvoidcooling water consumption
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The condensation task is segmented into two condensers working in sequence, each handling a portion of the condensation load. This segmentation reduces the total amount of cooling water needed compared to a single condenser attempting to condense all gas in one step.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The gas-liquid separation device acts as an intermediary that removes condensed alcohol between the two condensers. This prevents the second condenser from needing to handle both gas condensation and liquid separation, reducing overall water consumption while maintaining condensation effectiveness.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Device complexity

If batch process is used for diester production, then equipment requirements are simple, but productivity is low

Engineering Contradiction:
Improveequipment requirementsVSAvoidproductivity
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The reflux unit with the two-stage condensation system and gas-liquid separation device is designed to be universally applicable to multiple reactors. This multi-functional design allows the same equipment configuration to serve both batch and continuous production modes, improving productivity without proportionally increasing equipment complexity.

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

The method significantly reduces energy usage and enhances the overall efficiency and economic feasibility of the production process by optimizing the reflux process, allowing for more effective recovery and reuse of unreacted alcohol.

Implementation Method 1

partially condensing a mixed gas generated during the esterification reaction to separately obtain unreacted alcohol in a liquid state and the remaining mixed gas

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 2

condensing all of the remaining mixed gas and then performing layer separation to obtain a water layer and an alcohol layer

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 3

performing layer separation to obtain a water layer and an alcohol layer, wherein the unreacted alcohol in a liquid state obtained in Step S2 and the alcohol layer obtained in Step S3 are reused as the alcohol in Step S1

Methodology Applied
Scientific EffectLayer separation: Density Gradient

Data Source

PatentEP4036077B1Preparation method for diester-based composition
Publication Date: 2025.09.03 LG CHEM LTD
  • EP4036077B1 patent drawingFigure 1~2
  • EP4036077B1 patent drawingFigure 3~4
  • EP4036077B1 patent drawingFigure 5

AI summary

The present invention relates to a method for continuously producing a dicarboxylate-based composition and a production system therefor, the method improving a production yield by optimizing process variables of each reactor of a reaction unit in which a plurality of reactors are connected in series.