Reactor Cooler for Acetic Acid Production

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Solution Overview

Problem

Existing methods for producing acetic acid face challenges with heat surplus and high methyl acetate (MeAc) concentrations, which can lead to increased energy costs, material costs, and production disruptions.

Innovation Solution

The implementation of a reactor cooler system that controls reactor cooling and MeAc concentration, allowing for a higher feed rate, lower catalyst and methyl iodide concentrations, and potentially increasing acetic acid production by maintaining a target steady state MeAc concentration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the feed rate of reactants is increased to improve reactor production rate, then productivity increases, but heat surplus and methyl acetate concentration increase causing operating problems

Engineering Contradiction:
Improvereactor production rateVSAvoidheat surplus
Core Design Contradiction:
ProductivityVSTemperature

Solution Approach 1:

The patent extracts the heat removal function from the main reactor system by introducing a separate cooler for the recycle stream. This allows the reactor to operate at higher temperatures and productivity without being constrained by heat accumulation, as the cooler independently manages thermal load by cooling the recycled acetic acid stream before it returns to the reactor.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The cooler serves multiple functions: it removes heat from the recycle stream, controls methyl acetate concentration in the reactor, and enables higher feed rates without proportionally increasing heat surplus. This multi-functionality resolves the contradiction by addressing both thermal management and composition control simultaneously.

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

2Productivity

If the feed rate of reactants is increased to improve reactor production rate, then productivity increases, but methyl acetate concentration increases leading to phase separation loss and production disruptions

Engineering Contradiction:
Improvereactor production rateVSAvoidmethyl acetate concentration
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The patent implements feedback control by cooling the recycle stream, which selectively reduces methyl acetate concentration in the recycled portion. This feedback mechanism maintains stable reactor composition even at higher feed rates, preventing phase separation issues in the decanter while allowing sustained high productivity.

Inventive Principle:
Principle #23Feedback

3Loss of energy

If flash vaporization is used to remove heat of reaction, then heat removal is achieved, but acid is carried over with vapor requiring recycling through distillation

Engineering Contradiction:
Improveheat of reaction removalVSAvoidacetic acid loss
Core Design Contradiction:
Loss of energyVSLoss of substance

Solution Approach 1:

The patent extracts the heat removal step from the flash vaporization process by introducing a separate cooler for the liquid recycle stream. This separation allows heat removal without vaporization, eliminating the mechanism that carries acid into the vapor phase and subsequent distillation requirements, thereby reducing both energy consumption and acid loss.

Inventive Principle:
Principle #2Taking out (Extraction)

4Stability of the object's composition

If reactor temperature is increased to decrease methyl acetate concentration, then MeAc concentration decreases, but energy cost increases

Engineering Contradiction:
Improvemethyl acetate concentrationVSAvoidenergy cost
Core Design Contradiction:
Stability of the object's compositionVSUse of energy by stationary object

Solution Approach 1:

The patent segments the temperature control function from the main reactor by applying cooling specifically to the recycle stream rather than the entire system. This localized cooling achieves methyl acetate concentration control without requiring overall reactor temperature increase, thereby reducing energy costs while maintaining composition stability.

Inventive Principle:
Principle #1Segmentation

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 enables higher throughput in the reaction section, reduces acid recycle, and maintains stable reactor operation, potentially increasing acetic acid production by 10-100% or more while minimizing energy and material costs.

Implementation Method 1

cooling the portion of the reactor fluid received in the reactor cooler for a residence time sufficient to form a cooled reactor fluid

Methodology Applied
Scientific EffectHeat removal through cooling: Cooling

Implementation Method 2

cooling the portion of the reactor fluid received in the reactor cooler for a residence time sufficient to form a cooled reactor fluid having a second concentration of methyl acetate less than the first concentration of methyl acetate

Methodology Applied
Scientific EffectConcentration control through cooling: Cooling

Data Source

PatentEP4313928B1Methods and systems for producing acetic acid
Publication Date: 2025.04.16 LYONDELLBASELL ACETYLS LLC
  • EP4313928B1 patent drawingFigure 1
  • EP4313928B1 patent drawingFigure 2
  • EP4313928B1 patent drawingFigure 3

AI summary

Methods and systems for producing acetic acid, including glacial acetic acid. A first stream of a reactor fluid that includes methyl acetate, water, and a first amount of carbon monoxide may be forwarded from a reactor to a reactor cooler to form a cooled reactor fluid. The cooled reactor fluid may have a concentration of methyl acetate that is lower than the concentration of methyl acetate in the reactor fluid.