Divided Wall Column Benzoic Acid Purification

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current methods for purifying benzoic acid, such as two-column distillation, result in high energy consumption and investment costs while requiring significant space, and do not efficiently reduce byproduct formation.

Innovation Solution

A distillation method using a divided wall column, which separates low- and high-boiling components within a single column, reducing energy consumption and investment costs by minimizing the number of required devices and space, while maintaining high purification efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a two-column distillation system is used to purify benzoic acid, then high purification efficiency is achieved, but energy consumption increases significantly

Engineering Contradiction:
Improvepurification efficiencyVSAvoidenergy consumption
Core Design Contradiction:
Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The patent combines two separate distillation columns into a single divided wall column that performs both separations simultaneously. The divided wall column contains an first section for separating low-boiling components and a second section for separating high-boiling components, merging the functions of two columns into one structure, thereby reducing energy consumption while maintaining purification efficiency

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The divided wall column is segmented into multiple functional sections by vertical dividing walls. The column is divided into a first section with a first dividing wall for low-boiling component separation and a second section with a second dividing wall for high-boiling component separation, allowing simultaneous multi-component separation in a single column

Inventive Principle:
Principle #1Segmentation

2Manufacturing precision

If a two-column distillation system is used to purify benzoic acid, then high purification efficiency is achieved, but investment costs increase

Engineering Contradiction:
Improvepurification efficiencyVSAvoidinvestment costs
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent merges two separate distillation columns and their associated equipment into a single divided wall column system. This consolidation reduces the total number of devices required (fewer columns, heat exchangers, and pumps) while maintaining the purification functionality, thereby reducing investment costs

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The divided wall column is designed as a multi-functional device that simultaneously performs separation of low-boiling components, separation of high-boiling components, and collection of purified benzoic acid. This universal design replaces multiple specialized columns, reducing overall device complexity and investment requirements

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

3Manufacturing precision

If a two-column distillation system is used to purify benzoic acid, then high purification efficiency is achieved, but space requirements increase

Engineering Contradiction:
Improvepurification efficiencyVSAvoidspace requirements
Core Design Contradiction:
Manufacturing precisionVSArea of stationary object

Solution Approach 1:

The patent combines two distillation columns into one divided wall column structure, significantly reducing the footprint area required for the purification plant. The integrated design eliminates the need for two separate column installations and their associated spacing requirements, thereby reducing space requirements while maintaining purification efficiency

Inventive Principle:
Principle #5Merging (Combining)

4Manufacturing precision

If a two-column distillation system is used to purify benzoic acid, then high purification efficiency is achieved, but the number of required devices increases

Engineering Contradiction:
Improvepurification efficiencyVSAvoidnumber of devices
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent merges the functionality of two distillation columns into a single divided wall column, reducing the total device count. The divided wall column integrates the separation functions that would otherwise require two separate columns, heat exchangers, and pumps, thereby reducing the number of required devices

Inventive Principle:
Principle #5Merging (Combining)

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 achieves a 30% reduction in energy consumption compared to traditional methods, with similar purification efficiency, and reduces investment and space requirements, producing benzoic acid with high purity and low byproduct formation.

Implementation Method 1

A distillation method using a divided wall column, which separates low- and high-boiling components within a single column

Methodology Applied
Scientific EffectDistillation: Distillation

Implementation Method 2

A distillation method using a divided wall column, which separates low- and high-boiling components within a single column

Methodology Applied
Scientific EffectDistillation: Distillation

Data Source

PatentEP3148661B1Method for purification of benzoic acid
Publication Date: 2019.03.27 SULZER MANAGEMENT AG
  • EP3148661B1 patent drawingFigure 1
  • EP3148661B1 patent drawingFigure 2
  • EP3148661B1 patent drawingFigure 3

AI summary

The present invention relates to a method for purifying a crude benzoic acid (32) containing 5 to 20% by weight of byproducts and 80 to 95% by weight of benzoic acid, by means of distillation, wherein the distillation is performed in a plant comprising a first distillation system (54), which comprises a divided wall column (10). Preferably, the divided wall column (10) comprises: an upper portion having an upper undivided section (12) for concentrating low-boiling components, wherein the low-boiling components have a lower boiling point than benzoic acid, and an outlet for re moval of the low-boiling components from the column (10), a lower portion having a lower undivided section (14) for concentrating high-boiling components, wherein the high-boiling components have a higher boiling point than benzoic acid, and an outlet for re moval of the high-boiling components from the column (10), and a central portion arranged between the upper portion and the lower portion having at least one vertical dividing wall (20) for dividing the central portion into at least one feed section (16) and at least one withdrawal section ( 18), the feed section (16) having an inlet for the feed of crude benzoic acid (32) and the withdrawal section having a side draw outlet for the purified benzoic acid (34).