Divided-Wall Distillation for Alkanol Separation

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Solution Overview

Problem

Current methods for preparing alkanols, such as n-butanol, are inefficient in separating high-purity products while minimizing energy loss, particularly in the separation and refinement processes using traditional distillation techniques.

Innovation Solution

A device comprising a divided-wall distillation column and a general-type distillation column is used to separate and refine alkanols by introducing a raw material with components of varying boiling points, allowing for the exchange of heat between streams to optimize reflux ratios and reduce energy consumption, thereby enhancing the separation efficiency and purity of n-butanol and iso-butanol.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If traditional distillation techniques are used for separating alkanols, then the separation process can be performed, but energy consumption is high and separation efficiency is low

Engineering Contradiction:
Improveseparation efficiencyVSAvoidenergy consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The distillation system is segmented into multiple columns (first distillation column, second distillation column, third distillation column) that work in sequence. Each column handles a specific separation task, allowing for more efficient and targeted separation of alkanol components, thereby improving separation efficiency while optimizing energy distribution across the system.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent combines multiple distillation operations into an integrated system where the output of one column serves as input to the next. The heat exchanger merges thermal energy from hot streams with cold streams, recovering energy that would otherwise be lost. This merging of separation stages and heat recovery creates a synergistic effect that reduces total energy consumption while maintaining high separation efficiency.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If traditional distillation techniques are used for separating alkanols, then the separation process can be performed, but energy loss is high

Engineering Contradiction:
Improveproduct purityVSAvoidenergy loss
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The system recovers thermal energy from hot process streams that would otherwise be discarded. The heat exchanger captures heat from streams exiting the distillation columns and uses it to preheat incoming feeds or generate steam, significantly reducing energy loss while ensuring consistent product purity through the multi-column separation process.

Inventive Principle:
Principle #34Discarding and recovering

Solution Approach 2:

The patent combines multiple distillation operations into an integrated system where the output of one column serves as input to the next. The heat exchanger merges thermal energy from hot streams with cold streams, recovering energy that would otherwise be lost. This merging of separation stages and heat recovery creates a synergistic effect that reduces total energy consumption while maintaining high separation efficiency.

Inventive Principle:
Principle #5Merging (Combining)

3Productivity

If multiple distillation columns are used for separating alkanols, then separation efficiency is improved, but device complexity increases

Engineering Contradiction:
Improveseparation efficiencyVSAvoiddevice complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The distillation system is segmented into multiple columns (first distillation column, second distillation column, third distillation column) that work in sequence. Each column handles a specific separation task, allowing for more efficient and targeted separation of alkanol components, thereby improving separation efficiency while optimizing energy distribution across the system.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The heat exchanger serves multiple functions: it cools hot streams, heats cold streams, and potentially generates steam for the distillation process. This multi-functionality reduces the need for separate heating and cooling equipment, thereby managing device complexity while supporting the multi-column separation system's efficiency goals.

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 effectively reduces energy consumption by optimizing reflux ratios and stream exchanges, leading to the production of high-purity alkanols with minimized energy loss and improved separation efficiency.

Implementation Method 1

introducing a raw material including three components having a low boiling point, a middle boiling point and a high boiling point into a divided-wall distillation column to separate the compound of Formula 1 and isomer thereof from the raw material

Methodology Applied
Scientific EffectDistillation: Distillation

Implementation Method 2

the divided-type column top stream flows out from the divided-type column top region and passes through the divided-type column condenser, some of the divided-type column top stream passing through the divided-type column condenser is refluxed to the divided-wall distillation column

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 3

the divided-type column bottom stream of the divided-wall distillation column and the general-type column bottom stream of the general-type distillation column is refluxed to the divided-type column bottom region and the general-type column bottom region through the divided-type column reboiler and the general-type column reboiler

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 4

allowing some or all of at least one of inflow and outflow streams in the divided-wall distillation column and the general-type distillation column to exchange heat

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP2946830B1Process for preparing alkanol
Publication Date: 2019.05.29 LG CHEM LTD
  • EP2946830B1 patent drawingFigure 1
  • EP2946830B1 patent drawingFigure 2
  • EP2946830B1 patent drawingFigure 3

AI summary

The present application relates to a device and a method for preparing alkanol. According to the present application, energy can be reduced when preparing alkanol by reducing the amount of steam used in a reboiler or cooling water used in a condenser, and steam generated from a heat exchanger for overhead stream can be utilized in a variety of fields. Also, highly pure alkanol can be prepared according to the present application.