Chlorine Dioxide Production via Eductor Gas-Liquid Separation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing small-scale chlorine dioxide production processes for applications like water purification and bleaching often result in products contaminated with excess acid and salt, and do not efficiently produce chlorine dioxide as a gas or high-concentration aqueous solution.

Innovation Solution

A process involving the continuous reaction of alkali metal chlorate with acid and a reducing agent in a reactor, followed by dilution with a gaseous motive stream in an eductor, allowing for gas-liquid separation and subsequent absorption to produce chlorine dioxide as a high-concentration gas or aqueous solution, minimizing excess acid and salt by-products.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If chlorine dioxide is produced by reacting alkali metal chlorate with acid and reducing agent in small-scale units, then equipment and instrumentation requirements are reduced, but the product contains excess acid and salt contaminants

Engineering Contradiction:
Improveprocess equipmentVSAvoidexcess acid and salt
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The invention extracts and removes excess acid and salt from the product stream by introducing a gaseous motive stream in an eductor that selectively carries chlorine dioxide gas while leaving behind liquid contaminants (excess acid and salt). This separation allows small-scale production to achieve high-purity chlorine dioxide without extensive equipment.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

A gaseous motive stream is introduced as an intermediary medium in the eductor to facilitate the separation of chlorine dioxide from the reaction mixture. The gas acts as a carrier that selectively transports chlorine dioxide while leaving contaminants behind, enabling purification without complex equipment.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If chlorine dioxide is produced as high-concentration aqueous solution or gas, then application flexibility is improved, but decomposition risk increases

Engineering Contradiction:
Improveapplication flexibilityVSAvoiddecomposition stability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The invention changes the physical state parameter of chlorine dioxide from dissolved aqueous form to gas phase by using gaseous motive stream extraction. This parameter change allows the product to be delivered in a stable, concentrated form that can be easily applied while reducing decomposition risk associated with high-concentration aqueous solutions.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If extensive process equipment is used for large-scale chlorine dioxide production, then production efficiency is improved, but operational complexity and cost increase

Engineering Contradiction:
Improveproduction efficiencyVSAvoidprocess equipment
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The eductor system uses the energy of the gaseous motive stream itself to drive the separation and extraction process, eliminating the need for additional pumps, compressors, or complex mechanical equipment. The system serves itself by using the driving gas to create suction and separate chlorine dioxide, maintaining high productivity with minimal equipment.

Inventive Principle:
Principle #25Self-service

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 the production of chlorine dioxide with high concentration and reduced excess salts and acid, requiring less extensive equipment and minimizing decomposition risks, while allowing for flexible application as a gas or aqueous solution for various uses.

Implementation Method 1

bringing the product stream including any liquid and gas in the reactor from the reactor to an eductor and mixing it with a gaseous motive stream fed to the eductor

Methodology Applied
Scientific EffectEductor mixing: Venturi Effect

Implementation Method 2

bringing the diluted product stream to a gas-liquid separator; separating gas from liquid in the diluted product stream to form a gas stream comprising chlorine dioxide

Methodology Applied
Scientific EffectGas-liquid separation: Cyclone Separation

Implementation Method 3

bringing the gas stream comprising chlorine dioxide from the gas-liquid separator to an absorber; contacting said gas stream with a flow of water to form an aqueous solution containing chlorine dioxide

Methodology Applied
Scientific EffectAbsorption: Absorption (physical)

Data Source

PatentEP2004545B1Process for the production of chlorine dioxide
Publication Date: 2018.11.21 AKZO NOBEL NV
  • EP2004545B1 patent drawingFigure 1
  • EP2004545B1 patent drawingFigure 2
  • EP2004545B1 patent drawingFigure 3

AI summary

The invention concerns a process for the production of chlorine dioxide, said process comprising the steps of continuously: feeding to a reactor (1) an acid, alkali metal chlorate and a reducing agent; reacting the alkali metal chlorate with the acid and the reducing agent to form a product stream (2) comprising chlorine dioxide, water and alkali metal salt of the acid; and, bringing the product stream (2) from the reactor (1) to an eductor (3) and mixing it with a gaseous motive stream (4) fed to the eductor and thereby forming a diluted product stream (5) . The invention further concerns a production unit for the production of chlorine dioxide .