In-Line Surfactant Concentration Control Using COD and TOC

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Solution Overview

Problem

Existing industrial processes face challenges in accurately and rapidly determining surfactant concentrations in aqueous solutions, leading to inefficiencies and waste due to delayed testing and over-dosing of expensive surfactants.

Innovation Solution

A method and system that measures carbon-related parameters such as COD or TOC to indirectly determine surfactant concentrations, allowing for rapid and in-line adjustments to maintain concentrations within preset limits, using a controller to manage surfactant flow rates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If off-line chemical analysis methods are used to measure surfactant levels, then measurement precision can be achieved, but the testing time is excessively long (several hours or days)

Engineering Contradiction:
Improvesurfactant level measurement accuracyVSAvoidtesting time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent replaces traditional off-line chemical analysis methods with an on-line optical measurement system using a spectrophotometer. This substitution enables continuous real-time monitoring of surfactant concentrations through light absorption measurements at specific wavelengths (210 nm and 280 nm), eliminating the time-consuming nature of conventional chemical analysis while maintaining measurement accuracy through calibration curves.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces calibration curves as an intermediary tool that correlates optical density measurements (OD210 and OD280) with actual surfactant concentrations. These calibration curves, established through preliminary experiments with known surfactant concentrations, enable the conversion of optical measurements into accurate concentration values, bridging the gap between rapid optical measurement and precise concentration determination.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If traditional testing regimes are used, then equipment complexity is low, but surfactant over-dosing and waste occur due to inability to make rapid adjustments

Engineering Contradiction:
Improvetesting system simplicityVSAvoidsurfactant waste
Core Design Contradiction:
Device complexityVSLoss of substance

Solution Approach 1:

The patent implements a feedback control system where real-time surfactant concentration measurements are continuously monitored and fed back to the process control system. This enables dynamic adjustment of surfactant dosing rates to maintain concentrations within optimal ranges, preventing both over-dosing and under-dosing. The system automatically adjusts dosing based on measured concentrations, ensuring efficient surfactant utilization and eliminating waste associated with traditional fixed-dosing regimes.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent establishes continuous on-line monitoring of surfactant concentrations throughout the industrial process, replacing discontinuous off-line testing. This continuous measurement approach ensures that surfactant levels are constantly tracked and adjusted, maintaining optimal concentrations at all times and preventing the surfactant over-dosing that occurs with periodic traditional testing methods.

Inventive Principle:
Principle #20Continuity of useful action

3Productivity

If rapid in-line measurement is implemented, then productivity is improved through quick adjustments, but measurement precision may be compromised

Engineering Contradiction:
Improveprocess adjustment speedVSAvoidsurfactant concentration accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent replaces slow off-line chemical analysis with rapid on-line spectrophotometric measurement, achieving both speed and accuracy. The optical measurement system provides real-time data without the time delays of traditional methods, enabling immediate process adjustments while maintaining measurement reliability through validated calibration procedures.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent uses calibration curves as an intermediary to ensure measurement precision in the rapid on-line system. These calibration curves, established through rigorous experimentation with known surfactant concentrations, provide a reliable correlation between optical density readings and actual concentrations, ensuring that the speed of on-line measurement does not compromise accuracy.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Enables quick and efficient control of surfactant levels in industrial processes, reducing waste and optimizing product quality while ensuring compliance with environmental standards.

Implementation Method 1

A carbon related parameter is then measured from the fluid sample. The carbon related parameter, for example, can be Chemical Oxygen Demand (COD) or Total Organic Carbon (TOC).

Methodology Applied
Scientific EffectChemical Oxygen Demand (COD) measurement: Oxidation

Implementation Method 2

A carbon related parameter is then measured from the fluid sample. The carbon related parameter, for example, can be Chemical Oxygen Demand (COD) or Total Organic Carbon (TOC).

Methodology Applied
Scientific EffectTotal Organic Carbon (TOC) measurement: Combustion

Data Source

PatentEP4241077B1Method and system for determining surfactant concentration in industrial processes
Publication Date: 2026.01.21 KIMBERLY CLARK WORLDWIDE INC
  • EP4241077B1 patent drawingFigure 1
  • EP4241077B1 patent drawingFigure 2
  • EP4241077B1 patent drawingFigure 3~4

AI summary

A method and system are disclosed for determining surfactant concentration levels in aqueous solutions. In accordance with the method of the present disclosure, a related carbon parameter, such as COD or TOC, is measured in an aqueous solution. This measurement is then converted to surfactant concentration using a mathematical correlation or reference data. Through the method and system of the present disclosure, surfactant concentrations in process streams can be monitored and adjusted on the fly.