Weakly Basic Anion Resin for Polymerization-Safe Formaldehyde Deacidification

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Solution Overview

Problem

Existing methods struggle to deacidify highly concentrated formaldehyde solutions effectively without causing polymerization, and existing ion exchange systems are not suitable for industrial implementation, leading to inefficiencies and resin damage.

Innovation Solution

A method using a weakly basic anion exchange resin at specific temperature and pressure conditions, with controlled pH variation, to deacidify formaldehyde solutions, avoiding polymerization and resin damage, and allowing for industrial feasibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If ion exchange technology is used to deacidify formaldehyde solutions, then formic acid removal efficiency is improved, but formaldehyde polymerization occurs and resin damage arises

Engineering Contradiction:
Improveformic acid removal efficiencyVSAvoidresin durability
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent applies parameter changes by operating the ion exchange process at controlled temperatures (20-40°C) and pH levels (2-6) to prevent formaldehyde polymerization while maintaining effective formic acid removal. The controlled flow rate (0.1-10 m³/h) and residence time (1-60 minutes) are also optimized to balance deacidification efficiency with preventing resin damage and polymerization.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses a weakly basic anion exchange resin as an intermediary substance that selectively removes formic acid from the formaldehyde solution without causing polymerization. The resin acts as a mediator between the formaldehyde solution and the deacidification process, enabling formic acid removal while maintaining solution stability through controlled ion exchange mechanisms.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If conventional ion exchange systems are used for deacidification, then formic acid removal is achieved, but industrial implementation is not feasible

Engineering Contradiction:
Improveformic acid removalVSAvoidindustrial feasibility
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent segments the deacidification process into a modular column configuration that can be industrially implemented. The system divides the ion exchange process into manageable sections with controlled flow rates and residence times, enabling scalable industrial application while maintaining effective formic acid removal throughout the formaldehyde solution processing.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements a self-service system where the ion exchange resin automatically regenerates in situ through controlled flow of formaldehyde solution. The system uses the formaldehyde solution itself to regenerate the resin by flushing with water and controlled CO2 exposure, eliminating the need for external regeneration chemicals and simplifying industrial operation.

Inventive Principle:
Principle #25Self-service

3Productivity

If high flow rates are used to increase productivity, then processing speed improves, but resin damage and polymerization increase

Engineering Contradiction:
Improveprocessing speedVSAvoidresin integrity
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies dynamics by adjusting flow rates (0.1-10 m³/h) and residence times (1-60 minutes) dynamically based on operating conditions. The system optimizes the balance between productivity and resin integrity by allowing flexible flow rate adjustments while maintaining controlled contact time between the formaldehyde solution and resin, preventing both polymerization and resin damage.

Inventive Principle:
Principle #15Dynamics

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

Achieves high deacidification yield, reducing formic acid content to less than 50 ppm in formaldehyde solutions up to 56 wt.%, enhancing solution stability and resin longevity.

Implementation Method 1

a method for deacidification of an aqueous solution by ion exchange, wherein the method comprises: a stage of contacting a stream of an aqueous solution to be deacidified such as an aldehyde aqueous solution with a weakly basic anion exchange resin bed to obtain a deacidified aqueous solution stream

Methodology Applied
Scientific EffectIon exchange: Ion Exchange

Data Source

PatentEP4469202B1Ion exchange method for deacidification of an aqueous formaldehyde solution, and an installation for performing such method
Publication Date: 2025.10.01 FORESA TECH S L U
  • EP4469202B1 patent drawingFigure 1
  • EP4469202B1 patent drawingFigure 2
  • EP4469202B1 patent drawingFigure 3~4

AI summary

A method for deacidification of an aqueous solution by ion exchange, characterized in that the method comprises contacting a stream of a formaldehyde aqueous solution with a weakly basic anion exchange resin bed to obtain a deacidified aqueous solution stream. An installation for deacidification of an aqueous solution by said method.