Prussian Blue Methanol Adsorbent for Selective Thermal Desorption

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Solution Overview

Problem

Prussian blue analogs exhibit high affinity for both water and methanol, making it difficult to selectively desorb methanol when water is also adsorbed, and their effectiveness in recovering high-concentration methanol from liquids or gases containing water is unclear.

Innovation Solution

A methanol adsorbent comprising a Prussian blue analog with specific cations (M and M') is used, which selectively adsorbs methanol over water by desorbing water at a first temperature and methanol at a higher second temperature, utilizing a method involving adsorption, water desorption, and methanol desorption steps.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If Prussian blue analogs are used as adsorbents for methanol, then methanol adsorption capacity is improved, but selective desorption becomes difficult due to simultaneous water adsorption

Engineering Contradiction:
Improvemethanol adsorption capacityVSAvoidselective desorption
Core Design Contradiction:
Quantity of substanceVSEase of operation

Solution Approach 1:

The patent applies parameter changes by utilizing temperature as a control parameter to achieve selective desorption. The adsorbent is heated to different temperature ranges: water desorbs at lower temperatures (first temperature range) while methanol remains adsorbed, then methanol desorbs at higher temperatures (second temperature range). This temperature parameter differentiation resolves the contradiction by enabling selective desorption despite simultaneous adsorption of both substances.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent segments the desorption process into two distinct stages based on temperature ranges. The first stage removes water at lower temperatures, and the second stage removes methanol at higher temperatures. This segmentation of the desorption operation allows selective recovery of each substance, solving the problem of non-selective desorption while maintaining high adsorption capacity.

Inventive Principle:
Principle #1Segmentation

2Quantity of substance

If Prussian blue analogs adsorb both water and methanol, then adsorption capacity is improved, but methanol concentration in recovered liquid decreases

Engineering Contradiction:
Improveadsorption capacityVSAvoidmethanol concentration
Core Design Contradiction:
Quantity of substanceVSManufacturing precision

Solution Approach 1:

The patent uses temperature parameter changes to control which substance desorbs at each stage. By maintaining the temperature below a threshold during the first desorption stage, water is removed while methanol remains adsorbed. Then by increasing temperature above the threshold in the second stage, methanol is selectively desorbed. This parameter control ensures high methanol concentration in the recovered liquid while maintaining high overall adsorption capacity.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent performs preliminary water removal before methanol desorption. The first temperature treatment stage preliminarily removes water from the adsorbent, preparing it for selective methanol desorption in the second stage. This preliminary action prevents water contamination of the recovered methanol, ensuring high concentration while utilizing the full adsorption capacity for both substances.

Inventive Principle:
Principle #10Preliminary action

3Adaptability or versatility

If Prussian blue analogs are used in environments with coexisting substances, then adsorption capability is maintained, but selectivity between water and methanol decreases

Engineering Contradiction:
Improveadsorption capability in complex environmentsVSAvoidselectivity
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent maintains adaptability to complex environments (water-vapor-containing gases) while preserving selectivity through parameter changes. By controlling temperature as a parameter, the system can selectively desorb water or methanol regardless of their simultaneous adsorption. This parameter-based control mechanism works effectively in complex environments, maintaining both versatility and selectivity.

Inventive Principle:
Principle #35Parameter changes

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 adsorbent effectively recovers high-concentration methanol by selectively desorbing water and methanol at different temperatures, achieving methanol concentrations of 40% or higher, with a recovery device enhancing efficiency.

Implementation Method 1

a methanol adsorbent that adsorbs methanol from water or gas

Methodology Applied
Scientific EffectAdsorption: Adsorption

Implementation Method 2

this Prussian blue analog primarily desorbs water at a first temperature and primarily desorbs methanol at a second temperature which is higher than the first temperature

Methodology Applied
Scientific EffectThermal desorption: Desorption

Data Source

PatentEP4582408A1Methanol adsorbent, method for producing high-concentration methanol, and methanol recovery device
Publication Date: 2025.07.09 NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE & TECHNOLOGY
  • EP4582408A1 patent drawingFigure 1
  • EP4582408A1 patent drawingFigure 2(a)~2(b)
  • EP4582408A1 patent drawingFigure 3

AI summary

A methanol adsorbent for adsorbing methanol contained in a liquid or gas comprising water and methanol, wherein the methanol adsorbent comprises, as an active component, a Prussian blue analog represented by the following general formula (1):         AxM[M'(CN)6]y·zH2O     (1) (wherein x, y, and z satisfy 0 ≦ x ≦ 3, 0.1 ≦ y ≦ 1.5, and 0 ≦ z ≦ 6; A represents one or more of hydrogen ions, ammonium cations, alkali metal ions, and alkaline earth metal ions; and M and M' are cations independent of each other, excluding hydrogen ions, ammonium cations, alkali metal ions, and alkaline earth metal ions.)