Fractional Layer Crystallisation for High Melting Organic Purification

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Solution Overview

Problem

Current methods for purifying high melting organic compounds, such as sterols, face challenges including the use of solvents which lead to energy inefficiencies, contamination risks, and the formation of undesirable crystal forms, especially when dealing with compounds that melt at high temperatures, as they often require pressure-resistant equipment and complex solvent recovery processes.

Innovation Solution

A method utilizing fractional layer crystallization that condenses evaporated solvents back into the mixture, maintaining the original composition and avoiding pressure increases, allowing for the purification of high melting compounds without the need for filters or centrifuges, using a solvent with a lower boiling point than the compound to facilitate easy removal and prevent thermal degradation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If solvents are used in fractional layer crystallisation for high melting compounds, then the compounds can be purified, but the solvent evaporates causing composition variation, emissions, safety risks, and requiring pressure-resistant equipment

Engineering Contradiction:
Improvepurification qualityVSAvoidsolvent evaporation effects
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent converts the harmful effect of solvent evaporation into a beneficial process by intentionally allowing evaporation to occur and then condensing the vapor back into the crystallisation system. The evaporation helps maintain purification by removing solvent from the crystal lattice, while the condensation recovers the solvent and maintains system composition, transforming a harmful side effect into a controlled part of the purification mechanism

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent implements solvent recovery by condensing evaporated solvent vapor and returning it to the crystallisation system. This discards the solvent from the crystal structure (where it would cause contamination) while recovering it for continued use, eliminating emissions and preventing composition variation without requiring pressure-resistant equipment

Inventive Principle:
Principle #34Discarding and recovering

2Manufacturing precision

If solvents are used in fractional layer crystallisation, then compounds can be dissolved and purified, but energy consumption increases due to heating and cooling requirements

Engineering Contradiction:
Improvepurification qualityVSAvoidenergy consumption
Core Design Contradiction:
Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The patent implements continuous operation where the crystallisation process runs continuously with steady-state temperature control. The solvent evaporation and condensation occur continuously, maintaining constant purification action without intermittent heating and cooling cycles, thereby reducing overall energy consumption while sustaining purification quality

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The patent utilizes phase transitions (evaporation and condensation) of the solvent as the driving mechanism for purification. By allowing the solvent to evaporate and then condense it back, the process achieves purification through phase change rather than requiring continuous heating and cooling, significantly reducing energy consumption

Inventive Principle:
Principle #36Phase transitions

3Manufacturing precision

If solvents are used for crystallisation, then compounds can be purified, but the product becomes contaminated with solvent traces

Engineering Contradiction:
Improvepurification qualityVSAvoidproduct purity
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent converts the potential harm of solvent contamination into a benefit by allowing controlled evaporation of solvent during crystallisation. The evaporation removes solvent from the crystal lattice and surrounding environment, and the subsequent condensation recovers the solvent separately, ensuring the purified product contains minimal solvent traces while the evaporated solvent is recovered for reuse

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 efficient purification of high melting organic compounds, including sterols, by maintaining the mixture's composition, reducing energy consumption, and avoiding solvent contamination, while allowing for the use of conventional crystallizers, thus achieving high purity products with reduced operational costs and safety risks.

Implementation Method 1

A method utilizing fractional layer crystallization that condenses evaporated solvents back into the mixture

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 2

Because of the evaporation of the solvent the composition and hence the separating properties of the mixture vary

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 3

The purifying of organic compounds by means of fractional layer crystallisation on vertical heat exchanger surfaces

Methodology Applied
Scientific EffectCrystallisation: Crystallisation

Data Source

PatentEP1907088B1Method and device for purifying high melting organic raw products or compound mixtures by means of fractional layer crystallisation
Publication Date: 2012.01.04 SULZER CHEMTECH AG
  • EP1907088B1 patent drawingFigure 1
  • EP1907088B1 patent drawingFigure 2
  • EP1907088B1 patent drawingFigure 3

AI summary

This invention relates to a method and a device for purifying and/ or separating preferably high melting organic raw products or compound mixtures containing, in particular, high melting and/ or degradable sterols, by layer crystallisation on first heat exchanger surfaces. The raw product is received in a solvent or solvent mixture, and then brought into contact with heat exchanger surfaces. The desired product crystallises on the heat exchanger surfaces by slow cooling. Solvent evaporating during the crystallisation or sweating process is condensed and returned to the mixture.