Sterol Purification Process Using Composite Solvent Systems

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Solution Overview

Problem

Current methods for producing sterols from oil distillates or distillation residues face challenges in achieving high yields and purity while avoiding the use of toxicologically and ecologically unsafe solvents, and in improving the color quality of the sterol products.

Innovation Solution

A process involving transesterification mechanisms, including the conversion of sterol esters to free sterols using hydrolysis or transesterification, followed by purification steps such as adsorption and crystallization, utilizing a solvent mixture that includes aprotic and protic polar solvents to enhance purity and reduce impurities, and finally, melt-drying and particle forming to achieve high-quality sterol crystals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional crystallization methods are used with simple solvents, then the process is simple and economical, but the color quality and purity of sterol crystals are insufficient

Engineering Contradiction:
Improvepurity and color quality of sterol crystalsVSAvoidcomplexity of purification process
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent uses a composite solvent system comprising a polar solvent (such as methanol, ethanol, or water) and a non-polar solvent (such as hexane, heptane, or isooctane) in specific ratios. This composite solvent system enables effective removal of colored impurities and sterol esters while maintaining process economy, achieving both high purity/color quality and reasonable process complexity

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent optimizes specific parameters including solvent ratio (polar to non-polar), crystallization temperature (typically 0-25°C), and sterol concentration in the solution. By carefully controlling these parameters, the process achieves superior color quality (Gardner color < 4) and purity without requiring excessively complex purification steps

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If multiple washing steps with different solvents are performed, then the color and purity of sterol crystals are improved, but the processing time and operational complexity increase

Engineering Contradiction:
Improvecolor quality of sterol crystalsVSAvoidtotal processing time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent combines multiple washing functions into a single optimized washing step using the composite solvent system. This single step simultaneously removes colored impurities, sterol esters, and other contaminants that would otherwise require multiple separate washing steps, significantly reducing processing time while maintaining excellent color quality

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent maintains continuous useful action by performing crystallization and washing in an integrated manner without intermediate separation steps. The composite solvent system allows the washing to proceed continuously while effectively removing impurities, avoiding time losses associated with multiple discrete operations

Inventive Principle:
Principle #20Continuity of useful action

3Ease of manufacture

If traditional solvents are used for crystallization and washing, then the process is economical, but toxicologically and ecologically unsafe solvents are employed

Engineering Contradiction:
Improveeconomic feasibility of processVSAvoidtoxicological and ecological safety
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent changes the chemical nature of solvents from traditional toxic solvents (such as chlorinated hydrocarbons) to environmentally friendly alternatives (such as ethanol, isopropanol, or their mixtures with water or light hydrocarbons). By adjusting solvent ratios and crystallization parameters, the process maintains economic feasibility while eliminating toxicological and ecological hazards

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs readily available, biodegradable solvents that are inexpensive and environmentally benign. These solvents can be easily disposed of or recycled without special handling requirements, reducing both cost and environmental impact compared to persistent toxic solvents

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 process achieves high yields and purity of sterols with improved color quality, utilizing an economic and environmentally friendly method that avoids the use of hazardous solvents, resulting in a low sterol ester content and low solvent residue in the final product.

Implementation Method 1

transesterifying the sterol esters in the distillate or residue or - if steps (b) and (c) are applied - the product resulting from step (c) or - if step (d) is applied - step (d) with a lower alcohol in the presence of a basic catalyst to form free sterols

Methodology Applied
Scientific EffectTransesterification: Chemical Bonding

Implementation Method 2

crystallizing sterols in the mixture obtained from step (e), (f) or (g) - depending if such steps are employed or not - , optionally under mixing

Methodology Applied
Scientific EffectCrystallization: Crystallisation

Implementation Method 3

subjecting the distillate or residue or - if steps (b) and (c) are applied - the product resulting from step (c) to a purification step using adsorbents

Methodology Applied
Scientific EffectAdsorption: Adsorption

Implementation Method 4

conversion of sterol esters to free sterols using hydrolysis or transesterification

Methodology Applied
Scientific EffectHydrolysis: Hydrolysis

Data Source

PatentUS11781088B2Process for the production and purification of sterols
Publication Date: 2023.10.10 BASF HEALTH & CARE PROD FRANCE

AI summary

The presently claimed invention relates to a process for the production and purification of sterols from oil distillates or oil distillation residues, in particular from the latter. Specifically, the presently claimed invention relates to a process for obtaining sterols in a pure form with reduced impurity and improved color.