Anhydrosugar Alcohol Production via Solid Acid Catalyst
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for producing anhydrosugar alcohols, such as isosorbide, face challenges in achieving high yields and purity due to the use of corrosive acids and organic solvents, leading to inefficiencies and side reactions.
Innovation Solution
A process involving the heating of pentitol or hexitol sugar alcohols under elevated temperature and pressure with a solid acid catalyst, followed by purification through recrystallization and distillation in a film evaporator, to produce anhydrosugar alcohols like isosorbide without the need for harmful solvents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If concentrated acids and organic solvents are used for dehydration, then the dehydration reaction can proceed, but the process becomes corrosive and produces side reactions
Solution Approach 1:
The patent uses cation-exchange resin as an intermediary catalyst to mediate the dehydration reaction. Instead of directly using concentrated acids, the resin provides acidic functionality through its exchange sites, allowing the reaction to proceed without the harsh conditions and side effects of conventional acid catalysis. The resin acts as a solid intermediary that facilitates proton transfer while avoiding the corrosive nature of liquid acids.
Solution Approach 2:
The patent replaces the chemical mechanism of concentrated acid dehydration with a solid-phase catalytic mechanism. The cation-exchange resin provides a solid surface and active sites for the dehydration reaction, substituting the need for liquid concentrated acids and organic solvents. This mechanical/physical substitution eliminates corrosion and reduces side reactions while maintaining reaction effectiveness.
2Object-affected harmful factors
If acidic-cation-exchange resin is used instead of concentrated acids, then corrosiveness is reduced, but the yield of isosorbide product decreases
Solution Approach 1:
The patent optimizes several parameters of the cation-exchange resin system to improve yield: selecting resins with specific exchange capacities (1.8-2.0 eq/L), controlling reaction temperature (100-130°C), adjusting reaction time (2-6 hours), and optimizing the resin-to-substrate ratio. These parameter changes enable the resin catalyst to achieve both low corrosiveness and high isosorbide yield by fine-tuning the catalytic activity and reaction conditions.
3Productivity
If conventional purification methods are used, then product recovery is achieved, but the purity and quality of anhydrosugar alcohol are insufficient
Solution Approach 1:
The patent divides the purification process into multiple sequential stages: (1) filtration to remove solid resin and insoluble impurities, (2) concentration to remove bulk solvent, (3) activated carbon treatment to adsorb colored impurities and trace organics, and (4) crystallization to achieve final high purity. This segmented approach ensures both high recovery and high purity by addressing different types of impurities at different stages.
Solution Approach 2:
The patent employs activated carbon as a flexible adsorptive medium with high surface area and porous structure. The carbon's flexible pore network and thin-film-like surface properties enable efficient adsorption of trace impurities and colored substances from the solution, significantly enhancing product purity without compromising recovery yield.
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 method enhances the yield and purity of anhydrosugar alcohols, specifically isosorbide, by optimizing reaction conditions with solid acid catalysts and advanced purification techniques, resulting in high-quality products suitable for industrial applications.
Implementation Method 1
heating a pentitol or hexitol sugar alcohol or monoanhydrosugar alcohol starting material under elevated pressure until molten, with or without an organic solvent and with a catalyst
Implementation Method 2
distilling the reaction mixture in a film evaporator to provide the anhydrosugar alcohol
Implementation Method 3
heating a pentitol or hexitol sugar alcohol or monoanhydrosugar alcohol starting material under elevated pressure until molten
Data Source
Figure 1
AI summary
A process is provided for the preparation of anhydrosugar alcohols. The process involves heating a sugar alcohol or a monoanhydrosugar alcohol starting material in the presence of an acid catalyst and under pressure. Optionally the resulting product is purified. Very high purities are achieved, without necessitating the use of organic solvents in the process.