Ketose Hydrogenation Epimer Ratio Control
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Solution Overview
Problem
Existing processes for hydrogenating ketose or ketose-containing sugar mixtures typically result in a 1:1 ratio of stereoisomeric sugar alcohols, failing to control the ratio of cis-isomer to trans-isomer effectively, which is desirable for specific applications.
Innovation Solution
A process involving the hydrogenation of ketose or ketose-containing sugar mixtures using a solid nickel-based catalyst, such as Raney nickel, at controlled temperatures and heating rates to adjust the ratio of cis-isomer to trans-isomer sugar alcohols, allowing for the production of mixtures with predetermined ratios by varying catalyst concentration, starting temperature, and heating rate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If hydrogenation is carried out under conventional conditions (elevated temperature and pressure with catalyst), then the hydrogenation reaction proceeds efficiently, but the ratio of stereoisomeric sugar alcohols (epimers) is fixed at approximately 1:1 and cannot be controlled
Solution Approach 1:
The patent applies parameter changes by systematically varying multiple process parameters including temperature profile (starting temperature and heating rate), catalyst concentration (0.1-10% w/w), hydrogen pressure (10-450 bar), and substrate concentration (10-70% w/w). These parameter changes enable control of the epimer ratio while maintaining efficient hydrogenation reaction, resolving the contradiction between productivity and manufacturing precision
2Productivity
If catalyst concentration is increased to improve reaction rate, then hydrogenation efficiency increases, but the epimer ratio control becomes more difficult
Solution Approach 1:
The patent demonstrates that catalyst concentration (0.1-10% w/w) is one of multiple interdependent parameters. By adjusting catalyst concentration alongside temperature profile, pressure, and substrate concentration, the system achieves both high reaction rate and precise epimer ratio control. The catalyst concentration parameter change is integrated with other parameter changes rather than acting in isolation
3Productivity
If temperature is increased to accelerate hydrogenation, then reaction efficiency improves, but the epimer ratio deviates from desired values
Solution Approach 1:
The patent employs a specific temperature profile with defined starting temperature (20-80°C) and controlled heating rate (0.1-10°C/min) rather than a single high temperature. This periodic/controlled temperature action allows the reaction to proceed efficiently while maintaining epimer ratio control through the specific thermal profile
4Productivity
If high hydrogen pressure is applied to increase conversion, then productivity improves, but the epimer ratio cannot be controlled
Solution Approach 1:
The patent shows that hydrogen pressure (10-450 bar) is integrated with multiple other parameter changes including temperature profile, catalyst concentration, and substrate concentration. This multi-parameter optimization allows high substrate conversion to be achieved while maintaining control over the epimer ratio through the coordinated adjustment of all parameters
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
Enables the production of sugar alcohol mixtures with controlled ratios of cis-isomer to trans-isomer, achieving a wide range of GPM/GPS ratios from the same starting material by optimizing catalyst concentration, temperature, and heating rate, thereby addressing the limitations of prior art.
Implementation Method 1
A process for the hydrogenation of a sugar or sugar mixture to produce a product mixture comprising at least two stereoisomeric sugar alcohols
Implementation Method 2
heating a reaction mixture comprising the ketose or ketose-containing sugar mixture in the presence of hydrogen with a particular predetermined concentration of a solid nickel-based catalyst
Implementation Method 3
heating a reaction mixture comprising the ketose or ketose-containing sugar mixture in the presence of hydrogen
Data Source
AI summary
A process for the hydrogenation of a ketose or a ketose-containing sugar mixture to produce a product mixture comprising at least two stereoisomeric sugar alcohols is disclosed. The process comprises the provision of a reaction mixture comprising said ketose or ketose-containing sugar mixture, the addition of a concentration of solid nickel-based catalyst to said reaction mixture, and conducting a hydrogenation reaction in said reaction mixture in the presence of hydrogen gas. With this process, it is possible to obtain a predefined ratio of cis-isomer to trans-isomer of the two stereoisomeric sugar alcohols. The ratio of cis-isomer to trans-isomer can be decreased by increasing the concentration of solid nickel-based catalyst, by decreasing the starting temperature of the heating step, and/or by decreasing the heating rate of the heating step.