Hydrogenation of Aliphatic Dialdehydes Using Water Dilution
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Solution Overview
Problem
The hydrogenation of high molecular weight aliphatic dialdehydes in the liquid phase faces challenges such as high viscosity, formation of heavies, catalyst poisoning, and reduced yield due to secondary reactions and the presence of organophosphite ligands and their degradation products.
Innovation Solution
Incorporating water in an amount equal to or greater than 10 weight percent in the hydrogenation process to reduce viscosity, prevent catalyst poisoning, and minimize the formation of heavies by hydrolyzing organophosphite ligands and their degradation products, thereby increasing the yield of aliphatic diols.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If hydrogenation is carried out in the liquid phase for high molecular weight aldehydes, then the reaction can proceed, but the viscosity becomes unacceptably high making transport and handling difficult
Solution Approach 1:
The patent changes the physical parameter of viscosity by adding water to the liquid phase hydrogenation system. The water dilutes the high molecular weight aldehyde, reducing its viscosity to acceptable levels for transport and handling while maintaining the liquid phase reaction environment necessary for hydrogenation of C6+ aldehydes.
2Productivity
If hydrogenation is carried out in the liquid phase with high concentrations of aldehyde and alcohol, then the reaction efficiency is high, but secondary reactions promote formation of high boilers and heavies
Solution Approach 1:
The patent changes the concentration parameter by adding water to the reaction system. This dilution reduces the concentration of aldehyde and alcohol, thereby suppressing secondary reactions such as aldol condensations and self-condensations that form heavies, while still maintaining sufficient reactant concentration for efficient hydrogenation.
Solution Approach 2:
Water acts as an intermediary substance in the hydrogenation system. It serves as a diluent that reduces viscosity and suppresses unwanted secondary reactions, while also serving as a heat transfer medium to manage the exothermic hydrogenation reaction and prevent hot spots that could promote heavy formation.
3Ease of manufacture
If organophosphite ligands and their degradation products are present in the aldehyde feed, then the feed can be used directly, but these substances bind and poison the hydrogenation catalyst
Solution Approach 1:
Water serves as a diluting intermediary that reduces the concentration of organophosphite ligands and their degradation products in the feed stream. This dilution decreases their ability to bind to and poison the hydrogenation catalyst, thereby maintaining catalyst activity while still allowing the use of direct feed from hydroformylation processes.
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 effectively reduces the formation of unwanted by-products, improves handling and transportation of high molecular weight dialdehydes, and enhances the yield of desired aliphatic diols by maintaining catalyst activity and controlling reaction conditions.
Implementation Method 1
Incorporating water in an amount equal to or greater than 10 weight percent in the hydrogenation process to reduce viscosity, prevent catalyst poisoning, and minimize the formation of heavies by hydrolyzing organophosphite ligands and their degradation products
Implementation Method 2
The hydrogenation of aldehydes can be carried out continuously or batchwise in a gas or liquid phase. For the industrial production of alcohols via the hydrogenation of aldehydes obtained from hydroformylation of olefins
Implementation Method 3
Hydrogenation catalysts advantageously comprise at least one metal of Groups 6, 7, 8, 9, 10, 11, or 12 of the Periodic Table of the Elements
Implementation Method 4
Incorporating water in an amount equal to or greater than 10 weight percent in the hydrogenation process to reduce viscosity
Data Source
AI summary
A process of hydrogenating an aliphatic dialdehyde, preferably, a C6-C16 alicyclic dicarboxaldehyde, to form an aliphatic diol, preferably, a C6-C16 alicyclic diol, most preferably, cis/trans-(1,3)(1,4)-cyclohexanedimethanol. The process involves contacting one or more aliphatic dialdehydes in a liquid phase with hydrogen in the presence of a hydrogenation catalyst in a hydrogenation zone and in the presence of water in an amount equal to or greater than 10 weight percent, based on the weight of the total liquid feed to the hydrogenation. The alicyclic dicarboxaldehyde is preferably prepared via hydroformylation of an olefin with subsequent extraction of the alicyclic dicarboxaldehyde product from the hydroformylation product fluid.