Hydroxypivalaldehyde Crystallization Viscosity Control
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Solution Overview
Problem
Current methods for producing high-purity hydroxypivalaldehyde and its dimer face challenges such as high viscosity slurry handling difficulties, energy inefficiencies, and complex operational steps due to inadequate pH control and concentration ranges in the crystallization process, leading to reduced yields and increased wastewater treatment burdens.
Innovation Solution
A method involving the adjustment of pH values and concentration ranges in the aqueous solution containing hydroxypivalaldehyde and its dimer, achieved by distilling low-boiling components from the reaction mixture of isobutyl aldehyde and formaldehyde, followed by crystallization with a diluent and repeated use of separation liquids to maintain optimal conditions for crystallization and reduce energy consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the HPA-containing aqueous solution is diluted by addition of water to keep the total content of HPA and/or dimer within 23 to 30% by mass, then the concentration is optimized for crystallization, but the slurry product has extremely high viscosity or no fluidity at 15 to 20°C, making it very difficult to be handled industrially
Solution Approach 1:
The patent changes the temperature parameter from 15-20°C to 0 to 10°C during crystallization, which fundamentally alters the viscosity characteristics of the slurry. At this lower temperature range, the slurry maintains optimal viscosity for handling while still achieving effective crystallization at the desired HPA/dimer concentration of 23-30% by mass
Solution Approach 2:
The patent introduces dynamic temperature control during the crystallization process, maintaining the system at 0 to 10°C to dynamically optimize both crystallization efficiency and slurry fluidity. This dynamic parameter adjustment allows the slurry to maintain appropriate viscosity characteristics for industrial handling while achieving the target concentration range
2Productivity
If a large amount of HPA and/or dimer remain in the liquid obtained by solid-liquid separation, then the yield is reduced, but extracting with isobutyl aldehyde and circulating organic phase requires distillation of large amounts of isobutyl aldehyde, which is energetically disadvantageous
Solution Approach 1:
The patent extracts and removes isobutyl aldehyde through distillation before the crystallization step, eliminating the need for subsequent extraction with isobutyl aldehyde. This takes out the interfering component early in the process, allowing direct crystallization of HPA/dimer and avoiding the energy-intensive extraction and distillation cycle while improving yield
Solution Approach 2:
The patent performs preliminary distillation to remove isobutyl aldehyde before crystallization, preparing the system in advance for efficient HPA/dimer recovery. This preliminary action prevents the need for complex post-crystallization extraction operations and reduces overall energy consumption
3Ease of operation
If formic acid accumulates by circulation of filtrate and wash solutions, then the pH level decreases, but HPA and/or dimer are not easily crystallized, requiring deamination processing which adds complexity
Solution Approach 1:
The patent performs preliminary pH adjustment to 5.0 or more before crystallization, preventing formic acid accumulation from interfering with the crystallization process. This preliminary basic treatment neutralizes formic acid in advance, maintaining optimal pH conditions for crystallization without requiring complex deamination processing
Solution Approach 2:
The patent changes the pH parameter to 5.0 or more through basic treatment, which fundamentally alters the chemical environment to prevent formic acid accumulation and its negative effects on crystallization. This parameter change simplifies the overall process by eliminating the need for deamination processing
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 the efficient and simple production of high-purity hydroxypivalaldehyde and its dimer with improved industrial handling, reduced energy costs, and enhanced yield, while minimizing wastewater treatment burdens.
Implementation Method 1
cooling the aqueous solution to crystallize at least one of the hydroxyl-pivalaldehyde and the dimer thereof
Implementation Method 2
distilling off a low boiling point component including unreacted isobutyl aldehyde to obtain an aqueous solution
Data Source
AI summary
The present invention provides a method of producing high-purity hydroxypivalaldehyde and/or dimer thereof, including: reacting isobutyl aldehyde with formaldehyde in a presence of a basic catalyst; distilling a low boiling point component including unreacted isobutyl aldehyde to obtain an aqueous solution; adding a diluent to the aqueous solution; cooling the aqueous solution to crystallize the hydroxypivalaldehyde and/or the dimer thereof; and subjecting the aqueous solution to a solid-liquid separation, followed by washing with an organic solvent and/or water, in which the diluent and a basic compound are added to the aqueous solution containing the hydroxypivalaldehyde and/or the dimer thereof obtained by distilling the low boiling point component off so that a concentration of the hydroxypivalaldehyde and/or the dimer becomes 5 to 23% by mass, the concentration of formaldehyde becomes 0.2 to 2.5% by mass, and a pH value becomes 5.0 or more, the solution is crystallized at a temperature of 20 to 45°C and subjected to the solid-liquid separation. In this method, handling of a high-viscosity slurry and carrying out any complicated operation such as regeneration of an ion exchange resin are not required, so the high-purity HPA and/or the dimer thereof can be obtained in high yield with an energetically advantageous manner.