Trimethylolpropane Extraction Using 2-Ethylhexanol
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Solution Overview
Problem
Conventional methods for producing trimethylolpropane (TMP) require excessive amounts of starting materials and solvents, leading to increased costs, TMP loss during extraction, and high alkali metal residues that can cause decomposition during distillation, limiting commercial application.
Innovation Solution
A method involving aldol condensation and Cannizzaro reactions with n-butyl aldehyde, formaldehyde, and alkali metal hydroxide, followed by extraction with a 6-10 carbon alcohol and water washing to remove alkali metal ions, optimizing solvent use and separating extraction and ion removal steps to minimize waste and enhance yield.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional extraction methods are used with large amounts of solvent, then TMP extraction efficiency is improved, but solvent usage and facility costs increase
Solution Approach 1:
The invention changes the extraction parameter by using a specific alcohol with 6-10 carbon atoms (preferably 8 carbons, such as 2-ethylhexanol) instead of conventional solvents. This parameter change achieves high extraction efficiency while reducing solvent consumption to only 1-2 times the amount of raw material, compared to the conventional 7 times ratio.
2Productivity
If conventional extraction methods are used, then TMP can be extracted from reaction mixture, but alkali metal ion removal is insufficient causing discoloration during distillation
Solution Approach 1:
The invention segments the process into distinct steps: first extracting TMP with alcohol, then separately removing alkali metal ions by washing the extract with water. This segmentation ensures thorough alkali metal removal (reducing to below 10 ppm) without affecting TMP extraction efficiency, preventing discoloration during subsequent distillation.
Solution Approach 2:
The invention uses water as an intermediary substance to remove alkali metal ions from the alcohol extract. The water wash step acts as a mediator that selectively removes harmful alkali metal ions while leaving the TMP-alcohol extract intact, which is then distilled to obtain pure TMP without discoloration.
3Productivity
If excessive formaldehyde is used to increase production yield, then TMP yield is improved, but additional formaldehyde recovery process is required
Solution Approach 1:
The invention optimizes the formaldehyde parameter by using a controlled molar ratio (3-5 moles of formaldehyde per mole of n-butyl aldehyde) rather than excessive amounts. This parameter optimization achieves high TMP yield while avoiding the need for additional formaldehyde recovery facilities, simplifying the overall process.
4Productivity
If conventional methods use high temperature and high pressure conditions, then reaction efficiency is improved, but facility costs and safety requirements increase
Solution Approach 1:
The invention changes the reaction parameters by using ambient temperature and atmospheric pressure conditions with the novel alcohol extraction method. This parameter change maintains high reaction efficiency for TMP synthesis while eliminating the need for high-temperature and high-pressure facilities, reducing investment and operational costs.
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 reduces solvent and water usage, maximizes TMP yield, and minimizes alkali metal residues, ensuring high-purity TMP production without additional solvent recovery processes and avoiding discoloration, thus improving economic efficiency and product stability.
Implementation Method 1
synthesizing trimethylolpropane from n-butyl aldehyde, an aqueous solution of formaldehyde, and an aqueous solution of alkali metal hydroxide through aldol condensation reaction and Cannizzaro reaction
Implementation Method 2
CH3CH2C(CH2OH)2CHO+HCHO+NaOH→CH3CH2C(CH2OH)3+HCOONa
Implementation Method 3
extracting trimethylolpropane from the resultant mixture by using an alcohol having 6 to 10 carbons
Implementation Method 4
removing alkali metal ion from the resultant extract by using water
Implementation Method 5
distilling the alkali metal ion-removed extract
Data Source
AI summary
The present invention relates to a method for preparing trimethylolpropane (TMP) comprising the steps of: 1) synthesizing trimethylolpropane by using n-butyl aldehyde, an aqueous solution of formaldehyde and an aqueous solution of alkali metal hydroxide through aldol condensation reaction and Cannizzaro reaction; 2) extracting trimethylolpropane from a resultant mixture of the step 1) by contacting the resultant mixture with an alcohol having 6 to 10 carbons; 3) removing alkali metal ion from a resultant extract of the step 2) by contacting the resultant extract with water; and 4) distilling the alkali metal ion-removed extract obtained from the step 3). According to the present invention, a separate formaldehyde recovery process can be omitted, the extraction efficiency of TMP can be maximized with using a relatively small amount of extraction solvent, the separation and recovery processes for extraction solvent can be simplified since a mixture of solvents is not used for TMP extraction, and the yield of TMP can be maximized while the amount of generated waste water can be minimized, thereby producing TMP economically with good efficiency.