A kind of preparation technology of 2-ethylhexenal and 2-ethylhexanol

[0040] Example 1:

[0041] Such as image 3 As shown, a system for preparing 2-ethylhexenal provided by the present invention includes a first reactor 311, a second reactor 312, a first chromatograph 331, and a second chromatograph 332; The outlet of the first reactor 311 and the inlet of the first chromatograph 331 are connected by a heat exchanger 361 through a pipeline; the lower outlet of the first chromatograph 331 communicates with the outside through an alkaline liquid circulation pump 321, the first chromatograph The upper outlet of 331 is connected to the inlet of the second reactor 312 through a pipeline; the lye inlet of the second reactor 312 is connected to the lye tank 38 through a lye supply pump 35 through a pipeline, and the outlet of the second reactor 312 is connected to the second The inlet of the chromatograph 332 is connected by a pipeline through a heat exchanger 362; the lower outlet of the second chromatograph 332 and the lye inlet of the first reactor 311 are connected by a lye circulation pump 322 through a pipeline, and the second chromatograph 332 The upper outlet is connected to the downstream process through a pipeline through a delivery pump 34; a raw material inlet is provided on the first reactor 311.

[0042] Preferably, the lye inlet of the second reactor 312 is connected to the lye tank 38 via a pipeline through the heat exchanger 37 and the lye supply pump 35 in sequence.

[0045] Example 2:

[0046] See attached for process flow image 3 , 100ml/min of fresh raw material containing 99.8wt% n-butyraldehyde, and 31.2ml/min of the alkaline catalyst aqueous solution from the lye circulation pump 322 enter the first condensation reactor 311, mix and react, the reaction temperature is 80°C, With a residence time of 15 minutes, the discharge from the first condensation reactor 311 is cooled to 40°C by the cooler 361, and then sent to the chromatograph 331 for stratification. The lower layer of dilute lye is sent to the lye tank or discharged by the lye pump as required After reprocessing, the upper layer of the mixed liquid of butyraldehyde and octenal (2-ethylhexenal content 56.4wt%) was sent to the second condensation reactor 312 at 85ml/min, and 47ml from the lye supply pump 5 After mixing 2wt% lye per min, further reaction occurs. The reaction temperature is 120℃, and the residence time is 10min. The discharge from the second condensation reactor 312 is cooled to 40℃ by the cooler 362 and then sent to the chromatograph 332. After precipitation, 97wt% of 2-ethylhexenal and 0.7% of polybutyraldehyde, 0.15% of 2-ethyl-4-methylpentenal and 1% of unreacted n-butyraldehyde in the upper layer of solution are contained in the lower layer. The content of the alkaline catalyst aqueous solution is 1.8% by weight, and it is sent to the first condensation reactor 311 through the alkaline solution circulation pump 322 at 31.2 ml/min. The solution containing 2-ethylhexenal and impurities in the upper layer of the chromatograph is sent to the hydrogenation section. After hydrogenation, crude 2-ethylhexanol is obtained. The impurities are n-butanol, isobutanol and 2-ethyl- 4-methylpentanol, 2-ethylhexanol and heavy components, etc. After rectification of crude 2-ethylhexanol, normal, isobutanol and heavy components, the final product of 2-ethylhexanol ≥99.7% is obtained. The main impurity of the product is 2-ethyl-4-methylpentanol 0.1% , Water 0.1%, 2-ethylhexanal 0.05%.

[0047] Example 3:

[0048] The process flow and reaction conditions are the same as in Example 2, except that the raw materials are fresh 99wt% n-butyraldehyde and 1wt% isobutyraldehyde. After the first condensation reactor 311 completes the reaction, it is stratified by the chromatograph 331, and the upper layer of the mixed liquid of butyraldehyde and octenal (the content of 2-ethylhexenal is 53.1wt%) is reacted by the second condensation reactor 322 , Separated by the chromatograph 332, the upper layer solution is 96.4wt% 2-ethylhexenal and 0.7% polybutyraldehyde, 0.17% of 2-ethyl-4-methylpentenal and unreacted n-butyraldehyde 1% and other impurities. After hydrogenation and rectification, the final product of 2-ethylhexanol with a purity of ≥99.6% is obtained. The main impurities of the product are 2-ethyl-4-methylpentanol 0.14%, water 0.12%, 2-ethylhexanol Aldehyde 0.05%.