Processing method of butanol and octanol waste alkaline solution

Abstract

The invention relates to a processing method of a butanol and octanol waste alkaline solution. The method comprises the following steps: carrying out an acidification treatment on a waste alkaline solution with an inorganic acid until the pH value of the waste alkaline solution reaches 3 to 4.5; carrying out a pervaporation membrane evaporative concentration treatment on the acidified solution, carrying out an oil / water separation treatment on the evaporative concentrated solution, cooling to carry out crystallization, recycling the inorganic acid sodium salts, returning the crystallized residue to an acidification reactor to carry out a cyclic treatment, carrying out an adsorption treatment on the evaporative condensed liquid, returning the dehydrated part to a condensation reactor to prepare an alkaline solution, introducing the residue to a sewage processing field to carry out a bio-treatment, and finally discharging the sewage until the sewage reaches the discharge standards. The processing method can recycle organic substances in a waste alkaline solution, and turns the waste into valuable resources. At the same time the organic salts that are generated during the acidification process can be recycled as a by-product, and moreover, the processed effluent can be used to replace the fresh desalinated water to prepare fresh alkaline liquid, so the waste alkaline solution can be repeatedly used and production cost can be saved. The processing method has prominent environmental profits and economic profits.

Description

technical field [0001] The invention relates to a method for treating waste lye of butanol and octanol, and the method is also suitable for treating waste lye of decanol produced by condensation of valeraldehyde and waste lye of saponification produced by oxidation of cyclohexane to cyclohexanone. Background technique [0002] my country's existing butanol production process is mainly propylene oxo synthesis method. In the method, butyraldehyde is first synthesized by using propylene and synthesis gas as raw materials, and then the butyraldehyde is condensed under the catalysis of 2% sodium hydroxide to generate octenal. Butyraldehyde and octenal are finally hydrogenated to butanol and octanol. While butyraldehyde is condensed to form octenal, Cannizzaro Reaction also occurs at the same time, and the reaction formulas are as follows: [0003] [0004] 2CH 3 CH 2 CH 2 CHO+NaOH→CH 3 CH 2 CH 2 COONa+CH 3 CH 2 CH 2 OH+H 2 O (2) [0005] As can be seen from the ab...

AI Technical Summary

Problems solved by technology

The disadvantage of this method is that COD Cr Lower removal rate

[0010] Chinese patent CN1530334A adopts acidification heat separation technology to treat octanol waste lye. This method acidifies the waste lye to pH less than 4.5, heats the emulsion formed after acidification to a temperature of 95-100°C, and heats it for less than 0.5h, then statically Set the layers to form the oil-water two-phase. By setting the outlet height of the oil-water two-phase, the two phases can be separated automatically, and the organic phase can be recycled. This method does not need to add an extraction agent, but the COD Cr The removal rate is only about 50%, and the energy consumption is high

However, this process has high infrastructure investment, complex operating conditions, and high operating costs. It is still in the experimental stage and there are no reports of industrial applications.

[0017] Comprehensively analyzing the gains and losses of the above methods, it can be seen that although there are many recycling methods for octanol waste lye at present, and each has its own characteristics, it is still impossible to find a treatment method that is both environmentally friendly and economically beneficial.

Although the acidification method is the simplest and most economical and effective method for removing oily substances in spent octanol lye, it is difficult to recycle the butyric acid with high added value in the spent lye, and the existing extraction technology is also difficult to achieve the desired effect; and Although the multi-effect evaporation concentration method and rectification method have better effects, the treatment cost is high, and the sodium butyrate recovered by the concentration method is of poor quality and difficult to purify; the rectification method can only obtain about 81.4% (mass content) of sodium butyrate. Butyric acid azeotropic liquid, there is no relevant technical report on further concentration and purification; the acidification-macroporous resin adsorption method requires a large amount of resin, high investment costs, and the organic solvent used as a desorbent is easily lost

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