Method for treating octanol waste lye by miscellaneous alcohol acidization-extraction method

Abstract

The invention relates to a method for treating waste lye discharged by the reaction system when octanol is produced. The recycled lye part discharged by an octanol production device is sent to an acidification mixer, inorganic acid and fusel are added for acidification mixture, demixing fluid is clear and separated by quiescence; extraction phase returns to a fusel tank for recycling, wastewater after neutralization is discharged to sewage farms for carrying out biological treatment; the mixing time is 3-15 minutes, the proportion by volume between the extraction agent and the wastewater is 1:1-8, the pH value after acidification is 2.0-4.5, the proportion by volume between the wastewater and 93% of concentrated sulphuric acid is 40-80:1, normal temperature and normal pressure are kept, the separated time is 30-120 minutes, the pH value of the treated water by neutralization is 6-9, the deoiling ratio is over 82%, the ratio of CODcr removal reaches 50%, biodegradability of the wastewater after treatment is improved from 40% to over 90%, the wastewater after treatment can directly enter chemical sewage farms for carrying out biological treatment, and the extraction agent does not need be regenerated.

Description

Technical field: [0001] The invention relates to a treatment method for waste lye discharged from a reaction system during octanol production. In particular, it relates to a treatment method for the waste lye discharged from the system when the aldehyde condensation reaction generates octenal. Background technique [0002] In the octanol production cycle of the butanol plant, high-purity n-butyraldehyde is condensed under the condition of 2% NaOH as a catalyst to generate octenal, and at the same time, it also generates water equivalent to octenal. Water has diluted the catalyst. In order to maintain the balance of the catalyst system, a certain amount of dilute lye must be continuously discharged from the system. At the same time, a part of high-concentration lye must be added to keep the condensation reaction going on normally. In addition to the spent alkali with a concentration of 1.5-2.0% (weight), the liquid has a high content of organic matter, COD cr The concentrat...

AI Technical Summary

Problems solved by technology

However, this method does not take into account that a large amount of organic acid salts are contained in the spent lye. Due to the presence of organic acid salts, the concentration of organic acid salts also increases correspondingly with the increase in the number of times of concentration, so that the organic acid salts in the circulation process The pipeline will inevitably be blocked, and the method for the purpose of concentration and reuse is difficult to be feasible in technology, and many technical and other problems need to be solved in order to realize industrialization

German patent DE 4321513 (publication number: 0631.988.AI) has introduced and adopts acidification-extraction technology to govern this waste lye, and the selection of its extraction agent is based on C 8 Alcohol above or C 6 The above C and H compounds are used as extractants to acidify and extract the spent caustic soda, and the extract phase is reused after rectification and regeneration, and useful components are recovered. The regeneration temperature increases correspondingly. Within 35 cycles of the experiment, the regeneration temperature of the extraction agent rises from the original 180°C to 250°C. This is difficult to be feasible in terms of technology, and the investment and operation costs very high

At present, the existing treatment technology in China is the technology developed by us using acidification self-extraction to treat octanol waste lye. This technology adopts self-extraction method, which requires large separation equipment and high investment.

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