Recycling method for butylene oxidative dehydrogenation wastewater

Abstract

The invention relates to a recycling method for butylene oxidative dehydrogenation wastewater, which is mainly used for solving the problems that the wastewater quantity is large and the dosage of water vapor is much in the prior art. The recycling method comprises the following steps of: (a) enabling butylenes, oxygen gas or air and water vapor to carry out oxidative dehydrogenation reaction under certain conditions, wherein reaction products enter a water-cooling tower after being cooled, so as to countercurrent contact washing water from the tower top for removing organic acid; (b), pressurizing water-cooling tower top gas to 0.5 Mpa-2.0MPa, enabling the pressurized water-cooling tower top gas to enter an aldehyde washing tower kettle and countercurrent contact fresh desalted water from the tower top for removing aldehyde impurities in the generated gas; and feeding the aldehyde-containing wastewater of the tower kettle and wastewater of the water-cooling tower to a wastewater pretreatment tower; and (c), removing part of aldehyde and micro hydrocarbon in the wastewater pretreatment tower to obtain aldehyde-deficient water, returning the part of aldehyde-deficient water to a butylene oxidative dehydrogenation reaction system, recycling part the aldehyde-deficient water as water distribution, and discharging part of the aldehyde-deficient water to a wastewater treatment site. According to the technical scheme, the technical problems are solved, and the recycling method can be used for industrial production process of butylene oxidative dehydrogenation.

Description

technical field [0001] The invention relates to a method for recycling butylene oxidative dehydrogenation wastewater. Background technique [0002] Butadiene is an important monomer of synthetic rubber and synthetic resin, mainly used in the synthesis of butadiene rubber, styrene-butadiene rubber, nitrile rubber and ABS resin. Butadiene is also a variety of coatings and organic chemical raw materials. [0003] At present, butadiene is mainly produced in two ways: separation of C4 fractions and synthesis (including butane dehydrogenation, butene dehydrogenation, butene oxidative dehydrogenation, etc.). At present, except the United States, almost all butadiene in the world comes directly from the by-product C4 fraction (also written as C4 fraction) when hydrocarbon cracking is used to produce ethylene. About half of the sources of butadiene in the United States come from the dehydrogenation of butane and butene, and half come directly from cracking C4 fractions. [0004] W...

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Problems solved by technology

[0016] A large amount of water vapor is required in the reaction process of the above-mentioned patented technology. In order to protect the catalyst and control the reaction temperature, the molar ratio of water to butene is above 8, resulting in a large amount of water vapor and high energy consumption in the device.

Butene and oxygen react under the action of a catalyst to form butadiene. Due to the presence of oxygen in the reaction process, aldehydes such as acetic acid and acetaldehyde, organic acids such as formic acid and acetic acid, ketones such as acetone, and furans will inevitably be produced. Oxygen-containing compounds, generally, the yield of butadiene is 60%~80%, and the content of oxygen-containing compounds in the reaction outlet gas is less than 1%. Separation and butadiene extraction are both very harmful. Oxygen-containing organic acids can also cause corrosion to equipment, and unsaturated aldehydes are easy to self-polymerize and block equipment. Therefore, an oxygen-containing compound removal unit is required in the butene oxidative dehydrogenation process , while the oxygenated compounds are removed, the water in the butene oxidative dehydrogenation product gas is condensed, and the washing water will generate a large amount of waste water containing oxygenated compounds, resulting in a large amount of steam and waste water in the whole device, which seriously affects the Industrial application of butene oxidative dehydrogenation technology

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