Method for zero discharge processing of waste saponification lye of cyclohexanone produced by cyclohexane oxidation technology

Abstract

The invention provides a zero-emission method used for disposing the saponification waste lye generated during CYC production with a cyclohexane oxidation process. The method includes the following steps: (1) the saponification waste lye is filtered and sufficient carbon dioxide gas is injected into the lye; (2) the sodium carbonate is extracted through steaming, separating and extraction; (3) the acid oil is extracted through acid neutralization; (4) the sodium sulfate is extracted through separating and condensing. Besides, the method also comprises the extraction of pure sodium carbonate and sodium sulfate, the disposing of waste gas generated by acid neutralization and the disposal of condensed water, etc. steps. The invention completely avoids the contamination by the saponification waste lye to environment; the adopted apparatuses have low investment and the energy cost is low; the 'waste-disposal by wastes' can be actually realized; the inorganic and organic chemistry products can be recycled from the saponification waste lye; the water in the waste water can be thoroughly utilized. The invention has simple process and is suitable for the industrial scale disposal of saponification waste lye and the disposal process has no second-time contaminating emission so as to really reach zero-emission, with distinct environmental, social and economic benefits.

Description

technical field [0001] The invention relates to chemical wastewater treatment technology, in particular to a zero-discharge method for saponification waste lye produced by cyclohexane oxidation process to produce cyclohexanone. Background technique [0002] Cyclohexanone is a chemical raw material used in the manufacture of resins, synthetic fibers, etc. Industrial production of cyclohexanone generally adopts cyclohexane oxidation process. During the implementation of this process, a large amount of saponification waste lye will be produced. A certain amount of inorganic and organic chemical mixtures remain in these saponification waste lye, the liquid has deep color, strong smell, and the COD value seriously exceeds the standard. For this highly polluted chemical wastewater, the usual treatment method is to use acid to neutralize the alkaline substances and burn other substances with fuel oil. The former will generate a large amount of waste gas and waste water again; th...

AI Technical Summary

Problems solved by technology

The former will generate a large amount of waste gas and waste water again; the latter has large investment and high operating costs, which not only wastes fuel energy, but also generates a large amount of greenhouse gas carbon dioxide that needs to be discharged into the air

And because saponification waste lye cannot be effectively treated, it also directly affects the current situation that cyclohexanone is difficult to expand production

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