Device and production technology for treating ternary-monomer wastewater and extracting sodium sulfate

Abstract

The invention discloses a device and a production technology for treating ternary-monomer wastewater and extracting sodium sulfate. The device comprises a plate-and-frame filter press, a mother liquid heat exchanger, a stripping tower and a condenser which are sequentially communicated through a pipeline, wherein the condenser is communicated with a methane distillation tower through the pipeline. The production technology comprises the following steps of: (1) pumping neutralized mother liquid into the plate-and-frame filter press, preheating the mother liquid through the mother liquid heat exchanger, and then pumping the mother liquid into the stripping tower from the top of the stripping tower; (2) pumping steam into the stripping tower from the bottom of the stripping tower, after methane in the mother liquid is brought out by the steam, condensing the steam through the condenser, then entering the methane distillation tower, and separating to obtain methane; (3) pumping liquid at the bottom of a high-temperature tower into an evaporation and concentration kettle to be concentrated, steaming out moisture, and using the steam generated by the evaporation and concentration kettle for heating the mother liquid heat exchanger; and (4) after concentrating a material in the evaporation and concentration kettle, placing the concentrated material in a crystallizing pond, and feeding the mother liquid, Na2SO4.10H2O in which is separated out in the crystallizing pond, into a mother liquid neutralization pond to be reused.

Description

technical field [0001] The invention relates to a device for treating three-monomer waste water and extracting sodium sulfate and a production process thereof, which belong to the field of chemical production waste water treatment. Background technique [0002] Dimethyl isophthalate-5-sodium sulfonate (commonly known as three monomers, English abbreviation SIPM) is mainly used as the third monomer of cationic modified polyester CDP. Since the CDP fiber contains sulfonic acid groups, it is suitable for cationic dyes With good affinity, the dyed fiber has bright color, complete color spectrum, and can be deeply dyed. After dyeing, the dyed fabric is bright in color, and the dye exhaustion rate is high, which greatly reduces the discharge of printing and dyeing wastewater. It can make the dyeing of the modified polyester fiber more vivid and dense, with good colorability and anti-pilling effect. This kind of fiber not only guarantees cationic easy dyeing, but also increases t...

AI Technical Summary

Problems solved by technology

[0009] The disadvantages are: (1), the project investment is too large, taking the annual output of 3,000 tons / year three-monomer as an example, the total investment of the wastewater treatment plant is close to 18 million yuan; (2), due to the complex composition of the three-monomer wastewater, evaporation After running for a period of time, the heater and evaporator are easily blocked, and the blockage is relatively hard. It is necessary to stop the car, disassemble the heater and evaporator to remove the blockage, which has a great impact on the operation of the entire system; (3), methanol recovery Low efficiency, poor economic benefits, high operating costs

The disadvantages are: (1), the extraction agent and stripping agent used are expensive, and the consumption in the process is relatively large, which seriously affects the economic benefits of the obtained sodium isophthalic acid-5-sulfonate product; (2), The operation is cumbersome. Compared with the three-monomer production process, the preparation process of sodium isophthalic acid-5-sulfonate only reduces the esterification process, and the rest of the operations are similar; (3), using Ca(OH) 2 Neutralize sulfuric acid to produce secondary new CaSO 4 Waste residue pollution increases the difficulty of treatment and increases project investment; (4) The investment in wastewater treatment is relatively large, and the project investment is close to the investment in a new three-monomer production plant

[0014] The disadvantages are: (1) Since the three-monomer wastewater contains more than a dozen organic substances with different structures and properties, in the resin adsorption process, it is very likely to cause resin deactivation, decrease in resin adsorption, poor adsorption effect, and poor adsorption efficiency. Low consequences; (2), resin adsorption operation, the process parameters obtained on the basis of the small test, when the industrial device is running, the amplification effect is more prominent, and the industrial production time is dimethyl phthalate-5-sodium sulfonate and its Homolog crude product, Na 2 SO 4 10H 2 O The yield is greatly affected; (3), the project investment is large, and refrigeration is required to reduce the cooling crystallization and precipitation temperature of the three monomers, and the high energy consumption leads to high operating costs

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