How to gain of interest from the nanofiltration membrane technology?

How to gain of interest from the nanofiltration membrane technology?

In the current dye production process, the synthetic dye is separated from the aqueous solution through the salting out and the pressure filtration process. The salt introduced by the salting out can reduce the purity of the dye, which seriously affects the product quality. In the production process of water-soluble dyes (such as acid, direct, alkaline, cationic and other dyes), the final product liquid concentration is generally about 10%, and contains a considerable concentration of unreacted raw materials, intermediates, by-products and salts. class. The traditional process is to directly spray and dry the liquid, and the 1kg powder product evaporates about 9kg of water, and the energy consumption is very high.

The nanofiltration membrane separation technology is a pressure separation driving membrane separation process with a pore diameter of 0.002 to 0.005 μm, and effective separation of inorganic salts, small molecules and water having a molecular weight of 200 to 1000. If the technology is applied to dye production, the dye concentration can be increased to about 30%, and the subsequent evaporation energy consumption is reduced to 1/4 of the conventional process, which greatly reduces the salt content and production cost of the product, and improves the production efficiency. The nanofiltration membrane technology treats the dye synthesis aqueous solution as the salt permeates the membrane and the dye molecules are trapped, and the purpose of desalting and dye concentration is achieved by continuous washing.

The desiccant test was carried out on the nanofiltration membrane under the conditions of an average working temperature of 40 °C and a pressure of 44/38 to 105 Pa. After the crude dye slurry passes through the nanofiltration membrane system, the dye concentration is increased from 8% to 10% to 33% to 38%; the inorganic salt concentration is decreased from 6% to 8% to 0.2% to 0.5%, and the salt rejection rate is greater than 98%, the dye loss rate is less than 0.1%. According to the data, not only the salt can be separated in the dye, the dye strength is increased by 112% to 132%, and the dye purity is increased by 88.1%. The filtered water has a color of about 400 times. When the concentration is low after the nanofilm, the specific concentration of the membrane increases, the amount of filtered water gradually decreases, and the desalination effect is good. On the other hand, after c, the salt content increases, the salt content is low, and the desalination effect is greatly reduced. We also got the average operating temperature of Reactive Brilliant Blue KNR. 25 °C, 34μ 27×105 Pa. The results showed that the concentration ratio was 1.5, the strength was increased by 10%, and the purity was increased by 14.7%. It can be concluded that Ne separation technology can be widely applied to dye production and desalination, which not only can improve the economic benefits of enterprises, but also improve product quality.

Large foreign dye factories have used membrane technology to replace the traditional salting-out process to produce reactive dyes and acid dyes. Most of the current research focuses on membrane properties and the like.