Musk is known as the king of spice. The musk aroma is pure, rich and fragrant lasting. It is the leader in spice family. At present, annual output of the world's synthetic musk fragrances has exceeded 10,000 tons. Among them, there are 3000-4000 tons belonging to high-end macrocyclic musk. The musk-T macrocyclic belong to the main musk varieties with the annual output of 1,000 tons. In fine fragrances or high-end cosmetics, flavor, simply adding 1% of the musk-T amount, it has a noticeable effect. It is visibly a raw material with very wide application.

In 1960s, industrial production of musk-T began. Because it is based on tridecane acid synthesis as the starting material, the musk of the product name as the musk-T. Most of musk deer grow in the Kunlun Mountains and the Kunlun Mountains musk is most pure. So it is named for Kunlun musk.

Musk R-1 use tridecane acid and ethylene glycol polycondensation, high temperature solution poly cyclization method in preparation. Esterification polymerization tridecane acid and ethylene glycol heating the polymerization reaction, Determination of the polyester of acid value and ester value to determine the end of the reaction. However, the polymerization is to regulate polymerization, both must be controlled to a certain degree of polymerization, the polymerization reaction is generally believed to control 50 or less polymerization degree is appropriate. The polyester polymerization through the large, the performance of the viscosity is too high, is not conducive to the depolymerization process of heat transfer.

Synthetic musk-T polyester depolymerization process is the most complex technical problems. Need to address the following three issues; select efficient catalyst, the optimum conditions of the depolymerization reaction to solve the problem of good heat transfer and mixing device of the reactor engineering.

The musk-T synthesis route, the undecylenate law and erucic acid oxidation due to the longer reaction route, the total yield is low, the cost is the highest, most not suitable for industrial production. Alkanes by microbial fermentation of raw materials and easy to get the most simple process, the conversion rate is also high, but it must be completely resolved and alkane raw materials lead citrate and the purity of the product in order to ultimately ensure the quality of the musk-T. In the esterification of the polymerization process, the current Chinese production unit of acid value and ester value only as a reaction control indicators, the lack of determination and control the means and methods of the degree of polymerization should be strengthened the best relationship between the degree of polymerization and depolymerization in the future.

Solving the heat transfer and mixing from the point of view of physical chemistry and chemical engineering, designing the reactor that meets the requirements of the production process, now become a key issue in industrial-scale production of musk-T. Further strengthen in-depth study of the reaction mechanism and reaction kinetics is necessary. The study of reaction kinetics is just not so deep and reactor design is just based on the old experience. Therefore, in-depth study of the reaction kinetics is still a research topic.Source: