Views: 8 Author: Site Editor Publish Time: 2021-10-26 Origin: Site
Molecular distillation technology can be used for the separation of hydrocarbons, crude oil and the like in the fine chemical industry; the purification of surfactants and the preparation of chemical intermediates; the deodorization and decolorization of lanolin and its derivatives; plastic plasticizers and stabilizers Refining agent and refining silicone oil, paraffin oil, and high-grade lubricating oil, etc. In the separation of natural products, many aromatic oils are refined and purified by molecular distillation to obtain high-quality essential oils.
1. Purification of aromatic oil
With the rapid development of daily chemical, light industry, pharmaceutical and other industries and foreign trade, the demand for natural essential oils continues to increase. Essential oils come from aromatic plants. The methods for extracting essential oils from aromatic plants include steam distillation, extraction, squeezing and adsorption. The main components of essential oils are mostly aldehydes, ketones, and alcohols. And most of them are terpenoids. These compounds have high boiling points and are heat-sensitive substances, which are very unstable when heated. Therefore, in the traditional distillation process, the molecular structure will change due to long-term heating and the quality of the oil will decrease.
Molecular distillation technology is an effective method to purify essential oils. It can concentrate a certain main component in aromatic oils, remove odors and colored impurities, and improve its purity. Because this process is carried out under high vacuum and low temperature, the heating time of the material is extremely short, so the quality of essential oils is guaranteed, especially for aromatic oils with high boiling point and heat-sensitive ingredients, which shows its superiority.
In addition, the use of molecular distillation technology to separate the citral in the ginger fruit oil can obtain a product with w (citral) = 95% and a yield of 53%; in the separation of the effective components of dried ginger, by adjusting the different distillation temperature and The degree of vacuum can obtain different types of active ingredients and their relative content, and the appropriate distillation temperature and vacuum can be adjusted to obtain a relatively high content of active ingredients.
2. Purification of polymer intermediates
In the process of synthesizing polymers from monomers, there will always be excess monomer substances and some unwanted small molecule polymers will be produced. These impurities seriously affect the quality of the product. The traditional method of removing monomers and small molecule polymers is vacuum distillation, which has a higher operating temperature. Because polymers are generally heat-sensitive substances, the high temperature makes the polymers easy to disproportionate, condense or decompose. For example, to purify the dimer in the polyamide resin, the conventional distillation method can only make w (dimer polyamide resin) = 75% to 87%, and the molecular distillation technology can make w (dimer polymerization). Amide resin)=90%～95%. In the purification of phenolic resin and polyurethane, molecular distillation can be used to remove the monomer phenol content in the phenolic resin to w (monomer phenol) <; 0.01%, so that w (diisocyanate monomer) < ; 0.1%. Molecular distillation technology can excellently protect the quality of polymer products, improve product purity, simplify the process, and reduce costs.
3. Extraction of lanolin
Lanolin and its derivatives are widely used in cosmetics. Lanolin has a complex composition, mainly containing esters, free alcohols, free acids and hydrocarbons. These components have relatively large molecular weights, high boiling points, and heat sensitivity. The components are separated by molecular distillation technology, and the different components are modified by physical and chemical methods to obtain polyoxyethylene lanolin, acetyl lanolin, lanolin, isopropyl ester and wool polyoxyethylene resin with excellent properties. Lanolin series products.
