Abstract: Introduce the difference between the molecule distillation technology and the traditional distillation, expound the application characteristics of this technology, especially illuminate the application in fine chemistry using the examples. And introducing the development status of the technology in our country.

    　 When the mixed liquid flow down along the heating board, after heated the light and heavy molecules transgress towards gas, because of the different freedom of the light and heavy molecules, the freedom of the light molecule is big which can reach the cold board and flow down along the cold board after cold down. Freedom of the heavy molecules is small which can't reach the cold board, saturate in the gas, return to the liquid, flow down along the heating board. So the distributary and abruption of the light and heavy molecules.

    　Molecule distillation possesses the characteristics of high vacuum degree, short heating time, high abruption degree, so it is adapt to the abruption of the materials with high boiling point, heating sensitivity and easy oxidation.

The difference between the traditional distillation and the molecule distillation is shown in the following chart: 

Through compare with the traditional distillation above, the molecule distillation possesses the obvious technology and

economy advantage: 

      1. The product quality is high. Because of low operating temperature, short heating time, the product with high purity and high

quality can be obtained, which is important to the natural material.

  　2. The cost is low. Because the abruption of the molecule distillation is high and the obtain rate is high, the production cost

will be cut down dramatically.

Second： The application characteristics of the molecule distillation technology

From the theory and characteristics of the molecule distillation, the molecule distillation possesses the special and many

advantage.

  1. The light molecule materials in the heat sensitivity can be doffed easily.

             (1). Doffing the effluvium of the products

              Example 1. Doffing the effluvium from ginger oil.

crude ginger oil----pellicle evaporator----doffing gas----molecule distillation ---- doffing effluvium ----product1, remain----molecule

distillation---doffing color --- product2, remains.

    (2). Doffing production materials

            Example 2. doff cayenne red pigment

cayenne red pigment crude oil--film evaporator---doff ---solvent---remains ---Molecule Distillation---- doff under low temperature

----solvent (little) remains (products)

    (3). Doffing monomer from products material

            Example 3. Doffing the monomer hydroxybenzene from hydroxybenzene aldehyde colophony

Crude hydroxybenzene aldehyde colophony----film evaporator ---doff air --

Molecule Distillation--doff monomer---monomer hydroxybenzene and double hydroxybenzene ---colophony　

    2. Doffing the heavy material and color from the products

       There are some heavy molecule materials, even metal hydronium which is very difficult to distillation in the fine chemistry.

        The molecule distillation supply the efficient method.

        Example 4. Lactic acid refine.

Lactic acid crude product ---film evaporator ---doff air ---molecule distillation ---doff protein, metal hydronium, color,---protein,

metal hydronium--- refined lactic acid　

Others for instance the refine and decolor of the sub-oil acid, second assemble acid, erucamide, stearamide monomer ester, is

also need to use the molecule distillation technology.

    3. Decrease the heat injure of the heat-agile material

           Example 5. Decolor and concentrate of the fish oil ester

           Compared with the traditional kettle distillation, the advantage of the molecule distillation is very obvious:

 
    4. Improve the traditional technique, process the clean production

        Example 6. The refine of the fish oil three ester

Crude fish oil---- molecule distillation---- de-acid---fatty acid (byproduct)------ish oil three ester----decolor-----refined fish oil three ester

    Example 7. Reclaim of the deposed lubricant

The traditional technique of doffing the heavy impurity is the vitriol method, which will cause lots of environmental pollution and has been forbidden by the developed countries. While, the molecule distillation technology can prevent the pollution  and change the waste to the treasure.

    5. Optimize the composed techniques of the products and improve the product quality.

            Example 8. Refine of the APG 

With the development of the science, the products of the refine chemistry become more and more, the sort of the product

become more retailed, the purity demand become higher and higher. Molecule distillation technology has play a very important

part.

As the industrial practical proven, molecule distillation can take place of the traditional distillation technology, which can solve

the purifying question of series products besides some products.

     The following is part refine chemical fields and products of the molecule distillation technology application:

    1. Medicine: amino acid, dextrose ramification, terpene ester, composed and natural vitamin (VA, VE, βcarrot)

        2. Pesticide:

        3. Dope: two assemble acid,

        5. Daily chemicals: kinds of grease, wool acid, wool mellow, distiller from the natural plants, proteolysis, antiseptic. 

        6. Plastic assistant: oxidation alkene, 

        7. Surface active: APG, oleic acid 

        8. Mineral oil: composed lubricant, lubricant, olefin oil, tar, asphaltum, reclaim the deposed lubricant.

     Example 1: Production of the hi-pure two assemble acid

      The key of the production of the hi-pure two assemble acid is the purifying techniques. At present, many factories adopt the

vacuum distillation of the purifying of the two assemble acid, which has the disadvantage of high distillation, long heating time,

and low abruption rate. The color of the product is bad, purity is low, monomer acid contain is high and the purity only reach 70～

75%.
    
    The technique process is following: 

oil acid---activator----aggregation----two assemble acid mixture ----filtrate --activator impurity -----molecule distillation----monomer

acid----- 80%~85% two assemble acid-------molecule distillation hi-pure two assemble acid (90%~ 98%)

    Compared with the foreign technology and product quality: 

　　Example 2. The application in the assemble ammonia eater field.

　　The usage of the assemble ammonia eater is very abroad. In recent years, assemble ammonia eater dope is widely used as the top grade dope. But it contain poisonous material, especially the separate prussic acid ester. In our country, separate prussic acid ester used in the assemble ammonia eater dope is often the TDI.

　　The crude separate prussic acid ester contain about 5～10% monomer, the traditional processing method is the simple vacuum distillation. The monomer in the product can only reach 2～3%, but if adopt the molecule distillation, the contain of the monomer in the product can decrease under 0.5%.

　　The following is the technique process: 

crude separate prussic acid ester (5~10% monomer)------molecule distillation -----doff the monomer----- crude separate prussic

acid ester (<0.5%)

　　Cooperating with a factory of home, Beijing University of Chemical Technology has established the industrialized product line, which has solved series problems in the technology and produce eligible product.

Forth. The discovery situation of the molecule distillation technology home and abroad.

　　The 1930s to 1960s is the researching time of the molecule distillation technology. To the end of the 1960s, Germany, Japan, England, American and Russia have many big industrialized equipments launched into the industrialized application. But because of the lagged correlated technology, the technology and equipments of the molecule distillation is not complete enough in whole. For instance, the abruption efficiency of the molecule distillation evaporator has space to improve, the technology of airproof and vacuum need improving, the applying field also need to develop, the cost need decreasing. All of this is the orient of the subsequent researchers. During more than 50 years since the 1960s, the researcher of all the countries paid attention to the research in the field and the new patents and literature appeared continually. Meanwhile, some special technology companies engaging in the development and production of the  molecule distillation evaporator appeared, which make the industrial application of the molecule distillation technology improve further.

   　 At present, the product purified and detached by the molecule distillation technology used by the world countries has reached more than 150 kinds. Especially for the abruption of some difficult material, the technology has shown its perfect effect.

    　The research of the molecule distillation technology in our country is later, in the middle of the last century, the home literature and patents report have appeared. In the end of the 1980s, we have imported the foreign product line, which has played a promotion part in the industrial extend of the technology of our country.

　　In recent years, many universities and research units have developed the molecule distillation technology widely.

Beijing University of Chemical Technology has processed the research of the molecule distillation technology since the early 1990s and has established the experiments research base, testing base and industrial base, whose research emphases are on three aspects: first, the research of the molecule distillation theory; second, research of the equipments structure and setting system capability; third, research of the industrial application. So far, more than 60 kinds of new products have been developed. The industrial production of the refined fish oil, natural VE, α—flax acid and so on products with the molecule distillation technology have been accomplished successively. About 40 units molecule distillation production equipments have established, where covered 15 provinces and cities. All the products have filled the national blank, some of which have reached the advanced even the leading level.

　　The special research in Beijing University of Chemical Technology is making the product techniques combined with the molecule distillation equipments structure design. According to the experience of tens of big industrial equipments, the techniques and equipments design software with independent knowledge property right have been established. At present, kinds specification of big industrial equipments can be researched, developed, designed and produced independently. Herein the above, Beijing University of Chemical Technology "molecule distillation technology and industrialized application" project, in 1997 passed the appraisal of the Chemical Ministry; in 1998, obtained the first award of technology progress of the Chemical bureau; in the same year ranked the "national scientific fruit spread plan" project by the Scientific Technology Ministry; in 2001, obtained the second award of technology progress; in 2003, obtained the first award of Beijing Golden Bridge Project.

　　The molecule distillation technology in our country has reached the world advanced level. In the industrialized application especially the refine chemical products, it has been used widely. Believe that this technology will play more great promotion parts in the development of the refine chemical products.