After nearly a hundred years of development, China’s chemical industry has become the world’s fastest growing country, the industrial cycle than Europe, the United States and Japan and South Korea chemical industry cycle is significantly shortened, which in Europe and the United States and other countries need decades to reach the scale stage, China’s chemical industry only a few years has come to an end. The difference is that after the large-scale stage of the chemical industry in Europe and the United States, the number of fine chemical products supported by high-tech has increased sharply, while in China, due to the limited development of technology, the market supply volume of fine chemicals has grown slowly.

Believes that in the next 5-10 years, the large-scale process of China’s chemical industry will end, and the fine development process will accelerate. At present, there are many domestic research institutions, especially those affiliated with leading enterprises, are increasing investment in the research and development of fine chemicals.

For the development direction of China’s fine chemicals, Pingtou Brother summarized the following points, first, the use of low-carbon hydrocarbons as raw materials for deep processing direction research, downstream focused on pharmaceutical intermediates, pesticide intermediates and other fields. Second, for the deep processing and utilization of polycarbon hydrocarbons, the downstream in high-end fine chemical materials, auxiliaries and other fields; Third, for the separation and purification of high-carbon hydrocarbon raw materials and deep processing and utilization, downstream in the fields of surfactants and plasticizers.

From the perspective of cost, the extension of fine chemical industry of low-carbon raw materials is the lowest cost way of production and research at present. At present, a number of scientific research institutions in China are actively extending the research of low carbon hydrocarbons in fine chemicals. The representative products are the fine chemical extension of the isobutylene industry chain and the fine chemical extension of the aniline industry chain.

According to the preliminary investigation , the industrial chain of more than 50 fine chemicals in the downstream of high-purity isobutylene has been extended, and the industrial chain of downstream products has a higher refinement rate. There are more than 60 kinds of fine chemicals downstream of aniline industry chain extension, and many downstream application directions.

At present, aniline is mainly produced by catalytic hydrogenation of nitrobenzene, which is the hydrogenation production of nitric acid, hydrogen and pure benzene as raw materials. It is applied downstream in MDI, rubber auxiliaries, dyes and pharmaceutical intermediates, gasoline additives and other fields. Pure benzene in refining and chemical production enterprises can not be blended with oil products, which promotes the extension and utilization of the downstream industrial chain of pure benzene, and has become the focus of the chemical research and development industry.

According to the different industries used in the downstream products of aniline, it can be roughly divided into the following industries: First, the application in the field of rubber accelerators and antioxidants can be roughly divided into five products, which are p-amino-diphenylamine, hydroquinone, diphenylamine, cyclohexylamine and dicyclohexylamine. Most of these aniline products are used in the field of rubber antioxidants, such as p-amino-diphenylamine can produce antioxidants 4050, 688, 8PPD, 3100D and so on.

In the field of rubber accelerator and antioxidant consumption, aniline downstream in the field of rubber is an important consumption direction, accounting for about 11% of the total downstream consumption of aniline, the main representative products are p-amino-diphenylamine and hydroquinone.

Among the diazo compounds, using aniline and nitrate and other products, the products that can be produced are p-amino-azobenzene hydrochloride, p-hydroxyaniline, p-hydroxyazobenzene, phenylhydrazine, fluorobenzene and so on. These products are widely used in the fields of dyes, pharmaceuticals and pesticide intermediates. The representative products are: p-amino-azobenzene hydrochloride, which is a synthetic azo dye, a hose dye, a disperse dye, and also used in the manufacture of paints and pigments and as an indicator. P-hydroxyaniline is used in the production of sulfur blue FBG, weak acid bright yellow 5G and other dyes, the manufacture of paracetamol, antamine and other drugs, but also used in the production of developers, antioxidants and so on.

According to the investigation , at present, aniline compounds used in China’s dye industry are mostly p-amino-azobenzene hydrochloride and p-hydroxyaniline, accounting for about 1% of the downstream consumption of aniline, which is an important application direction of nitrogen compounds in the downstream of aniline, and is also an important direction of current industry technology research.

Another important downstream application of aniline is the halogenation of aniline, such as the production of p-iodoaniline, o-chloroaniline, 2.4.6-trichloroaniline, n-acetoacetanilide, n-formylaniline, phenylurea, bisphenylurea, phenylthiourea and other products. Due to the large number of aniline halogenation products, it is preliminatively estimated that there are nearly 20 kinds, which has also become an important direction for the extension of the downstream fine chemical industry chain of aniline.

The downstream products using aniline halogenation, such as o-chloraniline, are used for the production of sulfur blue FBG, weak acid bright yellow 5G dyes, the manufacture of paracetamol, antamine and other drugs, but also for the production of developers, antioxidants and so on. Diphenyl thiourea is used in the production of vulcanization accelerators, vulcanization capsules, water tires, wire and cable, as well as medicine and dye intermediates. N-acetoacetanilide is used in the production of sulfonamides, analgesics, antipyretic ice and preservatives, and rubber vulcanization accelerator.

According to the incomplete assessment , the number of aniline halogenated downstream aniline fine chemical products accounts for about 40% of the number of downstream aniline chemicals, but the products are mostly used in high-end fields, and the overall scale is not large. With the vigorous development of the pharmaceutical field, the technical research of aniline halogenation has also become an important development direction of China’s technology research and development.

Another important reaction of aniline is the reduction reaction, such as aniline and hydrogen to produce cyclohexane, aniline and concentrated sulfuric acid and soda ash to produce dicyclohexane, aniline and sulfuric acid and sulfur trioxide to produce p-aminobenzenesulfonic acid. This kind of reaction requires a large number of auxiliary materials, and the number of downstream products is not large, and it is roughly estimated that there are about five products. 

Among them, such as p-aminobenzenesulfonic acid, manufacturing azo dyes, etc., used as reference reagent, experimental reagent and chromatographic analysis reagent, and can also be used as a pesticide to prevent wheat rust disease. Dicyclohexylamine, is the preparation of dye intermediates, as well as the pesticide textile wheat rust, and the preparation of spices.

The reduction reaction conditions of aniline are relatively harsh, and at present, China is mostly concentrated in the laboratory and small-scale production stage, and the consumption proportion is very small, which is not the main direction of the extension of the downstream fine chemical industry chain of aniline.

The use of aniline as raw material of fine chemical industry chain extension, there are arylation reaction, alkylation reaction, oxidation and nitrification reaction, cyclization reaction, aldehyde condensation reaction and complex combination reaction. Aniline can participate in many chemical reactions, and there are many downstream applications. we will continue to conduct a certain analysis of it, please look forward to it.