Status and Development of Manufacturing Technology of Several Fine Chemical Intermediates Zhangmu Shanghai Dyestuff Co., Ltd. pointed out that the breakthrough of intermediate manufacturing technology is the key to the development of my country's fine chemical intermediate industry.
Fine chemicals have the characteristics of strong specialization, intensive technology and high added value, and their proportion in the chemical products of developed countries is increasing. According to statistics, at the beginning of the new century, the fine chemical intermediate industry in developed countries has also developed rapidly.
In the past ten years, with the tightening of regulations in Europe and the United States and the extensive development of the Greenpeace movement in the West, coupled with the fact that there are many synthetic units of intermediates, the yield is not high, the pollution is serious, and the treatment technology is difficult and the treatment cost is high, forcing the European and American countries and other countries. Many intermediate manufacturers have reduced or stopped production. However, Asian countries have relatively low requirements for environmental protection. Some countries also adopt incentive policies for the development of fine chemicals and their corresponding intermediates, which makes intermediate manufacturers in Europe and the United States change their strategies and use their technologies to support some intermediates in Asia. Manufacturers either transfer fine chemicals and intermediates to Asia to establish production bases or sell production technologies to intermediate manufacturers in Asia, thus promoting the development of intermediate industries in Asian countries and making their intermediate prices more and more marketable Competitiveness. Many dyes, organic pigments, pesticides and pharmaceuticals, such as large tonnage intermediates such as o-p-nitrochlorobenzene, nitrotoluene and naphthalene derivatives, have been obtained in the European and American markets due to their good quality and low prices in Asian countries, especially China. established dominant position.
Status of my country's Fine Chemical Intermediates In 1999, the output of various intermediates for fine chemicals in my country exceeded 800,000 tons, of which the output of dye and pigment intermediates was about 420,000 tons, the output of pharmaceutical intermediates was about 40,000 tons, and the output of pesticide intermediates was about 420,000 tons. The output of intermediates is about 34,000 tons, and the output of other intermediates is about 300,000 tons, and the export volume exceeds half of the output. Among the intermediates produced, the variety and quantity of benzene series are the highest, followed by naphthalene series intermediates. Although my country's intermediate industry has formed a certain scale and level, there are also some obvious weaknesses, so that my country's intermediates can only become the first source of users in the international market as a whole. Mainly, there is still a certain gap between the quality of intermediates and products in Europe and the United States, especially the consistency of products, including quality indicators and usability. Therefore, although the price of intermediates in my country is relatively low, many users in the international market still prefer European and American products, which is especially reflected in users who require high-purity products.
The pollution to the environment during the manufacture of intermediates has become more and more serious, and it has become one of the main sources of pollution in my country's fine chemical industry. In the manufacturing process of most intermediates, a large amount of waste gas, waste liquid and waste residue will be produced, and the components are complex, especially the value of waste liquid exceeds tens of thousands, the value of ammonia nitrogen is high, and some also contain nitrophenol compounds, sulfide cyanide, etc. , and some contain cationic organic substances, these waste liquids are difficult to deal with, and the technical requirements for treatment are very high. At present, my country is still lagging behind in the development of fine chemical intermediate wastewater treatment technology.
The variety of intermediates is far from meeting the needs of the market. According to incomplete statistics, there are more than 7,000 intermediates used in various fields of fine chemicals. At present, there are about 400 varieties of intermediates exported by my country, accounting for only 6.0% of the market demand, and some fine chemicals fields such as rubber chemicals and plastic additives are special Intermediates used in paper additives, leather chemicals and electronic chemicals are also controlled in the hands of countries such as Europe and the United States. There are both market and technical reasons.
The more important factors that cause the above problems are the production of manufacturing intermediates in my country, the cleaning process is not widely used, and the production process is mostly manual or semi-mechanized. It is not common, etc., so the yield of the main reaction is not high, and there are also many side reactions and the consequences of not being able to develop some difficult intermediates so far.
Comments on some fine chemical intermediates The following is a detailed analysis of the status quo of intermediate production in my country by commenting on the manufacturing technologies of several important fine chemical intermediates. 3.1 The production of p-aminophenol in the world has grown rapidly at an average annual rate of 5 since 1994. At present, the world's annual production capacity is 150,000 tons, and the annual output is about 120,000 tons. Although some countries in Asia are vigorously developing This intermediate, but the main producing countries in the world are still the United States, France and Germany. Among them, the output of the United States is the largest, and the annual production capacity of a single set of equipment of foreign p-helium-based phenol manufacturers is generally 7,000 to 10,000 tons. Among them, the main manufacturing technologies used are catalytic hydrogenation of nitrobenzene and electrolytic reduction of nitrobenzene. my country has developed p-aminophenol relatively rapidly in the past ten years. At present, there are nearly ten production plants, but the annual output is about 16,500 tons, accounting for only 6,000 tons of world output. Most of the production enterprises in my country and India are still It is produced by the backward reduction technology of p-nitrophenol iron powder, and the product has high cost and large iron content. At present, only two domestic enterprises, Chengde Fertilizer Factory and Qilu Pharmaceutical Co., Ltd., adopt the catalytic hydrogenation method of nitrobenzene to produce, and the output is not large.
Resorcin can be widely used in agricultural dyes, coatings, medicines, plastics, rubber, electronic chemicals and other fields. At present, there are 3 major foreign production enterprises, including 8 60 companies in the United States, Japan's Sumitomo Chemical Company and Well Oil Chemical Company, and Russia also produces. The annual production capacity of these companies reaches 48,000 tons. The only manufacturers in our country are Nanjing chemical manufacturers, with an annual production capacity of 2,000 tons, which cannot meet the needs of the domestic market, and the annual domestic consumption is about 3,000 tons. From the perspective of manufacturing technology, two methods are currently used, one is the benzene sulfonation alkali fusion method, and the other is the meta-cumene oxidation method. These two methods are basically equal in the world, and the future trend is to develop different Propylbenzene oxidation method, and my country currently only uses the synthetic route of benzene sulfonation alkali fusion to produce, and needs to use a large amount of strong acid and strong alkali during production, and the equipment is severely corroded and the environment is polluted.
o-p-Nitrochlorobenzene is currently the largest production and export place of this intermediate in Asia. In particular, my country's products are of good quality and low price, and have achieved a certain position in the European and American markets. At present, the domestic production capacity is about 250,000 tons per year. The main manufacturers are Nanjing Chemical Plant, 50,000 tons per year, Bengbu Chemical Plant, 40,000 tons per year, Henan Kaipu Chemical Company, 20,000 tons per year, Jiangyin Yonglian Group Corporation, 20,000 tons per year The company 2 tons per year and so on. Although the domestic production of o-p-nitrochlorobenzene has reached a considerable scale, the technological level still needs to be improved. Mainly now. 1 Most of the production enterprises in my country still use the traditional mixed acid nitrification process, and few manufacturers use the annular nitrification technology and adiabatic nitrification technology, which not only increases the amount of waste acid treatment but also increases the amount of nitrification; At that time, there were not many automatic controls. Although the Nanjing Chemical Plant has realized computer control of refining and crystallization processes, in order to improve product quality and reduce energy consumption nationwide, computer control must be vigorously used; 3 Isomer ratios The regulation technology is still very backward, the ratio of the output of p-nitrochlorobenzene produced in my country is about 21; 4 The quality and unit consumption of the products are not as good as those of foreign developed countries. In addition, using o-p-nitrochlorobenzene as a raw material can synthesize series of important organic intermediates such as o-chloroaniline-p-aminoaniline 3 chlorine 4 fluoroaniline 3,3 dichlorobenzidine etc., although some have been synthesized in my country, but need to develop There are still many middle and downstream products in my country, which is also the gap between China and foreign countries in the development of o-p-nitrochlorobenzene.
Dichlorinated benzidine is an important intermediate for the production of dichlorobenzidine series organic pigments. The output of organic pigments mainly produced by it accounts for about 25% of the total output of organic pigments. 10,000 tons, the main producing countries are Japan, the United States, South Korea and so on. my country has also developed rapidly in recent years. At present, there are 6 manufacturers with a total annual production capacity of about 3,000 tons. However, the main method of manufacturing this intermediate in my country is the formaldehyde hydrazine hydrate method. Out of about 50, and hydrazine hydrate is expensive and corrosive. At present, the two leading foreign companies are Japan's Kayama Chemical Company and the United States 1; both companies use catalytic hydrogenation. Although my country has also successfully developed a catalytic hydrogenation method using palladium-carbon as the main catalyst and quinone compounds as co-catalysts The hydrogenation reduction technology route has not been able to start normally, and it cannot be said that there is a mature industrialization technology.
Para-aminoaniline can be used in industries such as rubber products, dyes, textile printing and pharmaceuticals. In 2000, my country's p-aminoaniline production capacity has reached about 24,000 tons, with an annual output of about 17,000 tons, and some enterprises are building new devices, but at present, most manufacturers in my country are using the formanilide method for production. The reaction conditions are mild and the equipment requirements are low, but the waste pollution is serious and the product quality is unstable. Therefore, foreign developed countries basically do not use the formanilide method for production, but adopt the advanced aniline technology route, and its technological process is simple. The reaction conditions are mild and the energy consumption is small. The production cost is low; in recent years, a new nitrobenzene method has been developed abroad, and almost no waste is produced, but the production technical conditions are relatively high. Although Tongling Xinda Company in Anhui Province has also developed this new method, it has not yet been industrialized.
M-aminophenol can be used as a raw material for functional dyes, and has a good development prospect. At present, foreign developed countries mainly use the advanced resorcinol ammoniation method for production, while my country still uses the traditional benzene sulfonation alkali fusion technology for production, and the yield is low and the environmental pollution is serious. This limits the consumption and development of meta-aminophenols.
080 acid chemical name 4, 4 amino styrene 2, 2 sulfonic acid is used in the manufacture of fluorescent whitening agents and dyes. In 1999, Yuan Chemical Plant, Botou City, Hebei Province, Dye Chemical Plant, Henan Anyang Yingdi Chemical Company, etc., all used p-nitrotoluene-o-sulfonic acid as the raw material for air oxidation and then reduction production technology. The total yield is in Around 70, this process has been used internationally for more than 60 years. The disadvantage is that the pollution is serious and the product quality is also questioned. In recent years, foreign countries have successively developed the step-oxidation method, the yield can be increased to 84, and the solvent method cleaning process, and the total yield has reached about 90. Although my country is also studying it, there is not much industrialization.
The chemical name of jasmine aldehyde is 3,4 methyleneoxy formaldehyde. Many high value-added products can be synthesized in the industry. my country is one of the major countries producing this intermediate in the world, with an annual production capacity of about 500 tons, which are mainly sold to European and American markets. Taking safrole as the starting material for production is a kind of semi-synthetic route. With the increasing strengthening of ecological environmental protection, the available natural resources are less and less, and the production and operation are greatly restricted by the raw material market. Foreign countries have adopted the full chemical synthesis route using o-phenol as raw material. Although my country already has mature o-phenol synthesis technology, and basically has the technology to build a 10,000-ton-scale o-phenol industrial plant, at present, o-phenol is used as raw material to synthesize jasmine jasmine. The technical route of aldehyde has not been successfully developed, nor has it been industrialized.
The development trend of fine chemical intermediate manufacturing technology At present, there is still a big gap between my country's intermediate industrial manufacturing technology and developed countries such as Europe and the United States. If my country wants to progress and develop the intermediate industry, it must make breakthroughs in intermediate manufacturing technology, vigorously Various new green technologies have been developed, which can not only produce high-quality products, but also greatly reduce the waste generated in the manufacturing process, optimize the environment and protect the ecology. At present, 4.1 catalysis technology is typical in green manufacturing technology. This technology is used in hydrogenation reaction, alkylation reaction, hydrodehalogenation reaction, ammoniation reaction, isomerization, trans-ketone deacylation reaction and directional chlorination reaction, etc. There are many kinds of catalysts, the important ones are the precious metal catalysts distributed on the carrier, the precious metals are rhodium ruthenium such as gold+silver 8 iridium rhenium etc., the carrier has alumina silicon oxide activated carbon and titanium oxide etc.; 2 Metal catalysts, including nickel, cation, copper, copper, chromium, 1 cobalt, etc.; 3 are complex catalysts, and various organic complex compounds composed of ruthenium, gold, silver, iridium, rhenium, etc. are used; 4. There are 5 precious metal compounds such as various carbon black oxides, various chlorides and oxides composed of platinum palladium rhodium ruthenium gold silver iridium rhenium, etc.; 6 phase transfer catalysts, there are crown ether polyol quaternary ammonium salt compounds, etc.; 7 Molecular sieves; 8 enzyme catalysts, such as oxidoreductase synthase lyase isomerase and hydrolase, etc.
High-yield and low-pollution technologies use more sulfur oxide sulfonation technology, continuous nitration technology, solvent reaction technology, step reaction technology, etc.
Natural processing techniques such as photochemistry or biosynthesis.
Reactions that take place from harmless and recyclable raw materials.
These green technologies are not widely used in the manufacture of intermediates in my country. Once they are widely used in the manufacture of intermediates, my country's intermediates are one of the most important synthetic fragrances in the world, and at the same time, the intermediates industry will make a new leap. .
