In the early days, domestic cyclohexanone was only an intermediate product of caprolactam, and the cyclohexanone production capacity of the manufacturer matched that of caprolactam plant, and only a small amount of commercial cyclohexanone was supplied to the market. There are two main reasons for the growth and development of cyclohexanone as an independent industry. First, cyclohexanone, as a high-grade organic solvent, has been widely used in coatings, inks, adhesives and other industries, forming a larger commodity market. Second, there are some problems in the scale, technology, product quality and production cost of caprolactam in China, which leads to many difficulties in the domestic caprolactam plant. At present, except for caprolactam of Juhua Company, all other manufacturers only produce cyclohexanone. Many factories have successively expanded the production capacity of cyclohexanone plants, expanded the commodity volume of cyclohexanone, and formed a considerable scale industry, becoming a bulk petrochemical product.
Production technology and development progress of cyclohexanone
2. Traditional production process of1cyclohexanone
There are two main industrial production processes of cyclohexanone in the world: cyclohexane liquid phase oxidation and phenol hydrogenation. At present, more than 90% of cyclohexanone is produced by liquid phase oxidation of cyclohexane.
Liquid phase oxidation of (1) cyclohexane
At present, there are two oxidation processes for cyclohexane liquid phase oxidation in industrial production, one is catalytic oxidation process, and the other is non-catalytic oxidation process. Catalytic oxidation mainly uses cobalt salt, boric acid or metaboric acid as catalyst.
Cobalt naphthenate is generally used as catalyst for catalytic oxidation of cobalt salt, and cyclohexane reacts with air under the catalysis of cobalt salt. In this process, cyclohexane reacts with oxygen through free radicals to produce cyclohexyl hydrogen peroxide, and then the peroxide is decomposed by heat under the action of catalyst to produce cyclohexanone and cyclohexanol. The cyclohexane conversion rate is about 5%, the residence time is less than 50min, the temperature is about 160℃, the pressure is about 1. 1MPa, the residence time is short, the equipment requirements are low, the utilization rate is high, and the selectivity of cyclohexanol and cyclohexanone is about 80%. However, the carboxylic acid produced in this reaction process easily reacts with the catalyst to generate cobalt carboxylate, which remains in the catalyst.
Catalytic oxidation of boric acid is air oxidation of cyclohexane with boric acid or metaboric acid as catalyst, which can improve the conversion rate of cyclohexane and the selectivity of alcohol and ketone. In the oxidation process, boric acid reacts with cyclohexyl hydrogen peroxide to generate cyclohexanol perborate, and then it is converted into cyclohexanol borate. Boric acid can also directly react with cyclohexanol to form cyclohexanol borate and cyclohexanol metaborate. After esterification of cyclohexanol, it has oxidation resistance and thermal stability to prevent further oxidation. Catalytic oxidation of boric acid can increase the conversion of cyclohexane to 10% ~ 12%, and the selectivity of alcohol and ketone to 90%. The oxidation reaction temperature of boric acid is 165 ~ 170℃, the pressure is 0.9 ~ 1.2 LMPA, and the reaction time is 120 minutes. Boric acid oxidation method adds hydrolysis process and boric acid recovery process. In the process of hydrolysis, cyclohexanol borate is decomposed into cyclohexanol and boric acid to form two phases, and boric acid remains in the water phase. After the two phases are separated, the water phase is sent to the boric acid recovery process to crystallize boric acid, which is then converted into metaboric acid by heat treatment and recycled in the oxidation reaction. The reaction product of boric acid oxidation is very complex, and the organic phase after hydrolysis must be further treated to remove impurities, which is complicated and gradually neglected.
Non-catalytic oxidation was first developed by Rhone-Perlin Company in France. Its characteristic is that the reaction is carried out in two steps. The first step is that cyclohexane is directly oxidized to cyclohexyl hydrogen peroxide by air at 160 ~ 170℃, and the second step is that cyclohexyl hydrogen peroxide is decomposed into cyclohexanol and cyclohexanone under alkaline conditions and under the action of catalyst. The advantages of this process are that the reaction is carried out step by step, and no catalyst is used in the oxidation stage, thus avoiding the slagging problem of the oxidation reactor, enabling the device to run continuously under the conditions allowed by the equipment, and the yield of cyclohexyl hydrogen peroxide in the oxidation process can reach over 95%. Its disadvantage is that the selectivity of cyclohexanol and cyclohexanone in the decomposition process of cyclohexyl hydrogen peroxide is only below 88%, and a lot of alkali is needed. Due to the low single-pass conversion rate of cyclohexane, long process flow and high energy consumption.
(2) Phenol hydrogenation method
The process of synthesizing cyclohexanone from phenol is the earliest one used in industrial production of cyclohexanone. The early stage of the process is divided into two steps: the first step is the hydrogenation of phenol to cyclohexanol, and the second step is the dehydrogenation of cyclohexanol to cyclohexanone. In 1970s, a new process for synthesizing cyclohexanone by one-step hydrogenation was successfully developed. One-step hydrogenation of phenol has two ways: gas phase and liquid phase. Gas phase method is mainly used in industry. The process uses 3 ~ 5 reactors in series, the temperature is 140 ~ 170℃ and the pressure is 0. 1MPa. The reaction is complete and the yield can reach 95%. Cyclohexanone produced by phenol hydrogenation method has good quality and high safety, but the application of this process is greatly limited because of the high price of phenol and the use of precious metal catalysts, which makes the production cost of cyclohexanone higher.
2.2 Improvement of existing technology
In view of the shortcomings of cyclohexanone production technology mentioned above, many production enterprises and research departments have improved cyclohexanone production technology in many aspects.
(1) Extend the driving cycle. The advantages of cobalt salt method are mild reaction conditions, low temperature, low pressure, short residence time and low requirements for equipment. The biggest problem of cobalt salt method is that cobalt carboxylate generated in the reaction process remains on equipment and pipelines, and slagging blocks pipelines and valves. To solve this problem, many countries have done a lot of research. In the process, unreacted cyclohexane after oxidation is separated and recovered, and the water before oxidation is removed by boiling distillation to avoid slagging in the reactor. Regarding the reactor, Czechoslovakia patent proposed a horizontal reactor for liquid phase oxidation of cyclohexane, which was divided into several reactors by vertical baffles. Baffles are equipped with horizontal baffles, which are placed on both sides of the gas distributor to strengthen gas-liquid mixing and reduce resin by-product precipitation (slagging), thus prolonging the operation period between two cleanings of the reactor. In terms of catalyst, DuPont Company of the United States uses acid phosphate as cocatalyst, which has the function of coating the wall and makes the oxidation start-up period be 4-6 months. The domestic application of HEDP isooctyl ester, 1989, has not found slagging phenomenon since its implementation in April, and solved the slagging problem of cyclohexane catalytic oxidation.
(2) Improvement of catalytic decomposition technology. The traditional decomposition or low temperature decomposition technology developed by DSM company is carried out under alkaline conditions with cobalt salt as catalyst. The process is characterized by high conversion rate of cyclohexyl hydrogen peroxide, but its disadvantages are obvious. Due to the further condensation of alcohol and ketone in alkaline environment, the yield is reduced and a large amount of waste lye is produced, which brings great difficulties to the subsequent treatment. In the aspect of process improvement, the original one-step alkali addition was changed into two-step alkali addition, the reaction temperature was lowered, and the concentration was adjusted relative to the alkali, which not only reduced the alkali consumption, but also maintained a high yield of alcohol and ketone. In the aspect of catalyst, molecular sieve catalyst can promote the directional decomposition of cyclohexyl hydrogen peroxide, and at the same time, it can greatly reduce the production of waste lye.
(3) Alkane distillation system is controlled by alkali. After the decomposition and separation of waste alkali, a small amount of alkali water is still entrained in the organic phase of crude oxidation products, which enters the alkane distillation system, causing the reboiler to scale, which requires regular shutdown and cleaning. In severe cases, the production cycle is less than half a month. Water washing and oil-water coalescence separation processes are added to the waste alkali separation system, which reduces the alkali to below 5ppm, greatly prolongs the start-up period and reduces the loss of alkanes, alcohols and ketones during shutdown and cleaning.
2.3 Development of new technologies
(1) cyclohexene hydration. In 1980s, Asahi Kasei of Japan developed the process of hydration of cyclohexene to cyclohexanol. In this process, benzene was used as raw material, and cyclohexene was prepared by incomplete hydrogenation under the conditions of 100 ~ 180℃, 3 ~ 10 MPa and ruthenium catalyst. The conversion of benzene is 50% ~ 60%, the selectivity of cyclohexene is 80%, and 20% by-product is cyclohexane. In the presence of high-silica zeolite ZSM-5 catalyst, the process has low energy consumption, effectively avoids the waste lye produced in the process of cyclohexane oxidation, and reduces the pressure on environmental protection, which has obvious prospects.
(2) Bionic catalytic oxidation method. In 1979, Groves and others proposed the simulation system of iodobenzoyl-metalloporphyrin-cyclohexane, and carried out the artificial simulation reaction of cytochrome P-450 monooxygenase, which realized the hydroxylation of alkanes with high selectivity and high conversion rate under mild conditions. In recent years, Hunan University and other institutions in China have conducted a series of studies on the catalytic oxidation of cyclohexane by metalloporphyrin, and put forward the possible mechanism of this oxidation reaction. Continuous experiments show that under the catalysis of iron porphyrin or cobalt porphyrin, the conversion rate of cyclohexane can reach more than 7% and the selectivity of cyclohexanol and cyclohexanone can reach more than 87%, which shows a good application prospect. The advantages of this process are that the reaction temperature and pressure are reduced, the amount of catalyst is small, and it can be dissolved evenly in the reaction solution without separation. At present, the key of this technology lies in the price of catalyst. If it can be industrialized, not only the investment is low, but also the transformation workload is small, and the output of cyclohexanone and the technical and economic level of existing devices can be greatly improved.
(3) metal catalytic oxidation. BASF Company used molybdenum-based catalyst to react at 130 ~ 200℃ and 0.5 ~ 2.5 MPa. The product contains 0.39% cyclohexene, 5.78% cyclohexene oxide, 2.03% cyclohexanone, 9.35% cyclohexanol and 0.9 1% cyclohexyl hydrogen peroxide. UBE Company of Japan used cobalt octoate and N- methylimidazole as catalysts to react at 65438 060℃. The selectivity of cyclohexanol is 60. 1%, the selectivity of cyclohexanone is 22.8%, and the conversion of cyclohexane is 3.9%. Daicel Chemical Industry Co., Ltd. uses the mixture of N- hydroxyphthalimide (NHPI) and cobalt acetylacetonate as catalyst. When the ratio of cyclohexane, N- hydroxyphthalimide mixture and cobalt acetylacetonate is 943: 160:60, the reaction temperature is 160℃, the reaction time is 2h, and the pressure is 4.0MPa, the conversion rate of cyclohexane is 60. ZG-5 zirconium-based composite oxide catalyst developed by Dalian Institute of Chemicals has the advantages of high activity, good selectivity and mild reaction conditions. Under the conditions of 155℃ and 1.09MPa, cyclohexane was directly oxidized by air to form cyclohexanone (alcohol). After 25min, the conversion rate reached 6.4% and the selectivity of cyclohexanone (alcohol) reached 92.8%. When the reaction time is 50 minutes, the conversion rate reaches 14.9% and the selectivity of cyclohexanone (alcohol) reaches 83.6%.
The study of nano-particle metal catalysts shows that these catalysts have high catalytic activity. For example, in the presence of aldehyde initiators, the conversion rate of cyclohexane on nano-iron powder reaches 1 1%, and the selectivity of cyclohexanone (alcohol) reaches 95%; When reacting on metal Co(20nm) 10 ~ 15h, the cyclohexane conversion rate was 4 1% and the selectivity reached 80%, in which the ketone-alcohol ratio of the product was 0.2. On Fe2O3 (8 ~ 10 nm) catalyst, the conversion of cyclohexane was 16.5%, the selectivity was about 90%, and the ratio of ketone to alcohol in the product was 0.4. However, the stability of the catalyst in this technology remains to be solved.
(4) molecular sieve catalytic oxidation method. Ti-Si molecular sieve TS- 1 is one of the most studied molecular sieves at present. Using TS- 1 as catalyst has the following advantages: mild reaction conditions, high yield of oxidation target products, good selectivity, simple technological process and environmental friendliness. However, the catalyst itself is difficult to synthesize and its activity is unstable. HTS molecular sieve synthesized by petrochemical research institute and other units has solved the problems of difficult repetition of TS- 1 molecular sieve synthesis and unstable reaction activity. The experimental results show that the conversion rate of cyclohexane oxidation to cyclohexanone can reach more than 49%, which has a good research prospect. Brazilian scholar Spinace and others synthesized TS- 1 by hydrothermal method. The conclusion is that cyclohexane is oxidized to cyclohexanol on TS- 1 and then to cyclohexanone. Because of the shape selectivity, cyclohexanol will be further oxidized to cyclohexanone in TS- 1 zeolite cage, and oxidized to various oxides on the outer surface of TS- 1 zeolite cage. By adding 2,6-di-tert-butyl -4- methylphenol, the non-selective oxidation on the outer surface of the catalyst can be effectively inhibited and the selectivity of cyclohexanone can be improved.
3 China cyclohexanone production status
Cyclohexanone in China developed with the development of caprolactam industry. At that time, the production technology of caprolactam changed from phenol route to cyclohexane route. Cyclohexanone industry has only developed into an independent industry. In the early days, cyclohexanone was only an intermediate product of caprolactam and polyamide 66, and the products of various manufacturers were mainly for personal use, which did not form a commercial volume. With the adjustment of caprolactam product structure and the expansion of non-amide application field, a considerable commodity volume and cyclohexanone industry have been formed. In 2002, China's cyclohexanone production capacity was about 300,000 tons and 260,000 tons, of which 200,000 tons were used by manufacturers to produce caprolactam or polyamide 660, and about 40,000-60,000 tons were market commodities. Together with the annual import of about 40,000 tons, the performance demand of cyclohexanone in China is about 300,000 tons, and the commodity volume is about 654.38+10,000 tons. Although some of them are imported, production and sales are generally in balance.
Cyclohexanone production in China is mainly concentrated in nine manufacturers, among which there are six enterprises with the scale of 30,000-70,000 tons/year and above, namely Nanjing DSM Company, Baling Branch, Baling Petrochemical Co., Ltd., Liaoyang Petrochemical Company, China Shenma Group Nylon 66 Salt Company and Juhua Group Nylon Factory. The production capacity of these six enterprises reached 265,000 tons, accounting for more than 90% of the national total production capacity. Among them, Liaoyang Chemical Fiber and Shenma Group are both used to produce adipic acid, and Baling Branch and Nanjing DSM Company are imported devices, with caprolactam production capacity of 80,000 tons/year and 65,000 tons/year respectively, and supporting cyclohexanone production capacity of 70,000 tons/year and 55,000 tons/year respectively; The rest are domestic devices, among which the cyclohexanone devices of Baling Petrochemical Company and Juhua Nylon Factory have reached the advanced technology level abroad on the basis of digesting and absorbing advanced technologies at home and abroad. The other three companies are Taiyuan Chemical Plant, Jinxi Chemical General Factory and Shandong Tianyuan Chemical Company, and their production scale is below 6,543,800 tons/year. See table 1 for the main domestic manufacturers of cyclohexanone. Table 2 lists the production situation of some manufacturers in recent years.
Table 1 List of Major Domestic Cyclohexanone Production Enterprises (unit: 10,000 tons)
Enterprise name cyclohexanone production capacity reserve note
Packaging Branch 7 for Personal Use
Nanjing DSM Company 5.5 Personal Use
Baling Petrochemical Co., Ltd. 4.5 Commodity Quantity
4.5 Liaoyang Petrochemical Company's own use
China Shenma Group Nylon 66 Salt Company 3 for personal use.
Juhua Group Nylon Factory Part III Commodity Quantity
0.7 Part of Commodity Quantity of Taiyuan Chemical Plant
Jinxi Chemical General Factory 0.6 Commodity Quantity
Shandong Tianyuan Chemical Company 0.65 Commodity Quantity
Table 2 Production status of some manufacturers in recent years (unit: ton)
Manufacturer1999 2000 20012002 2003
Baling Branch 51346 58639 6195 69030 64001
Nanjing DSM 42774 51540 53488 55118 52331.
Baling Petrochemical Co., Ltd. 2830734010 38059 45280 45000
Chrysanthemum1103211506111/kloc-0.
(Data comes from statistics of various manufacturers)
Cyclohexanone in China cannot meet the domestic market demand, so it needs to be imported from abroad every year. Especially from 1996 to 2000, the annual import growth rate was above 20%, and from 2000 to 2002, the import volume gradually stabilized at about 40,000 tons per year (the import situation of cyclohexanone and methyl cyclohexanone in recent years is shown in Table 3).
Table 3 Import situation of cyclohexanone and methyl cyclohexanone in recent years (unit: ton)
Year1996199719981999 2000 2006 5438+0 2002.
Import volume1657015953 21203 34722 44558 43120 45825.
In recent years, the demand for cyclohexanone in China has been expanding. In order to develop, enterprises consider adopting advanced technology to expand production capacity, so as to achieve economic scale and improve the economic benefits of enterprises. See Table 4 for the proposed and under construction projects in China. If all the above projects are implemented, the cyclohexanone production capacity in China will increase substantially, reaching about 350,000 tons/year, which can fully meet the domestic cyclohexanone market demand.
Table 4 Cyclohexanone projects under construction and planning in China recently
(Unit: 10,000 tons/year)
Description of the capacity reached by the enterprise name
Sichuan Weiyuan Jianye Company 1 newly established, 65438+established in February 2003.
put into production
Shandong Tianyuan chemical company 2 expansion, commodity volume
Juhua No.4 Company has been expanded and put into production.
The seventh phase expansion of Baling Petrochemical Co., Ltd. is under implementation.
Expansion of Taiyuan Chemical Plant 1, under preparation.
4 General situation of cyclohexanone market in China
Cyclohexanone is mainly used as the intermediate of polyamide 6 and polyamide 66, and most of them are produced and used by manufacturers. Cyclohexanone for amide accounts for about 70% of the total consumption of cyclohexanone, and a small part of it enters the market as a commodity, while cyclohexanone for non-amide accounts for 30% of the total consumption of cyclohexanone.
As a monomer of polyamide fiber and engineering plastics, caprolactam is an important polymer raw material. In the international market, the overall supply of caprolactam exceeds demand, and the growth rate is slow, but it is still in the stage of rapid development in Asia (except Japan). In recent years, the import of caprolactam in Asia is about 500,000 ~ 700,000 tons/year, while the import of caprolactam in China in 2003 was 367,000 tons, showing a rapid growth trend. With the development of caprolactam in China, the demand for cyclohexanone will also increase greatly.
In recent years, the domestic cyclohexanone market price is generally at a low point. In 2002, the price of cyclohexanone was at the lowest level since 10, which was mainly affected by the following factors:
(1) Macroeconomy. In 2000, the macroeconomic situation at home and abroad was good, and the demand in the downstream market of caprolactam was strong, which prompted the price of cyclohexanone and caprolactam to rise. In 2002, the world economy was weak, the demand was not strong, and the prices of caprolactam and cyclohexanone fell accordingly.
(2) It is closely related to the caprolactam market. Cyclohexanone is mainly used as raw material for manufacturing caprolactam, mainly because large-scale caprolactam plant is matched with cyclohexanone plant. When the price of caprolactam changes greatly, caprolactam production enterprises will consider the comprehensive economic benefits to determine the commodity quantity of its intermediate product cyclohexanone entering the market, and the change of supply and demand will affect the price of cyclohexanone. In 2000, the price of caprolactam was firm, the domestic market price was 1.45 million yuan/ton, and cyclohexanone also looked good, basically at 1.05 million yuan/ton; However, from 200 1 to the end of 2002, the price of caprolactam dropped sharply, with the lowest price of only about 9,000 yuan/ton, and the price of cyclohexanone was only about 6,000 yuan/ton.
(3) The price of petroleum benzene. Petroleum benzene is the most important factor in the cost of cyclohexanone, and its cost accounts for about 60% of the cost of cyclohexanone. From the historical price analysis of petroleum benzene and cyclohexanone, there is a high positive correlation between the two prices. The market trend of cyclohexanone is very similar to petroleum benzene. Judging from the market situation in recent years, the fluctuation range of cyclohexanone market price is basically 2 ~ 2.5 times that of petroleum benzene, which maintains a certain profit margin, but it must be noted that the coefficient is decreasing year by year, indicating that the profit margin of cyclohexanone is shrinking year by year; There is an obvious time difference between the prices of cyclohexanone and petroleum benzene. Generally speaking, the price change of cyclohexanone often lags behind the price of petroleum benzene by about 1 ~ 3 months.
(4) Import volume. In recent years, with the rapid growth of cyclohexanone demand, the import volume has also increased significantly. The cyclohexanone plant abroad is equipped with caprolactam, which has a large scale, high technical level and certain price advantage.
Recently, the domestic market of cyclohexanone mainly declined slowly, and the price dropped from the previous 9400 yuan/ton to about 9000 yuan/ton. The main reason for the decline in domestic prices may be that domestic users resist high prices and downstream users are not active in purchasing. However, the reason for the slow price decline may be that the international price of pure benzene is still at a high level, around 550 US dollars/ton, and the domestic transaction price is also at the level of 5,500 yuan/ton, so the production cost of cyclohexanone remains at a high level.
In short, the domestic market demand for cyclohexanone will continue to grow steadily. However, the excessive expansion of the plant, the large increase of cyclohexanone imports, the small increase of exports and the recent uncertainty of petroleum benzene will lead to drastic fluctuations in the domestic cyclohexanone market and increasingly fierce competition, and commercial cyclohexanone will change from a profitable product to a meager profit or even a loss-making product.
5 Overview of downstream product development of cyclohexanone
70% of the total domestic consumption of cyclohexanone is used for caprolactam, and 30% is used for other purposes. Among them, organic solvents are the second largest field of cyclohexanone consumption in China. In addition, cyclohexanone is used to produce cyclohexanone formaldehyde resin and other fine chemical products, but the dosage is very small and needs further development.
Cyclohexanone is an excellent medium and high boiling point organic solvent with high solubility and low volatility. It can well dissolve polymers, including homopolymers and polymers of vinyl chloride, polyvinyl acetate, polyurethane, polymethacrylate, nitrocellulose, cellulose and ABS. Cyclohexanone is also an inert modifying solvent, which is used in polystyrene, phenol and alkyd resin, acrylic resin, natural resin, natural rubber, synthetic rubber, chlorinated rubber, wax and oxidized oil. When cyclohexanone is used as coating solvent, it has good spraying and brushing properties, which can improve the surface protection of the coating and improve the gloss of the coating. Cyclohexanone can also be used as solvent for screen printing ink, solvent for coating photosensitive materials, degreasing agent, polishing agent and coating diluent in leather industry. In pesticide industry, cyclohexanone is used to prepare spray insecticide, aerosol and emulsion in water; Cyclohexanone is also used for magnetic oxide coating of computer disks, audio tapes, copper wire coating, wallpaper pasting and so on.
Cyclohexanone can be used as a raw material for polymer production, which can be used to produce cyclohexanone formaldehyde resin, porphyrin resin, aromatic polyamine solid resin, dimer and so on. Compared with similar resins, cyclohexanone formaldehyde resin has the advantages of high hardness, good weather resistance and oxidation resistance, low viscosity and high gloss, and can be mixed with various coating materials. Mainly used as coating resin, widely used in paints such as oily resin, alkyd resin, amino resin, acrylic resin, epoxy resin, chlorinated rubber, etc., and also used as dispersant and brightener for ink and ballpoint pen oil. Porphyrin resin has special anticorrosion performance, which can resist acid corrosion and organic matter dissolution well. Can be used as an anticorrosive coating. The dimer formed by catalytic dehydration of cyclohexanone is a good solvent for carbamate pesticides, a modifier for epoxy resin, a polymer adhesive, a film-forming aid for latex paint and a saponifiable plasticizer, and can also be used to synthesize o-phenylphenol.
Cyclohexanone can be used to synthesize many fine chemical products, such as 2,2,6,6-tetrachlorocyclohexanone, epoxycyclohexane, o-chlorocyclohexanone, dodecanedioic acid, cyclohexanone peroxide, ε-caprolactone and cycloheptanone.
Although cyclohexanone production enterprises have done a lot of work in developing cyclohexanone downstream products in recent years, there are not many new uses of cyclohexanone.
6 Development trend of cyclohexanone industry in China
(1) The pattern of domestic supply and demand balance will be broken, and the market competition will become increasingly fierce. In the next few years, the construction of cyclohexanone production facilities will enter a * *, and the production capacity will increase exponentially. Although the market demand can grow steadily, it is difficult for the market to keep up with the development of production capacity. By then, the balance between supply and demand in cyclohexanone market will be broken, and the supply will exceed the demand. Commercial cyclohexanone will change from profitable products to low-profit or even loss-making products, and the market competition will become more and more fierce. This also suggests that those enterprises that want to enter this field have to make careful decisions, especially considering the technical choice of expanding and building new devices from the perspective of improving the core competitiveness of enterprises. There is a big problem in the consumption structure of cyclohexanone in China. Cyclohexanone used for amide abroad accounts for more than 90% of its total consumption, while cyclohexanone used for amide in China is only 70%, which is the biggest difference from cyclohexanone used in other countries. Although cyclohexanone is widely used, China, as the largest shoe leather manufacturing base in the world, still has a big market in this respect, but it lacks stable downstream products, so it will have a huge impact on the cyclohexanone market when the economic turmoil and caprolactam market fluctuate.
(2) The concentration of production has been further improved, and the advantages of economies of scale have emerged. If the new round of expansion projects can be implemented as planned, the cyclohexanone production capacity of Liaoyang Petrochemical Company, Baling Petrochemical Company, Baling Branch, Nanjing DSM Company and Shijiazhuang Refining and Chemical Company will approach or exceed 654.38+10,000 tons/year, forming a large-scale production capacity. Its market share has also been further improved, and the market has been further concentrated. The expanded economies of scale will show advantages. This has caused great pressure to some small-scale production enterprises.
(3) The increase of cyclohexanone import will impact the domestic market. Worldwide, large companies such as DSM Group in the Netherlands, Asahi Kasei Company in Japan, Germany and Taiwan Province Province in China have large-scale cyclohexanone production, and are still expanding their production capacity, some of which are aimed at the expansion of the China market. These large companies have obvious economies of scale and low cost advantages. If the import of cyclohexanone will maintain a high growth rate, it will inevitably have a great impact on the domestic cyclohexanone market and may repeat the mistake of caprolactam dumping. Domestic enterprises have to make plans as early as possible, formulate countermeasures as soon as possible, and maintain the active position of competition.
7 conclusion
Generally speaking, in recent years, the demand for cyclohexanone in China has been increasing, and the market has developed rapidly, which has brought infinite business opportunities to manufacturers and business units. However, with the completion and commissioning of many expanded and newly-built units, the supply of cyclohexanone exceeds demand, cyclohexanone products become bulk petrochemical products with meager profits, and many uncertain factors such as fluctuations in crude oil market bring great risks to cyclohexanone market. For the old cyclohexanone plant, efforts should be made to reach a certain economic scale and improve the technical content to cope with the international competition after China's entry into WTO. If the newly-built cyclohexanone plant wants to have a high starting point, it must have obvious comparative advantage and competitive advantage.