Secondly, in the "20021China Chemical Industry (Derivatives) Conference" on April 7th, Dalian Commodity Exchange indicated that it had started the research and demonstration of listing pure benzene futures. After the listing of pure benzene futures, the industrial chain of pure benzene and styrene will be more perfect, which will also help enterprises in the industrial chain to better realize risk management.
one
Brief introduction of pure benzene
Pure benzene belongs to flammable liquid hazardous chemicals, colorless, aromatic, toxic, volatile and flammable. Benzene is insoluble in water, but soluble in organic solvents such as ethanol, ether and chloroform. Pure benzene has a wide range of applications. It is a very important basic chemical raw material and a leading product in aromatic hydrocarbon industry chain. At present, the industrial chain of pure benzene is relatively perfect, and the downstream derivative fields are extremely extensive. The downstream products are mainly styrene, caprolactam, phenol, MDI, adipic acid, aniline, chlorobenzene, nitrobenzene and maleic anhydride, of which the largest downstream product is styrene, accounting for about 39%. Pure benzene can also be used to produce synthetic rubber, plastics, fibers, detergents, dyes, medicines and explosives, and can also be used as a solvent for paints, coatings and pesticides.
two
Production technology of pure benzene
At present, the main production processes of pure benzene in the world are: catalytic reforming of petroleum fractions, co-production of ethylene plants, aromatic hydrocarbon extraction of refinery reforming, toluene disproportionation of p-xylene plants and coal tar extraction. Among them, the top three are petroleum benzene, that is, petroleum routes; The last one is hydrogenated benzene, which is a coal chemical route. Therefore, pure benzene can be divided into petroleum benzene and coking benzene according to different sources, of which petroleum benzene is relatively pure in quality and the purity is above 99%; Coking benzene is extracted when coal is coked, and its purity is less than 96%. Petroleum benzene has fewer impurities than coking benzene and is widely used.
(1) catalytic reforming to produce benzene
The C6-C8 hydrocarbon fractions obtained from petroleum refining are aromatized into aromatic hydrocarbons such as benzene under the action of catalysts such as platinum, and then separated to obtain pure benzene. According to statistics, at present, pure benzene obtained by catalytic reforming accounts for about 38% of all sources in the world. The production of benzene by catalytic reforming is characterized by containing more toluene and p-xylene and less benzene. In the future, with the continuous construction of reforming unit in China Refinery, the processing capacity will also be expanded.
(2) Benzene, a by-product of cracking to produce ethylene.
The by-product pyrolysis gasoline of ethylene plant was separated by catalytic hydrogenation twice to obtain pure benzene. The by-product of pyrolysis gasoline is the second largest source of benzene, and BTX (benzene, toluene and xylene) produced by catalytic reforming oil aromatics and pyrolysis gasoline aromatics accounts for 83. 1% of all aromatic sources. However, from the point of view of subsequent development, in addition to the traditional ethylene cracking process, there is still a part of incremental shift to ethane route, thus limiting the output of pure benzene.
(3) toluene disproportionation
Production of pure benzene by toluene disproportionation and transalkylation. In recent years, China has vigorously developed oil refining projects above 10 million tons, and many projects have been actively promoted. In particular, the refining and chemical projects developed by several traditional polyester enterprises actively allocate PX capacity to ensure the supply of raw materials, and are equipped with toluene disproportionation devices accordingly, so the proportion of pure benzene produced by this process is gradually increasing.
(d) Benzene, a by-product of coal processing
Before 1960s, benzene was mainly produced from coal tar. There are three processing methods of coal: coking, gasification and liquefaction, from which benzene can be obtained. Coking benzene is the general name of pickling benzene, refined benzene and hydrogenated benzene, and its upstream raw material is coking crude benzene. Coking crude benzene is a derivative by-product in the purification process of coke oven gas; Pickled benzene is the product of pickling coking crude benzene with sulfuric acid and then distilling and purifying; Refined benzene is to finish the acid-washed benzene again. The main technological methods are pickling, extraction, adsorption separation and distillation. Hydrogenated benzene refers to high-purity benzene obtained by hydrogenation and extractive distillation of benzene after pickling.
three
General situation of pure benzene industry
(1) General situation of pure benzene industry in China
From the regional distribution of petroleum benzene production capacity, the main domestic petroleum benzene production capacity is concentrated in East China and Northeast China, accounting for about 70% of the total petroleum benzene production capacity, followed by petroleum benzene in South China, accounting for about 1 1%.
From the perspective of pure benzene industry structure, styrene is the largest downstream of pure benzene industry. According to Longzhong Information, in 20021year, the demand of styrene for pure benzene accounted for about 45% of the total domestic demand for pure benzene, caprolactam accounted for 17%, phenol accounted for 14%, aniline accounted for 12%, adipic acid accounted for 7%, and the other 5%.
According to China Customs data, in 2020, the country that imported the most pure benzene from China was 1039 1 12 tons, accounting for 49.53% of the total import. Followed by Thailand's 27049 1 ton, accounting for17.89% of the total imports; Brunei is 154385 tons, accounting for 7.36% of the total imports.
(II) Supply and demand situation of pure benzene industrial chain and production expectation of new devices
From 20 16 to 2020, the domestic pure benzene output and apparent demand will increase year by year. In 2020, the annual output of pure benzene will be about12.6 million tons, an increase of 3.65 million tons compared with 20 17. In 20021year1September, the output of pure benzene was about10.74 million tons, which has reached the level of 20 19.
Although the output of pure benzene is increasing year by year and the import of pure benzene is generally stable, the actual demand for pure benzene in the domestic market is still greater than the apparent demand for pure benzene (apparent demand = output+import-export). According to the total demand of pure benzene in styrene, caprolactam, aniline and phenol industries in 202 1 year mentioned above, it is calculated that the total demand of pure benzene accounts for 88%, and it is 65438+ in 20265438+ year.
In addition, as can be seen from Table 2, from 2065438+06 to 20265438+0, the output of styrene, caprolactam and phenol in the downstream of pure benzene all increased in different degrees, mainly because some industries put new devices into production. There are still a lot of new capacity expectations in the downstream industry of pure benzene, which is dominated by styrene. Although part of pure benzene will be put into production, the overall quantity is smaller than that of its downstream industrial units (as shown in Table 3). It is estimated that the domestic pure benzene supply will remain tight in 2022.
four
Industrial basis of pure benzene
At present, the supply of pure benzene is slightly loose. According to statistics, as of the middle and late of 165438+ 10, there are still more than10 million tons of styrene overhaul device capacity that has not been restarted. However, due to more shutdowns and maintenance of styrene plant, other downstream industries of pure benzene, such as caprolactam and adipic acid, have weakened, and the domestic spot supply of pure benzene is slightly loose. According to the statistics of Longzhong Information165438+122 October, the commercial inventory of pure benzene in East China ports was 14 1 10,000 tons, an increase of 22,000 tons compared with the inventory in the previous cycle10/0.9 million tons, an increase from the previous month. Compared with the same period last year, the inventory of 257,000 tons decreased by116,000 tons, down by 45. 1% year-on-year. At present, the commercial inventory of pure benzene has increased for five consecutive weeks, and the inventory of165438+1October 22nd increased by 84,000 tons compared with 57,000 tons in the middle of1October. And the news shows that a large factory in East China plans to start the fourth atmospheric and vacuum distillation and supporting reorganization during the year, and will continue to follow up the supporting PX. It is expected that the supply of pure benzene will still increase in the future.
The fundamentals of pure benzene have good expectations. During the year, most of the styrene plants overhauled in the early stage will be restarted gradually. In June 5438+February, new styrene plants with an annual output of 650,000 tons in yantai wanhua Chemical Industry and 720,000 tons in Li Huayi will be put into operation. The increase of styrene supply will correspondingly increase the demand for pure benzene, and the increase of pure benzene output of a large-scale plant in East China mentioned above may be less than the demand for pure benzene when styrene is added and restarted. In addition, in terms of import, the profit margin of pure benzene (excluding freight) imported from South Korea is gradually decreasing recently, and it is expected that the import of pure benzene may decrease with time.
The fundamentals of pure benzene are good, but its absolute price may not rise. At present, the price of pure benzene has dropped significantly recently due to the falling price of styrene, and the inventory of pure benzene is gradually increasing. If the fundamentals of pure benzene improve, the absolute price of pure benzene may rise, but it may also be affected by uncertain factors such as price fluctuation of styrene and crude oil.