The disadvantage of chlorohydrination method is that it consumes a lot of water resources and produces a lot of wastewater and waste residue. Every time 1t propylene oxide is produced, 40~50t chlorine-containing saponified wastewater and more than 2t waste residue are produced. This kind of wastewater has the characteristics of high temperature, high pH value, high chloride content, high COD content and high suspended solids content, and it is difficult to treat. At the same time, chlorohydrination also consumes a lot of chlorine and lime raw materials with high energy consumption, while chlorine and calcium are discharged into wastewater and waste residue, and hypochlorous acid produced in the production process also seriously corrodes the equipment.
The production of propylene oxide in China began in the 1960s, and the chlorohydrin process route was developed independently. In the late 1980s and early 1990s, China introduced chlorohydrination technology from Asahi Glass Company, Mitsui East Asia Company, Showa Electric Company and Dow Company. After the propylene oxide plants of Jinhua Chemical Company, Shandong Hua Bin Company, Sinopec Shanghai Gao Qiao Petrochemical Company and Tianjin Dagu Chemical Company were put into operation, good economic benefits were achieved and the production level was greatly improved. At present, except for the 250,000 t/a propylene oxide plant of China Shipping Shell, 80% of China's existing propylene oxide production capacity adopts chlorohydrin method. * * * oxidation method, also known as Haakon method, includes isobutane oxidation method and ethylbenzene oxidation method. Isobutane or ethylbenzene and propylene respectively undergo * * * oxidation reaction to generate tert-butyl alcohol or styrene and co-produce propylene oxide.
* * * The oxidation method was developed by Oakland Company of the United States and is now owned by Leandre Company of the United States. * * * oxidation method overcomes the disadvantages of large corrosion and much sewage of chlorohydrin method, and has the advantages of low product cost (joint product sharing cost) and little environmental pollution. Since the industrialization of 1969, it has developed rapidly in the world. Today, the production capacity of propylene oxide by oxidation accounts for about 55% of the world's total production capacity.
The disadvantages of * * * oxidation method are long process flow, many kinds of raw materials, high requirements for propylene purity, high process operation pressure, high equipment cost and large construction investment. At the same time, in the production of propylene oxide by * * * oxidation method, there are only/kloc-0 by-products, and the output is small, with 2.2~2.5t styrene or 2.3t tert-butyl alcohol as by-products per ton of propylene oxide. The source of raw materials and the sales of products have great mutual constraints and must be properly solved. Only when the market demand of propylene oxide and by-products matches, the advantages of this process can be shown. In addition, the sewage produced by * * * oxidation method also contains high COD, and the treatment cost accounts for about 65,438+00% of the total investment.
China has always used chlorohydrin method to produce propylene oxide. In March 2006, with the commissioning of China Shipping Shell's propylene oxide plant with an annual output of 250,000 tons, the production pattern of propylene oxide has changed to some extent. At present, China Shipping Shell Project is the largest 1 propylene oxide plant in China, and it is also the only propylene oxide plant that adopts propylene oxide/styrene oxidation co-production process. It is estimated that by the end of 2009, the 280,000-ton/year propylene oxide production plant jointly built by leander and Sinopec in Zhenhai will be completed and put into operation. Direct oxidation of hydrogen peroxide (HPPO) is a new process of propylene epoxidation to propylene oxide catalyzed by hydrogen peroxide. In the production process, only propylene oxide and water are produced. Simple technological process, high product yield, no other by-products and basically no pollution. Belonging to an environment-friendly and clean production system.
At present, the real hydrogen peroxide oxidation process is jointly developed and industrialized by Evonik Industrial Group (formerly Degussa), Uhde, Dow Chemical and BASF.
In 200 1 year, Evonik Industries Group and Wood Company built 1 set of hydrogen peroxide experimental device in Frankfurt, Germany, to test the best catalyst and determine the critical parameters, and started industrial design technology. In 2003, Evonik introduced the commercial process package of this technology.
In May, 2006, SKC Company, a South Korean manufacturer of propylene oxide and polyester film, purchased the patents of Evonik and Wood, and began to build a global 1 hydrogen peroxide propylene oxide plant in Ulsan, South Korea. The production scale of the plant is 654.38+10,000 t/a, which was completed and put into operation in July 2008, and the production runs well. Evonik Industries Group is negotiating with Sibur, a subsidiary of Gazprom, a Russian gas oligarch, to establish a joint production plant of hydrogen peroxide and propylene oxide in Russia.
200 1 Dow Chemical purchased the laboratory technology of producing propylene oxide with hydrogen peroxide as oxidant from EniChem Company, including the Italian 1 experimental device. In 2003, Dow Chemical and BASF began to cooperate to develop and commercialize hydrogen peroxide technology. In 2006, Dow Chemical and BASF announced that they would jointly build a 300,000-ton/year propylene peroxide plant in Antwerp, Belgium, which is scheduled to be completed and put into operation in early 2009. In June 2008, SCG-DOW Group, a joint venture between Dow Chemical and Siam Cement Group (SCG) of Thailand, started the propylene oxide plant in Thailand, using the hydrogen peroxide process jointly developed by Dow and BASF, with a production capacity of 390,000 t/a, and the project is expected to be put into production at 201. Dow Chemical also plans to start construction of a 380,000 t/a hydrogen peroxide propylene oxide project in Switzerland on 20 10.
China Dalian Institute of Chemical Physics is also engaged in the research of hydrogen peroxide technology. In 2002, Dalian Institute of Chemical Technology signed a pilot cooperation contract with Sinopec. In the first half of 2005, Dalian Institute of Chemical Technology passed the technical appraisal organized by Sinopec. In August 2008, the technology of producing propylene oxide by direct oxidation of propylene with hydrogen peroxide developed by Dalian Institute of Chemical Technology passed the appraisal organized by Liaoning Science and Technology Department. The production of propylene oxide in China began in the 1960s, and the initial production scale and technical level were low. After 1980s, China introduced advanced production technologies such as Asahi Glass, Mitsui Dongjin and Showa Electric, which promoted the development of domestic propylene oxide technology. After 2000, the development of propylene oxide industry in China entered a stage of rapid growth.
2004 was the fastest year for the development of China's polyether industry. In 2005, the growth rate of polyether industry decreased slightly due to the influence of macro-economy and raw material supply at home and abroad. From the perspective of product structure, the actual growth rate of rigid foam polyether industry in 2005 was not large, and the soft foam polyether industry developed rapidly in the second half of 2005.
2006 is a very important year in the development history of China Post. First of all, many sets of new and expanded equipment were put into production, and the relationship between supply and demand was gradually balanced from tension; Secondly, the market price dropped slightly from the previous high point; Producers' profits have fallen sharply. Finally, the demand market of downstream derivatives was released from repression in 2005, and the total demand of PO and its derivatives increased rapidly in 2006. At present, there are more than 30 polyether polyol production enterprises in China, and the production capacity in 2005 has reached1135,000 t, of which nearly 20 are over 10,000 t. The main manufacturers are Gao Qiao Petrochemical Company Polyurethane Division, China Shipping Shell, Jiangsu Zhongshan Chemical Co., Ltd., Tianjin Petrochemical Company Polyurethane Division, Jinhua Chemical Group Company, Shandong Dongda Chemical Group Company, Fujian Meizhou Bay Chlor-alkali Industry Co., Ltd., Tianjin Dagu Chemical Plant, etc. According to the development of polyurethane industry, it is predicted that the annual growth rate of consumption demand of polyether polyols in China will remain above 10% in the next few years.
In 2008, among the three methods for producing propylene oxide in China, chlorohydrin method and * * * oxidation method are still dominant, and these two technologies will coexist for a long time. * * * The oxidation method does not have the absolute advantage of eliminating chlorohydrin in a short period of time. Most enterprises in our country adopt chlorohydrin method, and now the sewage problem has been solved by increasing technical transformation, especially by adopting biochemical treatment technology. This process still has room for development in China. In the direct oxidation method, the process of producing PO by hydrogen peroxide oxidation is just beginning, and in the industrial direct oxidation method, the oxygen direct oxidation method is still in the conceptual experimental stage. In China, there may not be any industrial production facilities for direct oxidation to produce PO.
With the transfer of the world polyurethane industry center to Chinese mainland, it will greatly promote the development of polyurethane industry in China. At the same time, the promotion of building energy-saving policy and the sustainable development of automobile furniture industry will keep the polyurethane industry growing well, thus stimulating the development of PO industry. Therefore, in large petrochemical enterprises with raw material advantages, it is suggested to build a * * * oxidation production device to expand the scale. The minimum production capacity of propylene oxide production enterprises should be above 654.38+10,000 t/a. If the raw materials are adequately supplied and the transportation is convenient, a large-scale plant of 200,000-300,000 t/a can be built. Domestic consumption of propylene oxide for polyether polyols accounts for 85% of the total consumption, occupying a dominant position, and PG/DMC% accounts for 8%. In the future consumption of propylene oxide, polyether will still dominate and its proportion will increase.
The downstream demand of propylene oxide is mainly supported by polyether industry. As the main raw material of polyurethane industry, polyether polyol is mainly used in four fields, such as furniture, automobile, construction and industrial insulation, and its consumption accounts for more than 2/3 of the total consumption of polyurethane.
Since 1980s, the consumption of furniture and mattresses has increased rapidly, and the demand for flexible polyurethane foam has also increased greatly. After the 1990s, the consumption of polyurethane for automobile, construction, household appliances and other industries increased rapidly, and the domestic consumption of polyurethane increased steadily. From the perspective of domestic polyurethane consumption structure, furniture, household appliances and automobiles are the main consumption areas. In the field of construction, EPS products are mostly used in China, and the demand for polyurethane is relatively low. However, in the future, the demand for environmental protection and energy conservation will be higher and higher, which will bring a steady stream of development momentum to the polyurethane industry, thus stimulating the growth of the demand for propylene oxide. Based on the expectation of the rapid growth of polyurethane demand, the polyether industry has entered a stage of rapid expansion, and many polyether projects have been completed or will be completed in the next two years, such as Shaoxing Hengfeng's 65,438+10,000 tons of new production capacity and Jurong Ningwu's 65,438+10,000 tons of new production capacity. The polyether production capacity in 20 12 years will exceed 2 million tons. With the rapid growth of polyether industry, the consumption of propylene oxide will also increase greatly. Based on the new polyether production capacity of 6,543,800,000 tons in the next two years, it will take about 0.75 tons of propylene oxide to produce 6,543,800 tons of polyether. Therefore, from 2065.438+00 to 2065.438+02, the demand for propylene oxide in polyether industry alone will increase by about 700,000-800,000 tons, and the demand for propylene oxide will greatly increase. First, the main problems in the market of propylene oxide products
With the development of fine chemical industry and polyurethane industry in China, the market prospect of propylene oxide products is increasingly broad. However, at present, all propylene oxide production in China adopts chlorohydrin production process, which has some shortcomings such as serious equipment corrosion and serious environmental pollution caused by wastewater containing calcium chloride.
The main propylene oxide production facilities in China are mainly imported technologies, including those of Asahi Glass Company, Mitsui East Asia Company, Showa Electric Company and National Highway Chemical Company. Domestic technology is mainly the key technology of petrochemical company organization.
As a traditional production process, chlorohydrination has been gradually eliminated in foreign production because of its high discharge of "three wastes". The reason why there is no big breakthrough in the domestic capacity of propylene oxide by chlorohydrination is also related to this. The wastewater and waste residue produced by this production process are not easy to treat and cannot adapt to the increasingly strict environmental protection standards. Especially in the treatment of waste residue, because of its high salt content, there are few standard utilization methods. Most manufacturers use piling and burying methods, which will inevitably cause serious pollution to the surrounding environment and groundwater, and bring great hidden dangers to future environmental governance.
If the production of propylene oxide by chlorohydrin method can not effectively solve the problems of wastewater and waste residue, the greater the capacity of production equipment, the greater the environmental burden; The higher the output, the deeper the harm to the environment. Therefore, experts believe that the technology of producing propylene oxide by chlorohydrin method is not mature enough. The recognized mature technology was introduced about 50 years ago, which does not meet the current environmental protection requirements. Therefore, environmental protection has become the primary factor restricting the development of propylene oxide industry.
Solving the environmental problems in the development of propylene oxide industry has become the goal of current technical research. In addition to improving the original production process, how to realize the recycling of wastewater and waste residue will be related to the development of the whole propylene oxide industry. Once this key factor is solved, it will bring new opportunities to the industry.
China's propylene oxide industry has made great progress, but there is still a big gap compared with foreign advanced level and domestic downstream industries. In the future, it should develop in the direction of clean process, large equipment and refined application.
Second, the three bottlenecks in the domestic propylene oxide product market
"Eleventh Five-Year Plan" is a five-year period in which China's propylene oxide industry has developed vigorously and its quality has been Shuang Sheng. During this period, China became the world's largest producer and exporter of propylene oxide, with an annual production capacity of 6,543,800+0.545 million tons and an annual output of 6,543,800+0.4376 million tons in 2065+00. The product quality of large and medium-sized enterprises has generally improved, which can be used to manufacture high-quality electronic products and aerospace products.
However, there are also some problems worthy of reflection. Looking forward to the "Twelfth Five-Year Plan", the propylene oxide industry will strive to break through the following bottlenecks while consolidating and expanding its achievements.
First of all, China has become the world's largest producer and exporter, which is certainly the result of the vigorous development of "Made in China", but it is also affected by factors such as foreign enterprises transferring basic propylene oxide products and adding propylene oxide products specially. The production by adding resin is not only zero pollution, but also has better performance and higher price. At present, the products of propylene oxide products enterprises in China are still mainly based on basic propylene oxide products, with fierce market competition, shrinking profit space and long-standing industrial restructuring. And foreign manufacturers just take advantage of this opportunity, taking China as the supply base of propylene oxide products, and constantly expanding the production capacity of adding resin. This not only avoids environmental risks, but also makes a lot of money. Therefore, how to reduce the pollution in the production process of basic resin, open up the market of added resin and improve the added value of products is an important issue facing the whole industry.
Secondly, system construction needs to be put on the agenda. Multinational companies no longer only supply resin products, but prepare mixtures according to customer needs to provide systematic services. This mixture includes resin, curing agent, diluent, additive, etc. This can not only form the advantage of product chain, consolidate the market, but also fully expand the profit space. Specially developed products have strong pertinence and specific performance, which can better meet the needs of customers, so the profit level is higher and the customer loyalty is higher.
Thirdly, in view of the rapid development of domestic epoxy resin production capacity, slow development of basic curing agent device and insufficient supporting capacity, we should pay attention to the coordinated development of epoxy resin, curing agent, additives and raw materials, strengthen the research and development of special epoxy resin, and strengthen information exchange at the same time to avoid blind or repeated projects.
The demand for propylene oxide products in China is still developing rapidly, and it is estimated that the consumption will soon reach 2.756 million tons by 2020. The low operating rate of some devices is largely related to the unreasonable domestic product structure. Therefore, China can no longer compete for the same runway as before. We should consider the development level from the variety, quality and technical level. I. Analysis of the Future Development of Propylene Oxide
Driven by the price of raw material propylene, the price of propylene oxide finally began to rise sharply. However, in the case of rising market conditions, propylene oxide producers are still struggling, and losses are still the first factor they need to worry about all the time.
The trend of propylene price directly affects the production cost of propylene oxide. After the international entered the era of high oil prices, the price of propylene also rose. However, the sensitive fluctuation of oil price also affects the price of propylene. After the price of propylene began to fall, the price of propylene oxide rose without strong support from demand. Although, from the perspective of production enterprises, even if the market price of propylene oxide is increased, they still bear the burden of losses. However, after the price of raw materials began to fall, although manufacturers still expressed their intention to maintain high prices, it is not known whether downstream buyers can understand and accept it.
The price increase of propylene oxide naturally drives the price of polyether to float red. Like the price of propylene oxide, the weak downstream demand still makes the prospect of high price not optimistic.
In fact, the high market price of products unilaterally caused by the pressure of production cost can not fully explain the optimism of the product market, but more often it is the helpless move of production enterprises.
73% of polyether consumption in China is used to make elastic foam (soft foam), and most of the rest is used to produce rigid foam, while about 50% of polyether in developed countries is used in construction industry.
Due to the rapid market growth of coatings, adhesives, sealants, elastomers and other products, polyether will have great prospects in this field. With the development of automobile industry in China, the demand for polyether for automobile polyurethane parts is increasing rapidly. Therefore, the consumption structure of polyether is gradually diversified, which has become one of the important factors for the in-depth development of the industry. It is an effective way to fundamentally change the demand of polyether market to urgently expand the polyether industry in application fields.
For propylene oxide, the change of production process will be the future development direction. At present, the environmental problems caused by the production of propylene oxide by domestic enterprises are social problems and cost problems of enterprises. The popularization of advanced technology will be the fundamental way to solve the high production cost and serious pollution of propylene oxide. In 2008, BASF and Dow Chemical's plant for producing propylene oxide by direct oxidation of hydrogen peroxide in Antwerp, Belgium will be put into operation, and South Korea's SKC will also put into use the equipment adopting this technology. BASF and Dow Chemical plan to further build production facilities for producing propylene oxide by direct oxidation of hydrogen peroxide in Asia and the United States in 2009-20 10. Leandre plans to build new projects in China, and several other companies plan to implement projects in China in 2008-20 10.
In recent ten years, the domestic demand for propylene oxide has grown rapidly, driven by downstream derivatives, from the consumption of only 785,000 tons in 2006 to11546 million tons in 2006, which is more than twice as much as 1-2, with an average annual growth rate of 15.03%. Among them, the total consumption of polyether polyol industry reached 550,000 tons, accounting for 84.9% of the total consumption, far higher than the global average. With the rapid development of China's polyurethane industry, a large number of polyether polyol factories have been built and expanded in China, and the self-sufficiency rate of polyether polyol has increased year by year, reaching more than 90% by 20 1 1, and the demand for propylene oxide has also increased greatly.
Therefore, in fact, the development prospect of both propylene oxide and polyether market is still broad, but in the process of development, the twists and turns encountered need to be solved by effective means. To save the propylene oxide and polyether markets, it is not a long-term solution to increase prices alone. To reverse the loss situation, we need more diversified development paths.
Second, the future development direction of propylene oxide industrial technology
Following the virtuous cycle principle of sustainable development and protection of human living environment, various new processes have appeared in propylene oxide production, such as direct oxidation, chlorohydrination, double oxidation, biological fermentation, peracetic acid, electrochemical chlorohydrination and so on. Among them, the best method is direct oxidation of hydrogen oxide. Theoretically, H202. Its redox potential is higher than that of propylene oxide, so it can be used to directly oxidize propylene to propylene oxide. The mass fraction of active oxygen in H202 is much higher than other peroxides, reaching 47%. Its reduction product is only water, clean and pollution-free, and it is an ideal oxide. Therefore, some people tried to prepare propylene oxide from propylene oxide with H202 for a long time, but failed because of catalyst problems. When Ts- 1 catalyst was developed, this idea finally became a reality. Under the conditions of pressure of 0.4MPa and temperature close to room temperature, propylene and H202 reacted with methanol aqueous solution as solvent. Propylene oxide H202 was prepared by direct reaction. The conversion rate is over 98%, and the selectivity of propylene to propylene oxide is over 97%. At present, the process is still in the development stage, and the main research focuses on the influence of various factors on the performance and cost of the catalyst.
It can be predicted that the production trend of propylene oxide in the future will be large-scale and harmless, but the technical conditions will not reach the goal of harmless in the short term, especially for China, China still has the problem of economic affordability. Combined with this actual situation, it is imperative for the domestic propylene oxide industry to develop reasonably and rapidly, minimize environmental pollution and increase the treatment of propylene oxide wastewater, so our topic is of great significance.
Third, the overall planning and forecast of the overall industry in the Twelfth Five-Year Plan.
-Overall objective
Improve the energy-saving and environmental protection level of existing devices, strengthen the introduction of new technology HPPO, and improve the independent development ability of key technologies of new technology; Strengthen industry integration and improve the overall HSE level of PO industry; Through exchanges and communication between industries, we will create a good atmosphere for the development of the industry and effectively promote the rapid and healthy development of the industry.
-Main tasks
Under the condition of ensuring the production scale, continuously improve the level of energy saving and consumption reduction of existing devices, and recycle energy. At present, except for two sets of PO/SM devices, all domestic propylene oxide production devices are still chlorohydrin process. Some inherent environmental problems of chlorohydrination process, such as serious corrosion of equipment, waste water and waste residue pollution, have been restricting the sustainable development of this process. Especially in the environment of advocating environmental protection and low carbon at home and abroad, improving the energy saving and environmental protection level of chlorohydrination process has to be put on the agenda.