word20131-设计文档0-Abstract

Yangzi Petrochemicals annual output of 100,000 tons of MMA project AbstractCatalog1. Project Description12. Product & Raw material23. Process Design24. Energy-saving Design35. Equipment design56. Clean production107. Site selection and layout108. Security environment analysis139. Economic Benefit Analysis1310. Project Summary14Zhejiang University of Technology A4 Team 1/11. Project DescriptionThe project is a supporting subproject of Sinopec Yangzi Petrochemical, which is based on 10 million tons of oil refining and nearly one million tons of ethylene. It is planned to use the C4 pumping oil provided by Yangzi Petrochemical and the methanol supplied by the park as raw materials for the production of isobutylene. Utilization. In this project, the annual use of C4 pumping oil is 151,200 tons, with an annual output of 100,000 tons of methyl methacrylate (MMA). After the by-produced alcohol, the amount of C4 and methyl formate is 83,238 tons and 854 tons respectively. The north side of Yangzi Petrochemical in the industrial park is reserved for development on the open space. The team in the process design, taking into account economic benefits and cleaner production, clear thinking, highlights, mainly reflected in the following aspects: Recycling C4 pumping oil from the main plant, using reactive distillation and gas phase dehydration oxidization technology to purify MMA; Three major cycles of methanol, methacrolein and water are realized in the process to improve atomic utilization;The heat pump rectification technology, double-effect rectification, pinch analysis and heat integration technology are used to optimize the process to improve efficiency and reduce energy consumption.The use of extractive distillation to achieve efficient separation of the binary azeotrope system, reduce pollution, and detailed treatment of the subsequent three wastes;The use of the dividing column extractive distillation technology to improve the degree of product separation, the use of a new fluidized bed reactor, slurry bed reactor to improve the reaction capacity, the new tray to reduce product polymerization, the new shield pump to reduce energy consumption, the new heat exchanger components to improve heat transfer effectiveness.2. Product & Raw materialThe project is designed to use 15 tons/year of C4 pumping oil and isobutylene green to produce methyl methacrylate. The raw materials are C4 pumping oil from Yangzi Petrochemical and methanol supplied by Huisheng . The production process of this project is green and environmentally friendly, and it has created a huge economic benefit.Table 1 Composition and properties of C4 pumping oil from Yangzi Petrochemical componentcontent （Vol/%）componentcontent（Vol/%）N-butane6.52Isobutylene46.37Isobutane2.902-butene13.151-butene30.63Butadiene0.03Temperature：25Flow：18000kg/hrPressure：5barTotal flow：151200t In order to maximize the realization of economic benefits, and in line with the principle of green environmental protection, in addition to the main production MMA,the co-production of methyl formate and C4 after alcohol. According to the investigation of this project, both types of by-products can be sold locally, which greatly reduces the cost of sales and transportation, and also improves sales efficiency.Table 2 Main and Deputy Products of the ProjectSerial numberProductsSpecificationsoutputremarks1MMA99.95102497tmain product2Methyl formate96854.5tby-product3C4 after alcohol99.99983238tby-product3. Process DesignThe project was demonstrated by product selection and process plan, using the isobutylene hydration of Qil Research Institute, extractive distillation technology of dividing wall column and the oxidation of tert-butanol and the one-step oxidation esterification of methacrolein (MAL) by Zhang Suojiang Group of the Institute of Chinese Academy of Sciences. Process. The process flow consisting of t-butanol synthesis section, MAL synthesis section and MMA synthesis section was designed to realize the steady-state simulation and optimization of the whole process. The process flow is shown in Figure 1. For details, see Chapter 4, Chemical Process and System of Preliminary Design Specification.Figure 1 Process flow diagramAfter the C4 pumping oil from the main plant is mixed with water through the hydration pre-reactor, the C4 and the product t-butanol can be separated by the reaction rectification treatment, which overcomes the high energy consumption and the number of plates in the traditional rectification technology. Many problems, t-butanol enters the MAL synthesis section through the decarbonization tower, first dehydrates at high temperature to form isobutylene, and is mixed with air to oxidize to MAL, after pressure, washed with methanol, washed with exhaust gas and re-recovered methanol, and mixed with MAL and methanol. The liquid enters the MAL oxidation esterification reactor, and the product first separates the lighter methyl formate by-product, and the other enters the heat pump crude separation tower, separates the methanol, and extracts the MMA in the methanol by the cyclohexanone extraction, and the MMA refining tower. The resulting MMA product is mixed and eventually enters the product storage tank.4. Energy-saving Design Heat exchange netword optimizationIn this project, the amount of design public works is large. In order to make full use of energy, the project uses the Aspen Energy Analyzer software to match the flow pattern according to the pinch design method and the actual situation, and designs an optimal cold-heat stream matching scheme. At the same time, the optimized heat exchange network is returned to the process simulation and PID drawing, and the final solution is obtained through comparative analysis. See the Aspen process simulation source file and PID drawing for details. The whole plant heat exchanger network matching scheme is shown in Figure 2.Figure 2 heat exchanger netword matching schemeAfter heat integration to optimize the heat exchanger network, a total of 69.28 MW for cold-use projects and 15.47 MW for thermal utilities are required, which is 43.16 MW compared with that before optimization. Heat pump distillationFigure 3 Heat pump distillation Table3 Before and after heat Simulation flow chart pump distillation energy useThe use of heat pump rectification in the heat pump coarse separation tower has the advantages of simple equipment, low investment, good separation effect and low operating cost. After Aspen comparison simulation, the total energy consumption of heat pump distillation is saved by 83.2%. Double-effect distillationThrough double-effect rectification, the methanol recovery process is improved, and the total energy consumption is reduced from the original rectification of 4243.79kw to 2996.07kw, and the energy saving is 1247.72kw. Figure 4 double-effect distillation Table 4 Energy consumption before andsimulation Flow chart after the use of double-effect distillation Split wall column extractive distillationThe energy consumption is from the original two-column process of 25Gcal / hr, 21 Gcal / hr to a single divided-wall extractive distillation tower to save energy and energy 10%. Figure 5 Split wall tower Table 5 Energy consumption before and flow chart Split wall column extractive distillation5. Equipment designIn the design process of this project, the equipment such as the dividing wall tower and the methacrolein synthesis reactor were designed in detail, and the heat exchanger, pump, compressor and other equipment were selected. See Typical Equipment Design and Selection and Reactor Design Specification for details. Fluidized bed reactor Figure 6 Fluidized bed reactorThe fluidized bed of this project adopts a catalyst with small particle size and wide particle size range, which can eliminate the internal diffusion resistance, and removes the reaction in time by using the built-in heat exchange tube to release a large amount of heat, so that the entire bed can be operated under near-isothermal conditions, which is easy to control. Conducive to mass transfer. Since the catalyst particles are in a stable flow state, good fluidization conditions in the fluidized bed are maintained by means of additional catalyst. And the device structure is simple, suitable for large-scale production. The tubular heat transfer coefficient existing in the existing heat exchanger structure of the existing fixed bed reactor can be solved, and it is difficult to achieve heat transfer enhancement, the catalyst consumption is large, and it is difficult to achieve continuous or production problems. New type of shield pumpIn order to implement the concept of green energy conservation, the pump used in this project decided to adopt a new energy-saving shield pump through market research. This series of pumps was produced by Shanghai Hanuo Pump Valve Co., Ltd., which replaced the conventional high-energy conventional shield pump products.The conventional shielded motor is 10% lower in efficiency and lower in power factor than the same motor with the same power. However, the magnetic circuit of the series of pumps is a radial structure with simple structure and less magnetic leakage. Due to space constraints, this special magnetic isolation method is adopted to reduce the size of the magnetic isolation bridge to increase the magnetic resistance and reduce the leakage magnetic flux. Small, using less NdFeB permanent magnets can provide the air gap magnetic density required for the motor. The design improves the overall efficiency of the pump, and utilizes Hastelloy and NdFeB permanent magnet materials to make the motor have high efficiency, high power factor, high power density, strong overload capability, low temperature rise, low noise, and long-term high temperature operation. High reliability, no leakage, explosion-proof, corrosion-resistant, etc., and stable operation at 200 C.Figure 7 IMC series continuous continuous lining fluorine magnetic pump Application of new traysIn the rectification system of this project, t-butanol, methacrolein, methyl methacrylate, methanol and water are mainly present. Since methacrolein and methyl methacrylate have conjugated double bonds, the double bond is more It is active, resulting in the self-polymerization of methacrolein and methyl methacrylate, even if a stabilizer is added, the self-polymerization reaction cannot be completely inhibited. The actual production application proves that if the rectification column containing methacrolein and methyl methacrylate uses mass transfer of the filler, the tower block phenomenon will occur for a long time and cannot be operated normally for a long time.The use of the traditional valve tray can not solve the problem of blockage of the tray, and the valve tray is large. By consulting various materials, the New-vst Plus tray has large holes and no moving parts, which is generally difficult. Blocked by dirty or sticky materials. In addition, the gas and liquid are separated from the cap in the spray state, the gas velocity is high, and the cover hole itself has strong self-flushing ability, and impurities such as particles, polymers, dirt and the like contained in the flow are difficult to gather and block in the cover hole. Cover hole. Therefore, the New-vst Plus tray is more suitable for solving the above-mentioned problem of internal blockage, and the tray has been well applied and benefited in the actual factory.Figure 8 Schematic diagram of mass transfer process of New-vst Plus trayWith the New-vst Plus tray, the overall tower efficiency is increased by more than 10% compared to the F1 float valve. The pressure drop is equivalent to the F1 type float valve at low load, and is 20% 30% lower than the F1 float valve at high load, and the higher the load, the lower the pressure drop. It reduces equipment investment, reduces energy consumption, and solves the problem of internal blockage caused by self-polymerization of the system, and also has great economic benefits. “Twisted tube” useIn the metformin synthesis section of this project, a large amount of heat is released due to the oxidation reaction, and the temperature of the mixed gas exiting the reactor is high, and the heat is used step by step. The heat exchangers involved are gas-gas phase heat exchangers. The total heat transfer coefficient of the gas-gas phase heat exchanger is low, resulting in a large heat exchange area, an increase in equipment costs, and an increase in floor space. Moreover, the fluid is easy to foul in the tube, which seriously affects the heat exchange and causes the heat exchanger life to decrease and the energy consumption to increase. In view of the above problems, the project uses a heat transfer element that can simultaneously improve the heat transfer efficiency of the shell side and tube length of the heat exchanger in the methacrolein synthesis section heat exchanger - twisted tube, the working principle is as follows：Figure 9 Schematic diagram of twisted tube bundleThe twisted tube is made by flattening and twisting a common round tube. The cross section is elliptical, the two ends are still circular in cross section, and the elliptical section is continuously twisted to form a spiral flow path, which is rotated 360 degrees each time through a lead section; A point support is formed at the shaft, and a support is formed every 60 degrees of rotation, and a support point is six support points, and the space between the tube bundles is a spiral flow path. The fluid in the twisted tube rotates and flows, forming a secondary flow in the cross section; the self-supporting structure is formed at the long axis of the shell section, and the flow path is also spiral. The shell-side fluid rotates while flowing longitudinally, which enhances heat transfer and reduces pressure. Loss, in addition, the longitudinal flow also avoids fluid-induced tube bundle vibration.6. Clean productionThis project is a clean production process for the production of MMA by C4 raffinate oil and the production of M4 by-product and methyl ester after alcohol. The main manifestations are as follows: The C4 raffinate oil is purified and separated, and the C4, which is low in domestic resource utilization, is used as the raw material for the aromatics alkylation of the plant, which plays a role in energy conservation, emission reduction, clean production, waste utilization and improvement. The role of economic benefits.3 The process of the route carries out three major cycles of methanol, water and methacrolein, which not only improves the atom utilization rate, but also reduces the three wastes. Using high-efficiency reaction and separation technology to further recycle methanol-containing wastewater, reducing emissions of organic wastewater and expanding economic benefits.The project uses activated alumina and molybdenum ruthenium catalyst in the t-butanol dehydration reactor and the methacrolein synthesis reactor to ensure low pollution and even no pollution, and achieve environmentally friendly and economical production.7. Site selection and layout Site determination图10 Site determinationThe project will be located on the north side of Yangzi Petrochemical Reserve Development Open Space, as shown in Figure 10.The public facilities of the project construction site are perfect, and the enterprise cluster makes the internal industrial chain have obvious advantages; the flare gas waste gas is directly transported by the main plant to the project through the pipeline, which is convenient and quick; the three waste treatment and public works have supporting industry supply. The project site receives government policy assistance and financial support, and the sustainable development of the industry. General factory layoutAccording to the concept of separation of people and vehicles, the general layout is divided into traffic passages and personnel passages to reduce traffic resistance. Parallel arrangement is adopted, and the living area of the production area is arranged on both sides of the radial trunk road of the plant, so that the two do not affect each other. And according to the compact and centralized concept, the location of the building and workshop in the plant area is reasonably arranged to achieve an efficient, stable and safe production arrangement. The factory has a length of 410m and a width of 237m. The total production area is 97,170m2, which mainly includes the management area, auxiliary production area, production technology area and storage and transportation area. We use AutoCAD to carry out the flat design of the plant area. The layout of the plant area is shown in Figure 10.Figure 11 Factory layout Three-dimensional arrangementThis project uses Auto CAD to draw the equipment layout drawing, determine the placement position of the equipment, facilitate production, and design the three-dimensional design of the plant, as shown in Figure 10. See the workshop faade, the three-dimensional layout of the workshop and the three-dimensional layout source files of the plant.Figure 12 plant area three-dimensional renderings8. Security environment analysisThe project uses Risk System software to identify major hazard sources in the tank area such as methanol in the plant area and analyze the source phase of the tank material according to the physical properties of the material, and then predict th