设计文档word20034 设计文档集0-Abstract

Xinjiang Makor Chemical 300,000 tons/year VAC projectC E D CXIN JIANG MarkorChemthe project of an annual output of 300，000 tons of vinly acetate Project summaryDESIGN UNITCOLLEGE OF CHEMICAL ENGINEERING, NORTHWEST UNIVERSITYDESIGN TEAMRECYCLE NAME OF MEMBERWANG CHENGHUA FU WEN XUAN LI XUCHENG ZENG LONGHUI CAI YULU INSTRUCTORZHAO BINRAN CHEN LIYU LIU ENZHOU WU LE NIE YAN15 August 2019 Xinjiang Makor Chemical 300,000 tons/year VAC project Catalog1. Project Profile12. Determination of Raw Material Products13. Process planning24. Energy saving design45. Innovation Description95.1 Optimizing Separation Sequence95.2 Fluidized bed reactor95.3 Modified three-stage cyclic absorption acetylene separation tower95.4 Heat pump distillation technology105.5 Neighboring Column Technology105.6 New type guide sieve tray105.7 Finned heat exchanger tube106. Equipment design117. Cleaner production118. Site Selection and Layout of Plant Area129. Analysis of Safety Environment1510. Economic Benefit Analysis1511. Project summary17181. Project ProfileThis project is based on the subsidiary company of Makor Chemical Co., Ltd. and built in Xinjiang Makor Chemical Industrial Park. Vinyl acetate is synthesized from acetylene supplied by the general plant and acetic acid supplied by Xinjiang Tianyu Acetic Acid Chemical Plant by acetylene vapor phase method. The catalyst is zinc acetate- alumina studied by chemical engineering of Zhejiang University. On the basis of project feasibility study and project scheme design and preliminary process design, aluminium carbide has completed the process technology design of 300,000 tons/year vinyl acetate main unit, providing vinyl acetate raw materials for the production of fine chemical products such as coatings and adhesives in downstream park.The acetylene-based vinyl acetate process adopted in this project has the advantages of low emission, low energy consumption and low cost. It accords with the theme of green chemistry era and meets the 2020 target of green development proposed by Made in China 2025. The process has broad market and prospects.2. Determination of Raw Material ProductsAcetylene is supplied by Makor Chemical Genseral Plant. Acetic acid is obtained through outsourcing. The annual consumption of acetic acid is 209 000 tons and 90693.33 tons. Acetylene is collected by the General Plant and transported to the production area by pipeline. Acetylene is transported by steam to the production area.Table 2.1 Composition and Properties of Raw Materialsacetic acidacetyleneprojectindexprojectindexBoiling point117.9explosion limit %75.5Chroma (Pr-Co)/number10Ignition point305moisture%0.15flash point-32purity %99.8purity %98We use acetylene supplied by the General Plant and acetic acid supplied by Tianyu Acetic Acid Chemical Plant in Xinjiang as raw materials, with an annual output of 300,000 tons of 99.9% (wt%) vinyl acetate and 2,600 tons of 99.5% acetaldehyde products.Table 2.2 List of main and by-products of this projectNo.Produts Specifications（%）yieldRemarks1vinyl acetate99.9530w tonneMain Products2acetaldehyde99.52600 tonneBy-product3. Process planningAfter product selection and process scheme demonstration, this project adopts acetylene vapor phase synthesis process of vinyl acetate. The process flow composed of pretreatment and reaction section, acetylene recovery section, product section and acetic acid recovery section was designed, and the steady state simulation and optimization of the whole process were realized. See Chapter IV of for details of process flow. Chemical processes and systems。（1） Pretreatment and reaction section：The reaction of acetic acid and acetylene to produce vinyl acetate in a fluidized bed reactor was simulated.Pic 3-1 Pretreatment and Reaction Section（2） Acetylene recovery section：The main simulation is to separate and purify acetylene from mixed gas and recycle it back to pretreatment and reaction section.。Pic 3-2 Acetylene recovery section（3）Product section：The separation and purification of vinyl acetate and acetaldehyde were simulated.。Pic 3-3 Product section（3） Acetic acid recovery section：The process of recovering and recycling acetic acid after roughly separating the original mixture was simulated.。Pic 3-4 Acetic acid recovery section4. Energy saving design（1）Optimization of Heat Exchange NetworkIn this project, there are many public works involved. In order to make full use of energy, this project uses Aspen Energy Analyr software, according to pinch design method, combined with the actual situation, carries out stream matching, and designs an optimal cold and hot stream matching scheme. At the same time, the optimized heat exchanger network is returned to process simulation and PID drawings, and the final scheme is obtained through comparative analysis. See Aspen process simulation source file and PID drawings in detail. The matching scheme of heat exchanger network in the whole plant is shown in figs. 4.1 and 4.2.Pic 4.1 Automatic Design of Optimum Heat Exchange SchemeThere is cross-section heat transfer in the heat exchange network of automatic design. In practice, there is no cross-section heat transfer. Heat transfer between distant logistics will increase the cost of pipelines, increase the cost of equipment investment, and the operation is unstable. Such heat exchangers need to be deleted. At the same time, considering individual tower with high energy consumption, such as acetic acid tower, heat pump technology can be used to save energy and reduce consumption. Finally, it is determined that the form of heat exchanger network is reactor gas preheating two raw materials, and T0303 is set as partition tower, which achieves good energy-saving effect.。Pic 4.2 Manual Design of Heat Exchange NetworkCompared with heat exchanger networks without thermal integration technology, the energy consumption before and after thermal integration is compared as follows.：Table 4.1 Public Utilities Contrast TableProject Cold Public Works Gcal/hrThermal Public Works Gcal/hrTotal Gcal/hrDirect Public Works52.3560.35112.7Design of Heat Exchange Network44.2451.595.74Energy Reduction/%15.50%14.66%15.00%It can be found that the energy saving effect is remarkable, the energy reuse rate is higher, and the economy of the production process is strengthened. The energy recovery rate (energy saving rate) reaches 15.0%.（2）Heat pump distillation technologyThe temperature difference between the top and kettle of T0401 acetic acid tower is less than 10 C, and the boiling point of acetic acid is very high. If ordinary distillation is used, although the effect can be achieved, the energy consumption will be very large. In this project, heat pump distillation technology is adopted. The top steam of the tower is compressed and exchanged with the liquid extracted at the bottom of the tower to make it boil again. As the reboiling steam at the bottom of the tower, after heat transfer, the top steam condenses first and then partially recovers. In short, the use of heat pump distillation technology in the tower greatly reduces the energy consumption of the single tower, and has played an obvious energy-saving effect.Table 4-2 Contrast Table of Public Works before and after Heat Pump DistillationProjectConsumption of Cold Utilities (KW)Quantity of thermal utilities (KW)Ordinary distillation-5462.303826.31heat pump-1046.140Cost savings /%77.7/（3）Separation Column TechnologyIn the traditional process, the crude vinyl acetate tower and the refined vinyl acetate tower (T0303) are merged into a vinyl acetate partition tower. 99.95% of the high quality vinyl acetate is extracted from the side line, which saves energy consumption and equipment costs and achieves the goal of clean production.（4）ENERGY CONSUMPTION OF THE PLANTReferring to the General Principles for Computing Comprehensive Energy Consumption (GB2589-2008), the comprehensive energy consumption of this project is calculated. The calculation results are as follows.Table 4.3 List of Energy Consumption of the PlantNo.Project ConsumptionLow calorific value or energy consumption indexTotal energy consumption104Unit Energy ConsumptionUnit consumptionAnnual consumptionUnitNumber UnitNumber Unit Number MJ/aMJ/t1electrickWh/t126.869 104kWh3806.08MJ/t3.613701.89 456.73 2Process soft watert/t0.232 104 t6.96MJ/t14.2399.04 3.30 3Circulating cooling watert/t140.500 104t4215MJ/t40.6171129.00 5704.30 4Frozen brinet/t0.495 104t14.838MJ/t4005935.20 197.84 5LSt/t1.300 104t39.012MJ/t2302.6589830.98 2994.37 6MSt/t0.257 104t7.724MJ/t3122.0624114.79 803.83 7Instrument airNm3/t1.707 104 Nm351.2MJ/Nm31.1759.90 2.00 8Factory AirNm3/t0.893 104 Nm326.8MJ/Nm30.8823.58 0.79 9N2Nm3/t1.285 104 Nm338.55MJ/Nm311.72451.81 15.06 Total 305346.20 10178.21 5. Innovation Description5.1 Optimizing Separation SequenceAccording to patent CN 107011169A, the separation order of acetaldehyde, acetone and other light components was adjusted by traditional process, and then vinyl acetate was refined. Vinyl acetate and acetic acid were first roughly separated as light and heavy key components, then acetaldehyde, acetone and vinyl acetate were separated, avoiding the separation caused by the small content of acetaldehyde, acetone and other light components. High energy consumption。5.2 Fluidized bed reactorThe reaction feed is mainly acetic acid and acetylene, the main product is vinyl acetate, by-products are acetaldehyde, butenal, anhydride, acetone, carbon dioxide, etc.As far as production capacity is concerned, fluidized bed reactor has more advantages. The single production capacity of fluidized bed reactor can reach 180,000 tons per year, and the control of reaction temperature is relatively easy. The fluidized bed reactor can be operated by an automatic control device to optimize the reaction conditions.5.3 Modified three-stage cyclic absorption acetylene separation towerThree-stage cyclic absorption is adopted, the first stage mainly absorbs acetic acid and washes off catalyst powder, the second stage mainly absorbs vinyl acetate, and the third stage mainly absorbs acetaldehyde, which is compatible with fluidized bed reactor and reduces the amount of absorbent, thus reducing equipment and energy consumption in the second half of the process, and achieving the purpose of energy saving.The optimized acetylene separation tower was adopted, and the extraction position of reaction liquid was changed from the second stage to the third stage. At the same time, a certain amount of circulating acetic acid absorbent was added to the first and second stages, which improved the separation rate of vinyl acetate and acetaldehyde. The separation effect was good, the concentration of acetylene was high and the content of acetaldehyde was low.5.4 Heat pump distillation technologyThe temperature difference between top column and kettle of acetic acid tower is less than 10 C, which meets the conditions of heat pump distillation. After optimization, the energy consumption of single tower of acetic acid tower has been reduced by more than 70% and the energy consumption has been greatly reduced.。5.5 Neighboring Column TechnologyThe crude vinyl acetate tower and the refined vinyl acetate tower in the traditional process are integrated into an adjacent tower of vinyl acetate. The high quality vinyl acetate is extracted from the side line, while the equipment cost of the heat exchanger is reduced and the energy consumption is reduced.5.6 New type guide sieve trayA new type of guide sieve plate was selected to replace the cross-flow sieve plate in the crude fractionator of vinyl acetate. The horizontal airflow from the guide hole of the guide sieve tray tower drives the liquid flow on the tray uniformly and steadily, which greatly increases the anti-fouling and anti-blocking ability of the tower, and improves the mass transfer efficiency and production capacity. The pressure drop of tray can be reduced by 10%30% compared with that of traditional sieve tray column.5.7 Finned heat exchanger tubeIn the acetic acid superheater, finned tube is used instead of the original smooth tube, so that the purpose of heat transfer enhancement is achieved by adding fins to the ordinary tube. The heat transfer area of the heat exchanger is increased, and the turbulence of the heat transfer fluid is increased. The Reynolds number of the fluid in the shell side is increased, and the heat transfer of the heat exchanger is improved.6. Equipment designIn the design process of this project, the reactor of vinyl acetate and other equipment were designed in detail, and the heat exchanger, pump, compressor and other equipment were selected. See Typical Equipment Design and Selection in detail.7. Cleaner productionThis project is a clean production process of acetylene gas phase method, which is mainly embodied in the following aspects:（1）The fluidized bed reactor has high heat transfer efficiency and can give full play to the efficiency of catalyst；（2）Different from the traditional process, the new process of crude separation of acetaldehyde and vinyl acetate is adopted, which first crude separation of acetic acid and vinyl acetate, and then refining of vinyl acetate and acetaldehyde to reduce energy consumption；（3）The process realizes the total recycling of acetylene and the recycling of acetic acid absorbent with high utilization rate of raw materials；（4）In the design of this project, improved acetylene separation tower, heat pump distillation and partition tower technology are integrated, and the overall process is optimized to reduce by-products, energy consumption and carbon emissions；（5）The green catalyst is used in the reaction process, which basically ensures low pollution and even no pollution, and realizes the environmental friendly and economical production of the project.8. Site Selection and Layout of Plant Area(1) Location determinationPic 8.1 Site SelectionThe site of this project is located in Meike Chemical Industrial Park, covering an area of land 5km2。Meike Chemical Industrial Park is located in Korla Economic and Technological Development Zone. Korla Economic and Technological Development Zone is located in the southeast direction of Korla City. The Administrative Committee of the development zone is 8 kilometers away from the city center, 6 kilometers away from the new airport, 5 kilometers away from the Korla East Station, and from the north to the South Xinjiang Railway, the south to the Xiner Reservoir, the west to the new airport and the east to the Horla Mountain Cape. Depending on the mother city, the development zone can realize short-distance docking of roads, water, electricity and gas by means of the radiation function of the infrastructure of Korla City; secondly, the city brand effect of Korla City; and thirdly, it can rely on the abundant resources of Bazhou: there are 96 major rivers in Bazhou, such as the Tarim River, the Kaidu River and the Peacock River, and there are 96 large and small lakes. Among them, Bosten Lake, the largest inland freshwater lake in China, the largest power grid in Southern Xinjiang centered on Korla, the source of West-to-East Gas Transmission is abundant in petroleum and natural gas resources, and Luntai County in Bazhou is located in the territory of Bazhou. Bazhou is vast and has many geographic features, landscapes and cultural relics with its own characteristics. There are 56 kinds of mineral deposits in Kuerle and Yuli County, among which vermiculite, potassium salt, asbestos and jadeite account for the first place in the country. Complete public utilities and surrounding infrastructure in industrial parks can fully meet the needs of large industries and projects. (2) General plant layoutAccording to the concept of separation of passengers and vehicles, the general layout is divided into vehicle flow channel and personnel channel to reduce traffic resistance. Parallel arrangement was adopted to arrange the production area and living area on both sides of the radial trunk road in the plant area, so that they would not affect each other. And according to the concept of compact centralization, reasonable layout of the building and workshop location in the plant area, to achieve efficient, stable and safe production layout. The plant is 421m long, 281m wide in North and South direction, and its total area (excluding development reserve) is 113702m2. It mainly includes management area, auxiliary production area, production process area and storage and transportation area. We use AutoCAD to design the layout of the factory area. The layout of the factory area is shown in Figure 8.2.。Pic 8.2 Plane layout of plant area(3) Three-dimensional layoutThis project uses Auto CAD to draw the layout of equipment, determine the location of equipment, facilitate production, and design the three-dimensional plant area, as shown in Figure 8.3. See the source files of workshop facade, workshop three-dimensional layout and plant three-dimensional layout for details.Pic 8.3 Three-dimensional effect map of factory area9. Analysis of Safety EnvironmentBy using the software of Risk System