02-Design Abstract02-Design Abstract2010版

1“Tung Wah Group of science and technologyShaanxi Drum Cup”The tenth national undergraduate chemical engineering design contestZRCC 250kt/a PO and 80kt/a IPAproject PickDESIGN UNITChangzhou University Institute Of Petrochemical TechnologyDESIGN TEAMK.MTHE NAMES OF THE MEMBERSZhang Shaobo He Runxia Liu WenhaoMiao Kangjing Yang WenyaINSTRUCTORMa Jiangquan Gao Xiaoxin Wang Jun Wei Kenian Yang Deming2016. 8. 15镇海炼化25万吨/年环氧丙烷、8万吨/年二异丙醇胺生产项目 摘要1.Project IntroductionThe aim of this project is designing a branch factory to produce propylene oxide with clean production process for Zhenhai Refining and Chemical Corporation.Through the comprehensive utilization of propane which is pretreated by desulfurization unit in main factory , hydrogen peroxide and other raw material from Ningbo Zhenhai Chemical Industrial Park,The branch factory produces high value-added products such as 99.9% propylene, 99.98% of propylene oxide and 99.9% IPA,by processes of pressure swing adsorption separation, propane dehydrogenation, selective hydrogenation,epoxidation of propylene,etc.The expected production capacity of the branch factory is 250,000 tons propylene oxide per year as main products.200,000 tons propylene per year and 80,000 tons IPA per year are the by-product of this project.The whole plant is divided into propane dehydrogenation section, propylene purification steps, the epoxy chemical segment and isopropanolamine section.2.The introduction Of Process Selection2.1 Process selectionThis project use Oleflex and HPPO process, have the advantages of the short process flow, less by-products and environmental protection. The high purity product manufactured by this project, and the product can be used as high quality polymerization product raw material. Meanwhile, IPA manufactured by supercritical process, has the advantages of high selectivity, without catalyst and short reaction time, compared with the traditional process. By controlling the reaction time, also can adjust the proportion of the MIPA, DIPA, TIPA. This project has ample, high value-added products and strong ability to resist risk.2.2 Process IntroductionFigure 2.1 Process flow chart3.Energy-saving Design And Innovation3.1Application of heat pump rectificationT0203 for propylene refining tower, tower temperature 41.86 , column reactor temperature 53.78, the temperature difference is small. Separated system components due to close boiling point is difficult to separate, must use higher reflux ratio, and thus consume large amounts of steam heating. Because propylene refining tower operating pressure is higher, so this project adopts the tower kettle flash heat pump distillation, bottom discharging liquid as working medium, the throttling flash buck, as a cooling agent after cooling, heat transfer into the heat exchanger.T0203 process below for propylene refining tower, tower temperature 41.86 , column reactor temperature 41.86 , temperature difference is small. Separated system components due to close boiling point is difficult to separate, must use higher reflux ratio, and thus consume large amounts of steam heating. Because propylene refining tower operating pressure is higher, so this project adopts the tower kettle flash heat pump distillation, bottom discharging liquid as working medium, the throttling flash buck, as a cooling agent after cooling, heat transfer into the heat exchanger. Process the diagram below:Figure3.1 the Schematic diagram of heat pump rectificationprojectConventional rectifying columnHeat pump rectifying columnOverhead temperature /41.8641.86Column temperature /53.7853.78Overhead pressure /MPa1.751.75Top propane concentration /wt%0.9990.999Condenser heat load /kW79003.7/Thermal load of tower kettle /kW76903.9/The flash tank heat load /kW/58150.1Compressor load /kW/56049.3Total energy consumption /kW155907.6114199.4Energy conservation26.75%Table3.2 the contradistinction of heat pump rectification and conventional rectificationAlthough the use of heat pump distillation adds a compressor, a flash tank, but the energy saving effect is very obvious, feasible.3.2 Dividing Wall ColumnIndustrial separation three-component system to use more conventional distillation model, and the use of divided Wall Column enables column heat integration, and ultimately play a role in energy conservation. Compared to conventional distillation model, dividing wall distillation less a distillation column, in a distillation tower to complete the task, reducing equipment investment. Isopropanolamine section conventional distillation process requires two towers (MIPA separation column, DIPA separation column), equipment costs and energy consumption is very high, so we use the dividing wall distillation. Dividing wall distillation column is actually the equivalent of a thermally coupled distillation column, it will be two towers of conventional processes condense them into one column, while eliminating the need for a reboiler and a condenser, the flowcharts are as follows:Figure 3.2 the model of heat pump rectifying columnSimulation results show that, after the use of dividing wall distillation, to achieve the same product purity requirements, dividing wall distillation column a distillation savings. Reduce total energy consumption 904.69kW, saving 20.84%. Comparative results are shown in table 3.2.Table 3.2 the contradistinction of different application of columnProjectTwo tower separationDividing Wall Column Column ColumnMIPA separation塔DIPA separation塔process parametersTheoretical plate number202030reflux ratio559Operating pressuredecompressiondecompressiondecompressionFeeding position7712MIPA discharge positionTop of a tower/Top of a towerDIPA discharge position/Top of a tower15Steam distribution ratio/0.70Liquid phase distribution ratio/0.71Energy consumption indexCondenser heat load / (kW)-6851.49-5458.62-10908.6Saving energy /%11.38Heat load of the boiler（kW）7048.935467.6011117.4Saving energy /%11.18Product indexMIPA w/%99.9999.92DIPA w/%99.9899.99TIPA w/%99.9099.524.The innovation of progress4.1 The process of reactive distillation and hydrogenationPropane dehydrogenation feed gas mixture through the reaction in the presence of a small amount of MAPD (propyne and propadiene), in order to increase the propylene yield and purity, selective hydrogenation method often used industrially mixed gas of MAPD conversion of olefins and alkanes. We refer to petroleum cracking component C3 hydrogenation process, combined with the propane dehydrogenation process with its own characteristics, the original selective hydrogenation reactor and a deethanizer merged into a reaction distillation column, the details are as follows :Figure 4.1 the model of reactive distillation rectifying columnShown in Figure 4.1, by the pressure swing adsorption device for separating a mixture of gas and hydrogen gas into the reaction distillation column. The feed gas mixture from the reaction zone above the liquid hydrogen from the gas phase reaction zone below the feed contacting gassed react。Overhead vapor recovery and unreacted hydrogen oxide; propylene oxide recovery column reactor mixture, wherein the content of 36ppm MAPD.The project uses reactive distillation process has the following advantages: improved selectivity to olefins; Reducing byproducts green oil pollution of the catalyst bed；Column temperature is determined by the boiling point at the operating pressure of the column material, easy to control；Eliminating the need for selective hydrogenation reactor and connected devices, shorten the process and reduce the cost of investment.5.Site selection and plant layout5.1 Site selectionNingbo Chemical Industry Zone is located in the south bank of Hangzhou Bay, the northwest side of the vast sea area of Ningbo Zhenhai coated with a planned area of 56.22 square kilometers. Currently Chemical Industry Park has developed an area of 6.5 square kilometers, Zhenhai Refining & Chemical, LG Yongxing, gold Petrochemical Co., Ltd., Hangzhou Bay, acrylic, Sinochem import and export companies, more than 70 enterprises settled in the park. In accordance with the Ningbo Chemical Industry Zone Master Plan (2002-2020), focuses on the development in oil refining and ethylene as the leading source of petrochemical industry, synthetic materials industries, polymer products industry and fine chemical industry. Park, water and land transportation convenient, accessible, regional obvious advantages, this project is located in the development of the park land in the north.5.2 Plant layoutConsider the plant arrangement terrain, geological structure of the plant and other factors, the project integrated production and product properties, characteristics and processes to finalize the plant layout. Figure 5.1 layout chartFactory setting five import and export. One in which the East Gate is the main entrance of the plant, is on the administration building, mainly for company employees out of work, which belongs to the flow entrance. East Gate and North Gate II is connected with the main road, dedicated to trucks transporting goods (raw materials and products).Simon entrances for the fire, convenient and close to the tank production plant area, an emergency fire access, easy to fire the first time.6.Economic evaluationTable 6.1 main technical and economic indicatorsNAMEQUANTITYUNITCOST/（MILLION）PERCENTAGE OF TOTAL COST/%PROPANE580KT16820041.72HYDROGEN PEROXIDE600KT7500018.60LIQUID AMMONIA1KT2020.560.50METHANOL75T13.050.003Pt-Sn/Al2O3 CATALYER333T149853.72TS-1 CATALYER170.3T17030.42COOLING WATER397256KT39725.69.85LOW PRESSURE STEAM（1.4MPa）3392KT5088012.62MEDIUM PRESSURE STEAM（4.3MPa）149KT2607.50.65ELECTRICITY40145KKT/H2609.420.65COOLING WATER CIRCULATION222900KT4458011.06THE CONSUMPTION OF GAS2604KM3/N822.860.20TOTAL403147.00100.007.SummaryFirstly, we review of the literature and market research to determine the raw materials and product solutions, in order to determine a production of propylene oxide as the core, by-product propylene, DIPA process route. Then using Aspen Plus software to complete the detailed calculation of the whole process, the use of Aspen and other software to complete the process simulation, equipment selection and design, design automation, integrated network computing and thermal economic evaluation; use checking conducting towers Cu