Word20130-Abstract

Zhenhai Refining & Chemical 180 kt propane resources utilization projectfev 四川大学远航团队1. Project DescriptionThis program is designed for Sinopec Zhenhai Refining a propane gas utilization, effectively combines petrochemical to polyurethane industry. The project uses 180000 tons propane , annual output of 207000 tons of epoxy propane, builds in Ningbo petrochemical economic and technological development zone. In the process of designing, we give considerations to both economic benefits and cleaner production. Clear thinking and highlight outstanding mainly embodied in the following aspects： In main plant light hydrocarbon recovery unit of C3LPG and gas separation device of purified carbon as raw material, is obtained by separation of the by-products can return factory specific device, realization of system integration; Process of hydrogen gas, propane, propylene, methanol and high pressu-re；steam six big circulation, improving the utilization ratio of atoms； The quench boiler, steam turbine, waste heat pump distillation, condensation on the double effect distillation, intermediate technology optimize the technological process, several energy saving technologies such as to improve efficiency, reduce energy consumption;Adopts the PSA process and HPPO environmentally friendly technolo-gy, efficient separation, reduce pollution, and the subsequent three wastes treatment in detail;Using new type reactor, improve the ability to respond to heat pipe reactor, the new plate separation ability, a new type of shielding pump to reduce energy consumption and heat exchanger to enhance performance.2. Product & Raw materialThis project design is 180000 tons/year of propane epoxy propane resource-oriented utilization system, the scheme USES the mixed feeding raw materials, from the main plant light hydrocarbon recovery unit of 178000 tons/year C3LPG and gas fractionation unit of 76000 tons/year of Refined carbon triple:Figure 1 C3LPG Component Figure 2 Refined carbon triple ComponentFormed mainly epoxy propane product and by-product propanediol methyl ether and hydrogen system of products.Table 1 Product schemeProducts namepropylene oxidePropylene glycol methyl etherhydrogenTechnical requirementGB/T14491-2001HGT3939-2007GB/T 3634.1-2006Specifications99.98%(mass fraction)99.95%(mass fraction)99.8%(mass fraction)Output219000 ton/year10800 ton/year7000 ton/year3. Process DesignAfter the product selection and process plan demonstration, we choose the improved Lummus Catofin companys ABB technology combined with the Heying and Wood companys HPPO technology. The process consists of the section for dehydrogenation of propane, propylene refining section, Po synthesis section. We have also realized the simulation of the whole process in steady state and optimized it. The design of methanol and itrile in the total process of recycling reflects the idea of circular economy. The process flow chart is shown in Figure 3, 4 and 5, detailed in the fifth chapter of the preliminary design specification.Figure 3 Process flow diagramFrom main plant oil refining light hydrocarbon recovery unit, C3LPG through hydrogenation of organic sulfur, dry off after inorganic sulfur and mix with purified carbon three from gas fractionation unit of purified carbon three, remove C4, C5 restructuring, then into reactor after preheating.Main stream through quenched waste heat boiler and other heat transfer equipment finished multi-stage heat recovery, after three compression removing residual moisture; Then enter the cryogenic separation system, start multi-stage cooling, separate the light components (hydrogen, methane, C2) and C3. Light gas through pressure swing adsorption, high purity hydrogen can be obtained. The main logistics after further removal C2 hydrocarbons, with raw materials mixed with aqueous acetonitrile solvent extraction distillation are then refined propylene, isolated propane cycle.Propylene into the propylene epoxide synthesis and purification steps, mixed with the raw material of hydrogen peroxide and the solvent methanol, then into the propylene epoxidation reactor. The reaction produces propylene oxide portion. After purging recover unreacted propylene, through the pre-refined column then separate crude propylene oxide, and then purify them to obtain the main product propylene oxide. Remaining materials are in methanol solvent for recycling and refining of propylene glycol methyl ether, obtain by-products propylene glycol methyl ether.4. Energy-saving Design Heat exchanger network optimizationThis project involved in many Utilities. In order to make full use of Energy, this project by using the Aspen Energy Analyzer software, according to the pinch design method, combined with the actual situation of the factory equipment arrangement, in meeting the design goal utility cost minimum and equipment cost minimum, under the condition of the various process flows and heat of the matching between the utility, designed a kind of optimum matching scheme of cold and hot flow stocks. more details will be shown in the Aspen process simulation source files and PID drawings.Each section of heat transfer network matching scheme as shown in figure4,5,the energy saving effect as shown in Table 3.Figure 4 the first and second heat exchanger network station matching schemeFigure 5 third stage of the heat exchanger network matching schemeTable 3 energy saving effect (unit: kW)55.7%48.9%We carried out the design of the heat exchanger EDR, see the source file in Exchange Design and Rating inside. Application of steam turbine Quenching waste heat boiler for heat recovery steam water mixture, after gas-liquid separation in the drum, saturated steam is heated and then promote turbine of three stage compression system of compressor acting directly instead of the original electric to energy supply. Which saved electric energy 57.1%. See more details in the “innovative notes”, the third chapter.Figure 6 steam turbine simulation flow chart Table 4 Before and after the comparison of power consumption Heat pump distillationHeat pump distillation in propylene purification device has many advantages simple equipment , low investment, good separation, low operating cost.After Aspen simulation comparison, the total energy consumption of the heat pump will save rectification 66.7%.See more details in the “innovative notes”, the third chapter.Figure 7 Heat pump distillation Table 5 Before and after the heat simulation flow chart pump distillation energy use Double-effect distillation Large amount of methanol and water will be separated after the epoxidation reaction.This heat pump distillation method can effectively reduce the condenser and reboiler heat load, reduce utility consumption and reduce production operating costs.This will save cold consumption 50.0%, save heat consumption 41.7% .See more details in the “innovative notes”, the third chapter.Figure 8 Double-effect distillation Table 6 Energy consumption before andsimulation flow chart after the use of double-effect distillation Intermediate reboiler technologyThe temperature difference between top and bottom PM recovery column reaches 25, so we use intermediate reboiler technology.Intermediate reboiler put in place, thereby reducing the diameter of the column and reduce operating costs.While doing so sufficiently reduce the high-energy, improved thermodynamic efficiency, operating cost savings of 21.6%. See more details in the “innovative notes”, the third chapter.Figure 9 Intermediate reboiler technology to simulate flow chart5. Equipment DesignThe project design process, mainly design detailed for off the heavy fractionator, epoxidation reactor and other equipment, select for the conduct heat exchangers, pumps, compressors and other equipment.For details see Typical equipment design and selection and reactor design specifications. Heat pipe isothermal reactorIn propane dehydrogenation reaction system, we used a heat pipe type isothermal reactor, isothermal guaranteed conversion rate.Isothermal reactor adopted a high heat transfer coefficient of heat pipe buried heating the reaction medium, enabling multi-stage adiabatic conversion rate of 34% to 38% increase on the basis of an isothermal reactor.See more details in the “innovative notes”, the fifth chapter. Figure 10 Heat pipe isothermal reactor Plate reactorIn the PO synthesis section, the epoxidation reactor is used industrial new plate reactor. The projects are designed tubular and plate reactor several different programs to compare the conversion of propylene oxide and propylene yields , correla-tion results see reactor design specifications and COMSOL source files. Compared to commonly used industrial tubular reactor, plate reactor can effectively reduce energy consumption, the amount of catalyst, to solve the problem of small heat transfer coefficient.See more details in the “innovative notes”, the fifth chapter.Figure 11 Plate reactor structures and simulation results The use of the new trayUsing new efficient 3 d in the taking off the heavy tower round valve tray, the structure as shown in figure 12. Using the new plate making bubbling evenly, mass transfer more fully, reduce the entrainment, improve the efficiency of mass transfer; Weakened part of the float valve closed under low load caused by the pulsation phenomenon, reduce the total plate pressure drop; Overcome the F1 type valve in the valve hole rotate, lead to wear and falls off easily float valve and unstable faults, weaken or eliminate tray arch of vortex and the viscous flow dead zone.See more details in the “innovative notes”, the fifth chapter.Figure 12 3D circular valve plate structure diagram New energy-saving shielding and magnetic pumpPumps used in this project adopted the new energy-saving shielding pump, it is fully enclosed, without the unique structure of the mechanical seal;Stator is made of stainless steel sleeve respectively shielding seal, conveying cooling liquid into the internal motor, so as to solve the common pump as the transmission medium, environmental pollution, poor reliability and maintenance difficulties, etc; Rotating part adopts stone mill bearings, lubricating medium, is an upgrading generation substitute for low noise green environmental protection. This project tankage pump adopts new no-load magnetic pump for the use of special customized rolling ceramic bearing, using imported non-metallic materials of sleeve, with the unique air cooling circulation structure design, so as to realize all-weather magnetic pump fluid deficiency no-load running temperature rise of the no, zero leakage, make sure the safety of production.See more details in the “innovative notes”, the fifth chapter. effective quenching waste heat boiler This project propane dehydrogenation section by high quenching waste heat boiler, adopt unique thermal protection structure and high efficiency dense spiral finned tubes, greatly enhancing heat transfer surface, can effectively guarantee the rapid cooling, inhibit the main logistics propane decomposition, and 10% of the high pressure steam to increase production. See more details in the “innovative notes”, the fifth chapter. 6. Cleaner production1This project uses the cleaner production processes of resource utilization of propane to product propylene oxide, mainly reflected in:2 Using route that C3LPG, refined carbon triple as a starting material, propane raw material resources utilization is an important way to the development of the petrochemical industry propane recycling economy and achieve energy saving, clean production, waste utilization and economic efficiency;3 Routing process for recycling propane, propylene and methanol, both to improve the utilization of the atom, but also reduce the waste discharge; By-product can be returned Plant: C1, C2 light components to the light hydrocarbon recovery unit, C4, C5 heavies to the hydrocarbon cracking apparatus, by-product hydrogen to the olefin hydrogenation apparatus;oxygen-enriched liquid to gas and methanol combustion pipe network, the rest of the liquid and solid wastes are 4treated effectively, realize the three wastes recycling use.Epoxidation process using the HPPO method and TS - 1 green catalyst , which can ensure a low level of contamination to no pollution, to achieve the project environmentally friendly, economical production.5Using efficient reaction, separation technology, at the same time complement carbon dioxide gas combustion, sent to the factory to recycle, reduce the yield of carbon emissions. 7. Plant location&Layout Site identificationFigure 13 Plant LocationThis project will be the site of factory in located in Ningbo Zhenhai Petrochemical Economic and Technical within the development area, close to Sinopec Zhenhai refining & Chemical Plant. Specific location shown in Figure13.Park in Zhejiang province as one of petroleum chemical industry focus on the development of oil refining bases, public facilities, the cluster to internal industrial chain advantage is obvious; Raw materials for liquefied petroleum gas (LPG) directly from the factory, convenient and quick; Three wastes treatment, utilities are supporting industrial supplies; Park has the governments preferential policy support and technical support of funds, pay attention to the health of the industry sustainable development. Plant arrangementAccording to the concept of the separation of people and vehicles, general layout sets traffic channel and channel staff, reduce traffic resistance. Using a parallel arrangement, production area and living area are arranged on both sides of the plant radial roads, so that the two do not affect each other. According to the concept of centralized and compact, rational planning plant construction area and workshop locations to achieve efficient production of stable and secure arrangement. Plant length is 325m, width is 240m, total area is 78000m2, including life and management areas, production support areas, production areas and storage areas and other technology areas. We use Autocad to conduct plant graphic design (the plant layout is shown in Figure 14).Figure 14 Plant layout The three dimensional layoutThis project use Auto CAD drawing of the layout of equipment, determine the location of the equipment, convenient production, for the factory 3 d design, as shown in figure 15. Flat facade detailed see workshop, workshop 3 d layout and 3 d layout source files.Figure 15 The factory 3 d renderings8.Security environment analysisEnvironment safetyFigure 16 Environmental safety design partThis project use Risk System software for the factory of epoxy propane, C3LPG, methanol storage area for major hazards identification and according to the material physical property are analyzed in the terminal material source, then according to the result of source phase analysis model of pool fire accident forecast, boiling liquid expanding vapor explosion prediction vapor cloud explosion prediction analysis, the damage of the accident; In addition to using the software of related tank vapor cloud explosion accident, BLEVE accident, pool fire accident, poisoning accident simulation; Using Noise System software in the factory and its surrounding environment Noise evaluation; Atmospheric estimation, using Screen3Mod EIAW water quality evaluation prediction software has carried on the aspects of the environmental impact assessment; Also adopted the HAZOP analysis software, dow chemical fire and explosion hazard index evaluation on the risk prediction for major hazards assessment set up after the combination of SIS and DCS and ESD control system, the implementation of the equipment and system stability control.9. Economic Benefit AnalysisOur economic and technical analysis follow relevant economic indicators and analysis methods. We fully understand the market price, aid of Aspen Economic Analyzer assisted calculation, make a detailed description of the whole plant investment, profits and cash flow estimates. Calculation shows that our total investment is 123307.0million yuan, annual profit was 72069.3 million yuan, the payback period is 6.55years. The results show that the factory is economically feasible, with high economic efficiency. For details, you can refer to the Feasibility Study Economic Analysis of chapter 19 - chapter 20.Table 10 comprehensive economic and technical indicatorsNummberIndex NameunitQuantity1Design scale10kt/year202Annual operation timehour/year80003Total project investmentMillion123307.04Investment in Fixed AssetsMillion68376.75Direct material costsMillion / year79761.16Total Capacityperson1347Annual costsMillion / year139759.98The whole plant output valueMillion / year2272609The total annual net profitMillion / year72069.310Investment profit rate%48.111Investment tax rate%56.512Internal Rate of Return%6.5513Payback periodyear21.9414Investment NPV (a