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NUC 1104m/h Flue Gas Desulfurization Unit Project of Sinopec TianjinAbstracttDonghua-shangu Chemical Cup the 11th National college studentss Chemical Design competition.NUCMember：t.Qi zw.Xia d.Liu lh.Li jj.ZhangAdviser：tc.Li y.Cheng yh.Wang zp.Ma zz.YangMind & Hand NUC 1104m/h Flue Gas Desulfurization Unit Project of Sinopec TianjinAbstract1.Project Profile Sinopec Tianjin is located in Tianjin Binhai New Area, east of Bohai Oilfield, south of Dagang Oilfield, of which refining capacity up to 15.5 million tons per year and monthly imports of high-sulfur crude up to 100 tons, thus generating a huge quantities of sulfur containing waste gases and causing serious environmental pollution.The goal of this design is to design a 1.4104/h flue gas desulfurization unit for Sinopec Tianjin, using Super Claus and SSR Technology. Its combustion section of acidic gas using Oxygen-enrichment Technology, with SO2 concentration of 6.36 mg/m3 and less than 35 mg/m3, thus achieve the standard of deep desulfurization.2.Technology Description2.1Raw Materials and Products Specifications2.1.1Exhaust Gas PropertiesTable 2-1 Composition Table of Sulfur Containing Waste GasMass Fraction/%H2SCOSNH3CH4H2OCO2Sour Water Stripping Unit89.4-1.7-7.11.8Amine Regeneration Unit82.10.78-0.31 Products SpecificationsMajor Products:StatusMolten SulfurPurityw% 99.9H2S Contentppm wt 10Few% 0.003Ash Contentw% 0.03Organic Matterw% 0.03Waterw% 0.1 Acidity (H2SO4)w% 0.003ASw% 0.001Mechanical Impurity无Colour (Solidity)Luminous YellowBy-products:Medium Pressure Steam: 4.4MPa; Light Pressure Steam: 1.2MPa.2.2Technology DescriptionThe project is divided into two workshops of sulfur recovery and tail gas treatment, and four sections of acid gas combustion, Claus reaction, tail gas treatment and molten sulfur degasification. The engineering flow sheet is as follows.Figure 2-1 The engineering flow sheet picture3.Equipment and Control3.1Equipment SelectionWe have designed the non-standard equipment burner, tower, reactor and gastube boiler. In this project, the reactor is designed independently, and the selective oxidation reactor is a fixed tube array reactor, which conforms to the characteristics and requirements of this process and is designedin a reasonable and detailed way. In addition, equipment selection for pump, compressor and tank is also carried out.3.2 Control SystemOur designed control system is mainly composed of DCS (Distributed Control System), which mainly uses information feedback to control the opening of the decompression valve, heating steam flow, cooling water yield and each bypass and valve flow, as well as the pressure, temperature and liquid level of each pressure vessel and piping.4.Energy Conservation and Consumption Reduction4.1 Heat-integrated Energy RecoveryThere is lots of logistics that needs to be heated or cooled in the process, and the demand for public works is huge. The energy recovery is very critical for a chemical industry that consumes a lot of energy, will directly affect the economic efficiency of the enterprise. We have used Aspen Energy Analyzer V8.6 on the process to optimize the design of heat exchanger network, and achieved the purpose of energy recycling and consumption reduction. The grand composite curve is as follows.4.2 Heat Pump Distillation TechnologyHeat pump distillation technology makes full use of the rectifying tower with small temperature difference and cross-pinch heat transfer, makes the flows originally cannot transfer heat have the possibility of heat exchange by changing the steam level, thereby increasing the ratio of recyclable energy to achieve a greater degree of energy saving.Table 4-1 Comparison of Energy Consumption of Normal Distillation and Heat Pump Distillation ProjectCondenser Duty (kW)Reboiler Duty (kW)Normal Distillation1674.141982.69Heat Pump Distillation51.900Electro-thermal Conversion:1224.16Total Energy Efficient65.10% Figure 4-1 Comparison of Energy Consumption of Normal Distillation and Heat Pump Distillation5.Cleaning ProductionThe project obtains value products though waste vapor treatment, with less three wastes in the process of production and convenient treatment. The amount of SO2 emissions reaches the standard of deep desulfurization, and thewaste residue is mainly the catalyst, which can be sent to the manufacturers for recycling after cyclic utilization. Industrial waste and domestic waste will be entrusted to the sanitation department to timely clean and make sanitary landfill and other harmless disposal. Furthermore, low-noise equipments are chose to make sound insulation, sound reduction and sound absorption measures. In addition, the plant is landscaping to improve the ecological balance. The HAZOP (Hazard and Operability Analysis) is used to quickly and effectively identify the dangers and put forward the corresponding measures.6.Factory Location and Layout6.1Factory LocationThe project is located in Nangang Industrial Zone, China. At present, the park is in accordance with the “multi-garden park” model and the development concept of circular economy, building thorough basic chemistry area, fine chemistry area, rubber and plastic processing area and food area, as well as further strengthening the landscaping of the park. The site of this project has convenient communications convenient for goods transportation.6.2 Factory LayoutThe factory is 170m long and 235m wide, with total floor surface of 39950m2, mainly including auxiliary production area, production area, storage tank area and plant front area. The non-production and non-storage areas of the plant are all equipped with green belt, which can be used to isolate noises and harmful factors to ensure the safety and environmental protection.We have used Auto CAD for the graphic design of the plant site, as well as 3D modeling software for the rendering of the stereo image. Figure 6-1 Factory layout picture6.3 Workshops and Pipes LayoutWe have used PDMAX to arrange the equipments layout and detailed piping layout for the tail gas treatment section.Figure 6-2 Pipes layout picture7.Economic AnalysisEconomic analysis is an important basis for the core content and decision-making of project feasibility study and assessment. Its role lies in maximizing risk and increasing investment efficiency. The economic analysis results of this project are shown in the following table:ItemDataOperationsFixed Assets178.16804 million yuanTotal Investment317.15024 million yuanRaw Material Cost3.7495 million yuan/yearOperating Cost34.9386 million yuan/yearSales Revenue113.667 million yuan/year Normal Period Gross Profit78.7284 million yuan/year Normal Period Net Profit66.7779 million yuan/year Normal Period Net Cash Flow66.7779 million yuan/yearProfitability Profit Rate of Investment22.21% Profit-tax Rate of Investment 24.8%Static Payback Time10 yearsFinancial Internal Rate of Return9%Financial Net Present Value-31.8582 million yuanUncertaintyAnalysisProduction and Sales Break Even Point41,900 tons/yearProduction and Sales Maximum Allowable Reduction50.67%Unit Price Break Even Point67.44 yuan/tonMaximum Allowable Price Reduction92%Operating Cost Sensitivity-1.058Output Sensitivity2.2Raw Material Price Sensitivity-0.118.ConclusionWethroughliteraturereviewa