02-Design Abstract1-设计文档Design Abstract2010版

1“Tung Wah Group of Science and TechnologyShaanxi Drum Cup”The Eleventh National Undergraduate Chemical Engineering Design ContestThe Project of Tianjin SDIC Jinneng Electric Power Co. 23,000,000Nm/h Flue Gas Desulfurization & Production of IS AbstractDESIGN UNITChangzhou University Institute Of Petrochemical TechnologyDESIGN TEAME.R.STHE NAMES OF THE MEMBERSZhu Xiaolei Yuan Qiao Yao EnTong Zhifang Jiang YunjiaINSTRUCTORMa Jiangquan Wang Jun Qi Lv Wei Kenian Gao Xiaoxin 2017年7月20日国投天津北疆21000MW机组烟气脱硫制IS项目 摘要1. Project DescriptionThe goal of this project is to design a deep desulfurization and resource utilization workshop for the Tianjin SDIC Jinneng Electric Power Co. The device is fully utilized the pre-treatment of the power plant flue gas and Binhai New Area Industrial Park to provide carbon monoxide as raw materials. The membrane absorption and desorption, reduction of sulfur, sulfur polymerization process and insoluble sulfur refining and purification process increase the value of products: 99.2% insoluble sulfur 、99.9% sulfur and 99.1% sodium sulfite. The treatment capacity of design flue gas is 6 million Nm3 / h and the amount of insoluble sulfur are 65,000 tons 、 the sulfur are 55,000 tons and the sodium sulfite are 6,160 tons.Finally, Sulfur dioxide emission concentration reached 5.9mg/Nm3 .The whole workshop is divided into absorption and desorption section, sodium sulfite preparation section, sulfur preparation section, insoluble sulfur preparation section and tail gas treatment section.2. Selection and Introduction of Process2.1 Waste Gas SourceIn recent years, Chinas eastern city of the sky was covered with a thick layer of veil. Poor air quality, low visibility, and severe weather pollution. People face the sudden changes in the weather attack by surprise - haze. The haze of the harm, not only for personal health, but also for social traffic caused a significant impact can not be ignored. The main cause of the haze problem is the large amount of sulfide emissions.The fog haze problem in the Beijing-Tianjin-Tangshan region is particularly serious, especially in the past few years in Tianjin haze problem is particularly prominent. Tianjin Jinneng Power Generation Co., Ltd. is a large coal power generation company in Tianjin. Taking into account the sulfur dioxide is the main source of atmospheric sulfur pollution, the project should eventually Zengneng Power Co., Ltd. desulfurization needs, select the power plant sulfur exhaust as a source of exhaust gas.SmogTianJinBeiJingFigure2.1 North China Haze ChartThe components of flue gas are as follows:Table2.1 Components of Flue GasNameComponent（%）N273.94CO219.79O25.99SO20.20NO20.05NO0.01HCl0.01HF0.012.2 Selection of ProcessThe flue gas selected from the Tianjin SDIC Jinneng Electric Power Co. is treated through the process of the membrane absorption and desorption, the intermediate sulfur, the use of low temperature melting method and the preparation of high purity insoluble sulfur. Finally, the flue gas is generate into a higher level of product in the market.This project uses membrane absorption reactor (absorbent is sodium sulfite) to absorb sulfur dioxide in flue gas. Comparing with the traditional process, the process has a higher selectivity of sulfur dioxide and absorbent can be recycled. For the production of high-purity sulfur dioxide wastewater by gas-liquid separator, sodium sulfite is the comprehensive by-product .At the same time, taking into account the low temperature melting method of low energy consumption, the device corrosion is small and environmentally friendly. In the end, we choose the low temperature melting method to produce insoluble sulfur.2.3 Introduction to the ProcessFigure2.1 engineering flow sheet2.4 Sulfur RecoveryThe sulfur content of flue gas in this project is 12.58 million tons per year, and the purity of 99.2% is 65,000 tons of insoluble sulfur, 99.9% of sulfur is 55,000 tons and 99.1% of sodium sulfite is 6160 tons.Taking into account the exhaust treatment section of ammonium sulfite and other sulfuric acid solution can still be resource utilization, the specific amount of ammonium sulfiteRecovery of sulfur: ：6.599.2%+5.599.9%+0.61603212699.1%=12.10 million tonsSulfur recovery: 12.1012.58100%=96.18%It can be seen that the recovery rate of sulfur is high and the resource utilization rate is high.3. Energy - saving design and innovation3.1 No large-scale public worksThe main product is insoluble sulfur and the byproducts of this project is sulfur. Due to the standard condition of insoluble sulfur is solid, we just need physical separation without the need of large-scale public works. The production of insoluble sulfur includes the quenching and the extraction. Considering insoluble sulfur and extractant CS2, respectively, in solid phase and liquid phase, we only need filter to get the product insoluble sulfur.During the general chemical production process, the energy consumption takes up about 40% of the total energy consumption, but the project does not need to set the distillation tower and energy-saving effect is quite obvious.3.2 The Optimization of Heat Exchange NetworkThis project uses the pinch analysis and thermal integration energy saving technology, combined with Aspen Energy Analyzer V9.0 software, has been applied to the system of heat exchange network program, so that the plant area of hot and cold process logistics in a reasonable range of heat transfer, so as to achieve Save energy for the purpose. Compared with the heat transfer technology, the energy recovery rate (energy saving rate) of the heat exchange network after thermal integration is 31.9% compared with the heat transfer network which is not directly connected with the common engineering.Heat exchange network as shown:Figure3.1 Heat Exchange NetworkThe use of thermal integration before and after the energy comparison is as follows:Table3.1 Comparison of Energy Consumption Before and After OptimizationCold Utility 2orks /MWHot Utility 2orks /MWTotal/MWOptimize the Amount of Utility Before Use317.9215.8533.7Optimize the Amount of Utility After Use284.778.27362.97Energy Saving /%10.5%63.7%31.9%Annual Reduction in Carbon Dioxide Emissions/ton1,010,0003.2 Application of mechanical steam recompression (MVR) technologyIn this project, the mechanical steam recompression (MVR) technology is used to treat the cooling tower wastewater. The process is as follows：Figure3.2 MVR flow chartWhen the waste water enters the evaporator, most of the water is evaporated into low pressure steam, which is compressed by the steam compressor to improve the temperature and pressure, increase the enthalpy value, and improve the taste of the steam. The compressed steam is sent into the evaporator to carry out heat exchange with the material so as to make full use of the latent heat of the steam so as to achieve energy saving effect.Compared with multi effect evaporation, multi effect evaporation needs to consume a lot of steam and cooling water, and can not effectively utilize heat energy. The advantage of MVR evaporation technology is its low energy consumption.4. Process plan innovation4.1 Membrane absorption processThe composition of pretreatment of the flue gas from the power plant is complex. The proportion of SO2 is low and the most is N2 and CO2. The conventional absorbent is alkaline, but the absorption of SO2 is generally not high and it is difficult to be absorbed after the use of desorption. In view of this, we use membrane separation technology for flue gas desulfurization and combine with WL FGD method to improve the selectivity of sulfur dioxide. Meanwhile, the process of Na2SO3 absorbing SO2 is chemical absorption and the driving force is huge. The product is Na2HSO3 which is instability. Na2HSO3 can decompose into Na2SO3 which can be recycled.Figure 4.1 membrane absorption reaction principleAs shown in Figure 4.1, the flue gas from the power plant enters the hollow fiber membrane tube. The absorber walks the shell. O2 and N2 quickly reaches the saturation in the absorption solution. Therefore the mass transfer stops. When the absorption liquid pH 8.2 , alkaline sodium sulfite solution only absorbs SO2.Considering the small amount of soot particles in the flue gas, in order to reduce membrane fouling, the hollow fiber membrane module is made of stepped membrane, as shown in figure 4.2:Figure 4.2 shoulder holeBecause the ash particles are large and can not pass through small holes, the pollution of the membrane is mainly caused by the pollution of the filter cake layer, and the utility model can be used continuously only by simple washing.Using membrane absorption process includes following advantages: increasing selectivity to sulfur dioxide absorption, increasing sulfur dioxide purity, reducing tower equipment costs, saving investment costs, reducing sulfur dioxide re-separation requirements and saving energy.4.2 Highly efficient and energy-saving technology of refining ISTaking into account the added value of sulfur dioxide as raw material, the complexity of the production process and the energy consumption of the production process, the insoluble sulfur was selected as the target product after investigation. As the raw materials of sulfur and product of insoluble sulfur in carbon disulfide solubility varied greatly by the reactor after discharge are often warm water quenching, filtration, middle grade insoluble sulphur extraction, drying, filtration, high grade insoluble sulphur dry, insoluble sulfur can obtain high quality, without the need for rectification the complex operation, save cost, reduce energy consumption. The scheme is green and valuable, the market can be adjusted and the economy is feasible.4.3 The utilization of infusion pump and liquid delivery pipeline degassing device In the desorption section, the rich liquid transported from the front stage membrane absorption section contains the superfluid gas permeated through the membrane. After desorption, the target product SO2 is mixed with other gases and the separation energy is high. Therefore, the project intends to use liquid infusion pump liquid delivery pipeline degassing device to separate gas-liquid phase from the rich liquid in the pump, to solve the problem of separating the desorption of gas mixing.Figure4.3 schematic diagram of degassing device for infusion pump 5. Site selection and plant layout5.1 Site selectionIn recent years, China has gradually become one of the harsh haze of the country, the annual winter and spring season, many cities and regions will be a wide range of haze weather, not only affect the travel safety, but also endangering the health of the people. Among them, the North China, especially in Beijing, Tianjin, the pollution situation is worrying.One of the important causes of haze is the emission of sulfur-containing emissions, while SO2 in the tailings of thermal power plants is the main source of sulfur-containing waste gas. Taking into account the requirements of Tianjin Guozheng Jinneng Power Generation Co., Ltd., as well as the strength of the surrounding chemical industry, we will choose the site in Tianjin Binhai New Area, Tianjin Guozheng Jin Power Co., Ltd. expansion of the land.5.2 Plant layoutFigure5.1 General layout planThe layout of the plant takes into account the factors such as the terrain and geological structure of the plant. The production and product nature, characteristics and technological process of the project are finally determined.Factory set up five import and export. One of the East Gate for the main entrance of the factory, is the central control room, mainly for the workshop staff to get off work and out, belong to the people out of the entrance. East Gate on the 2nd and the East Gate for the fire entrance, near the tank area and the production area, an emergency when the fire truck to facilitate access to the first time fire. No. 2 East Gate and North Gate connected with the main road, specifically for trucks to transport goods (raw materials and products) and so on.6. Economic evaluationTable6.1 Major technical and economic indicatorsNO.Project NameUnitNumberProduction scalet/a65,000Product scheme1ISt/a65,0002St/a55,000Main raw and auxiliary materials dosage1flue gasMNm3/a45,0002COMNm3/a5453Na2SO3t/a88.684Ammoniat/a36,0005（NH4）2S2O8t /a4676FeClt /a9.27CS2t/a9608NaOHt/a53689Cu-Al2O3 t /a2.2Annual working dayday330Utility Consumption1Annual Power ConsumptionkWh /a28,068,0002Cooling Watert/a5,274,0003Low Pressure Steam（0.8MPa）t/a672,0004Medium Pressure Steam（4MPa）t/a98,0005Molten saltt/a265,0006AirNm3/a25,200,000Project PersonnelPerson54Total Project InvestmentYuan546,000,0001Construction InvestmentYuan468,000,0002Working CapitalYuna56,253,300Total Sales RevenueYuan543,000,000Annual Total CostYuan516,000,000Total Annual ProfitYuan236,000,000Annual Sales Taxes and SurchargesYuan76,407,500Annual Income TaxYuan146,285,400XIIIFinancial Evaluation Index1Investment Profit Margin%43.322Investment-Profit and Tax Ratio%84.063Payback Period of Investmenta7.054Financial Internal Rate of Return%25.07SummaryFirst of all, we access the literature and market research to determine the raw materials and product programs. Finally, we draw a desulfurization target of a power plant flue gas and decide to restore the sulfur as the intermediate process and produce insoluble sulfur as the core. The by-product is sulfur. And then we use Aspen