对二甲苯辽宁石油化工大学设计中英文摘要

1、齐鲁石化23万吨/年对二甲苯项目-设计摘要设计摘要一.工艺设计1.1 原料消耗及产品方案1.1.1原料消耗本项目利用齐鲁石化的脱戊烷油和裂解汽油为主要原料生产对二甲苯，大力发展芳烃联合装置一体化产业链，实现资源多级利用。原料具体规格、消耗量及来源见表1。表1主要原料消耗原料名称级别数量（万吨/年）来源脱戊烷油工业级52总厂提供裂解汽油工业级38总厂提供甲醇优等品9.74山东兖矿集团氢气优等品3.17总厂提供乙二醇优等品0.012华鲁恒升1.1.2产品方案本项目主要生产优等品对二甲苯，同时副产苯、混合二甲苯和C9芳烃等，丰富产品的结构，具体规格、级别和产量见表2。表2 产品生产方案产品名称规格（

2、%）级别产量（万吨/年）对二甲苯99.9优等品23苯99.9优等品21.75混合二甲苯99.8一级品15.33C9芳烃99.3工业级14.331.2工艺选择本项目分为三个单元：芳烃抽提单元、甲苯甲醇烷基化单元和熔融结晶单元。芳烃抽提单元采用的是GTBTX工艺，该工艺优点在于Techtiv-100th溶剂溶解性和选择性好，芳烃收率和产品纯度高，且溶剂循环比低；甲苯甲醇烷基化单元采用的是大连理工大学开发的工艺，该工艺优点在于对二甲苯选择性高达97%，并且利用了产能过剩、价格相对低廉的甲醇，使对二甲苯产品成本降低；熔融结晶单元采用的是苏尔寿MWB工艺，该工艺的优点在于能耗低，污染小，且对二甲苯的回收

3、率达96%，纯度达99.9%以上。三种先进的工艺联用从根本上达到了节能、降耗、减污和增效的目的，可实现对二甲苯项目的清洁生产要求。1.3催化剂的选择本项目选择的是Si、P、Mg复合改性的ZSM-5催化剂，以达到提高对二甲苯选择性的目的。通过Si改性可以覆盖催化剂外表面的强酸中心，抑制PX异构化，同时对孔口也有一定的微调作用。P和Mg改性可以覆盖催化剂孔内的强酸中心，因而酸度降低，同时孔径缩小，孔道弯曲度增加，从而加大了孔内扩散阻力，因此PX的选择性接近100%。同时，Si-P-Mg/nHZSM-5中分子筛含量约67%，此时催化剂强度较好，积碳速率较慢。1.4 工艺模拟本项目采用Aspen Pl

4、us软件进行了工艺模拟。首先对连续操作的芳烃抽提单元和甲苯甲醇烷基化单元进行了全流程模拟，对间歇操作的熔融结晶单元进行了单独模拟；然后对精馏塔进行了工艺优化、工况分析以及塔径校核，对精馏塔的工艺参数和结构参数进行了初步设计，为CUP-Tower水力学校核和SW6-2011机械强度校核做好了准备；本项目还对反应器进行了反应动力学模拟，结果发现经过一段反应器，甲苯转化率为11.18%，,对二甲苯选择性为97.65%，停留时间为0.26s；最后对换热器、结晶器、泵、压缩机和储罐进行了初步设计。图1 连续操作全流程模拟图2熔融结晶单元模拟二.节能设计2.1热集成通过Aspen Energy Analy

5、zer软件，然后根据夹点设计法，最终确定换热网络方案如下：图3 优化后的换热网络图4 换热网络优化对比2.2水集成通过Water Design软件，然后通过水夹点技术分析，最终确定的用水网络方案如下：图5 优化后的用水网络表3 用水网络优化对比用水网络水源新鲜水用量节水率初步全部新鲜水213.06t/h50.35%优化再生复用105.79t/h2.3双效精馏由Aspen Plus流程模拟结果可知：甲苯塔（T0201）再沸器热负荷为33488.701 KW。拟采用双效精馏技术，以达到节能的目的。模拟结果发现，高压塔塔底再沸器热负荷为25992.033 KW，单塔塔底再沸器热负荷为33488.70

6、1 KW，节能22.39%。2.4热偶精馏同样，对于本项目的苯、甲苯和二甲苯（BTX）分离，拟采用热偶精馏技术，以达到节能的目的。模拟结果发现，主塔塔底再沸器热负荷为26189.526KW，单塔再沸器热负荷之和为31281.734KW，节能16.28%。三.控制方案3.1控制系统的选择本项目选择了较为先进的DCS控制系统，它集分散控制、集中操作和分级管理于一体，不但提高了操作系统的稳定性，且功能更加齐全、使用更加灵活，且易于维护。3.2典型控制在常规控制方案的基础上，本团队绘制了24张PID图。并应用分程控制系统和比值控制系统分别对结晶器的温度、反应器的进料比例进行了有效控制。 图6 溶剂回收

7、塔PID图3.3原因-后果分析法对于精馏塔常出现的灵敏版温度上升问题，分析其原因是塔釜采出量减少，塔的温度升高。造成的后果是塔的压降增加，塔的分离效果下降，采取的措施是增设温度控制和液位连锁。3.4动态控制本项目运用Aspen Dynamics软件模拟了精馏塔的动态控制，并通过添加干扰来分析其对控制参数的影响。现以苯塔为例，其动态模拟截图见如图7。图7 苯塔动态模拟四.厂区布置4.1厂址选择通过对山东省淄博市临淄区、广东省茂名市茂南区、上海市金山区这三个备选场址条件的对比，最后山东省淄博市临淄区以其优越的地理位置、丰富的原料来源以及优惠的国家政策成为最佳建厂地址。本项目的厂区总面积为89457

8、.9m2，主要包括工艺区、辅助生产区、储运区、生活区等功能区。如图8为厂区总平面布置图。图8总平面布置图4.2厂区布置本项目运用PDMS软件绘制了三维车间、三维配管和管廊图。图9芳烃抽提车间三维图五.环境与安全5.1三废及噪声的处理（1）本项目废气主要是可燃烧气体，送往厂区锅炉房。（2）本项目废水主要有工艺废水和生活污水。对于工艺废水，送往厂区的污水处理站进行初步处理后部分循环使用，部分通往园区污水处理总站集中处理；对于生活污水，直接排入厂区排水主干沟进入城市污水管网。（3）本项目的废渣，主要是废催化剂等，按照协议交给催化剂厂家处理。（4）本项目的噪声，主要是生产中机泵产生的，因而采用低噪声的

9、电机。此外，本项目还采取种植抵抗和吸收有害气体的绿色植物和应用环境生物技术等方案实现环保生产。5.2环境模拟评价本项目在提出合理的三废及噪声的处理方案的基础上，运用分别EIAProA、Eiaw和Eian软件对大气环境、水环境和噪声环境进行模拟评价。由大气环评软件EIAProA，由SO2筛选结果得到SO2排放后，大气等级为三级。由淄博市城区环境空气质量功能区管理规定，临淄区为三类区，执行环境空气质量标准（GB3095-1996）三级标准，因而SO2可以直接排放，如图10所示。图10 污染物SO2的筛选结果由噪声预测评价软件Eian得到厂区噪声分布图，如图11所示。其噪声声级和面积见表4所示。图1

10、1 厂区噪声分布图表4 噪声声级和面积声级面积51.0-59.04.49E0456.0-61.06.33E0461.0-66.03.57E0466.0-71.01.44E045.3环境风险评价本项目运用Risksystem软件对厂区的重大危险源进行了辨识。如图12是对二甲苯的蒸气云爆炸模型伤害范围图。图12 对二甲苯的蒸气云爆炸模型伤害范围6.经济分析本项目采用用友T6财务软件对本项目的现金流量、投资成本估算、风险评估以及可行性分析进行了较详细的说明。分析结果表明，本项目在经济上是可行的。表5 经济技术指标总工程投资（万元）98079.40固定资产投资（万元）64495.37总成本（万元/年）

11、683035.93投资利润率（%）43.72年销售收入（万元/年）747620投资回收期(年）6.37投资利税率（%）58.13盈亏平衡点BEP（%）69净现值NPV（万元）63112财务内部收益率（IRR）(%)237.总结本项目确定了一条GT-BTX芳烃抽提、大连理工大学开发的甲苯甲醇烷基化工艺和苏尔寿MWB工艺相结合生产对二甲苯并副产苯和混合二甲苯的工艺路线，编写了可行性报告和初步设计说明文档并绘制了相应图纸。本项目使用Aspen等软件完成了工艺流程模拟、反应器动力学模拟、精馏塔动态模拟、设备选型与设计等；使用AutoCAD软件绘制了工艺物料流程图（PFD）、管道及仪表流程图（PID）、

12、总平面布置图、关键设备装配图和车间设备布置图；使用 PDMS软件进行了车间管道布置及车间三维配管设计以及管道碰撞分析等工作；使用Risksystem、EIAProA、Eiaw和Eian进行环境影响评价分析；最后结合3D模型用3Dmax、Lumion和会声会影软件制作了厂区3D漫游视频。Design Summary1. Process design1.1 Raw material consumption and product solutions1.1.1 Raw material consumptionIn this project, para-xylene is produced with

13、pentane oil and pyrolysis gasoline of Qilu petrochemical company. The industrial integration of the aromatic combination plant is developed vigorously, to realize the multilevel utilization of resources. Raw material specifications, consumption and sources are shown in the table 1.Table 1 Main raw m

14、aterial consumptionName of raw materialLevelThe number(ten thousand tons/year)SourcePentane oilIndustrial-grade52Factory to providePyrolysis gasolineIndustrial-grade38Factory to provideMethanolClassy article9.74Shandong YanKuang groupHydrogenClassy article3.17Factory to provideEthylene glycolClassy

15、article0.012China Shandong HengSheng1.1.2 Product solutionsIn this project, the main production is classy article p-xylene, at the same time, by-product, benzene, xylene mixture and C9 aromatic. These enrich the structure of products. Their specifications, level and yield are shown in the table 2.Ta

16、ble 2 Production planName of raw materialSpecifications（%）LevelProduction (ten thousand tons/year)Paraxylene99.9Classy article23Benzene99.9Classy article21.75Mixed xylene99.8First class15.33C9 aromatic99.3Industrial-grade14.331.2 Process selection This project is divided into three modules: microcou

17、lometric yuan bills of lading, toluene, methanol alkylation unit and melt crystallization unit. Aromatic extraction unit is the GT-BTX process. Techtiv-100th solvent has good solubility and selectivity, and high aromatics yield, high product purity, and low solvent circulation.In the toluene and met

18、hanol alkylation unit, the process developed by Dalian university of technology is utilized. The process has many advantages, such as high P-xylene selectivity, low price methanol because of excess production capacity, to make P-xylene product cost reduction. In the melt crystallization unit, MWB pr

19、ocess is used fully. The process features low energy consumption, low pollution, and 96% of P-xylene recovery rate, more than 99.9% of purity.The combination of three advanced technology achieved fundamentally the energy conservation, consumption reduction, the purpose of reducing the pollution and

20、increasing the efficiency, and can realize clean production requirements for xylene project.1.3 The selection of the catalystIn the project, Si, P, Mg composite modified ZSM-5 is used as catalyst, in order to improve the P-xylene selectivity. Through Si modification, the acid center in the surface c

21、atalyst is covered, to inhibit PX isomerization, fine-tuning to orifice. P and Mg modification can cover the hole of the acid center, thus reducing acidity. The narrowing aperture, increasing holes curvature enlarges the holes diffusion resistance, thus reaching almost 100% of PX selectivity. At the

22、 same time, in the Si-P-Mg/nHZSM-5, molecular sieve content is about 67%. The catalyst has good strength, and slow carbon deposition rate.1.4 Process simulation The process is simulated with Aspen Plus software. The whole process is simulated for aromatic extraction and toluene and methanol alkylati

23、on process. At the same time, the process for melt crystallization unit is simulated. The rectification tower is optimized, the condition is analyzed and tower diameter is checked. The process parameters and structure parameters of rectification column are obtained. This is preparing for the Cup-Tow

24、er hydraulics and mechanical strength SW6-2011 respectively. In this project, reactor dynamics simulation has been done for the reactor. The results show that the toluene conversion was 11.18% after a reactor, P-xylene selectivity is 97.65%, and residence time is 0.26 s.Finally, the heat exchanger,

25、crystallizer, pump, compressor and storage tank has been designed.Figure 1 Continuous operation process simulationFigure 2 Melt crystallization unit simulation2. Energy saving design2.1 Heat integrationBy Aspen Energy Analyzer software, the heat exchange network scheme is determined according to the

26、 pinch design method. The results are as follows:Figure 3 The optimized heat exchange networkFigure 4 Comparison of heat exchange network2.2 Water integrating Through the Water Design software, the scheme of Water network is finally determined by the Water pinch technology analysis. The results are

27、as follows:Figure 5 Water networks after optimizationTable 3 Comparison of Water network optimizationWater networkWaterFresh water consumptionWater saving ratePreliminaryAll the fresh water213.06t/h50.35%OptimizationRegeneration reusing105.79t/h2.3 The double-effective distillationThe process simula

28、tion results show that the heat load for toluene (T0201) tower reboiler is 33488.701 KW. The double-effective distillation technology is utilized to save energy. Simulation results show that the heat load for the high pressure tower bottom reboiler is 25992.033 KW, heat load for the double tower bot

29、tom reboiler is 33488.701 KW, saving 22.39% of energy.2.4 The thermal coupling distillationFor the separation of benzene, toluene and xylene (BTX), thermal coupling distillation technology is adopted, in order to save energy. Simulation results show the heat load of the main tower bottom reboiler is

30、 26189.526 KW, the heat load of heat exchanger is 31281.734 KW, saving 16.28% of energy.3. Control scheme3.1 The choice of control systemIn the project, advanced DCS control system is chosen, which combines with decentralized control, centralized operation and decentralized administration. This cont

31、rol has not only the stability operating system, and f complete unction, more flexible application, and easy to maintain.3.2 A typical controlOn the basis of conventional control scheme, 24 PID figures are made. With Ratio and relay control, the crystallizer temperature and the feed rates in the rea

32、ctors are controlled effectively. Figure 6 PID of solvent recovery tower 3.3 Cause-consequence analysisThe reason is tower kettle flow decreasing for sensitive temperature rising. The consequence is pressure drop increasing, the separation effect of tower is dropping. The measure is establishing the

33、 temperature control and liquid level chain.3.4 Dynamic control In this project, the dynamic control of rectification tower is simulated with Aspen Dynamics software, by adding the disturbance to analyze the effect on the control parameters. As an example of the benzene tower, the screenshot of dyna

34、mic simulation is shown in figure 7.Figure 7 Dynamic simulation of benzene tower 4. Plant layout4.1 Site selectionCompared with Zibo Linzi district, Shandong province, Maoming city, Guangdong province, southern district, Jinshan district, Shanghai, the site is chosen to Zibo Lnzi district, Shandong

35、province because of excellent geographical location, abundant raw material sources and preferential policiesThe total area of the plant is 89457.9 m2, mainly including the process area, auxiliary production area, storage area, living area and other functional areas. The general layout is shown in fi

36、gure 8.Figure 8 General layout4.2 Factory layoutIn the project, with PDMS software, 3D workshop, 3D piping and pipe rack pictures are made. Figure 9 Three-dimensional figure of the aromatics extraction plant5. Environment and security5.1 Three wastes and noise treating(1)In the project, these are ma

37、inly non-organization waste gas and combustible gases. It is sent to the main factory after collection for the non-organization waste gas. It is sent to boiler room for combustible gas.(2)The wastewater mainly includes process waste water and domestic sewage.For process wastewater, it is mainly the

38、circulation cooling water and waste water containing little methanol, sent to the factory after preliminary treatment, and then sent to the main plant for centralizing treatment. For sanitary waste, it is directly discharged into the main drainage ditch in the factory and to the urban sewage pipe ne

39、twork.(3) The slag is mainly waste catalyst, in accordance with the agreement to the catalyst factory processing.(4) The noise is mainly from high frequency noise in the machine pump. The low noise of process and devices are adopted. And the measures for ound insulation, sound absorption, noise elim

40、ination and vibration isolation and damping and comprehensive control are adopted in order to achieve noise standard.In addition, take plant resistance, absorbing harmful gases, and application of environmental biotechnology are adopted in order to realize green production.5.2 Environmental simulati

41、on evaluationOn the basis of reasonable three wastes and noise process schemes, with EIAProA, Elaw and Eiaw software, atmospheric environment, water environment and noise environment are simulated and evaluated.With environment EIAProA soft, the results show that the atmospheric level is three level

42、s after SO2 emission. By the regulation on administration of Zibo city ambient air quality function, 1996 city for three types of area, Linzi is determined as level 3 standard and should execute the ambient air quality standard (GB3095-1996). So, SO2 could be discharged directly. The results are as

43、shown in Figure 10. Figure 10 The screen results of pollutants SO2 By noise environmental impact assessment EIAW software, the factory noise maps are shown in the Figure 11. Its noise sound level and area are shown in the Table 4. Figure 11 Factory noise distributionsTable 4 Noise sound level and ar

44、eaNoise sound levelArea51.0-59.04.49E0456.0-61.06.33E0461.0-66.03.57E0466.0-71.01.44E045.3 Environmental risk assessmentBy the risksystem software, major hazard sources in the factory are identified. P-xylene vapor cloud explosion range model figure is shown in the Figure 12.Figure 12 P-xylene vapor

45、 cloud explosion range model6. Economic analysisBy Yongyou T6 financial software, the cash flow, investment cost estimation, risk assessment and feasibility analysis are explained. A total investment is 981 million yuan, payback period is 6.37 years. The results show that the project is feasible economically. Table 5 Economic and technical indexThe tota