基于Aspen Plus的原油常减压蒸馏装置的模拟

在Aspen Plus软件平台上,以标定数据为主要输入数据,以产品控制指标为主要约束条件,建立了某厂原油常减压蒸馏装置的稳态模拟流程。在建立过程中,采取对装置流程进行简化处理、将总板效率作为调节变量等方法,使模拟流程的工艺参数、物料平衡和产品恩氏蒸馏数据与生产基本相符。     

常减压蒸馏装置转油线管道设计

列出了大型常压和减压蒸馏装置加热炉出口转油线管道设计的有关原则及常见的配管方式,适用于常压转油线和减压转油线的管道设计。     

Optimal operation strategy of batch vacuum distillation for sulfuric acid recycling process

Vacuum distillation techniques are widely used in food, biological, pharmaceutical, and wastewater treatment industries. Because of its operation at low temperatures, vacuum distillation prevents the thermal decomposition of materials and alleviates corrosion processes; however, condenser size can be dramatically increased because of reductions in mean temperature differences under the vacuum operation. In batch vacuum distillation processes, vapor generation rate and mean temperature differences are changed with time. In view of these characteristics of batch operation, this paper suggests a novel methodology to minimize the condenser size in batch vacuum distillation processes. The target process is a sulfuric acid recycling system in semiconductor manufacturing plants. In this paper, an equation-oriented dynamic model is established and optimization problem is formulated. By solving the nonlinear programming problem, the condenser size is dramatically reduced when operation time is fixed. In contrast, operation time is greatly shortened when the installed condenser surface area is fixed.     

减压蒸馏法和高温模拟蒸馏法分析减压侧线油馏程

油品的生产加工过程中,减压侧线油馏程的分析在控制油品质量、提高原油回收率、提高油品生产经济效益等方面都具有重要意义。目前,减压侧线油馏程的分析应用比较广泛的方法是减压蒸馏法和高温模拟蒸馏法。通过对两种方法进行比较,浅谈两种分析方法的特点,得出结论。     

塔河石化常减压装置减压蒸馏模拟分析与改进

塔河石化减压蒸馏装置为A级沥青产品生产提供满足其指标要求的减压渣油原料。当前生产存在的主要问题是：减压渣油闪点指标偏低且波动较大;蜡油馏分中沥青质和重金属含量较高,影响了A级沥青产品的正常生产。为此,调研收集塔河石化常减压蒸馏装置的生产数据,通过建立其工艺计算模型,进行模拟计算数据与装置标定数据、液相产品分离精度的对比,分析影响减压渣油作为沥青产品原料闪点不合格等问题;并利用SULPAK3.0工具分段对减压塔进行水力学计算,分析影响减压蒸馏分离精度的塔结构问题,提出了改进措施和方案,为减压深拔操作生产A级沥青产品提供依据。     

Feasibility study of a thermally coupled reactive distillation process for biodiesel production

Biodiesel fuel represents an interesting alternative as a clean and renewable substitute of fossil fuels. A typical biodiesel production process involves the use of a catalyst, which implies high energy consumptions for the separation of the catalyst and the by-products of the reaction, including those of undesirable side reactions (such as the saponification reaction). A recently proposed process involves the use of short-chain alcohols at supercritical conditions, avoiding the use of a catalyst and the occurrence of the saponification reaction. This process requires fewer pieces of equipment than the conventional one, but its high energy requirements and the need of special materials that support the reaction conditions makes the main product, biodiesel fuel, more expensive than petroleum diesel. In this work, a modification of the supercritical process for the production of biodiesel fuel is proposed. Two alternatives are proposed. The process involves the use of either reactive distillation or thermally coupled reactive distillation. Simulations have been carried out by using the Aspen One™ process simulator to demonstrate the feasibility of such alternatives to produce biodiesel with methanol at high pressure conditions. A design method for the thermally coupled system is also proposed. Both systems have been tested and the results indicate favorable energy performance when compared to the original scheme. Furthermore, the thermally coupled system shows lower energy consumptions than the reactive distillation column.     

生物燃料乙醇分壁塔萃取精馏新工艺的研究

针对生物燃料乙醇生产中的"蒸馏-脱水"过程,建立基于分壁式萃取精馏塔的三塔工艺和两塔工艺,对2种工艺进行模拟计算,比较其分离效果和过程能耗。结果显示,在满足产品质量的前提下,三塔工艺比两塔工艺节约66.6%的冷凝器热负荷和77.9%的再沸器热负荷。对三塔工艺的分壁式萃取精馏塔的工艺条件进行优化,优化结果为,主塔回流比1.5,溶剂比1.0,原料进料位置为第22块板,隔板底端位置在第28块板,气相分配比为8.4。在优化工艺条件下对三塔工艺进行全流程模拟,可得到质量分数99.96%生物燃料乙醇和99.49%的水,回收萃取剂乙二醇质量分数为99.97%。     

常减压蒸馏装置的技术改造

介绍中国石化股份有限公司武汉分公司常减压蒸馏装置的技术改造特点及工艺流程,针对常压塔各侧线分离效果差、能耗高、产品分布不合理、轻质油收率低等问题,分别对常压系统、减压系统、电脱盐与精制系统进行改造。装置改造后,总拔出率提高了4.84%,轻油收率提高了3.59%,能耗降低了150.65MJ/t,产品分布趋于合理。     

Superhydrophobic modification of ceramic membranes for vacuum membrane distillation

The hydrophobically modified ceramic membranes have great potential for energy-efficient membrane distillation.In this work,flat-sheet ceramic membranes with a superhydrophobic surface were fabricated by grafting 1H,1H,2H,2H-perfluorooctyltrichlorosilane or 1H,1H,2H,2H-perfluorodecyltriethoxysilane and followed by ultraviolet irradiation.The surface water contact angle was improved from 46° of original ceramic membrane to 159°,which exhibited a stable and excellent superhydrophobic effect.The modified membranes showed a high flux of 27.28 kg· m-2.h-1 and simultaneously maintained an excellent retention rate of 99.99％,when used in vacuum membrane distillation process for treatment ofa 1 wt％ NaCl (75 °℃) aqueous solution.These results suggested that superhydrophobic modification of ceramic surface is a facile and cost-effective way to achieve higher membrane distillation performance.The superhydrophobically-modified ceramic membrane with an excellent desalination capacity would show considerable potential in practical membrane distillation utilizations.     

热泵耦合甲醇多效精馏节能新工艺

粗甲醇精馏的能耗是影响甲醇生产成本的关键因素之一。虽然五塔多效精馏可以降低精馏过程能耗,但仍存在相当的低品位余热未利用,为进一步降低五塔多效精馏工艺的能耗,本研究引入机械蒸汽再压缩式（MVR）热泵,在常压塔提馏段增设辅助再沸器,形成热泵耦合多效甲醇精馏新工艺。基于新工艺的全流程模拟数据,文章利用夹点技术对热泵设置的合理性进行分析,采用能耗、效能系数（COP）和年总成本（TAC）等指标对新工艺过程进行评价。结果表明：热泵耦合多效甲醇精馏新工艺中热泵设置合理,冷负荷为24.7MW,再沸器总热负荷为22.25MW,COP为22.5,相比五塔多效精馏工艺,冷负荷、热负荷以及TAC分别降低33.76%、32.64%和26.97%。热泵耦合多效甲醇精馏新工艺节能效果显著。     

甲苯氯化连串反应的RD和SRC过程分析与比较

侧反应器与精馏塔集成(SRC)是塔内耦合反应精馏(RD)的新拓展,同时适用于反应与精馏处于相同工况和不同工况两种情形。以甲苯氯化连串反应为研究对象,分别建立了RD和SRC过程的数学模型,在相同总塔板数和塔釜上升蒸气量条件下,计算了相同工况下(反应与精馏压力均为101.3 kPa),RD与SRC过程的气/液流率、温度、组成分布,发现两者性能具有一致性。在此基础上,以产品氯化苄的生产成本为目标函数、标志系统产能的氯气进料流率和分配比例为优化变量,对甲苯氯化连串反应的相同工况RD与SRC过程、不同工况SRC过程(反应压力为101.3 kPa、精馏压力为10 kPa)进行优化,结果表明,相同压力工况下,优化得到的RD与SRC的装置产能与产品质量一致;但在不同压力工况下,SRC的产能明显提升、产品质量也有所提高,反映出不同工况SRC明显的优势。     

常减压蒸馏装置缓蚀剂的合成与复配研究

根据常减压蒸馏装置腐蚀环境的体系特点,合成了一种耐酸性强的高效缓蚀剂HS-1,并与目前炼厂使用的2种缓蚀剂HS-2和HS-3进行了对比。通过静态和动态挂片失重实验,对3种缓蚀剂进行了配伍性的研究。结果表明,综合评价缓蚀剂的效率HS-1>HS-3>HS-2,单独使用HS-1,用量在10～30 mg/L,平均缓蚀率达87.6%;静态挂片实验中,最优复配方案为HS-1∶HS-2=1∶1(体积比),平均缓蚀效率为94.9%;动态挂片实验中最优复配方案为HS-1∶HS-3=1∶2(体积比),平均缓蚀效率为87.3%。     

A method for the design of flexible distillation sequence

A simple method has been developed to optimally design a distillation sequence with a fixed degree of flexibility in feed composition and flowrate, and accounts for uncertainty in stage efficiency, K-value and beat transfer coefficient calculations. The method minimizes a weighted cost function and ensures both optimal and feasible operation in the range of flexibility/uncertainty by using an approach termed “practical feasibility”. The method was tested on a 4 column distillation sequence separating a 5 component light alkane feed mixture. Results are presented to illustrate the effect of uncertainty on sequence cost and column overdesign.     

丙烯酸正丁酯的连续减压精馏新工艺研究

为了能寻求一种更高效、节能、环保的丙烯酸正丁酯的生产工艺,改变传统的间歇反应,利用连续减压精馏新型工艺合成丙烯酸正丁酯,提高丙烯酸正丁酯的选择性.重点研究利用连续减压精馏催化合成丙烯酸正丁酯的反应,确定了最佳反应条件:以对甲苯磺酸为催化剂,催化剂质量分数为1.20％,醇酸物质的量比为1.2∶1,对苯二酚作为阻聚剂,反应时间停留在2.5～3.0h之间,温度为105 ～1 10℃时,酯收率大于93％.     

我国氯化法钛白技术的进展和展望

回顾了国内研制氯化法钛白的历史过程,特别介绍了锦州钛白粉公司1.5万t/a氯化法钛白生产技术的进展,分析认为国内具有发展氯化法钛白的有利条件.     

Novel design of lubricant-type vacuum distillation process for lube base oils production from hydrocracking tail oil

Dividing-wall columns (DWCs) are widely used in the separation of ternary mixtures, but rarely seen in the separation of petroleum fractions. This work develops two novel and energy-efficient designs of lubricant-type vacuum distillation process (LVDP) for the separation of hydroisomerization fractions (HIF) of a hydrocracking tail oil (HTO). First, the HTO hydroisomerization reaction is investigated in an experimental fixed-bed reactor to achieve the optimum liquid HIF by analyzing the impact of the operating conditions. A LVDP used for HIF separation is proposed and optimized. Subsequently, two thermal coupling intensified technologies, including side-stream (SC) and dividing-wall column (DWC), are combined with the LVDP to develop side-stream vacuum distillation process (SC-LVDP) and dividing-wall column vacuum distillation process (DWC-LVDP). The performance of LVDP, SC-LVDP, and DWC-LVDP are evaluated in terms of energy consumption, capital cost, total annual cost, product yields, and stripping steam consumption. The results demonstrates that the intensified processes, SC-LVDP and DWC-LVDP significantly decreases the energy consumption and capital cost compared with LVDP. DWC-LVDP further decreases in capital cost due to the removal of the side stripper and narrows the overlap between the third lube oils and fourth lube oils. This study attempts to combine DWC structure into the separation of petroleum fractions, and the proposed approach and the results presented provide an incentive for the industrial implementation of high-quality utilization of HTO through intensified LVDP.     

釜式光催化氯化生产氯化石蜡-52新工艺

根据目前国内外氯蜡—52的生产工艺，特别是光催化氯化工艺情况，选择了釜式光催化氯化工艺生产氯蜡—52。介绍了该工艺的技术要点，该工艺的优越性为：工艺简单合理、投资少；光源利用率高；反应周期短，生产能力高；产品色泽好。     

The kinetics modeling and reactor simulation of propylene chlorination reaction process

The kinetics experiments of fast reaction process of propylene chlorination at low temperature (30–90°C) and high temperature (420–480°C) are respectively conducted, and the corresponding reaction mechanisms and kinetics models are proposed. The radical mechanism at high temperature and the molecular mechanism at low temperature are found to be most likely with the experimental results. Specifically, the kinetics model, firstly considering the reversible reaction step of forming C₃H₆Cl · and direct hydrogen abstraction of forming C₃H₅ · , shows better agreement with the experimental data. Furthermore, the critical reaction temperature T_critical is firstly proposed to determine the dominant reaction mechanism in different conditions, and correspondingly the combination method of the high-temperature and low-temperature kinetics models has been adopted for tubular reactor simulation, which can reasonably reflect the influence of wide variation range of temperature in the reactor and guide the industrial reactor design in the further work.     

一种新的生产计划与催化裂化装置过程操作集成的闭环策略

Production planning models generated by common modeling systems do not involve constraints for process operations, and a solution optimized by these models is called a quasi-optimal plan. The quasi-optimal plan cannot be executed in practice some time for no corresponding operating conditions. In order to determine a practi- cally feasible optimal plan and corresponding operating conditions of fluidized catalytic cracking unit （FCCU）, a novel close-loop integrated strategy, including determination of a quasi-optimal plan, search of operating conditions of FCCU and revision of the production planning model, was proposed in this article. In the strategy, a generalized genetic algorithm （GA） coupled with a sequential process simulator of FCCU was applied to search operating conditions implementing the quasi-optimal plan of FCCU and output the optimal individual in the GA search as a final genetic individual. When no corresponding operating conditions were found, the final genetic individual based correction （FGIC） method was presented to revise the production planning model, and then a new quasi-optimal production plan was determined. The above steps were repeated until a practically feasible optimal plan and corresponding operating conditions of FCCU were obtained. The close-loop integrated strategy was validated by two cases, and it was indicated that the strategy was efficient in determining a practically executed optimal plan and corresponding operating conditions of FCCU.     

Development of novel surface modified phase inversion membranes having hydrophobic surface-modifying macromolecule (nSMM) for vacuum membrane distillation

Eleven PES membranes, into which newly synthesized surface-modifying macromolecule (nSMM) was incorporated, were prepared by using the ‘phase inversion technique’ with different preparation conditions to find the effects of membrane casting parameters on the characteristics and performances of the surface modified PES membranes. The membranes so prepared were characterized by solute separation data from ultrafiltration experiments. The results showed that the mean pore size as well as the surface hydrophobicity increased with an increase in evaporation time for the casting solution blended with nSMM (without PVP). When PVP was added into the casting solution, the mean pore size as well as the contact angle decreased while the pure water permeation flux increased. The surface hydrophobicity decreased with an increase in gelation bath temperature.Four membranes were further prepared and subjected to vacuum membrane distillation (VMD). They were characterized by different analytical instruments and pure water permeation test before being used to VMD. The results showed that a distinctive surface layer was formed in nSMM blended PES membranes. It was also found that nSMM blended PES membranes were sufficiently hydrophobic and porous to be used for the separation of an ethanol/water mixture.