粒子群算法求解边值固定的化工动态过程优化问题

针对化工过程系统优化中广泛存在着边值固定的动态优化问题,该问题的求解数学上还没有有效的方法,现今的方法之一是将问题转化为多目标优化问题.本文在粒子群优化(PSO)算法的基础上,提出在PSO算法中加入惩罚项,同时对局部极值与全局极值作进一步的调整,使PSO算法适用于求多目标优化问题理想有效解,该算法对多目标问题起到边优化边求理想有效解的功效;即只用一步即可求理想有效解,这使得在求解速度上大为加快.最后将其用于间歇反应器的最佳反应温度边值固定动态优化控制的实际运用中,取得良好效果.     

Optimization of a Fluid Catalytic Cracking Kinetic Model by Improved Particle Swarm Optimization

Fluid catalytic cracking (FCC) kinetic models are characterized by high dimension, nonlinearity, discontinuity, and non-differentiability. Particle swarm optimization is easy to fall into local optima prematurely when it is applied to the optimization of kinetic models. To solve this problem, an improved two-swarm cooperative particle swarm optimization (ITCPSO) is proposed. Considering the reaction mechanism of FCC, an 8-lumps kinetic model was developed. According to the pilot data, nine PSO algorithms and ITCPSO are presented to estimate the parameters. The results demonstrate that better performance of global searching is gained by ITCPSO compared to other PSOs, thus, ITCPSO is expected to be implemented in the optimization of complex kinetic models.     

A Comparative Theoretical and Computational Study on Robust Counterpart Optimization: I. Robust Linear Optimization and Robust Mixed Integer Linear Optimization

Robust counterpart optimization techniques for linear optimization and mixed integer linear optimization problems are studied in this paper. Different uncertainty sets, including those studied in literature (i.e., interval set; combined interval and ellipsoidal set; combined interval and polyhedral set) and new ones (i.e., adjustable box; pure ellipsoidal; pure polyhedral; combined interval, ellipsoidal, and polyhedral set) are studied in this work and their geometric relationship is discussed. For uncertainty in the left hand side, right hand side, and objective function of the optimization problems, robust counterpart optimization formulations induced by those different uncertainty sets are derived. Numerical studies are performed to compare the solutions of the robust counterpart optimization models and applications in refinery production planning and batch process scheduling problem are presented.     

Optimization of fish-oil-based biodiesel synthesis

In this study, the optimum conditions (methanol/oil mole ratio, temperature, and so on) for producing biodiesel with fish oil (menhaden oil) were established. The length of the carbon chain of fish oil is frequently greater than that of general vegetable oils. Therefore, the use of fish-oil based biodiesel with larger cetane number may improve diesel engine performance and result in a reduction of pollutant emissions. The optimum conditions of the manufacture of biodiesel with menhaden oil were reaction time of 120 min, reaction temperature of 55 °C, methanol/fish oil molar ratio of 12, and alkaline catalyst content of 2.0 wt%. In the performance evaluation of the biodiesel produced, the acid value (0.20 mg KOH/g), kinematic viscosity (4.60 cSt at 40 °C), and higher heating value (42.1 MJ/k) biodiesel quality standards were suitable.     

Optimization of Potassium Dinitramide Preparation

The synthesis of potassium dinitramide (KDN), an intermediate in the ammonium dinitramide (ADN) synthesis, was optimized to reduce the costs of the ADN synthesis in order to facilitate competitiveness of this oxidizer with ammonium perchlorate (AP). The optimal conditions for the synthesis of KDN like feedstock molar ratio, nitration time, and temperature were determined. KDN was obtained in ca. 48 % yield. The modifications introduced allowed to reduce feedstock consumption and energy intensity of the process.     

天冬甜精中间体的合成优化

用均匀设计法优化了天冬甜精中间体———N 乙氧硫羰基天冬氨酸的合成反应条件。优化工艺条件为 :反应温度 72℃ ,n(甲基乙基黄原酸酯 )∶n(天冬氨酸 ) =1 5 0∶1 0 0 ,m(天冬氨酸 )∶m(氢氧化钠 ) =0 5 0∶1 0 0 ,m(水 )∶m(天冬氨酸 ) =4 0 0∶1 0 0 ,m(甲醇 )∶m(水 ) =0 15∶1 0 0。N 乙氧硫羰基天冬氨酸的收率为 88 92 %。     

头孢甲肟酸合成工艺的优化

在头孢酸合成生产中,借助原料分析,采用了高效液相法测定反应原料残余量的方法,对生产中影响收率的关键工序进行工艺优化。优化工艺条件为:n(AE-活性酯)∶n(7-氨基头胞烷酸)、反应温度15～25℃、反应时间1h、原料的残留浓度1.60%以下,此条件下产品收率提高至90%以上,并且每批产量均比较稳定。     

Optimization of antistatic additives in polypropylene

The antistatic behavior of glyceryl monoesters in polypropylene (PP) is measured at concentrations down to 0.30 wt%. Water contact angles and XPS analyses are used to explore the mechanism of internal antistats. Orientation of glyceryl monostearate (GMS) at the surface of PP is determined. Several new antistat compositions for PP are introduced.     

膜生物反应器处理小区污水条件的优化

由于膜污染是限制膜生物反应器(MBR)应用与推广的主要因素。为此,本研究以MBR处理某小区污水为例,选择粉末活性炭投加量、活性污泥浓度及曝气量进行L12(43)正交试验,确定最佳的操作条件分别为2 g/L、7 g/L、6 m3/h;并在此基础上进行平行对比试验,其膜阻的最大差值达21.05 kPa,导致膜污染形成和发展的主要物质蛋白质/多糖值与膜压差上升速率存在线性关系。     

优选法确定提取卵磷脂的最佳条件

对用乙醇从大豆油脚中提取卵磷脂的条件进行了研究,首次将pH值作为提取卵磷脂时影响因素进行考虑。通过对L8（2^7）正交试验结果分析,发现pH值及乙醇浓度是影响卵磷脂提取率的关键因素。然后,用0.618法快速地确定了最佳pH值及乙醇浓度。经研究,用乙醇提取卵磷脂的阳佳条件为：提取温度－－室温;乙醇－85.5％;提取时间－20min;pH＝10.82;料液比－1：1（V／V）。     

碘海醇的合成工艺优化

以5-硝基间苯二甲酸为原料,依次通过酯化、还原、碘代、乙酰化等反应得到中间体5-(乙酰氨基)-N,N’-双(2,3-二羟基丙基)-2,4,6-三碘-1,3-苯二甲酰胺,缩水甘油与上述化合物缩合得到碘海醇。目标产物及相关杂质均符合药典要求,路线操作简便,适宜工业化。     

Optimization of protein encapsulation in PLGA nanoparticles

Influences of process parameters were investigated on the efficiency of encapsulation of bovine serum albumin (BSA) in poly(dl-lactic-co-glycolic acid) (PLGA) nanoparticles produced by w₁/o/w₂ (water-in-oil-in-water) double emulsion-solvent evaporation method. According to a 5-factorial 3-level Box-Behnken type experimental design aqueous solution of BSA was emulsified in an immiscible organic phase composed of dichloromethane and various quantities of dissolved PLGA to get water-in-oil (w₁/o) emulsion. This latter was then dispersed in a second aqueous phase (w₂) containing poly-vinyl-alcohol (PVA) surfactant as an emulsifier/stabilising agent. PLGA nanoparticles with encapsulated BSA were obtained by evaporating the dichloromethane from the w₁/o droplets. Encapsulation efficiency was determined as the weight ratio of BSA remained in the PLGA nanoparticles relative to the total weight of BSA used in the process. By statistical evaluation of the experimental results an equation was proposed to predict the encapsulation efficiency as a function of five process variables. Two optimization procedures were carried out to increase the efficiency of encapsulation, with and without constraints referring to the required mean particle size. Correlation was found between the latter and the achievable maximal encapsulation efficiency under optimal process conditions.     

Optimization study of nanoporous cubic Ti-SBA-16

The present study investigates the direct one step hydrothermal synthesis of three-dimensional (3D) Ti-SBA-16 (cubic, Im3m) by optimizing with ammonium fluoride (F/Si ratio ≤0.05), hydrothermal heating (40–130 °C) and aging time (24–120 h). The effective 3D mesoordering through silica condensation, in less acidic environment, co-solvent n-butanol and fluoride was observed through small angle X-ray diffraction, N₂ physisorption technique (BET), ²⁹Si-MAS NMR, transmission electron microscope and UV–visible spectroscopy. The study shows the variability of Si/Ti atomic ratios (249-9) of TiSBA-16 with improved surface area between 799 and 910 m²/g at average pore diameter of 8.7 nm. A test reaction of cyclohexene oxidation shows that TiSBA-16 (22) is more selective towards 2-cyclohexen-1-one (58%) formation.     

响应面法优化羟丙基壳聚糖的合成工艺

以壳聚糖(CTS)、环氧丙烷为原料合成了羟丙基壳聚糖(HPCS),采用红外光谱(FT-IR)、核磁共振氢谱(¹ H NMR)、X射线衍射(XRD)和环境扫描电镜(ESEM)对其结构和形貌进行了表征,并考察了合成工艺对其特性黏数的影响。结果表明,羟丙基被成功接枝到壳聚糖上,HPCS已经成功合成。在单因素试验的基础上,采用响应面分析法对其工艺进行优化,得到HPCS合成的最佳工艺条件为反应温度60 ℃,反应时间6 h,碱液质量分数30%,碱化时间20 min,环氧丙烷用量12.6 g。在此条件下,HPCS特性黏数为206.32 mL/g,相对分子质量为2.738×10⁵,取代度(D_S)为0.426。     

Optimization of NOM Removal during Water Treatment

Abstract

The aim of this paper is to describe the removal efficiency of individual fractions of natural organic matter (NOM) and the aluminum transformation during treatment of two types of surface water with an increased concentration of NOM of various origins. The coagulation conditions (dose of destabilization reagent and reaction pH value) were optimized for the best NOM and aluminum removal. The results show that the NOM removal efficiency depends on the NOM character, using destabilizing reagents and reaction conditions. The optimized doses of destabilization reagents influence especially the removal of hydrophilic charged (CHA) and very hydrophobic acids (VHA) fractions during treatment of both types of raw water. In contrast to this, the removal of hydrophilic neutral (NEU) fraction is very low (? _NEU =0.13–0.22). The optimal destabilization reagent dosage is characterized by the lowest content of the total reactive aluminum concentration and relatively low concentration of dissolved organic aluminum.     

十溴联苯醚萃取条件优化研究

针对十溴联苯醚(BDE-209)难溶性和萃取方法的复杂性,通过从萃取剂和萃取条件上对BDE-209进行萃取优化.结果表明:①上清-沉淀复合法的萃取效率仅为21.8％.②烘干温度对样品的萃取效率影响不显著,在80、100和120℃条件下的萃取效率均达到95％以上,但高温条件有可能使BDE-209发生降解.③不同萃取剂和分...     

化工过程分离循环系统的多目标模糊优化研究

Separation-recycle system is an important part in chemical process, and its optimization is a multiobjective problem. In this paper the process optimization procedure is proposed. The fuzzy optimization algorithm with the concept of relative importance degree (RID) is utilized to transfer multi-objective optimization (MO-O) model into a single-objective optimization (SO-O) framework. The treatment of process condensate in synthesisa mmonia plant is taken as example to illustrate the optimization procedure, and the satisfactory result demonstrates feasibility and effectiveness of the suggested method.     

Optimization of coal liquefaction reactors

The method of Lagrangian multipliers of classical calculus is applied to obtain the optimum operating conditions of three continuous stirred tank reactors (CSTR) in series, to liquefy coal with minimum gas yield. In the formulation of the problem, the gas conversion was assumed to be the cost function. Results obtained were supported by the experimental findings in terms of liquefaction temperatures, reaction times, and conversion of coal into various liquefaction products.     

奥沙利铂的合成研究

对奥沙利铂的合成工艺进行优化。以顺式-二氯（反式-（-）-1.2-环己二胺）合铂为起始原料,以硅藻土作为反应物载体,以纤维触媒smopex-10作纯化剂,合成高纯度的奥沙利铂,总收率达到70.5%,含量达到99%以上。 更多还原     

微生物絮凝剂生产条件的优化

以淀粉废水为碳源培养高产絮凝剂的菌株NII4,研究培养菌投加量、温度、通气量、氮源和氮投加量对微生物絮凝剂絮凝效果的影响。结果表明,微生物絮凝剂的最佳培养条件是:菌悬液投加量为3 mL、温度为30℃、摇床转速为160 r/min,淀粉发酵培养基中有机氮源脲与无机氮源硫酸铵复合使用最佳比的情况是:当总氮的质量浓度为500 mg/L时,脲与硫酸铵的质量比为3∶2,此时絮凝率最高达91.58%;当总氮的质量浓度为200mg/L时,脲与硫酸铵的质量比为3∶1,此时絮凝率最高达90.88%。