甲苯-乙醇共沸体系的萃取精馏模拟与优化

利用Aspen Plus化工模拟流程软件对甲苯-乙醇共沸体系进行了萃取精馏模拟分离研究。应用Flash 2模块来筛选出萃取精馏的适宜溶剂为正丁苯。确定了萃取精馏的工艺流程,并且通过灵敏度分析模块分别考查了萃取精馏塔和溶剂回收塔的进料板位置、回流比以及溶剂比对分离效果的影响。当溶剂质量比为2.2时,产品乙醇的质量分数可达99.9%,甲苯可达99.5%,溶剂回收率约为99.5%。

甲苯-乙醇介质中二茂铁催化分解过氧化氢机理的探讨

以甲苯 乙醇混合体系作溶剂 ,用循环伏安法和交流阻抗法研究了二茂铁在铂电极上的电化学行为 ,进而测试了H2 O2 存在时二茂铁的循环伏安曲线。结果表明 ,混合溶剂中溶液电阻和二茂铁在铂电极上的电化学反应电阻均随甲苯含量的增加而增大 ,二茂铁正离子能与H2 O2 发生均相化学反应 ,其电极反应机理为包含随后转化步骤的催化反应过程 ,即EC历程。

变压精馏分离甲苯-乙醇体系的经济最优化设计

甲苯-乙醇体系的共沸组成与相对挥发度对压力比较敏感,可用变压精馏分离该体系。利用Aspen化工流程模拟软件,以年度总费用最小为目标函数,以NRTL为热力学计算模型,采用序贯迭代法确定普通、部分热集成和完全热集成的变压精馏最优工艺参数。结果表明完全热集成更具有优势。

豆甾醇在甲苯-乙醇二元溶剂中的溶解特性研究

为了研究豆甾醇在甲苯-乙醇二元溶剂中的溶解特性;采用动态法测定豆甾醇在甲苯-乙醇二元溶剂中的溶解度,并采用Appellant模型对豆甾醇溶解度与温度的关系进行拟合。实验结果表明在实验温度范围内,当二元溶剂中的甲苯体积分数相同时,豆甾醇的溶解度随着温度的升高而增加;在温度相同时,随着甲苯-乙醇二元溶剂中的甲苯体积分数的增加,豆甾醇的溶解度呈先增加后减小的趋势。当甲苯-乙醇二元溶剂中的甲苯体积分数为0.8时,豆甾醇的溶解度最大。采用Appellant模型对豆甾醇在甲苯-乙醇二元溶剂中溶解度与温度进行拟合,标准偏差小,精度高。

热集成变压精馏分离乙醇-甲苯体系的过程模拟和优化

由于乙醇-甲苯体系为压力敏感体系,本文提出了热集成变压精馏分离乙醇-甲苯共沸体系的工艺方法,并通过实验数据验证了NRTL模型对模拟分离该体系的适用性。利用Aspen模拟软件,以NRTL方程为物性计算模拟,以乙醇和甲苯的纯度为约束变量,分离过程能耗最低为目标函数,采用优化分析,得到了模拟的优化参数,并通过模拟计算,制取了纯度不低于99.9%的甲苯和乙醇产品,收率达到99.9%以上。用高压塔的塔顶气相潜热作为常压塔再沸器热源的热集成变压精馏,与两塔均采用外界蒸汽供热的传统变压精馏方式相比,节能高达49%。

对甲苯磺酸-β-甲氧基乙酯的合成

在氢氧化钠催化下 ,乙二醇单甲醚与对甲苯磺酰氯发生酯化反应合成对甲苯磺酸 -β -甲氧基乙酯 ,讨论了氢氧化钠用量、反应温度、反应时间、对甲苯磺酰氯与乙二醇单甲醚的摩尔比等因素对酯化收率的影响 ,在优化条件下 ,平行实验结果表明 ,对甲苯磺酸 -β -甲氧基乙酯的收率和纯度分别达到 76 2 %、97 6%。经IR、1 HNMR。

IN-SITU POLYMERIZED SYNTHESIS AND PROPERTIES OF NANO-ZnO/PEG/PET COMPOSITE

Nano-ZnO particle （nZnOp） reinforced polyethylene glycol （PEG）/polyethylene terephthalate （PET） （nZnOp/PEG/PET） copolymeric composites with different mass fractions and molecular weights of PEG are synthesized via in-situ polymerization. The dispersion of nZnOp in copolymer matrixes and the effects of PEG and nZnOp particles on the crystallization behavior of the composites are studied by TEM, differential scanning calorimetry（DSC）, XRD and Fourier thansform infrared spectroscopy （FTIR ）. The results reveal that nZnOp particles are dispersed in the matrixes with nano-scale, and the addition of PEG induces more homogeneous dispersion of nZnOp. Simultaneously, these nanoparticles become nucleating centers during the crystallization of the matrixes. PEG segments can improve the flexibility of the PET molecular chain, resulting in the drop of the cold crystallization temperature and the rise of the crystallization rate of the composites. Furthermore, PEG （4 000） with the mass fraction of 10% can promote the crystallization rate of the composites. The mechanical properties show that the nano-particles strengthen and toughen the PET matrix, whereas PEG weakens these improve- ments.

以乙醇-甲苯混合溶剂测定石油产品中机械杂质的研究

建立用乙醇-甲苯混合溶剂代替甲苯等有机溶剂测定油品中机械杂质含量的方法。用乙醇-甲苯混合溶剂进行溶解洗涤,分析实验数据的重复性和再现性,用有证标准物质验证新方法数据的准确性。检测数据的重复性和再现性符合GB/T511—2010要求,测定结果的准确性高。该方法降低了有毒有害试剂的消耗,操作简化,保证了实验的精度,完全能够满足测定机械杂质的要求。

Isobaric vapor–liquid equilibrium for ternary system of ethanol, ethyl propionate and para-xylene at 101.3 kPa

Isobaric vapor–liquid equilibrium(VLE) data for the binary system ethyl propionate(2) + para-xylene(3) and ternary system ethanol(1) + ethyl propionate(2) + para-xylene(2) at atmospheric pressure(101.3 k Pa)were obtained by a VLE modified othmer still. All the experimental data passed a point to point consistency test of Van Ness method, which verified the data reliability. The Wilson and UNIQUAC activity coefficient models were employed to correlate the binary VLE data to obtain binary interaction parameters. Based on binary interaction parameters, ternary VLE data of ethanol(1) + ethyl propionate(2) + para-xylene(3) were predicted by Wilson and UNIQUAC models, which proved that predicted values are consistent with the experimental data.Furthermore, azeotropic phenomenon between ethanol and ethyl propionate disappears when the mole ratio of para-xylene and binary system of ethanol and ethyl propionate is 1:1. Therefore, this paper convinced that para-xylene is a proper extractive additive that could be used in extractive distillation to separate the binary azeotropic system of ethanol and ethyl propionate.

Asymmetric Bioreduction of 3,5-Bis（trifluoromethyl） Acetophenone to Its Corresponding Alcohol by Candida troplcalis

(S)-3,5-bistrifluoromethylphenyl ethanol is a key chiral intermediate for the synthesis of NK-1 receptor antagonists. Enantioselective synthesis of (S)-3,5-bistrifluoromethylphenyl ethanol was successfully performed in high enantiomeric excess (e.e.) through asymmetric reduction of 3,5-bis(trifluoromethyl) acetophenone catalyzed by Candida tropicalis 104 cells. The influence of some key reaction parameters such as substrate concentration, co-substrate and its concentration, biomass and reaction time was examined, respectively. The results showed that these factors obviously influence the yield, but the optical purity of the prepared product remains intact. The opti-mum conditions for the preparation of (S)-3,5-bistrifluoromethylphenyl ethanol were found to be as follows: sub-strate concentration 50 mmol?L?1; 50 g·L-1 of maltose as co-substrate; wet cell concentration 300 g·L-1; reaction for 30 h. Under above optimal conditions, the maximum yield for (S)-3,5-bistrifluoromethylphenyl ethanol reached 70.3% with 100% of product e.e.

In-situ Polymerization-modification Process and Foaming of Poly（ethylene terephthalate）

Most of traditional linear poly(ethylene terephthalate)(PET)resins of relatively low molecular mass and narrow molecular mass distribution have low melt strength at foaming temperatures,which are not enough to support and keep cells.An in-situ polymerization-modification process with esterification and polycondensation stages was performed in a 2 L batch stirred reactor using pyromellitic dianhydride(PMDA)or pentaerythritol(PENTA)as modifying monomers to obtain PETs with high melt strength.The influence of amounts of modifying monomers on the properties of modified PET was investigated.It was found that the selected modifying monomers could effectively introduce branched structures into the modified PETs and improve their melt strength.With increasing the amount of the modifying monomer,the melt strength of the modified PET increased.But when the amount of PENTA reached 0.35%or PMDA reached 0.9%,crosslinking phenomenon was observed in the modified PET.Supercritical carbon dioxide(ScCO2)was employed as physical foaming agent to evaluate the foaming ability of modified PETs.The modified PETs had good foaming properties at 14 MPa of CO2pressure with foaming temperature ranging from 265°C to 280°C.SEM micrographs demonstrated that both modified PET foams had homogeneous cellular structures,with cell diameter ranging from 35μm to 49μm for PENTA modified PETs and38μm to 57μm for PMDA modified ones.Correspondingly,the cell density had a range of 3.5×107cells·cm 3to 7×106cells·cm 3for the former and 2.8×107cells·cm 3to 5.8×106cells·cm 3for the latter.

Study on Morphology and Non-isothermal Crystallization Behavior of Poly(phenylene sulfide)/Poly(ethylene-co-cyclo-hexane 1,4-dimethanol terephthalate) Blend

A binary alloy consisting of poly（phenylene-sulfide） （PPS）/poly（ethylene terephthalate-co-l,4- cyclohexanedimethanol） （PETG） was prepared by the melt blending technology using a twin-screw extruder. The morphology and crystallization behavior of the alloy material were investigated by means of SEM, POM and DSC. The SEM study of the alloy samples revealed that PPS and PETG comprised an incompatible system and the interface structure of two phases could be observed distinctly when the composition of the binary alloy was being changed. The POM results had revealed that incorporation of PETG into PPS could lead to formation of larger spherulite crystals in the course of PPS crystallization, but small and grainy spherulite crystals appeared with further increase in the PETG concentration. The DSC analyses revealed that addition of PETG to the alloy composition could shift the PPS crystallization temperature towards the high-temperature region.

The biomimetic catalytic synthesis of acetal compounds using β-cyclodextrin as catalyst

Based on the principle of biomimetic catalysis, β-cyclodextrin was applied to the acetalation reaction as a facile and efficient catalyst, and the synthesis was environmentally friendly with atomic economy. The influencing factors of the acetalation reaction e.g. the reaction time, the volume of water-carrying agent,the molar ratio of catalyst to benzaldehyde and the molar ratio of glycol to benzaldehyde had been studied.The yield of benzaldehyde glycol acetal would reach a maximum of 81.3% under the conditions approached.Six of other acetals were also synthesized. Moreover, a plausible reaction mechanism for the formation of acetal had been proposed.

Nonisothermal Crystallization Kinetics of Poly(butylene adipate-co-terephthalate) Copolyester

Nonisothermal crystallization behavior of poly(butylene adipate-co-terephthalate)(PBAT) synthesized via direct esterification and polycondensation reactions was investigated by the differential scanning calorimetry(DSC).The Avrami equation modified by Jeziorny and the Z.S.Mo equation were employed to describe the non-isothermal crystallization kinetics of copolyester samples.The test results showed that the Avrami equation was successful in describing nonisothermal crystallization process of PBAT copolyesters.PBAT copolyester could give birth to secondary crystallization.The crystallization parameter(Zc) increased with an increasing cooling rate and the Avrami exponent(n) was around 2.3.For a given cooling rate,the value of Zc demonstrated a sagging trend with an increase in adipic acid(AA) content.The equation proposed by Z.S.Mo was successful in describing the nonisothermal crystallization kinetics of PBAT copolyesters.

Heterogeneity of Adsorption Sites and Adsorption Kinetics of n-Hexane on Metal–Organic Framework MIL-101(Cr)

The heterogeneity of adsorption sites and adsorption kinetics of n-hexane on a chromium terephthalate-based metal-organic framework MIL-10^1 （Cr） were studied by gravimetric method and temperature-programmed desorption （TPD） experiments. The MIL-101 crystals were synthesized by microwave irradiation method. The ad- sorption isotherms and kinetic curves of n-hexane on the MIL-101 were measured. Desorption activation energies of n-hexane from the MIL-10^1 were estimated by TPD experiments. The resulthowed that equilibrium amount ofn-hexane adsorbed on the MIL-10^1 was up to 5.62 mmol.g- 1 at 298 K and 1.6 x10^4 Pa, much higher than that of some activated carbons, zeolltes and so on. The isotherms of n-hexane on the MIL-101 could be well fitted with Langmuir-Freundlich model. TPD spectra exhibit two types of adsorption sites on the MIL-101 with desorption activation energies of 39.41 and 86.69 kJ. mol-1. It reflects the surface energy heterogeneity on the MIL-10I frameworks for n-hexane adsorption. The diffusion coefficients of n-hexane are in the range of （1.35- 2.35 ） x 10 - 1 o cm2. s - 1 with ad sorotion activation enerv of 16.33 kl. mol - 1.

Nonisothermal Crystallization Kinetics of Poly(phenylene sulfide)/Poly(ethylene-co-cyclohexane 1,4-dimethanol terephthalate) Blend

Binary alloy samples consisting of poly（phenylene sulfide） （PPS）/poly（ethylene terephthalate-co-cyclohexane 1,4-dimethanol terephthalate） （PETG） blend were prepared by the melt blending technology using a twin-screw extruder. The nonisothermal crystallization kinetics of binary alloys made of poly（phenylene sulfide） （PPS） and poly（ethyleneco-cyclohexane 1,4-dimethanol terephthalate） （PETG） was studied by the differential scanning calorimetry （DSC） at different cooling rates. The test results revealed that the addition of PETG could shift the crystallization temperature of PPS toward the high-temperature direction. The nonisothermal crystallization kinetic parameters of the PPS/PETG alloy samples were calculated by the methods proposed by Avrami and Mo. Test results demonstrated that the PPS/PETG alloy could give birth to apparent secondary crystallization. The value of Avrami exponent was lower relatively, while Mo＇s method was more suited to the nonisothermal crystallization process of the PPS/PETG alloy.

Screening of Polymer Additives in Drinking Water Stored in PET Bottles by UHPLC-ESI-IT-TOF MS

In this study, Ultra High Performance Electrospray Ionization Ion Trap Time of Flight Mass Spectrometry （UHPLC-ESI-1T-TOF MS） method is used to screen the polymer additives in drinking water that is stored in Polyethylene Terephthalate （PET） bottles. After directly analyzing the commercially available water samples, 3 polymer additives （chimassorb 81, irgafos 168 and oleamide） were detected. However, after exposure to sunshine for 8 days, two additional polymer additives （antioxidant 2246 and Butylated Hydroxytoluene （BHT）） were detected besides the former three additives.

An agent-based service-oriented integration architecture for chemical process automation

In reality, traditional process control system built upon centralized and hierarchical structures presents a weak response to change and is easy to shut down by single failure. Aiming at these problems, a new agent-based service-oriented integration architecture was proposed for chemical process automation system. Web services were dynamically orchestrated on the internet and agent behaviors were built in them. Data analysis, model, optimization, control, fault diagnosis and so on were capsuled into different web services. Agents were used for service compositions by negotiation. A prototype system of poly(ethylene terephthalate) process automation was used as the case study to demonstrate the validation of the integration.

In-situ Enhanced Toughening of Poly（ethylene terephthalate）/elastomer Blends via Gamma-Ray Radiation at Presence of Trimethylolpropane Triacrylate

Gamma-ray radiation has always been a convenient and effective way to modify the inter- facial properties in polymer blends. In this work, a small amount of trimethylolpropane triacrylate （TMPTA） was incorporated into poly（ethylene terephthalate） （PET）/random terpolymer elastomer （ST2000） blends by melt-blending. The existence of TMPTA would induce the crosslinking of PET and ST2000 molecular chains at high temperatures of blend- ing, resulting in the improvement in the impact strength but the loss in the tensile strength. When the PET/ST2000 blends were irradiated by gamma-ray radiation, the integrated me- chanical properties could be enhanced significantly at a high absorbed dose. The irradiated sample at a dose of 100 kGy even couldn＇t be broken under the impact test load, and at the same time, has nearly no loss of tensile strength. Based on the analysis of the impact- fractured surface morphologies of the blends, it can be concluded that gamma-ray radiation at high absorbed dose can further in situ enhance the interfacial adhesion by promoting the crosslinking reactions of TMPTA and polymer chains. As a result, the toughness and strength of PET/ST2000 blend could be dramatically improved. This work provides a facial and practical way to the fabrication of polymer blends with high toughness and strength.

Study on Structure and Crystallinity of A New Biodegradable Aliphatic-Aromatic Copolyester

A series of biodegradable aliphatic-aromatic copolyesters, poly(butylene terephthalate-co-butylene adipate-co- ethylene terephthalate-co-ethylene adipate) (PBATE), were synthesized from terephthalic acid (PTA), adipic acid (AA), 1,4-butanediol (BG) and ethylene glycol (EG) through direct esterification and polycondensation. The sequence structure and crystallinity of the copolyester were investigated by 1H NMR spectroscopy and the wide-angle X-ray diffractometry (WAXD). The analytical results showed that the PBATE copolyester was a random copolymer and the composition of PBATE copolyester was almost consistent with the feed molar ratios. The crystal structure of PBATE copolyester belonged to the triclinic crystalline system; The variation in melting point of the synthesized PBATE copolyester agreed well with the estimation obtained by the Flory equation and was applicable to the random copolymer.