高沸点热敏体系精馏过程的研究进展

在精馏系统中，高沸点、热敏性物系分离存在物料受热温度高且时间长的问题，容易引起热敏性物质变质，一直是高效分离与提纯的难点。本文对高沸点热敏性物质精馏分离理论基础进行归纳，提出操作压力低和停留时间短的工艺要求。基于此，总结了分子蒸馏和真空精馏（包括真空蒸馏、真空分馏、真空间歇精馏）在高沸点热敏性物系分离中的优缺点及应用，发现分子蒸馏的真空度和分离程度较真空精馏高，但分离效率和工业化程度比真空精馏低。最后，文章指出，对于采用精馏分离高沸点热敏性体系仍需在新工艺和新设备等方面进行探索，以提高分离效率和降低分离能耗，便于实现工业规模应用。     

响应曲面优化粗锡真空蒸馏

采用响应曲面法优化粗锡真空蒸馏工艺,研究了蒸馏温度、保温时间和原料质量对粗锡真空蒸馏提纯效果的影响. 结果表明,蒸馏温度和保温时间对粗锡真空蒸馏影响较大,原料质量的影响较小,蒸馏温度1350~1400℃、保温时间40~60 min时可有效去除粗锡中杂质. 以97.4185%的粗锡为原料,在蒸馏温度1400℃、保温60 min的条件下,锡纯度达99.8752%,含0.012% Pb, 0.045% Sb, 0.0005% Bi和0.0005% As,Fe和Cu含量无变化,Sn直收率达99.89%.     

Fabrication of Arsenic Selenide Optical Fiber with Low Hydrogen Impurities

Arsenic selenide glass optical fibers typically possess extrinsic absorption bands in the infrared wavelength region associated with residual hydrogen and oxygen related impurities, despite using purified precursors. We report a purification process based on the addition of 0.1 wt% tellurium tetrachloride (TeCl₄) to the glass. During melting, the chlorine from TeCl₄ reacts with the hydrogen impurities to produce volatile products (e.g., HCl) that can be removed by subsequent dynamic distillation. The processing conditions have been modified accordingly to give very low H–Se impurity content. Consequently, the H–Se absorption band centered at 4.57 μm has been reduced from tens of dB/m to 0.2 dB/m.     

气相色谱-质谱联用测定DEIP中的微量组分

建立了气相色谱-质谱联用(GC/MS)检测间苯二甲酸二乙酯(DEIP)中微量杂质的方法,DEIP样品经减压蒸馏分离,用GC/MS对其中的微量杂质进行分析,结合生产工艺、谱库检索和人工解谱,鉴定出11种主要杂质,用面积归一法确定了11种杂质的含量,该方法的建立对生产及工艺优化有较好的指导作用。     

高纯透红外硫系玻璃材料的制备

高性能透红我硫系玻璃材料的开发和应用在很大程度上受到杂质对透过性能影响的制约。本综述系统地阐述了存在于不同硫系玻璃中的杂质之种类、来源、形成过程及其对玻璃透过性能的影响，并介绍了旨在有效地消除杂质、降低玻璃的非本质 原料纯化措施和与此相关的硫系玻璃制备新工艺。     

利用分子蒸馏技术再生废旧轧制油

重点介绍化工分子蒸馏技术原理,它是利用不同分子自由程差别来实现分离,是远离沸点的分离,区别于传统的化工蒸馏采用不同物质的沸点差实现分离;它是在传统蒸馏和真空技术发展基础上的一个创新技术,废旧轧制油是铝带箔生产企业在使用中被润滑油、液压油、机械杂质、水污染更换下来的废油。文章重点介绍利用分子蒸馏技术在再生废旧轧制油方面的成功运用。     

Numerical Analysis and Experimental Validation of Distillation Process for Purification of Tellurium

Numerical analysis was performed on a vacuum distillation process for Te purification. The effects of temperature gradient and Ar gas flow rate and vacuum level on the evaporation behavior of Te were investigated through a series of simulations with a diffusion-coupled convection model. An overall yield of up to 95% of 4 N pure Te was achieved at an average distillation rate of ～5.6 × 10^?4 g · cm^?2 · s^?1 from 2 N pure indigenous Te. The diffusion and condensation factors of impurities were investigated under different distillation conditions such as vacuum degree, temperature and argon flow rate. It was found that the numerical model could be used to predict impurity level during vacuum distillation process of Te and designing and optimization of a larger-scale distillation process also could be possible with a sufficient reliability.     

渣油掺炼煤焦油的减压蒸馏过程

为提高资源利用率,考察了掺炼煤焦油对渣油减压蒸馏的影响。结果表明,在渣油中掺炼一定比例的煤焦油可以提高其减压蒸馏的拔出率,为后续加工提供更多的原料。相比较于纯渣油,在550℃对渣油掺炼20%的煤焦油进行蒸馏,可多获得近15个百分点的催化裂化加工原料。扣除煤焦油馏分油后,渣油的拔出率也提高5个百分点。同时,蒸馏残渣的软化点有一定的提高,更适合用做沥青原料。最后探讨了煤焦油对渣油蒸馏过程的强化机理。     

Fabrication of Arsenic Sulfide Optical Fiber with Low Hydrogen Impurities

Arsenic sulfide glass optical fibers typically possess extrinsic absorption bands in the infrared wavelength region associated with residual hydrogen and oxygen related impurities, despite using purified precursors. We report a purification process based on the addition of tellurium tetrachloride (TeCl₄) to the glass. During melting, the chlorine from TeCl₄ reacts with the hydrogen impurities to produce volatile products (e.g., HCl) that can be removed by subsequent dynamic distillation. The processing conditions have been modified accordingly to produce optical fibers with significantly reduced loss due to hydrogen sulfide impurity content (1.5 dB/m).     

Interrelation between glass formation, liquidus temperature, and the cooling rate of barium-bismuth-borate melts

The diagram of glass formation in a BaO-Bi₂O₃-B₂O₃ system dependent on the cooling rates of the melts and the temperature of the liquidus has been plotted. The glass-forming ability of the melts of all the known binary and ternary crystalline compounds of the investigated system has been discovered.     

超纯溴的制备

加溴化钠于溴中除氯;蒸馏,加热(850℃)蒸馏出来的溴蒸气分解有机物以除去有机物;高真空低温分级蒸馏及升华纯化。产品溴的产率为75％,产品的光谱分析指出,杂质的总含量为10~(-7)(质量百分数),红外光谱分析指出,产品中不存在水和有机化合物。     

从桉叶油副品中间歇精馏纯化α-松油醇

研究了从桉叶油副品—松油醇馏分中纯化α-松油醇的间歇减压精馏工艺。GC-MS分析了原料组成。通过绘制目标组分α-松油醇及γ-松油烯、4-松油醇、trans-松香芹醇三个主要杂质组分的馏出曲线,探讨了水和四种有机溶剂进行塔预处理对分离α-松油醇的影响,并在此基础上优化回流比,确定较佳工艺：以水进行塔预处理,变回流比操作,在回流比为6条件下收集α-松油醇,绝对压力5.0 kPa左右,沸程129～132 oC,纯度> 90%,回收率50.0%。     

机械抽真空系统在减压蒸馏装置中的应用

在过去与现代的减压蒸馏装置中,具备一、二、三级抽空器的蒸汽抽真空系统始终占据着主导地位。而近年,一种新型的抽真空系统——机械抽真空系统正在慢慢地改变传统的抽真空方式。相对于传统的蒸汽抽真空系统,它的出现和逐步应用将会引领一场减压蒸馏中划时代的变革,通过对这两种抽真空方法的比较,浅析两种方法在减压蒸馏装置中的应用情况。     

Thermooxidative stability of vegetable oils refined by steam vacuum distillation and by molecular distillation

Semi‐refined rapeseed and sunflower oils after degumming and bleaching were refined by deodorization and deacidification in two ways, i.e., by steam vacuum distillation in the deodorization column Lurgi and by molecular distillation in the wiped‐film evaporator. The oxidative stability of the oils before and after the physical refining has been evaluated using non‐isothermal differential scanning calorimetry. Treatment of the experimental data was carried out by applying a new method based on a non‐Arrhenian temperature function. The results reveal that refining by molecular distillation leads to lower oxidative stability of the oils than refining by steam vacuum distillation. Practical applications : (i) A method for the refining of edible oils by the molecular distillation in the wiped film of a short‐path evaporator is presented and applied. (ii) Oxidative stability of the oils refined by molecular distillation and steam vacuum distillation is compared. It has been found that refining by molecular distillation leads to lower oxidative stability of the oils than refining by steam vacuum distillation. (iii) Experimental data were treated by applying a new method based on a non‐Arrhenian temperature function. The method enables trustworthy predictions of oil stabilities for the application temperatures.     

辽河催化裂化澄清油中间馏分恒温热转化反应研究

辽河催化裂化澄清油中芳烃含量高、沥青质含量低、分子量分布窄，是生产针状焦的优质原料，但其所含的灰分对澄清油的加工利用有着较大影响。先将澄清油中加入絮凝剂脱灰，再经减压蒸馏切割420～500℃的馏分，富集可生成针状焦的有效组分，去除原料中不利于热转化反应的因素，并以此中间馏分为原料进行恒温热转化。实验结果表明：澄清油预处理效果明显，原料组成趋于合理，所得中间馏分具有较低的nH／nC（H／C原子比）和适宜的组成分布。恒温热转化半焦产物的光学组织结构属于各向异性发达的广域-流线型结构。     

原油常减压蒸馏塔的流程模拟

常减压蒸馏装置是炼油加工的第一道工序,它的运行状况对后续装置乃至全厂都有着重要影响。针对初馏塔、常压蒸馏塔和减压蒸馏塔的稳态流程模拟,选取适合的蒸馏塔中段循环设定变量和减压塔模拟方法,最终流程模拟结果与实际工艺参数相似度极高,说明常减压蒸馏塔的流程模拟能够如实体现实际工艺状态,可以作为指导工艺生产、操作优化的有效方法。     

GASES IN GLASS*

An apparatus is described for extracting the gas from glass at glass-furnace temperature and determining its composition. Results are given for glasses of various compositions and various melting histories. All ordinary glasses were found to contain appreciable quantities of dissolved (or chemically combined) gas, the amount varying from a few hundredths to a few tenths per cent. Water is frequently the most abundant gas, the content being highest in borosilicate glasses. Carbon dioxide is also usually present, the amount depending on the basicity of the glass. Nitrogen, carbon monoxide, and hydrogen were never found present in appreciable quantities. All oxidized glasses contain some oxygen. Glasses containing arsenic give off a comparatively large volume of oxygen. The effect of this oxygen on fining is discussed. It has been found that remelting a glas has little effect on the gas content. The gas content is greatly influenced by the size of the melt, being the lowest in small experimental melts.     

New water distillation system incorporating a membrane mist separator

A comparative study was made on a new distilled water production system vis-a-vis the conventional one. In this new distillation system a PTFE porous membrane is used as a mist separator which is pervious to steam but not to mist entraining feed water impurities such as salts, pyrogens and fine particles. An analysis of distilled water produced by the new distillation system demonstrated that the concentration of nonvolatile impurities therein was no more than one fifth that of distilled water produced by the conventional distillation system.     

水环真空泵组在常减压装置抽真空系统中的应用

通过某常减压装置抽真空系统改造的实例,介绍了水环真空泵的工作原理、改造设计方案和应用情况。应用结果表明,采用蒸汽喷射泵+水环真空泵组合抽真空工艺,能在达到同样抽真空效果的前提下,较常规全蒸汽抽真空工艺操作费用降低,节能效果明显,在环保方面也有较好的收益。