甲苯蒸馏法具体原理

原理：沸点不同则能分馏。苯的沸点80.10，甲苯沸点110.63。主要仪器：烧瓶、球形冷凝管、温度计、T型头、牛角头、锥形瓶等，装配为蒸馏冷凝装置。步骤：加热至略高于苯的沸点，保持温度，持续蒸馏，收集冷凝液即可。注意事项：缓慢升温；防止暴沸；

最初的几毫升白色的乳状液是因为你用的蒸馏装置没有干燥含有水或者是你的蒸馏体系（液体）中没有完全干燥，含有少量水。

一般你不会蒸馏纯甲苯的，可能是甲苯溶液吧，如果甲苯中的物质对水稳定的话，含少量的水没有影响，反之要完全干燥，在蒸馏脱溶。

不建议用水浴来进行加热甲苯。

甲苯法有专门的蒸馏装置，国标上面有，你可以去看。馏出的水份会流到配套的刻度量管内，到时直接读数就好了。

甲苯，是一种有机化合物，化学式为C7H8，是一种无色、带特殊芳香味的易挥发液体。有强折光性。能与乙醇、 乙醚、丙酮、氯仿、二硫化碳和冰乙酸混溶，极微溶于水。易燃，蒸气能与空气形成爆炸性混合物，混合物的体积浓度在较低范围时即可发生爆炸。低毒，半数致死量（大鼠，经口）5000mg/kg。高浓度气体有麻醉性，有刺激性。

基于两种互不相溶的液体二元体系的沸点低于各组分的沸点，将样品中的水分与甲苯的共沸液蒸出，冷凝并收集馏液，由于密度不同，馏液在接受管中分层，根据馏出液中水的体积可计算样品中水分的含量。在密闭中进行，温度低，适用于易氧化、分解、热敏性以及含有大量挥发性组分的样品的测定，优于干燥法。将供试品和与甲苯（相对密度 0.866）混合蒸馏，水分可随甲苯一同馏出。水与甲苯不相混溶，收集于水分测定管下层，甲苯收集于水分测定管上层，水与甲苯完全分离。因为水的相对密度为 1.000，故可直接测出（读取）供试品水的重量（g），并计算出制剂中的含水量。 二仪器装置

500ml 圆底烧瓶通过收集器 2 与回流冷凝器 3 联接，连接处均为磨口玻璃。此装置各部件的关键性尺寸如下：连接管内径为 9～11mm，收集器 2 长 235～240mm，如为直形冷凝器，约长 400mm，内径不小于 8mm，接受管容量 5ml，其圆筒形部分长 146～156mm，刻度到 O.1 ml 的细分度，指示体积的读数误差不大于 0.05ml，热源最好是变阻器控制的电热器或油浴。烧瓶上部和连接管可采取绝热措施。 另需准备止爆剂(如玻璃珠)、长刷及铜丝等。

测定法

取供试品适量(约相当于含水量 1～4ml)，精密称定，置 1 瓶中，加甲苯约 200ml，必要时加入干燥、洁净的无釉小瓷片或玻璃珠数粒，将仪器各部分连接，将 1 置电热套中或用其他适宜方法缓缓加热，待甲苯开始沸腾时，调节温度，使每秒钟镏出 2 滴。待水分完全镏 出，即测定管刻度部分的水量不再增加时，将冷凝管内部先用甲苯冲洗，再用饱蘸甲苯的长刷或其他适宜方法，将管壁上附着的甲苯推下，继续蒸馏 5 分钟，放冷至室温，拆卸装置，如有水黏附在 B管的管壁上，可用蘸甲苯的铜丝推下，放置使水分与甲苯完全分离(可加亚甲蓝粉末少量，使水染成蓝色，以便分离观察)（甲基蓝可不用）。检读水量，并计算成供试品的含水量(％)。

注意事项

1 装置使用前，应先用铬酸洗液洗涤接受管及冷凝器，用水充分漂洗，烘干。全部仪器应保持清洁，干燥。 2 圆底烧瓶中需加入 1～2 粒止爆剂（如玻璃珠、沸石、碎瓷片等）以防爆沸。 3 注意控制电热套温度，使每秒钟馏出 2 滴。 4 蒸馏时宜先小火，控制馏出的速度,不宜太快。 5 蒸馏完成后,应充分放置至室温后,再检读水量,否则使检测结果偏高。

Benzene and toluene are important organic chemical raw materials. Benzene as raw materials in order to be more than 250 kinds of synthetic organic chemicals, but the main derivatives for ethylbenzene, cumene, cyclohexane and nitrobenzene. Toluene can be used for gasoline blending components, solvents and through disproportionation and transalkylation of benzene and xylene system, and a variety of synthetic organic chemicals.

The Graduation Project, through the production of a given set of operating conditions designed benzene - toluene matter of the distillation separation devices, used 250Y structured packing tower type separation. Benzene and toluene through a number of specific data such as vapor-liquid equilibrium relationship and balance data, than the hot-melt, and calculate the temperature of its tower, tower reactor temperature, feed temperature tower, condenser and other heat load. Design task by the book and calculate the number of data obtained through the graphical method of theoretical plate packed column, and then calculated the actual plate number. And then there are the viscosity, density calculated with the above data and design a number of book data provided to derive a high tower, Tower Drive, a distillation device also includes heat exchanger, the heat exchanger in our selection the calculation, cooling water and gas in opposite directions, when the gas flows to the cold heat exchanger, the film thickness to thinning, heat transfer coefficient, heat transfer through the area seeking their way to find the most suitable heat exchanger, However, the top heat exchanger including a condenser, tower reboiler kettle and so on, is why we wanted to take some of the most suitable heat exchanger. Finally, select a suitable centrifugal economy.

Key words: benzene toluene packed tower condenser

Separation of benzene and toluene distillation unit

Benzene and toluene are important organic chemical raw materials. Benzene as raw materials in order to be more than 250 kinds of synthetic organic chemicals, but the main derivatives for ethylbenzene, cumene, cyclohexane and nitrobenzene. Toluene can be used for gasoline blending components, solvents and through disproportionation and transalkylation of benzene and xylene system, and a variety of synthetic organic chemicals.

The Graduation Project, through the production of a given set of operating conditions designed benzene - toluene matter of the distillation separation devices, used 250Y structured packing tower type separation. Benzene and toluene through a number of specific data such as vapor-liquid equilibrium relationship and balance data, than the hot-melt, and calculate the temperature of its tower, tower reactor temperature, feed temperature tower, condenser and other heat load. Design task by the book and calculate the number of data obtained through the graphical method of theoretical plate packed column, and then calculated the actual plate number. And then there are the viscosity, density calculated with the above data and design a number of book data provided to derive a high tower, Tower Drive, a distillation device also includes heat exchanger, the heat exchanger in our selection the calculation, cooling water and gas in opposite directions, when the gas flows to the cold heat exchanger, the film thickness to thinning, heat transfer coefficient, heat transfer through the area seeking their way to find the most suitable heat exchanger, However, the top heat exchanger including a condenser, tower reboiler kettle and so on, is why we wanted to take some of the most suitable heat exchanger. Finally, select a suitable centrifugal economy.

关键词：Packed tower condenser benzene toluene

芳烃分馏的原料为来自抽提装置的C芳烃、歧化单元的C芳烃、异构化单元的C8+芳烃。来自抽提装置的C8芳烃先经过白土塔进料加热器16E01加热后经过白土塔16D01AB进行处理，然后与歧化单元的Cg芳烃、异构化单元的Cg+芳烃

起进入二甲苯塔16C02。塔顶物流大部分作为抽余液塔重沸器17E05和抽出液

塔重沸器17E08的热源，其余的进入蒸汽发生器16E02来产出1.0MPa的蒸汽：

冷凝液进入二甲苯塔回流罐16D03,经回流泵16P03AB升压后一部分作为回流

返回二甲苯塔，另一部分作为吸附单元的原料进入吸附分离原料缓冲罐16D04。

二甲苯塔底物料经泵16P02A/B/C升压后在部分作为热源送至以下各重沸

器和加热器：白土塔进料加热器16E01、汽提塔重沸器15E06、甲苯塔重沸器15E11、重芳烃塔重沸器16E05、成品塔重沸器17E14、脱庚烷塔重沸器18E08换热后至加热炉16F01AWB升温至300℃后返回二甲苯塔：另一部分作为原料送至重芳烃塔16C07进行分离，塔顶产品C,芳烃作为原料送至歧化单元。塔底C10芳烃作为副产品经过冷却器16E08冷却后送出装置。

甲苯减压蒸馏温度和真空度分别是60度和20000pa。温度和真空度分别是60度和20000pa情况下，甲苯能顺利蒸出来且馏分量较大，水能蒸出来，馏分极小，在20000pa的真空度下水沸点是60度。

二甲苯可容少量水，这样使其前期水饱和，以后样品里的水不会溶于二甲苯，而使结果受影响。 基于两种互不相溶的液体二元体系的沸点低于各组分的沸点这一事实，将食品中的水分与甲苯或二甲苯或苯共沸蒸出，冷凝并收集馏液，由于密度不同，馏出液在接收管中分层，根据 馏出液中水的体积，即可计算出样品中水分含量。 蒸馏法的原理是：将不溶于水的有机溶剂和样品一起放到蒸馏瓶中加热，样品中的水分与有机溶剂共同沸腾，汽化，把水和有机溶剂收集到一个刻度管中，最后读出水层。 不过如果样品是对热不稳定的，一般不用二甲苯，而采用沸点低的苯或甲苯。 此方法一般适用于含有大量挥发性成份的样品，如香料、调味品等，禾业科技专专门做水分测定的。