What is Distillation: Definition and 73 Discussions

Distillation, or classical distillation, is the process of separating the components or substances from a liquid mixture by using selective boiling and condensation. Dry distillation is the heating of solid materials to produce gaseous products (which may condense into liquids or solids). Dry distillation may involve chemical changes such as destructive distillation or cracking and is not discussed under this article. Distillation may result in essentially complete separation (nearly pure components), or it may be a partial separation that increases the concentration of selected components in the mixture. In either case, the process exploits differences in the relative volatility of the mixture's components. In industrial applications, distillation is a unit operation of practically universal importance, but it is a physical separation process, not a chemical reaction.
Distillation has many applications. For example:

The distillation of fermented products produces distilled beverages with a high alcohol content, or separates other fermentation products of commercial value.
Distillation is an effective and traditional method of desalination.
In the petroleum industry, oil stabilization is a form of partial distillation that reduces the vapor pressure of crude oil, thereby making it safe for storage and transport as well as reducing the atmospheric emissions of volatile hydrocarbons. In midstream operations at oil refineries, fractional distillation is a major class of operation for transforming crude oil into fuels and chemical feed stocks.
Cryogenic distillation leads to the separation of air into its components – notably oxygen, nitrogen, and argon – for industrial use.
In the chemical industry, large amounts of crude liquid products of chemical synthesis are distilled to separate them, either from other products, from impurities, or from unreacted starting materials.An installation used for distillation, especially of distilled beverages, is a distillery. The distillation equipment itself is a still.

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  1. Dario56

    Derivation of McCabe - Thiele Method

    McCabe - Thiele method is used to find minimum number of separation stages or theoretical plates for a given efficiency of separation in distillation for two - component mixture if components have similar enthalpy of vaporization. If components have similar enthalpy of vaporization ,than on...
  2. watersplit

    Purify water by distillation

    Hi I want to to make 100% (or close to it) pure water and I guess distillation is the way. I know there are VOCs that can vaporize at different temperatures. And then we have the chloramines in our tap water. When water gets vaporized does the chloramines vaporize too? Can anyone provide some...
  3. Kaushik

    What exactly is fractional distillation?

    Could someone please explain fractional distillation? I find it really confusing to understand. Thanks!
  4. Mcp

    Phase diagrams for fractional distillation

    https://www.chemguide.co.uk/physical/phaseeqia/idealpd.html#top I learned about phase diagrams involving partial Vapour composition, temperature and composition of binary solutions from this website. You can find it if you scroll down to a little above the end First it considers a binary...
  5. Crafticharli

    How can I dissolve plant material without changing-

    I have a question which is ungoogleable. Question: What is the most efficient way to fully dissolve plant matter without destroying its chemical make up, for distillation purposes? Background Information: I started down this rabbit hole while researching the viability of a artisanal soap...
  6. D

    Effect of impurities on the boiling point of ethyl ethanoate

    After carrying out reflux and distillation to produce ethyl ethanoate (ethyl acetate) I measured the boiling point and I got 71 degrees Celsius whereas the true value is 77.1 degrees Celsius. Impurities increase the Boiling point (BP) as well as concentration. However my calculates BP is lower...
  7. B

    Exploring Vertical Retorts for Coal Distillation Processes

    This is regarding vertical retorts, specifically those used in "distillation" of coal to produce coal (town) gas, tar and other by products. It is understood that the distillation of coal is done by heating coal in an air (oxygen) free container (ie in a retort). The vertical retort is...
  8. alphaj

    Are open-air distillation and simple distillation the same?

    Homework Statement There really is no problem for this. I am just writing my procedure for orgo lab and I haven't don't any distillation before. I tried googling "open-air" distillation to see if it was equivalent to simple distillation, but I can't seem to get a straight answer. Homework...
  9. E

    How to pump liquid from vacuum to atmosphere

    Greetings, The application is a wiped film evaporator (~1.2-1.5 kg/hr throughput). The concentrate and the distillate gravity feed round bottom flasks. I'm not worried about the cold-trap waste. The evaporator volume is under vacuum (~0.003Torr). I want to pump the liquid from the...
  10. G

    Difference between Steam and Vacuum Distillation

    Hello Guys... I know this is simple but this two concepts confuse me a lot. Like in vacuum distillation Pressure is reduced to increase the difference in boiling point between two components and steam distillation is where steam is introduced in the mixture to reduce the vapor pressure. So what...
  11. A

    Simple distillation of compounds with similar boiling points

    I just had a lab, and the results really aren't adding up to what i expected. And this is specifically about simple distillation, not fractional distillation. Lets say i have a solution of two liquids, one's boiling point is 90°C and the other is 110°C, a 20°C difference which is pretty close...
  12. Rizwan Yaseen

    What is Damping in a distillation column

    Why this troubleshoot occurs and how we can minimize it ??
  13. R

    Advanced distillation of air

    What is the best textbook resource (or comprehensive publications, etc) on multi component distillation? particularly the separation of nobel gases from air. Air has all of the nobel gases (except maybe krypton) but they are trace so finding the off takes for these would be incredibly difficult...
  14. Umar Awan

    Fractional distillation calculations

    Say I have got a super cooled cylinder of half hydrogen and half helium. This cylinder has a pressure of 100,000 Pascal's. At this pressure, hydrogen boils at 20 Kelvin and helium at 4.21 Kelvin. I hope to separate helium by cooling gas down to 4.21 Kelvin but I know that even at the...
  15. E

    Is a binary distillation column limited by Carnot?

    Hi Physics Forums, I'm wondering if a distillation column is limited by the carnot efficiency and, if so, how this limitation can be used to determine the maximum efficiency of a distillation column with particular hot and cold side temperatures. A distillation column has a hot and cold side...
  16. T

    Steady State Distillation Process

    A steady state distillation process is shown diagrammatically as FIGURE 1. Assuming no heat losses to the atmosphere: (i) Write four balanced equations for this system. (ii) Identify where any constitutive equations may be required for the modelling processes.There are two states that I can...
  17. gfd43tg

    Distillation Column Sieve Tray

    I'm reading McCabe and Thiele's classic "Unit Operations of Chemical Engineering" section about the design of sieve-plate columns. Below is a figure showing a column. I have a few questions and some clarification would be great. 1. Isn't the weir for plate n-1 simply the downcomer for plane n...
  18. faiziqb12

    Boiling and distance traveled

    i have got a question with distillation . in distillation as we know the mixture is boiled and the mechanism then goes like substances with high boiling points condense at the bottom and substances with lower boiling points condense on the way to the top. i don't know why , but i am having...
  19. Y

    Why membrane for distillation has to be hydrophobic

    I have a question about membrane distillation. I have read the following from a review paper about membrane distillation: The membrane distillation should be applied for membrane operations having the following characteristics: - The membrane should be porous. - The membrane should not be...
  20. J

    Can you get rid of alcohol in water (without keeping it)?

    Hello. My name is Jack. New member to the forums. Nice to meet you all! I have a general question that is part of a project I am working on for graduate school. I'm looking to distill water through solar energy in a closed solar still and am in a pickle finding a way to prevent alcohol from...
  21. gfd43tg

    Theoretical number of plates for distillation column

    Homework Statement Homework EquationsThe Attempt at a Solution With my solution, I think cold feed means ##q = \infty##, which is seen from my xy diagram. I have some issue understanding the statement "for each mole of feed 0.15 mol of vapor is condensed at the feed plate". I assumed that...
  22. S

    How can I calculate wall thickness for vacuum distillation?

    Hi everybody, I want to design two industrial vacuum distillation systems. The dimension of my distillation tanks are as follow: (1) A Horizontal Cylinder Tank with 200 cm length and 200cm diameter (total volume = 6300 liter) (2) A Horizontal Cylinder Tank with 400 cm length and 290cm diameter...
  23. maistral

    Ponchon Savarit for distillation + overall efficiency?

    I'm having trouble trying to figure this out. I am aware how to employ overall efficiencies on McCabe-Thiele - IIRC it goes like: "draw a pseudoequilibrium curve in between the equilibrium line, and the rectifying/stripping lines - 100% efficiency means that it coincides with the equlibrium...
  24. H

    Exploring How Heating & Pressure Affect Distillation Separation

    I'm having trouble understanding why 1) Heating a solution more slowly would increase separation in a distillation and why 2) Lowering the pressure above the solution, i.e. with a vacuum, would decrease separation. Distillation depends on you collecting one component before the second...
  25. W

    Vacuum distillation advice for a non-chemist?

    I'm a home-scale experimenter/dabbler in the arts of distilling liqueurs/spirits and essential oils, and right now I'm trying to see what vacuum distillation(at very low temperatures) can add to the finished product as far as taste, aroma, and color go. For my initial experiments, I've been...
  26. M

    Cooling for Distillation

    Hi, I am new to the forum and would like your thoughts and idea on a project I am currently working on as a chemical engineering student. I have to design a cooling system for a distillation column using water pumped from a pond nearby. I have been given the distance to pump this water and...
  27. P

    Distillation column feed preheating

    Refer to the attached drawing for more details . In this distillation column acetone is to be separated from a mixed feed coming at ambient temperature. It is a packed column with mellapack packings. Steam is used in the reboiler (thermo syphon) for heating. Details of these streams are...
  28. R

    Optimizing Temp. Tappings on Distillation Columns - Ideas/Experience?

    We have a distillation column with insufficient temperature tappings. In order to do a rough survey of the temperature profile externally an idea is to drill small (say 1 inch) holes in the insulation and take external temperature readings. Would a IR temp. gun like this one be a good idea...
  29. G

    Explaining Mass Loss in Differential Distillation

    Hi, i just perfomed a differential distillation experiment, the initial solution cointaned ethanol-water solution with 4.9% in mass it weighted 399.63g Water Mass:381.25 Ethanol Mass:19.96 We distilliled the solution for 20 minutes and obtained two solutions, the distilled had 35.87g and the...
  30. F

    Microbial contaminants in water distillation

    Hello all, I have a few questions regarding purification of water of microbial contaminants by boiling. 1. If water containing microbial contamination is boiled, and the vapor is collected, is the condensed vapor going to be free of microbes? I would think so because if the microbes don't die...
  31. J

    Hydrostatic Vacuum Distillation Idea

    Hey, I came across this idea a couple of years ago. It's been a long time since I took introductory physics. But I'm curious as to whether this is feasible. If I'm crazy, just say so! See attached image. 1. Intake tube, vacuum chamber and condenser are initially filled with water. Valve (A)...
  32. J

    Visual fractional distillation demo - thwarted

    I wanted to do a demo of fractional crystallization that would have a nice visual result. I had intended to make a saturated solution of ferric chloride, nickel chloride, and sodium chloride, put the solution in a very broad shallow petri dish, and allow natural evap to produce concentric...
  33. S

    No bubbles in distillation of phenylacetone under vacuum

    hello, i have no bubbles in distillation of phenylacetone under vacuum, the heat is about 120c, and the vacuum pump produce around 20 torr. is that normal? please help me
  34. J

    Organic chem:fractional distillation

    Hi, During fractional distillation,crude oil is heated to a certain temperature,then it is pumped into the fractional tower. As you know,petroleum is a mixture of alkanes.When it is heated in the furnace(to about 400°C),it does not burn.But lower alkanes(e.g.CH4) are extremely flammable,why it...
  35. J

    Safety precautions to be taken in fractional distillation of petroleum

    Homework Statement My textbook states that one of the safety precautions to be taken in the fractional distillation of petroleum(in school laboratory) is using a small flame to heat the rocksil(rocksil is soaked with petroleum),and avoil using stationary flame for heating. Can anyone explain...
  36. B

    Fractional Distillation Calculations

    Homework Statement 4-bromotoluene was synthesized and purified by distillation. There are 5ml of the crude product. A fractional distillation is being carried out in a 100ml round bottom flask. Assume that the volume of the column is 16ml. Determine the number of moles of 4-bromotoluene that...
  37. C

    Method to remove salt from water (Not distillation or RO)

    Hello all. I'm tutoring a high school student and am having trouble with a seemingly simple science project that was assigned: How to remove table salt from water. Having graduated as a Chemical Engineer, I said distillation! But the problem statement says you can't be that boring. Then I said...
  38. G

    Multicomponent Distillation

    Hi folks I'm currently in my last year of my chemical engineering degree and doing a design project on the manufacture of acrylic acid. I have the job of designing a solvent recovery column, where a mixture of Methylisobutylketone (MIBK) solvent (heavy key) and acrylic acid (light key) are...
  39. F

    Fractional Distillation: Troubleshooting Reflux in Cyclohexane-Toluene Mixture

    Homework Statement For fractional distillation, should the cyclohexane-toluene mixture appears to reflux at the bottom of the fractionating column but is not going up the column, what is the most appropriate action to do? Homework Equations - The Attempt at a Solution I was...
  40. S

    Using Endothermic Solvation To Assist Distillation

    From time to time I find myself dissolving potassium nitrate in water (endothermic solvation) and a while back i considered that if i was boil a saturated solution of potassium nitrate that it would be easier than boiling distilled water; as evaporation would have to be exothermic, which would...
  41. S

    PID temp control for distillation (was Before i ask )

    PID temp control for distillation (was "Before i ask") I am 68 years old and never studied physics-- i am not a college student and only completed 1 year of college. I have a hobby of distilling and need questions amswered-- is it ok if i aske questions here about distilling? :smile: Scotty
  42. S

    Fractional distillation of crude oil

    Homework Statement What fractions of crude oil would be distilled off, if you did the fractional distillation of crude oil in a lab? Homework Equations The Attempt at a Solution I think light petroleum and light naphtha, but I am not sure.
  43. P

    Problems with Extractive Distillation of C4 to Get Butadiene

    Hello, I am currently being assigned in doing a project entitled "Extractive Distillation of C4 to Obtain Butadiene using DimethylFormamide(DMF)". It was rather challenging and I am heading nowhere as I had take a long time in trying to carry out the material balance. One of the challenges is to...
  44. G

    Fractional distillation

    Liquid mixture boils at the same temperature, and on the fractionating column are series of trays with bubble caps and overflow pipes, that circulates the liquid mixture. Then how comes the column contains trays at diferent temperatures?
  45. G

    Distillation material balance

    Homework Statement Question: A mixture of 40/60 mole% pentane/heptane is to be separated to give a top product of 95 mole% pentane and a bottom product of 5 mole% pentane. The column will operate at 1 bar witha reflux ratio of 0.5 kmol/kmol. It will have a total condenser and a partial...
  46. G

    Vacuum Distillation Setup on a Budget

    I've got a simple vacuum distillation setup but no vacuum source. I need to pull 10 Torr. I also don't want to break the bank. I'm considering using an air compressor and aspirator, but I don't know if it will be adequate. this is the...
  47. T

    Vapour Pressure in Fractional Distillation: Understanding its Impact

    Homework Statement During the process of fractional distillation, discuss vapour pressure. Homework Equations This is a theoretical question, so I believe no equations are necessary. The Attempt at a Solution I think that since the bottom of fractional distillation column is the...
  48. A

    Help with Chem- Azeotropic Distillation

    Hello, I am curious on how azeotropic distillation works. I know it has to do with the gas law, PV=nRT but I would like to know in depth analysis how this process works. I have organic 2 lab final coming up (this Tuesday) and it may happen we might be asked to explain how azeotropic...
  49. A

    Azeotropic distillation Please help final coming up

    Homework Statement Hello, I am curious on how azeotropic distillation works. I know it has to do with the gas law, PV=nRT but I would like to know in depth analysis how this process works. I have organic 2 lab final coming up (this Tuesday) and it may happen we might be asked to...
  50. A

    Azeotropic distillation

    Hello, I am curious on how azeotropic distillation works. I know it has to do with the gas law, PV=nRT but I would like to know in depth analysis how this process works. I have organic 2 lab final coming up (this Tuesday) and it may happen we might be asked to explain how azeotropic...