How to Make 100% Ethanol (Anhydrous/Absolute/Biofuel)

Intro

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This is a comprehensive guide to making 100% ethanol from 2 simple household materials, cooking wine and magnesium sulfate (Bath salt). The written part of this Instructable will contain the instruction framework required for you to complete this project, while the video will also include specific scientific details regarding the whole experiment, feel free to check out the above video to see it in action.

Outline (For the written Instructables)

1. Material to be used
2. Start the fractional distillation
3. Dry the ethanol
4. Filter the drying agent
5. Redistill ethanol for purification
6. Storage of anhydrous ethanol

Outline (For the above video)

1. Problem statement
2. Safety precautions and disclaimer
3. Material to be used
4. Assemble the distillation setup
5. Loading the distillation setup
6. Why cooking wine?
7. Why is fractional distillation needed?
8. Concept of fractional distillation and HETP
9. How to adjust the heat source and fractionating column
10. Difference between 95% and anhydrous
11. Selection of drying agent
12. How to dry ethanol
13. Let the drying agent sit overnight
14. Filter the drying agent
15. Redistill ethanol for purification
16. Analysis of the recovery rate and error
17. Proper storage of anhydrous ethanol
18. Cost breakdown
19. Not suitable for water-sensitive reaction

For those who just need the instructions for making it but not the scientific details, please follow the steps below, some of the information (Background/Science) is skipped. Otherwise, for a more comprehensive experience, you can watch the video above.

Chemicals:

1. Cooking wine (17.5% ethanol) or any cheap alcoholic beverages that you can find that has high alcohol content.
2. Anhydrous magnesium sulfate (Made from Bath salt, check out my previous Instructable or video)
3. (Optional) Other drying agent of your choice if you don't want to use anhydrous magnesium sulfate (Such as 3A molecular sieve, anhydrous sodium sulfate, etc)

Glassware:

1. Complete fractional distillation setup with at least a 300mm Vigreux column or equivalent fractionating column.
2. 1L Erlenmeyer flask or Round bottom flask (Depends on your choice of heat source)
3. 250mL Erlenmeyer flask or Round bottom flask (At least 2 pieces)
4. A filtration setup (Ranging from simplest filtration using a coffee filter to vacuum filtration)

If you don't already have and need a basic fractional distillation setup (w/o heat source), consider the Vevor 13pcs Distillation set

Tools:

1. Heat source (Hotplate, heating mantle or even electric stove would work too) (DO NOT USE OPEN FLAME)
2. (Optional) Vacuum pump (If you are using vacuum filtration)

Slendor Hotplate Stirrer is also a good entry-level option if you are into chemistry.

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Safety precautions and disclaimer

All experiments should be carried out with extreme caution, please read till the end to fully understand this experiment before proceeding.

1. The context in this instructable will assume you have basic chemistry knowledge to operate glassware and heat sources.
2. I solely make ethanol as a precursor for other chemistry projects, there are also many other uses that you can think of, but if you can't think of any then you probably shouldn't proceed in making this.
3. The ethanol made in this project is not suitable for consumption.
4. Do not use open flame when making ethanol.
5. Please refer to your local laws regarding alcohol distillation.

Assemble the fractional distillation setup

Assemble the fractional distillation setup using the distillation glassware with a 300mm Vigreux column or equivalent, you can refer to this link for some more example setups.

Again, if you have difficulties understanding "how to assemble a distillation setup", you probably shouldn't proceed with this experiment as it requires some basic chemistry knowledge.

Choice of heat source

Use a hotplate for the heat source if you are using an Erlenmeyer flask, and use a heating mantle if you are using a round bottom flask.

Turn up the heat to start distillation

I am using 250°C on my hotplate setup, but the exact temperature will depend on your hotplate, the length of the fractionating column, ambient temperature,etc, so 250°C is just a reference point, adjust it accordingly.

You need to measure the vapor temperature at the top of the distilling head, and ensure the temperature is roughly at ~78.1-78.2°C, turn down the heat source if it exceeds 78.5°C, and turn up the heat if the vapor struggles to reach the distilling head.

Collect the distillate

Collect everything drips over at ~78-78.5°C with a 250mL Erlenmeyer flask, stop collecting once you can't maintain proper vapor temperature, you should be able to collect close to 100% of liquid if you are using 600mL of 17.5% cooking wine.

Adding the drying agent

Dry the ethanol using your choice of drying agent, I recommend using anhydrous magnesium sulfate as it is readily accessible and can be easily made from bath salt.

Add 8g of anhydrous magnesium sulfate to dry every 100mL of 95% ethanol we just distilled, you need to do your own calculation/experimentation if you are using other drying agents.

Stopper the flask and let it sit for 24 hours

Stopper the flask and let it dry the ethanol for at least 24 hours, preferably with an occasional swirling (every 2-3 hours) of the flask for the best results.

Use vacuum filtration or a coffee filter to get rid of the drying agent, either way should be fine. Some particle may go through the filter but it should be fine.

Setup a simple distillation setup

Distill the filtrate from the above step with a simple distillation, to remove any particles that get through and dissolved magnesium sulfate.

Collect the distillate

The distillate should be distilled over at 78.2°C, run the distillation setup till almost dry maximum recovery rate but never to complete dryness.

Measuring the density

Optional step, but if you want to ensure the distillate is 100% ethanol, measure its density with a hydrometer or by weighing the content with a measuring cylinder, the density of 100% ethanol at 20°C should be 0.78945g/ml

Store it over 3A molecular sieve

Also an optional step, you can store it over a small amount of 3A molecular sieve to prolong its shelf life.