How to Make known Concentration of Potassium Hydroxide Lye for Your Hand Made Soap or Biodiesel

Individuals from any part of the World without the Knowledge of Chemistry can Prepare their own Lye (Potassium Hydroxide) with known concentration from Plant Ash (in this case, dried plantain peels) as the first step to soap-making or self-made Biodiesel production, if the primary intention is to reduce or eliminate cost and ensure Autonomy; by following the simple steps prescribed below:

Preparation Of Plantain Ash Or Starter

Discarded Plantain bunch or Peels can be collected and well dried (under the sun) to generate dry lye starter. The starter burns easily to ash without the usual formation of unwanted Charcoal in the case of Hard wood. The Ash must be well packed into a plastic bucket with a small hole pre-pierced with nail at the bottom of the side of the bucket.

Preparation Of Lye Water

Rainwater must be pre-collected, boiled and poured gradually on the top of the Ash with the minimum amount of boiled water required being at least half of the volume of the bucket. Though the water remains immobile (after the initial vigorous bubbling effect) at the first instant, it begins to sink in after some time and flows out as lye water from the hole, and is collected with a heat-able material placed at the bottom. When all the water has sink through the Ash, the lye water is transferred to the fire to be evaporated (concentrated).

Concentration Of Lye Water

Lye water generated in this form is an absolutely diluted Potassium Hydroxide (KOH) which is one of the two major Alkaline (KOH and NaOH) used in soap making or Bio-diesel production. In traditional soap making, Lye water has to reach an effective concentration before it can be suitable for soap making. Such process involves: Continuous boiling to evaporate the water content, Re-pouring the lye through the pre-used ash in the bucket, re-boiling, and testing the required concentration at every interval using one or both of the Test methods below:

The Chicken Feather Test

This involves placing a chicken feather into the Lye. If the Feather dissolves, the lye is concentrated enough to make the soap, if it does not dissolve, further boiling and pouring through the ash is carried out to increase the concentration until the result is positive. A precaution to be learnt from this procedure is that care must be taken when handling lye because it can be hazardous (burning sensation) when in contact with the skin or the eyes.

The Fresh Egg Test

In this case, fresh egg (with the shell) is placed into the lye after cooling. If the Egg sinks to the bottom, the lye solution is not yet concentrated enough; If it floats at the top of the lye solution, it is over concentrated. But if the egg floats such that it is covered with just little lye at the top, it is in the right concentration for soap making. And it is ready to be used.

But standard lye crystals (potassium hydroxide crystals) can be produced from lye generated by this process by exposing concentrated lye solution to the sun to evaporate the water content. KOH produced in this form is useful in the preparation of Bio-diesel. Otherwise, any concentration of KOH required for Bio-diesel production or soap preparation can be calculated at any interval of the preparation process (or after the preparation) by using a more accurate calculation model formulated to create a standard chemical from plant Ash for anybody no matter how isolated in any part of the World.

The Calculation Model

Actual laboratory concentration of KOH in the lye solution at every phase can be calculated using knowledge of elementary Chemistry which involves titrating an acid against the lye solution in the presence of an indicator to detect the end point. Materials required for this process are: Burette, Pipette, Volumetric Flask, Beaker, and a retort stand. Other chemicals required are acid and indicator.

A simple process involves,

1.Clamp the Burette to the Retort Stand at the upper part with the lever, rinse, and use the beaker to Pour 10% (2.87Mol/dm3) Hydrochloric Acid (HCL) into the Burette to the mark level.

2.Use the Pipette to measure 25cm3 of the lye solution into the volumetric flask and add two drops of phenolphthalein. This will assume a pink colouration.

3.Take down the volume of the the filled Burette as V1 and place a white background at the bottom of the retort stand and titrate the acid against the lye solution by carefully opening the Burette tap gradually releasing the acid into it until the colour just begins to change. At this point, begin to add the acid in drops until the last drop where the lye solution just turn from pink to colourless.

4. Observe the volume of acid used by placing your eyes at the bottom of the convex mark formed at the top of the acid in the Burette and take down the reading as V2.

5.Calculate the actual volume of acid used Va by subtracting V2 from V1 thus, Va=V1-V2 .

6.Because it is KOH and HCL, The stoichiometry is 1:1 Therefore, CaVa=CbVb. Where Ca=concentration of acid=2.87Moldm-3, Va=volume of acid, Cb=concentration of KOH or lye solution, Vb=volume of lye solution used in the reaction=25cm3

But, Cb=(Va/Vb)Ca=(Va/25)2.87Moldm-3

This is the standard Value of KOH in the lye solution. And it is useful for accurate reaction in Bio-diesel production, Soap Preparation, or any other endeavour

For further reading on the use of plantain peel to prepare KOH lye solution, visit: http://www.bioline.org.br/request?ja02016

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Comments 12 comments

silysavg 4 years ago

How many banana peels are required to obtain 5g of crystals?


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James Agbogun 4 years ago Author

Thank you Didge! Appreciate your very nice comment!


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Didge 4 years ago from Southern England

:)P Awesome hub and a good addition to Hubpages! Thanks for sharing!


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James Agbogun 4 years ago Author

Oyelade Kazeem Tobiloba! Go to the top of this page and click on "join now" to fill a simple form. You may start writing immediately! You may also follow any Hubber, Topic (e.g. chemistry). Here, you will learn how to write and perhaps begin to create a source of monthly income! Don't forget to visit the fotum! Wishing you good luck!


Oyelade kazeem tobiloba 4 years ago

In fact this is very great!!But hw could some-one be part of this?Am really enjoying chemistry here,in fact it is good to be a chemist...Yes...I mean....A great Chemist.


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James Agbogun 4 years ago Author

Hello Nagatang! Am happy to see how this article contributed to your soap-making and Biofuel production quest. Wishing you good luck all the way!


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Nagatang 4 years ago from Miri, Sarawak, Malaysia

Good information. One step nearer to my soap making & Bio fuel production. Cheers!


Sora Edwards-Thro 5 years ago

How much ash does 1 plaintain peel generate? How many would I need to make about a pint of this stuff?


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James Agbogun 5 years ago Author

dearabbysmom! I wish to Inform you on how I love the Hub, "HubPages Lessons Learned in 8 Weeks". Also, I recognised that you love soap-making. That is Interesting! I appreciate you endorsed this Hub as useful. Thanks!


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dearabbysmom 5 years ago from Indiana

James, I own a small hand-crafted soap business, and never again will I complain about the price of the lye I order online. What a process. Maybe some day I'll have time to try to make my own, but for now I'm very happy others are producing it in orderable bulk! Great hub, up and useful.


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James Agbogun 5 years ago Author

Ramona M, Plantain peels, Cocoa pod, and empty palm fruit bunch; are various native sources of lye for soap making. Sadly, they are becoming unpopupar at a fast pace. Thank you for visiting!


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Ramona M 5 years ago from California

Very good explanation of the process. I knew how to make lye from hardwood ashes, but didn't know that plantain peels are better. Very interesting.

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