WVO Titration, Terminology, As well as some definitions

[Chris Senior Member Find all posts View Profile Close Chris]

Hi All
Hopefully the post on FFA's has been of some assistance to people here
the post on titration some weeks back most likely has been of some assistance as well
I thought that it may be a good idea to summarise here as well as define some terms used in these post's
Unfortunately as much as one wants to avoid the use of chemical terminology they will and do crop up
I will attempt to keep those technical terms used commonly in chemistry relating to biodiesel production within the parameters of the post on titration as well as Free fatty acids
Here we Go;
Titration: A method for a quantitive analysis of a substance by an essentially complete reaction in solution with a measured quantity of a reagent of known concentration
Equivalence point:The point in a titration at which one reactant has been exactly consumed by addition of the other reactant
End point:The point in a titration at which the indicator signals that a stoichiometric amount of the first reactant has been added to the second reactant
The last two definitions quite often are bundled in one by chemist's for practical reasons
Stoichiometry: The study of mass relationships in chemical reactions
May be we need to elaborate a bit on the last point
When we say that we must titrate, we do so we can find how much extra lye we need to use
We titrate to find the "acid value" of the WVO
We add that to the 1% that is required to catalyze the perfect oil with no FFA's
This 1% of 100% lye has been worked out Stoichiometrically
If we use a lye with less purity than 100% we need to add the difference
If the lye we have is 90% pure we must add an extra 10% on top of the amount indicated
So much for Titration Now on some other terms used in our endeavours
Esters: Carboxylic acids or Fatty acids as found in oils and fats from plants or animals
Tri-esters: Another name for triglycerides or fatty acids attached to glycerol
(FFA's can thus be considered as an ester as they are a Carboxylic acid)
Esterification: The process of reacting a Carboxylic acid with an alcohol in the presence of a strong acid
Transesterification: The displacement of one alcohol with another alcohol from an ester, it is also called Alcoholysis (cleavage by alcohol)

Taking into account what we know or learned so far and given a clear understanding of the steps as well as how the materials involved are used in the whole process it is how it works

And this is exactly what we do in making biodiesel, in the final step we displace the glycerol, which is an alcohol, in the fat or oil, with methanol or ethanol so as to get biodiesel
If we use Methanol is called a Methyl ester
Another name that better defines it is FAME Fatty Acid Methyl Ester
Comments as well as correction will be welcomed

[gwalker Senior Member Find all posts View Profile Close gwalker]

Re: WVO Titration, Terminology, As well as some difinitions

Chis, your chemistry notes are really helpful so please keep doing it.

Can I suggest this:

Layman's Terms: Titration: The simple test you do to check how bad this lot of fish and chip oil is so you can find out how to fix it and make good biodiesel.

George

[Chris Senior Member Find all posts View Profile Close Chris]

Re: WVO Titration, Terminology, As well as some difinitions

Chis, your chemistry notes are really helpful so please keep doing it.

Can I suggest this:

Layman's Terms: Titration: The simple test you do to check how bad this lot of fish and chip oil is so you can find out how to fix it and make good biodiesel.

George

Hi George
I can say that this is as good a definition as it gets for our endeavours in producing biodiesel
I do want to say that people who want to make soap out of that oil would not give a hoot
Horses for courses
And since this is our horse, we have to put it in the right course if we want to win the race

[tillyfromparadise Senior Member Find all posts View Profile Close tillyfromparadise]

Re: WVO Titration, Terminology, As well as some definitions

Hello Chris

I do find it interesting that while you say you wish to "avoid the use of chemical terminology" you then seem to use an overabundance of chemistry "Jargon" and supply a fair bit of information that in my mind is of no real importance for the average fellow like myself who knows very little about chemistry.
While I feel I understand what is going on in a titration pretty well, I certainly did not find your above post easy to read or understand.

Just to straighten up one or two points.

When we titrate, we are not finding the Acid Value of the WVO, we are finding out how many ml of 0.1% KOH/NaOH is required to achieve a pH of 8.5 in the titration solution when titrating 1ml of oil.
A 0.1% NaOH/KOH solution has been chosen because this can be directly translated into extra Grams of NaOH/KOH per litre WVO required in the reaction.
To find the Acid Value of the oil readThis Post by neutral.

End point: For our biodiesel titration purposes, this is when the solution reaches a pH of 8.5 or if you are using an indicator, the indicator turns the appropriate colour for the appropriate amount of time.

Stoichiometry: I am not sure why you have introduced this term into a discussion about titration, you are the first person to mention it in a titration discussion.

Lye: Lye means both NaOH and KOH. As the amounts of NaOH and KOH required in the reaction are quite different, it would be much less confusing if you did not use the word Lye and use NaOH or KOH instead.

Tilly

[Chris Senior Member Find all posts View Profile Close Chris]

Re: WVO Titration, Terminology, As well as some definitions

Hello Chris

I do find it interesting that while you say you wish to "avoid the use of chemical terminology" you then seem to use an overabundance of chemistry "Jargon" and supply a fair bit of information that in my mind is of no real importance for the average fellow like myself who knows very little about chemistry.
While I feel I understand what is going on in a titration pretty well, I certainly did not find your above post easy to read or understand.

Just to straighten up one or two points.

When we titrate, we are not finding the Acid Value of the WVO, we are finding out how many ml of 0.1% KOH/NaOH is required to achieve a pH of 8.5 in the titration solution when titrating 1ml of oil.
A 0.1% NaOH/KOH solution has been chosen because this can be directly translated into extra Grams of NaOH/KOH per litre WVO required in the reaction.
To find the Acid Value of the oil readThis Post by neutral.

End point: For our biodiesel titration purposes, this is when the solution reaches a pH of 8.5 or if you are using an indicator, the indicator turns the appropriate colour for the appropriate amount of time.

Stoichiometry: I am not sure why you have introduced this term into a discussion about titration, you are the first person to mention it in a titration discussion.

Lye: Lye means both NaOH and KOH. As the amounts of NaOH and KOH required in the reaction are quite different, it would be much less confusing if you did not use the word Lye and use NaOH or KOH instead.

Tilly

I am sorry you found this post of not much help Tilly
May be you want to read it in the context of the other post's
I think Neutral is perfectly correct, obviously you have difficulties in understanding his post as well
If you did read it carefully he explains it quite well, it is the way you determine the Acid no or Acid value By the way it is an internationally accepted method an ISO std
End point, it has been defined already and I did not do it it has been around chemistry before I was born and let me tell you that is a long time ago
If you understood Neutral's post it tells you about Stoichiometry and Please take it up with him not me if you want to verify
It appears to me that confusion was already set, in by the time I used the term "Lye" I do take your point though "Base" or as you suggest would have been better
Once again I do apologise to the average person like you However there may just be some here that do get something out of it
I did say corrections as well as pointers are welcome and I thank you for pointing out the "Lye" issue
I fell in the trap that people already had a grip on the titration of non polar solutions such as WVO and the indirect way of finding out the adjustments needed to neutralise the FFA's
Besides thinking about titration to find the Acid value of oils one does use Koh as it is the std,
My use of the word "lye" did refer to Koh but it would not be obvious to someone that does not understand why he titrates the oil so as to find it's acid value, so that number would be understood universally
Here is a definition for you from Wikipedia It will save you looking it up
I do know your views on the Journey to forever site, I do hope that you do not have the same views on material in Wikipedia

In chemistry, acid number (or "neutralization number" or "acid value" or "acidity") is the mass of potassium hydroxide (KOH) in milligrams that is required to neutralize one gram of chemical substance. The acid number is a measure of the amount of carboxylic acid groups in a chemical compound such as a fatty acid. In a typical procedure, a known amount of sample dissolved in organic solvent is titrated with a solution of potassium hydroxide with known concentration and with phenolphthalein as a color indicator.
The acid number is used to quantify the amount of acid present, for example in a sample of biodiesel. It is the quantity of base, expressed in milligrams of potassium hydroxide, that is required to neutralize the acidic constituents in 1 g of sample.

AN = (Veq-beq)×N×56.1/Woil. Veq is the amount of titrant (ml) consumed by the crude oil sample and 1ml spiking solution at the equivalent point, and beq is the amount of titrant (ml) consumed by 1 ml spiking solution at the equivalent point.
The molarity concentration of titrant (N) is calculated as such:

N = 1000×WKHP/(204.23×Veq). In which WKHP is the amount (g) of KHP in 50 ml of KHP standard solution, and Veq is the amount of titrant (ml) consumed by 50 ml KHP standard solution at the equivalent point.
Acid number (mg KOH/g oil) for biodiesel is preferred to be lower than 3.
There are standard methods for determining the acid number, such as ASTM D 974 andDIN 51558 (for mineral oils, biodiesel).
As fats rancidify, triglycerides are converted into fatty acids and glycerol, causing an increase in acid number.

I promise I will try to do better next time Tilly
May I say that you are quite helpfull if not very helpfull to most people that have an issue with biodiesel production
It is obvious that you know what is going on from many years of practicing the art of making biodiesel
There is nothing better than experience and you certainly have it
besides, your post's at infopop that are in excess of 5000
If one assumes a couple of replies per post that is a lot of input as well as information exchange all very beneficial to you as well as the recipients of your good help
It would be fair to say that some people may be interested in having a deeper understanding of the process as well as how it comes about
Therefore the post's