There is sure a lot of talk about " Le Chateleir's principle"
Is that similar to "Lady Chatterley's Lover"
I watched the video. Interesting.
I Gotta move to Perth. In the US the government gets really upset with us if we pour highly caustic, poisonous, flammable liquids into the public sewer system. So in Perth, as long as it's thin like water, there is no problem with pouring anything in the sink. I love it.
Of course water is ONLY produced when Methoxide is actually produced. Dissolving KOH in methanol does not produce water.
Everyone I know who makes biodiesel is aware that water is produced when you make methoxide by mixing KOH or NaOH with methanol. It is common knowledge. It puzzles me why you think most people who make biodiesel were unaware of this.
Like the current pipeline oil spill near St Louis that threatens rivers and public water supplies alike?
But no, seriously, glycerol and methanol are supposed to be okay in foulwater systems.
A common sight in downtown Perth.
A few years back Dr. Van Gerpen's academics claimed Le Chateleir's principle was the reason for the 6:1 molar ratio of oil to methanol. They put out a video not long ago that implied the real reason for the 6:1 molar ratio has more to do with Dalton's Law, than Le Chateleir's Principle.
Mark is claiming that
You might find this interesting, I suspect that making methoxide with the cement may let you use less KOH than simple mixing of KOH with methanol.
I'd still like to see four or five people with open minds try Mark's method (less pouring raw glycerin down the drain) and reporting back on water content of the oil and how it did in the 3/27 test and soap test. Repeatability is where that other foolproof method failed.
I'm not sure where you live, but the laws where you are are probably the same as they are here.
As long as it's water-miscible you can dump it down the sink. If you are doing it on a regular basis, such as a food or beverage manufacturing plant, the water corp will require you to take regular samples and have them tested for BOD. According to that BOD, and therefore the load that is being placed on the system, you will then have to pay a certain amount per Kl.
I have worked in the waste management industry for years, and have been involved in several plants where we have designed a WWTP for the purpose of lowering the outfall BOD. Then it's just a numbers game. The cost of the WWTP is compared with the savings made on lowering the BOD, and then a decision is made on whether it's economically viable to build the plant.
But in the case of dumping glycerol waste down the sink, everything in it is water-miscible and biodegradable, and therefore it's perfectly legal to send it to waste,
Correct. Perfectly legal. See post above.
One more thing. I'm constantly making the mistake of assuming knowledge in others that is obvious to me, and I've done it again.
One obvious reason why I know that this process is a very high yield process is because it's based on a high concentration of catalyst. It's such a basic principle of chemical manufacturing (and physical chemistry) that there is no more certain way to obtain a high reaction yield than to increase the level of catalyst, whether it be homogenous or heterogenous, as it overcomes any variation in reaction kinetics caused by the Boltzmann distribution.
Dr Chemical; You wrote "since the methoxide is a catalyst". The methoxide is not a catalyst, it is the product of a catalyst (KOH). A catalyst regenerates itself. A methoxide molecule is consumed in the production of the ester.
Correct. A technical point, but quite correct. It's more accurate to say "higher concentration of catalyst (KOH), resulting in a higher concentration of the nucleophilic intermediate (the methoxide).
But I think you've just explained something else. I've sat down and done that thing that organic chemists do, drawing arrows between atoms and bonds, to work out where the electrons go, and made a discovery that explains something I haven't been quite able to figure out.
The glycerol that this method produces is incredibly thin - essentially like water - and is easily disposed of down the sink (see video). I thought this was because of the thinning effect of the MeOH, but was never really happy with that explanation, mainly because I noticed that when I sit it in a beaker in the atmosphere for a few days it thickens into the syrup that I've observed before, without a significant change in the volume.
Here's what I think, after my scribbling exercise with arrows and stuff - the by-product of my reaction is not glycerol, but the potassium salt of the glycerol. To generate glycerol (and regenerate the KOH), the water is required that I have removed:
K3C3H5O3 + 3H2O = 3KOH + C3H8O3
So in the absence of water, I don't have glycerol at all - I have its potassium salt. And that explains why it's so thin - NO HYDROGEN BONDING. The viscosity of glycerol is wholly explained by its hydrogen bonding, and in the absence of hydrogen bonding it's as thin as water.
And that explains why it thickens upon standing - it sucks up water from the atmosphere according to the above reaction (Le Chateleirs principle again) until the mixture is composed wholly of the reaction products KOH and glycerol.
Glad I figured that out - I was never really happy with the "thinned by methanol" explanation
Making assumptions about what is and is not legal can bite you really hard. Please, take the time to verify your assumptions even though it's based on your previous experiences, laws change.
Like Tilly said earlier, yield is not an indicator of quality. It is used as an economic indicator. You have put forth no evidence of quality, other than for your clarification process.
All that said, I would like to see your process be proven, with repeatable results by multiple people using multiple oil sources.
WesleyB, Would you be willing to try it on a test batch scale? You have always sounded like the open minded type. This would be experimentation for the sake of knowledge.
Anyone else interested in trying it on a test batch scale?
Tell me about it. This happens to me all the time! I will just forget about my superior intellect for an instant, and before I know it I will be engaged in a meaningless conversation with someone who does not even have the intellect to wipe dog poo off their shoe.
As I said to Bertrand just last week at the monthly Mensa meeting, having a superior intellect can be such a burden. People are constantly talking to you about meaningless drivel.
I now wear a badge that says:
"Unless your IQ is over 140 and you have a PhD in Physics and Mathematics,
you have nothing to say to me that I do not already know.
Go talk to someone else"
To read the process may require going to another web site. I gather the process is like the Imisides cold transesterification method, using cement powder to dry regular methoxide thereby pushing the reaction to the right which increases methoxide concentration. I already did a cold process method using calcium oxide to dry the methoxide (it worked fine at 25 degrees celcius). My cold method biodiesel passed a 10/90 test with no fallout.
There is also the fact that you are producing a large quantity of soap.
For some reason you erroneously equate a large By-Product layer (that which you refer to as glycerol) as an indication of a "full" reaction. That is not the case.
A large By-Product layer is an indication of a large amount of soap being produced.
You say you produce about 22% By-Product
Let me help you understand this.
The By-Product layer (which you call glycerol) is usually composed of four main ingredients;
Methanol (with KOH)
It is easy to do a rough calculation of the quantities of each ingredient.
Glycerol- There is about 79ml of glycerol in every litre of oil. That means in in a full reaction, the glycerol will be about 7.9% of the total volume of oil reacted which is about 6.6% of the total content volume of your reactor keeping in mind you added 17% methanol to the oil.
Methanol- There is a rule of thumb that says that about 1/3 of the excess methanol is in the biodiesel phase and 2/3 of the excess methanol is in the By-product phase.
The Stoichiometric amount of methanol for a complete reaction is considered to be about 12% of the volume of the oil. You used 17% (170ml per litre of oil) methanol in the reaction. That means there is an excess of 5% methanol that will be divided between the biodiesel and by- product phases.
If 2/3 of this excess is in the byproduct, that is about 2.8% methanol of the total content volume in the reactor keeping in mind that you added 17% methanol to the oil.
If you produced no soap, there would be virtually nothing else in the Byproduct Layer.
In that case the By-Product Layer would be about 9.4% by volume of the total volume of the reactor..
Testing I have done shows that this is pretty accurate.
However, you say you have about 22% glycerol in the reactor
So what is the additional 12.6% By-product you are producing?
It is Soap and biodiesel
The Rule of thumb here is that for every 2 litres of soap produced it will take about 1 litre of biodiesel with it into the By- product.
So about 2/3 of the additional 12.6% by-product or about 8.4% of the total volume in the reactor is soap and about 4.2% is Biodiesel.
So your byproduct layer ,expressed as a percentage of the total volume of the contents of the reactor contains about;
As you can see, your by-product layer is actually only about 30% glycerol.
I hope you have found this explanation helpful and has sorted out your confusion in this matter.
Please do not hesitate to contact me if I can help clear up any other misunderstandings you have.This message has been edited. Last edited by: Tilly,
Yes it works a treat. I'm just kicking myself for not working out the chemistry of the glycerol phase earlier. I never knew why my glycerol was so thin - I always assumed it just hadn't partitioned completely. But in fact it had, and all I was doing by letting it sit for so long was letting it suck up water from the atmosphere and get converted from the potassium salt to the glycerol.
Of course it's my bloody fault for being too lazy to sit down and work out the reaction stoichiometry. It was your comment about the catalyst that got me thinking, so thanks for that.
BTW, don't make the mistake of either reading or replying to every post on this site. There's a certain serial pest on this and other biofuels sites who cannot bear the thought that someone may have come up with a biodiesel method that makes his obsolete. But in fact his knowledge of chemistry could be written on the back of a postage stamp, and I stopped reading his contributions years ago.
Of course it significantly lowers the signal to noise ratio of every thread he contributes to, but as long as the site administrators allow him to post his babble there's not much we can do about it
There are no assumptions or guesses. Like I said, I've worked in the industry for years. And unlike some people on this site I don't guess, and then pass it off as gospel truth.
There are two things that will get you into trouble for going down your sink - stuff that is either non-miscible with water or stuff that is non-biodegradable. In the former case it's usually greases or oils, in which case you'll need to put in a greasetrap (if you're a restaurant for example) and the latter case usually refers to chlorinated solvents, although they are pretty much ancient history now.
And of course, it's because people can't put oil down the sink we that we have a source of WVO for making bio.
And in terms of repeatability of my method, the whole point about it is that it's foolproof - as long as you can follow basic instructions it's not possible to get it wrong. I've been making it by this method for about 15y now.
But just in case the vids don't convince you of the simplicity of the method, I'll be doing a public demonstration with my next batch.
WesleyB, what can you tell us about the oil you used? Titration,water content, anything else?
I'm not going to try to get you to change anything especially how you dispose of glycerin. Keep doing however you feel is appropriate.
Repeatability is at the core of the scientific method. You have done all you can. Now it is up to others to verify your method is repeatable.
RickDaTech; I used new corn oil from a grocery store. I did not want to complicate matters so I used new oil. I was researching if room temperature tranesterification proceeds at a reasonable rate. Used vegetable oil can be wet. It didn't make sense to use dried methoxide with potentially wet oil. I titrated the new corn oil once at about 0.6, it was not zero.
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