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Advantages and disadvantages of using TBD as a catalyst for transesterification
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Newdivide 1701
Advantages and disadvantages of using TBD as a catalyst for transesterification
Hi nick1124:, I've merged your two threads on essentially the same topic, since you seem likely to reference them to each other, its best for everyone one to be on the same page.
To prevent soap formation in the production of biodiesel from methanol, its required to have everything scrupulously anhydrous. That is, start with everything anhydrous, keep everything anhydrous before you start, keep the reaction tightly sealed while it progresses, and then ... dry everything before you start. Then accept that there will still be some soap formed. Sorry to be flippant, but this is the gist of what I've read.
I'm describing bench-top glassware biodisel production. For industrial purposes, you want to apply industrial engineering concepts, that some people here can help you with. But again, its tricky.
For production in a shed on a farm, our citizen chemists can try to combine the above concepts as best they can.
The final answer needs some info from you regarding scale: are you paragraph one, two or three?
Hi nick1124:, I've merged your two threads on essentially the same topic, since you seem likely to reference them to each other, its best for everyone one to be on the same page.
To prevent soap formation in the production of biodiesel from methanol, its required to have everything scrupulously anhydrous. That is, start with everything anhydrous, keep everything anhydrous before you start, keep the reaction tightly sealed while it progresses, and then ... dry everything before you start. Then accept that there will still be some soap formed. Sorry to be flippant, but this is the gist of what I've read.
I'm describing bench-top glassware biodisel production. For industrial purposes, you want to apply industrial engineering concepts, that some people here can help you with. But again, its tricky.
For production in a shed on a farm, our citizen chemists can try to combine the above concepts as best they can.
The final answer needs some info from you regarding scale: are you paragraph one, two or three?
Sodium hydroxide reacts with methanol to form methoxide, which makes a stronger base than just methanol due to its greater polarisability with a carbon atom next to the nucleophilic oxygen in methoxide compared to the oxygen next to the hydrogen in hydroxide
Sodium hydroxide reacts with methanol to form methoxide, which makes a stronger base than just methanol due to its greater polarisability with a carbon atom next to the nucleophilic oxygen in methoxide compared to the oxygen next to the hydrogen in hydroxide
Sodium hydroxide is not a catalyst! It is a stoichiometric reagent. Methoxide is a catalyst. Can you come up with a reason why?? Quote from:
Hi all,
I am doing a transesterification reaction, reacting canola oil and methanol with sodium hydroxide as the catalyst. The product that I make after leaving to settle for a day looks pretty good, with clear separation of the glycerol and biodiesel.
However, when i attempt to wash the biodiesel with water, a layer of soap forms under the biodiesel, and emulsions form as well between the biodiesel and water layer.
Is there a way I can wash the biodiesel to remove impurities, but not form the soap (or at least stop the formation of emulsions)??
Here is the link to my procedure: http://inside.mines.edu/~jobush/gk12/lessons/Biodiesel.pdf
Sodium hydroxide is not a catalyst! It is a stoichiometric reagent. Methoxide is a catalyst. Can you come up with a reason why?? Quote from:
Hi all,
I am doing a transesterification reaction, reacting canola oil and methanol with sodium hydroxide as the catalyst. The product that I make after leaving to settle for a day looks pretty good, with clear separation of the glycerol and biodiesel.
However, when i attempt to wash the biodiesel with water, a layer of soap forms under the biodiesel, and emulsions form as well between the biodiesel and water layer.
Is there a way I can wash the biodiesel to remove impurities, but not form the soap (or at least stop the formation of emulsions)??
Here is the link to my procedure: http://inside.mines.edu/~jobush/gk12/lessons/Biodiesel.pdf
I am doing a transesterification reaction, reacting canola oil and methanol with sodium hydroxide as the catalyst. The product that I make after leaving to settle for a day looks pretty good, with clear separation of the glycerol and biodiesel.
However, when i attempt to wash the biodiesel with water, a layer of soap forms under the biodiesel, and emulsions form as well between the biodiesel and water layer.
Is there a way I can wash the biodiesel to remove impurities, but not form the soap (or at least stop the formation of emulsions)??
Here is the link to my procedure: http://inside.mines.edu/~jobush/gk12/lessons/Biodiesel.pdf
I am doing a transesterification reaction, reacting canola oil and methanol with sodium hydroxide as the catalyst. The product that I make after leaving to settle for a day looks pretty good, with clear separation of the glycerol and biodiesel.
However, when i attempt to wash the biodiesel with water, a layer of soap forms under the biodiesel, and emulsions form as well between the biodiesel and water layer.
Is there a way I can wash the biodiesel to remove impurities, but not form the soap (or at least stop the formation of emulsions)??
Here is the link to my procedure: http://inside.mines.edu/~jobush/gk12/lessons/Biodiesel.pdf
7th Figure (named Scheme 2). I personally prefer pathway a. This paper demonstrates evidence for a lower energy barrier for pathway b, which is based more on the hydrogen bonding characteristics and geometry of TBD.
7th Figure (named Scheme 2). I personally prefer pathway a. This paper demonstrates evidence for a lower energy barrier for pathway b, which is based more on the hydrogen bonding characteristics and geometry of TBD.
I believe i'm paragraph one from your descriptions.
Thing is, the sodium hydroxide tablets I use are fresh from the bottle, sealed and just opened, and the methanol that I use is also procured from a new bottle of methanol, so I believe in terms of the reactants, they should be pretty dry.
I believe i'm paragraph one from your descriptions.
Thing is, the sodium hydroxide tablets I use are fresh from the bottle, sealed and just opened, and the methanol that I use is also procured from a new bottle of methanol, so I believe in terms of the reactants, they should be pretty dry.
Even if it does deprotonate methanol ( MeOH pKa > H2O pKa ) it still does not matter because the two things are in equilibrium (i.e. deprotonation is not the rate determining step). What does matter is that once hydrolysis occurs due to hydroxide, then the alcohol will become irreversibly deprotonated forming RCOO- and R'OH; for this reason, the reaction has to be run dry. Quote from:
Hey there,
Sodium hydroxide reacts with methanol to form methoxide, which makes a stronger base than just methanol due to its greater polarisability with a carbon atom next to the nucleophilic oxygen in methoxide compared to the oxygen next to the hydrogen in hydroxide
Even if it does deprotonate methanol ( MeOH pKa > H2O pKa ) it still does not matter because the two things are in equilibrium (i.e. deprotonation is not the rate determining step). What does matter is that once hydrolysis occurs due to hydroxide, then the alcohol will become irreversibly deprotonated forming RCOO- and R'OH; for this reason, the reaction has to be run dry. Quote from:
Hey there,
Sodium hydroxide reacts with methanol to form methoxide, which makes a stronger base than just methanol due to its greater polarisability with a carbon atom next to the nucleophilic oxygen in methoxide compared to the oxygen next to the hydrogen in hydroxide
... since it doesn't form water that may potentially cause soap?
Thankssss
Whats this bit about soap?
Also I assume TBD is triazabicyclodecene. Just in general, without a strong understanding of organic chemistry this is going to be a difficult question to boil down. It has to do with the unique electronics and acid/base properties of a bicyclicguanidine compound. It has the ability ability to form a sort of "activated" amide and be a fairly strong base at the same time.
... since it doesn't form water that may potentially cause soap?
Thankssss
Whats this bit about soap?
Also I assume TBD is triazabicyclodecene. Just in general, without a strong understanding of organic chemistry this is going to be a difficult question to boil down. It has to do with the unique electronics and acid/base properties of a bicyclicguanidine compound. It has the ability ability to form a sort of "activated" amide and be a fairly strong base at the same time.
To prevent soap formation in the production of biodiesel from methanol, its required to have everything scrupulously anhydrous. That is, start with everything anhydrous, keep everything anhydrous before you start, keep the reaction tightly sealed while it progresses, and then ... dry everything before you start. Then accept that there will still be some soap formed. Sorry to be flippant, but this is the gist of what I've read.
I'm describing bench-top glassware biodisel production. For industrial purposes, you want to apply industrial engineering concepts, that some people here can help you with. But again, its tricky.
For production in a shed on a farm, our citizen chemists can try to combine the above concepts as best they can.
The final answer needs some info from you regarding scale: are you paragraph one, two or three?
To prevent soap formation in the production of biodiesel from methanol, its required to have everything scrupulously anhydrous. That is, start with everything anhydrous, keep everything anhydrous before you start, keep the reaction tightly sealed while it progresses, and then ... dry everything before you start. Then accept that there will still be some soap formed. Sorry to be flippant, but this is the gist of what I've read.
I'm describing bench-top glassware biodisel production. For industrial purposes, you want to apply industrial engineering concepts, that some people here can help you with. But again, its tricky.
For production in a shed on a farm, our citizen chemists can try to combine the above concepts as best they can.
The final answer needs some info from you regarding scale: are you paragraph one, two or three?
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Sodium hydroxide reacts with methanol to form methoxide, which makes a stronger base than just methanol due to its greater polarisability with a carbon atom next to the nucleophilic oxygen in methoxide compared to the oxygen next to the hydrogen in hydroxide
Sodium hydroxide reacts with methanol to form methoxide, which makes a stronger base than just methanol due to its greater polarisability with a carbon atom next to the nucleophilic oxygen in methoxide compared to the oxygen next to the hydrogen in hydroxide
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Quote from:
Quote from:
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I am doing a transesterification reaction, reacting canola oil and methanol with sodium hydroxide as the catalyst. The product that I make after leaving to settle for a day looks pretty good, with clear separation of the glycerol and biodiesel.
However, when i attempt to wash the biodiesel with water, a layer of soap forms under the biodiesel, and emulsions form as well between the biodiesel and water layer.
Is there a way I can wash the biodiesel to remove impurities, but not form the soap (or at least stop the formation of emulsions)??
Here is the link to my procedure: http://inside.mines.edu/~jobush/gk12/lessons/Biodiesel.pdf
Thanks <3
I am doing a transesterification reaction, reacting canola oil and methanol with sodium hydroxide as the catalyst. The product that I make after leaving to settle for a day looks pretty good, with clear separation of the glycerol and biodiesel.
However, when i attempt to wash the biodiesel with water, a layer of soap forms under the biodiesel, and emulsions form as well between the biodiesel and water layer.
Is there a way I can wash the biodiesel to remove impurities, but not form the soap (or at least stop the formation of emulsions)??
Here is the link to my procedure: http://inside.mines.edu/~jobush/gk12/lessons/Biodiesel.pdf
Thanks <3
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https://www.researchgate.net/publication/229772530_Organocatalytic_Depolymerization_of_Polyethylene_terephthalate/figures?lo=1
7th Figure (named Scheme 2). I personally prefer pathway a. This paper demonstrates evidence for a lower energy barrier for pathway b, which is based more on the hydrogen bonding characteristics and geometry of TBD.
https://www.researchgate.net/publication/229772530_Organocatalytic_Depolymerization_of_Polyethylene_terephthalate/figures?lo=1
7th Figure (named Scheme 2). I personally prefer pathway a. This paper demonstrates evidence for a lower energy barrier for pathway b, which is based more on the hydrogen bonding characteristics and geometry of TBD.
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I believe i'm paragraph one from your descriptions.
Thing is, the sodium hydroxide tablets I use are fresh from the bottle, sealed and just opened, and the methanol that I use is also procured from a new bottle of methanol, so I believe in terms of the reactants, they should be pretty dry.
I believe i'm paragraph one from your descriptions.
Thing is, the sodium hydroxide tablets I use are fresh from the bottle, sealed and just opened, and the methanol that I use is also procured from a new bottle of methanol, so I believe in terms of the reactants, they should be pretty dry.
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What am I missing?
What am I missing?
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Quote from:
Quote from:
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Whats this bit about soap?
Also I assume TBD is triazabicyclodecene. Just in general, without a strong understanding of organic chemistry this is going to be a difficult question to boil down. It has to do with the unique electronics and acid/base properties of a bicyclicguanidine compound. It has the ability ability to form a sort of "activated" amide and be a fairly strong base at the same time.
Whats this bit about soap?
Also I assume TBD is triazabicyclodecene. Just in general, without a strong understanding of organic chemistry this is going to be a difficult question to boil down. It has to do with the unique electronics and acid/base properties of a bicyclicguanidine compound. It has the ability ability to form a sort of "activated" amide and be a fairly strong base at the same time.
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soz mate, I mean TBD instead of sodium hydroxide
soz mate, I mean TBD instead of sodium hydroxide
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