[dazza95]

Well our last graphs were a bit dodgy, so we have changed them a bit, so hopefully they make more sense this time,

The first one is, the amount of water we had in the fermentation process (water is the variable in our experiments), against total ethanol produced in grams.
To get the total ethanol produced, we first worked out the density of the liquid produced after distill, we put this on a density vs % ethanol curve, to see what percentage of ethanol was produced, This was then multiplied by the mass of the liquid produced, ending up in grams how much ethanol we actually made. It seems that the optimum amount of water is between 200ml-300ml of water in the fermentation process. We are currently working on an explanation for this, we post soon,

The second graph, shows the amount of water in the fermentation process, against the heat produced per gram of ethanol. We used a % ethanol against heat produced graph, which gave us the heat produced then this was divided by the mass of the total ethanol produced to give heat produced per gram of ethanol. Don't really know whats happening in this graph??, the first free points line up, but from 300ml onwards its a bit bizarre, do you know whats happening?  

In terms of using this process to create ethanol as an alternative energy supply. we are about to conduct another experiment to find out the wattage of the gas tap and to see if this process if worthwhile for the amount of heat we get out of it, or are we using to much heat to get a little amount out of making it completely pointless.

The 3rd picture shows all the information we have so far. Any suggestions on what extra things we should look out/find with this information (graphing, calculating or conducting another experiment. Or any suggestions on what we should do next?

Thanks

{MOD Edit}
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[billnotgatez]

I am basing this answer on my experiences talking to brewers of beer and wine, plus my reading into brewing.

Your trend in the graphs after 200 ml water is not what I expected. I may be failing to take into some other effect.

Your second graph seems not to follow your first graph as you have it nor as I would have expected it. I do not know what technique you used to determine the heat.

Your third graph is not clear to me at all since we do not know how you are taking all your measurements.

As a side note, I just found out from your last post that you used distillation to get the amount of ethanol produced, which you did not mention earlier. I could have guessed it but I had expected you would tell us.

Here are some of my thoughts that may assist but I am not entirely sure what you are doing without seeing it.

Do not rule out that you technique may be flawed.
For instance, you may have ran each of the different concentrations of water on different days. The temperature of the room may not have been the same on each day, thus confounding your results. That is one example.

The way you measured the heat may take extra care on you your part to do it correctly. Sometimes we are just not consistent.

Just as another side note, you title here says Molasses but all your descriptions say Honey.

If I were doing this I would have
Read about fermentation
If I had a chance, talk to some brewers.
(maybe a rum maker for Molasses or a mead maker for Honey)
Figured out what in the Honey gets fermented into ethanol.
Understand the formula of what in the Honey gets fermented into ethanol.
Estimated the theoretical maximum ethanol from what is in the Honey that I have measured out.
Estimated the theoretical maximum heat from that ethanol.
Those 2 estimates would give me a reality check for my experiment.

As a high school student you might not be expected to do this, but I would run the experiment several times to make sure I am consistent.

Now the above may seem like I am chiding you but I am only putting it out there bluntly. I am not meaning to be negative.

Does this post give you some insight?

[dazza95]

@Billnotgatez,

Thanks for the reply,
We will look into what you have said , and post back soon

[dazza95]

At the start our project it was going to be with molasses but we changed it to HONEY after this post was made...

Yes, there is an explanation,

Yield of ethanol is mostly about survivability of the yeast. Yeast can't survive too high concentrations of sugars (osmotic pressure) and too high concentrations of ethanol (denaturation of proteins). You want them to process as much sugar as possible in as small volume (less processing) as possible. 
So there is an optimum amount to produce the most amount of ethanol as what you would expect. The less water, the more concentrated the honey is, because it is so concentrated it is killing the yeast. Honey keeps, it doesn’t go off. It doesn’t go off because it is so concentrated in sugar that the osmatic pressure in the bacteria cell wall sucks all the water out so it is becomes with lower levels of water, it is more concentrated than the bactiral cell wall so it is much more concentrated than the yeast. So the water inside the yeast just comes out inside the honey drying the yeast out and killing it.

Figured out what in the Honey gets fermented into ethanol.
Understand the formula of what in the Honey gets fermented into ethanol.
Estimated the theoretical maximum ethanol from what is in the Honey that I have measured out.

All the sugars in honey get fermented into ethanol,
38% of honey is Fructose, 31% of honey is Glucose, 17% is water, and the rest is other sugars.
Since fructose and glucose have the same molecular formulas the approximate equation for
honey->ethanol is
C6H12O6 --> H3CH2OH + 2CO2
Using that formula,
It was estimated that we should get 41g of ethanol out of how much honey we put in.
This was used to work out the percentage yield and turns out our method wasn't very efficient as the most ethanol that was made was about 5g, so how highest percentage yield was about 10%.

[billnotgatez]

The general structure for ethanol is

  H H   
  | |   
H-C-C-OH
  | |   
  H H   

So the formula is C₂H₅OH or H₃CCH₂OH not

H3CH2OH

  or H₃CH₂OH

Also the formula you wrote is not balanced

You explained

too high concentrations of sugars (osmotic pressure)

but I do not see where you explained

too high concentrations of ethanol (denaturation of proteins)

[dazza95]

Oops,
it was supposed to be,
C6H12O6-->2CH3CH2OH + 2CO2

[Arkcon]

Yield of ethanol is mostly about survivability of the yeast. Yeast can't survive too high concentrations of sugars (osmotic pressure) and too high concentrations of ethanol (denaturation of proteins). You want them to process as much sugar as possible in as small volume (less processing) as possible. 
So there is an optimum amount to produce the most amount of ethanol as what you would expect. The less water, the more concentrated the honey is, because it is so concentrated it is killing the yeast. Honey keeps, it doesn’t go off. It doesn’t go off because it is so concentrated in sugar that the osmatic pressure in the bacteria cell wall sucks all the water out so it is becomes with lower levels of water, it is more concentrated than the bactiral cell wall so it is much more concentrated than the yeast. So the water inside the yeast just comes out inside the honey drying the yeast out and killing it.

I'm glad you've managed to come up with this explanation.   This helps you make sense of one of your statements early in this thread:

 

It was found that,
The higher the concentration of water in the fermentation process, the more pure the ethanol produced is, however the less the yield is.

[dazza95]

I'm glad you've managed to come up with this explanation.

Is there anything else we should discuss in relation to the experiments?

[billnotgatez]

you have told me how you are measuring the weight of the ethanol by distilling and and then weighing
you have not told me how you are determining the heat produced by the resultant ethanol
You mentioned that you were thinking of determining the energy put in to the distillation process, but you have not said how

you still have not answered
but I do not see where you explained

too high concentrations of ethanol (denaturation of proteins)

[Arkcon]

I'm glad you've managed to come up with this explanation.

Is there anything else we should discuss in relation to the experiments?

Try to write out an outline on paper of how your report should go, and then ... write it up and submit it to the instructor.  I think you're at a good stage now.

[dazza95]

too high concentrations of ethanol (denaturation of proteins)

Not sure if this is entirely correct, but it makes sense,
Alcohol denatures proteins by disrupting the side chain intramolecular hydrogen bonding. New hydrogen bonds are formed instead between the new alcohol molecule and the protein side chains.

Proteins depend heavily on "hydrophobic" interactions
Water molecules like to form strong hydrogen bonds with each other, if there's a large surface area of protein in the solution, these interactions are disrupted. In order to minimise exposed surface area, the bits of the protein which aren't able to interact with each other tend to fold over themselves to minimise exposed surface area. In like a ball or coil.
The more pure the ethanol is, the tendancy for non-interacting regions to stick together is much weaker so proteins tend to unfold.

The more water that is added, the more pure the ethanol is because it denatures protein too quickly and forms a thin outer layer of denaturated protein beyond which the cell lives on.
Too much alcohol = dead yeast.
Hydrogen bonds cause the tertiary structure (ethanol) to stuff up. Only one hydrogen bond needs to stuff up and the whole process is over and the yeast dies.   

you have not told me how you are determining the heat produced by the resultant ethanol
You mentioned that you were thinking of determining the energy put in to the distillation process, but you have not said how

A side experiment was conducted by another group where they burnt different percentages of ethanol and got the heat produced per gram. From this graph we got the equation and what ever percentage we made, we put into the equation and divided by how much we made giving the theoretical heat produced per gram of ethanol. So in other words its how much heat we should have got if we were to burn it.
It is planned for next week, to try and determine the wattage of the gas tap used for the distillation process to see how much the energy put into compares with the energy we can get from the ethanol produced (real-life application, alternative energy). A method or results havnt been discussed yet, will let you know when we have done it.

[billnotgatez]

The more water that is added, the more pure the ethanol is because it denatures protein too quickly and forms a thin outer layer of denaturated protein beyond which the cell lives on.

I am not sure about this reasoning


-----
Question are you repeating the experiment or are you keeping the results you posted on the graphs?
------

A side experiment was conducted by another group where they burnt different percentages of ethanol and got the heat produced per gram.

Do you know what device they used to get the heat value?

-------------------------------------

As a side note I just read the WIKI on honey -- fascinating

http://en.wikipedia.org/wiki/Honey

By the way the estimated concentrations of sugars are at

http://en.wikipedia.org/wiki/Honey#Nutrition


Some other sites on Honey and Mead that are most interesting

http://store.homebrewheaven.com/nectar-of-the-gods-mead-kit-p550.aspx
http://www.honey.com/
http://www.stormthecastle.com/mead/what-you-need-to-make-mead.htm
http://www.beerdude.com/howto_brew_first_mead.shtml
http://www.leeners.com/mead/index.shtml
http://www.meadmadecomplicated.org/mead_making/
http://www.homebrewtalk.com/f30/sticky-mead-making-faqs-83030/

[billnotgatez]

@dazza95

I am curious
What was the brand of honey used?
What was the brand of yeast used?
When you did the distilling how much liquid did you leave in the boiling pot?

How is the experiment going so far -- are you done?

[dazza95]

@dazza95
I am curious
What was the brand of honey used?
What was the brand of yeast used?
When you did the distilling how much liquid did you leave in the boiling pot?
How is the experiment going so far -- are you done?

Sorry about the late reply,
We used 100% pure honey straight from the bee hive,
ahhh we used turbo yeast, but this wasnt a independant variable

Yes we have finished all experimentations and are currently writing up a report (almost finished).