[billnotgatez]

Has anyone here made bio-diesel fuel?

http://journeytoforever.org/biodiesel_make.html

[billnotgatez]

Part of the process for making bio-diesel requires [sodium hydroxide and methanol] or potassium hydroxide and dehydrated ethanol]. Could I find how to step by step make dehydrated ethanol on Google, nope. Throttling the next person who says “Google it” seems to me the best way to relieve frustration.

[billnotgatez]

Greeting All Fellow Listoids,

Once upon a time, long long ago, in a far away land (lab), I put two liquids in a flask. One of these liquids had a compound in it that migrated to the other liquid. Since the to liquids would not mix I could decant off the liquid that had lost the compound and via another reaction release the compound from the remaining liquid. Can I do this with ethanol in water, losing the ethanol to an oil (whatever)? After that react said oil with something else to release pure ethanol.

In the past I have asked such questions and received resounding silence. Egotism suggests I ask a question that has stumped the best, but practicality may indicate it was a less than intelligent (stupid) question.

Hope springs eternal.

Regards,
Bill

[P-man]

So you're trying to make ethanol by making it as a by-product and then realeasing it? Well I don't know if you can do that with water but you could probably do it with another liquid. But if your looking to make environmentally friendly, then you might want to be careful with what liquids you use, so that you get no harmful pollutants from the reaction. Have fun! Experiment! And maybe you'll find an answer to your question. I've done that a lot, and it can be rewarding. You might discover a totally new fuel!

[billnotgatez]

P-man,

Seems I confused you slightly. To make bio-diesel they use oil, but they also need alcohol and a strong base as a catalyst. The process is on the web site I posted above. The case I am looking at is for a catalyst is 100% ethanol mixed with potassium hydroxide. I thought it would be interesting to make my own ethanol, which would be easy. The hard part is getting it to 100%. They mention generally ways of getting the alcohol to that percentage, but not step by step. I was hoping some of the forum members might give me a few different methods to try that they have been successful at accomplishing. Again the ethanol in this process is part of the catalyst and not the fuel itself.

As a citizen scientist I try to read about science often. I sometimes experiment or tinker. I have at least once published. Some of the hands on stuff have taken a hiatus while I do other things like pottery or statistics or computer courses. Currently, statistics is driving me crazy. In the meantime it does not hurt to do some thought experiments about bio-diesel. Later on I actually might do some hands on and it is very tempting. Since I have a day job that keeps me busy along with other activities my time is scarce.

In this case Google is not helping much and I really would like other ideas about purifying ethanol that people have done.

Regards,
Bill

[constant thinker]

I know your probably looking to have fun and do whatever reaction it is your looking for, but if you want Bio-Diesel fuel I've read articles where guys simply went to their local McD's and got the oil from the fry-u-lator and then filtered it. With some modification to their diesel engine they burnt that stuff.

Making a Bio-Diesel vehicle has more than what I stated but I'm only talking about the fuel.

[billnotgatez]

The article I first posted talks about the pros and cons of making bio-diesel versus using straight vegetable oil.

[oldddog]

a couple of ways of purifying alcohol is by the fractional distillation of an azeotropic mixture (e.g ethanol and benzene forms an azeotropic mixture which can be distilled to separate the ethanol from the water). You can also use molecular seives to remove water from ethanol. Good luck finding a source of benzene (also, watch out this stuff is a slow killer of your internal organs). Molecular seives should be easier to obtain, but it'll take longer to remove "all" the water. The molecular seives can be regenerated by warming in an oven at a moderate temperature.
You need to remove water from the formation of the bio-deisel, as water will change the equilibrium of the saponification of the trigryceride esters that make up the fat or oil. You will find that the energy output required to form the biodeisel increases the "wetter" your starting material is. Unless you have a cheap source of electricity then it only becomes economically feasable if 1. your deisel supply is expensive or 2. you can make tons of bio-deisel and plan to sell some to your freinds.

[Dude]

Found this site about preparation of biodiesel.  It has an experimental section.

http://www.biodiesel.org/resources/reportsdatabase/reports/gen/19960101_gen-224.pdf

If I remember correctly, ethanol is distilled to get a low water content and then molecular sieves (4 angstrom absorbs water) are used to make anhydrous ethanol industrially.  When regenerating the sieves with heat, make sure that you removed most of the ethanol via evaporation or in a vacuum oven.  I don't have access to a step by step experimental procedure, however, a column should work with a slow rate of feed or simply adding and mixing ensuring not to exceed the absorption capacity followed by filtration and perhaps redistillation.  Some more elaborate (and expensive) ways to get ultra-dry ethanol might be described in "Vogels Textbook of Practical Organic Chemistry".

[P-man]

Yeah okay, I get now. I read once about making 100% ethanol for an experimental engine, but I forget where. You might wanna try like the library, lokking at stuff like 'alternative fuels' or 'bio-diesel' or 'ethanol'. I dunno... I'm just suggesting...

[Oldtimer]

To remove water from a fuel you will need to either use Ethylene Glycol or a Zeolite. The first will require a reboiling of the ETOH and the second will require purchasing the small crystaline components from a Manufacturer. You might use an  Acid- Base reaction as the ETOH is basic. That would only add more water as you may know, but the precipitate of a Sodium Salt with the addition of Sodium Peroxide would do you no better. As noted elsewhere here this is the reaction of water and Na2O2 - 2 Na2O2 (s) + 2 H20 (l) ---> 4 NaOH (aq) + O2 (g) . Plus the heat evolved could be distrous C2H5OH. + Na2O2 --- > C2H6 + H2O + NaOH {unbalanced}.
http://www.aecom.yu.edu/ehs/Lab%20Safety/LS_incompat.htm

Strong base and a Weak base mixtures result in what precipitates? Perhaps you were actually refering to affinity in which case Sodium Peroxide wouldn't be your best bet. What you want is a immiscible fluid that will seperate from the ETOH. That would likely be a chorinated component of which the law has removed form our uses due to environmental concerns. Then we are talking polar and nonpolar fluid dynamics.

So drying methods is much easier if you think for a moment of a means of using seperatory films and membranes instead of chemical componentry. That would also bring to mind density divergence of several  things like vegetable oils themselves.

Use of Sodium Peroxide is not the right and safe way to do any off this denaturing. Conversion to straight Ethane or Ethene would be preferable to blowing up your ETOH!
Andy

[billnotgatez]

Could you use molecular sieves without distilling first and just dry the sieves more frequently. Thus not using chemicals like benzene and high energy processes like distillation.  

[Borek]

... just dry the sieves more frequently. Thus not using ... high energy processes like distillation.  

How much energy is needed for drying molecular sieves compared to distillation?

[billnotgatez]

Do we care about the energy cost if we dry the molecular sieves in a solar oven? So again,  "Could you use molecular sieves without distilling first and just dry the sieves more frequently"?

[Borek]

Do we care about the energy cost if we dry the molecular sieves in a solar oven? So again,  "Could you use molecular sieves without distilling first and just dry the sieves more frequently"?

Do we care about the energy cost if we distill in a solar oven?

As for you main question - honestly I don't know, but I doubt it will be not widely used solution if it was economically viable. It is not used - so there are reasons that make this approach expensive. I believe it was Dude who stated that they don't keep all those PhD's and engineers in oil industry for nothing.