[tasmodevil44]

I give up.There seems to be absolutely no catalytic method whatsoever for chemical combination of two ethanols into butanol at room temperature.Especially not in a simple,single transition step.I have contemplated every possible (impossible?) exotic,unconventional,far-out twilight zone catalytic method known to science.Is there something simple right under my nose?

      I have even entertained the idea of cold temperatures below room temperature.This sounds about as counterintuitive as other ideas I've toyed around with.The reaction would proceed at a slow rate,if it even happened at all.If it actually produced butanol in small trace amounts,it would be for pure academic laboratory curiosity rather than practical production in commercial quantities.
     
      According to one theory,Organic precursor molecules of life formed in ice instead of at higher temperatures like always previously believed.
     
      Could try some sort of insane,whacky combination of unconventional ideas:like freezing ethanol molecules in ice and zapping them with a certain frequency of radio (probably just wind-up with melted booze...Heh,heh,heh.LOL.         

[billnotgatez]

Thanks for contemplating this process.

On thing, the goal is to be not using energy to create the compound. Also, we don’t want to change the environment so much that it affects the yeast.

The process the yeast uses is done at room temperature and probably uses energy within the sugar to with its enzyme to produce the ethanol.

I am now leaning to break up the ethanol rather than combining. Maybe ethane or ethane is the way to go.

[tasmodevil44]

Here recently,I have been surfing the web to see what is all out there. I was amazed to see how many other people think along the same intuitive lines that I do. Not just thinking about things,but already doing it. I'm also amazed at how many people,even collge educated professors,are ill informed,closed-minded,and simply not "up-to-date" on all the newest technology and inventions out there. I found an endless amount of information about microwave catalyzed reactions. Some about cold-cracking long hydrocarbon chains into shorter ones with almost no heat transfer or pyrolysis involved at all. This involves a combination of very high frequencies much higher than a conventional kitchen microwave. This involves use of klystron tube emitters as opposed to using a magnetron tube as the emission source.

      There are other websites that describe my ideas about physical catalysts assisted by radio waves and/or ultrasound. One site describes building up larger molecules out of methane by using a zeolite zsm-5 catalyst in the presence of microwaves. Normally,these zeolites work only at very high temperatures. But the microwave assisted zsm-5 works at room temperature which implies greater energy efficiency.

      Of course,this requires an external energy input to drive the microwave transmitter. Furthermore,microwaves and/or ultrasound would probably kill the yeast. The ethanol would probably have to be first separated to a second processing step before dimerization of ethanol to butanol by a microwave assisted catalyst  could take place.

      I still think it would be nice if there's a miracle molecule out there that alone by itself could pull-off the trick. Butanol is a more desirable fuel,but like you say,it has a less desirable odor.   

[Borek]

This involves a combination of very high frequencies much higher than a conventional kitchen microwave.

Which moves us from the low energy radiation to high energy radiation - or from the realm of fairy tales to the realm of chemistry.

All that you quote is about delivering right amount of energy into right place. The less energy is used to heat up things that don't need to be heated, the better - but the chemistry is still the same. Or at least there is no need for new phenomena to explain what is happening. That is just Occam's razor at work.

[minimal]

Single microwave usually doesn't carry enough energy to start any chemical reaction. You need something much closer to visible light for that. E=hν. In microwave owen you use a lot of microwaves, so you transfer a lot of energy on the whole - but in very small portions.

If the microwave frequency wasn't strong enough in the first place it would do nothing correct?  I was under the assumption that adding quantity does nothing if the initial energy requirement is not met.  Photoelectric effect I believe.

[Borek]

If the microwave frequency wasn't strong enough in the first place it would do nothing correct?

Almost.

I was under the assumption that adding quantity does nothing if the initial energy requirement is not met. Photoelectric effect I believe.

Molecules do move, vibrate, rotate and can have their electrons excited (ie moved to othe molecular orbitals). Each of these has its own energy range - motion and rotation is somewhere at the far IR/microwaves, vibration at IR frequencies, electron excitation in the visible/ultravioler range. Microwaves can either speed up molecule (no spectrum here) or make it rotate faster (that's rotational spectroscopy). Photoelctric effect is about knocking electron out of the atom/molecule, so it is not exactly the same situation. But you are partially right - for example if the wave energy is too low it will be not able to make molecule rotate faster.

That's all oversimplified, but I don't feel like going into details. Not my area.

[tasmodevil44]

There are three possibilities that can happen when a target material is exposed to microwave radiation:

    #1.Thermal transfer without chemical reactions: ....This is what happens with water in a conventional kitchen microwave at a frequency of 2.45 Ghz.,using a magnetron tube.

    #2.Thermal transfer with chemical reactions: ....This is almost like merely replacing a laboratory bunsen burner with another alternative heat delivery system.

    #3.Chemical reactions with almost no heat transfer: ....This third possibility is the one that intrigues me the most.This is usually done with klystron tubes that generate higher frequencies than a magnetron.I can't find the website anymore,but there's a website that describes work by Chinese researchers who made an ethanol to butanol catalyst (normally high temp. catalyst) work at room temperature by assistance from microwaves.I don't know what frequency in hertz it must have been.

      BORAK may be correct for the most part in that these frequencies are highly specific.Instead of shaking-up and vibrating an entire molecule of zeolite or whatever else is employed,causing an enormous amount of waste,certain frequencies may specifically target only certain active reaction sites on the catalyst molecule (Perhaps William of Occam can let me borrow some of his Razor blades.This is perhaps the simplest scientific explanation of how I can get a closer shave.....Heh,heh,heh.

[weiguxp]

have you thought about inorganic catalysts, such as metal / ligand complexes?

[tasmodevil44]

I think perhaps the only way to synthesize butanol in large commercial quantities so as to be real cheap would be to genetically engineer yeast to make butanol instead of ethanol in the first place.Some type of butyric acid pathway I think.This would require insertion of gene(s) with the right DNA sequences.I think researchers are already taking this approach with yeast and E.coli bacteria.The organisms also have to be genetically resistant to butanol because toxicity will kill them at high concentrations.

    Also,there are several inorganic,crystalline and metallic catalysts out there that can dimerise ethanol into butanol by splitting-off the hydrogens and hydroxyl groups on the ends and making water molecules.But most of these work only at high temperatures and/or pressures.The MgO catalyst will work at a temp. of 470 K,and 1 bar,while producing lots of other additional byproducts like acetaldehyde and crotonaldehyde.I'm still intrigued by the possibility of some type of microwave assisted catalyst that can drop the temperature and pressure substantially.Perhaps the right combination of frequencies could fine tune it so that less unwanted byproducts are produced (Want to subtract Scooby Snacks for proposing heretical ideas?Go ahead.I'm on a diet.The fictitious cartoon character probably needs them more than I.LOLOL. )

[billnotgatez]

I think the butanol making bacteria are already being studied. My impression was that normal breading selection processes, not genetic engineering, selected the bacterium. From my memory on reading about this is that butanol is more stinky than ethanol.

[AWK]

Clostridium fermentation producing butanol is first reported by Pasteur some 150 years ago

http://www.butanol.com/

[Rabn]

I read someone...didn't pay enough attention as I scrolled through this discussion...said that radio waves don't or can't have an effect in chemistry.  Plasmas are produced with radio waves.  THese plasmas certainly make multitudes of chemistry occur. I'm probably out of context as it is late...but ignoring plasma chemistry produced with radio waves, used extensively in the production of semi-conductors, should be reconsidered. Maybe it wasnt...I don't know, I need sleep. Cheers.

[Borek]

I read someone...didn't pay enough attention as I scrolled through this discussion...said that radio waves don't or can't have an effect in chemistry.  Plasmas are produced with radio waves.  THese plasmas certainly make multitudes of chemistry occur. I'm probably out of context as it is late...but ignoring plasma chemistry produced with radio waves, used extensively in the production of semi-conductors, should be reconsidered. Maybe it wasnt...I don't know, I need sleep. Cheers.

I think you have missed the point, it happens when skimming. Please read my message:

http://www.chemicalforums.com/index.php?topic=346.msg89643#msg89643

Radio waves are used to heat up the gas to produce plasma, they are not directly involved in chemistry.

[Rabn]

I finally read through it and I was certainly, actually completely, out of context. Sorry for muddying stirred waters.

[tasmodevil44]

I would like to correct an error I made peviously about the modified MgO catalyst that can dimerise methanol.I misquoted the wrong temperature in which it is operational.It is not 470 degrees Kelvin,but instead is 450 degrees Celsius (wonder what 450 C translates into on the Kelvin scale.I forget).But this is still way above room temperature regardless.I'm still curious if sonication(utilizing high frequency ultrasound) and/or high freq.microwave could possibly reduce the operational temperature of this or other catalysts.Even if not reduced all the way down to room temperature,I still wonder if there is a way to get it lower than 450 C for the modified MgO catalyst or others.I'm also still trying to locate the  website about the catalyst Chinese researchers were working on.And I'm also still looking into other possible methods of catalysis for butanol that may be unique or novel.