Well here is an update for what it's worth; I have been conducting experiments in a test tube with 20 ml new canola oil and fresh industrial grade methanol. As per the suggestion I started with smaller electrode gap and lower voltage to obtain the 15 to 20 v/mm field strength as required in the abstract. Electrode configuration is a rod sharpened to a point to concentrate field strength adjacent to a flat plate. Electrode material is copper. Mixture is an emulsion of 20% (v/v) methanol agitated by a stir bar and heated to 60 degrees centigrade. With a gap of 1mm I increased the applied voltage eventually to 120 Vdc which is the limit of my (little) supply. There was very little current (in the tens of microamperes) at this stage. I expected to see bubbles at the anode but the cloudiness of the emulsion made this difficult. A solution with disolved methanol saturated (I do not know the exact percentage as some methanol remained undisolved on the surface) which is optically clear did not exhibit any gas generation. Next I increased the gap to 3 mm and brought out the scary supply. I installed a 300 ma fuse at the HV output to protect the innocent and a milliameter. Then, fire extinguisher in hand, I tried again. At roughly 2kv the dielectric breakdown occured with 3mm gap for a Vbr of about 670 V/mm. Of course there were many bubbles in that case. No explosion though which was nice. Interestingly the protection fuse was not taken out by the arc whch was my expectation. At this point I do not know if this fact is due to the internal resistance of the supply limiting current to a value the fuse could handle for the brief duration of the arc or whether current was limited by conditions within the arc. I will have to do a short circuit test of the supply tonight to find out if it really has the balls to do 300 mA as I expect it should. Since the abstract calls for 100% conversion and with excess methanol a etherified glycerine which remains in solution, it is not clear what to expect the end result to look like. There should not be a separation of layers as in the traditional chemically catalyzed reaction. Since I do not see bubbles I do not think much is happening. I wish I knew more chemistry. I expect the reaction should take place on the surface of the anode and it should not be in the presence of an arc. Close observation at the tip at a voltage just below breakdown reveals a tiny whisker of something black (carbon??) grows towards the cathode and dances in the swirling current until it gets close enough and precipitates another arc. This could be something very interesting but I expect it has nothing to do with fuel :-( . The abstract does talk about very high temperatures at the anode surface and a strong oxidizing environment which makes me wonder if an arc is supposed to be sustained? Anyone on the list care to comment? Asside from proton NMR at this point I do not know how to shed more light on the contents of the test tube after these shocking experiments. This will require negotiations and the consumption of beer.......
I wish I had some exciting news.... Joe David Miller wrote: > Joe Street wrote: > >> Hi Joe; >> >> Right. The abstract talks about a relationship between higer >> voltages and longer carbon chains in the ester which translates into >> higher fuel energy content (cetane rating? I don't know if that is >> equivalent I am no chemist). I suspect the issue is more > > > > I missed the beginning of the thread, but it sounds like you're on a > great test to see if you can refine something with an electric field. > I just wanted to make two comments to try and help. > > 1) Cetane rating is a measure of the ignitability of the fuel. A high > cetane rating is good in a diesel engine because it means the fuel > starts combustion as soon as it's injected. It's the opposite of > octane, which is a measure of a fuels ability to not ignite. > > Neither has anything to do with energy content, they're just measures > of ignition properties. > > 2) If you're looking for electrochemical effects they're quite > certainly subject to electric field strength, not absolute voltage > differential. This is how you can scale production: move the plates > twice as far apart and you can get twice the fuel through it. But > you'll need twice the voltage to maintain E (electric field > strength). You made a reference to this effect, I'm just confirming it:) > > Hope this helps, > > --- David > >> correctly related to field strength than absolute voltage and >> electrode area and configuration is a dependant variable in this >> relationship. I could be wrong. I have designed a configuration >> which allows quick and easy modification of the electrode spacing and >> I also have developed a variable DC supply so I can control these >> variables. I can start with small spacing and low voltage, and still >> have a high field strength somewhere on the order of 15 V/mm. I also >> want to control flow rate. I am getting very close to being able to >> run a test. Currently my reactor is in use with the traditional >> chemical process but I plan to use the same vessel for these tests. >> I am planning to use the hydrogen as it is produced as an energy >> source for heating and drying zeolite which will be used to dry the >> ethanol used in the process. There is a lot to do. I'll keep you >> posted on the progress. It's so exciting! >> Joe > > > _______________________________________________ Biofuel mailing list Biofuel@sustainablelists.org http://sustainablelists.org/mailman/listinfo/biofuel_sustainablelists.org Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Search the combined Biofuel and Biofuels-biz list archives (50,000 messages): http://www.mail-archive.com/biofuel@sustainablelists.org/
