H2 from Ethanol by dehydrogenation.

[GasSavers_RoadWarrior]

Hi folks,

I found out a little while ago that copper + heat catalytically dehydrogenates ethanol making H2 + ketones in the lower range of activation temperatures. Thus I am ultimately planning to copper plate my intake ports, the heat soak into a typical cylinder head seems to be in just the right range for the reaction, and since MPFI and SEFI injector programming typically sprays into a closed port in low demand situations, any ethanol in the fuel has ample time in there to get cracked. Higher temperatures are contraindicated, as this biases the reaction in favour of formaldehydes and acetic acid, which are not prime candidates for improvement of combustion.

However, there's also the "Hail Mary" approach, which does not require engine modifications....

Methanol is known to promote the dehydrogenation of Ethanol reaction. There's something synergistic there that makes the process more efficient. The best bang/buck ratio for this to happen is meant to be at 5% methanol to ethanol. This is the point where it shows high promotion activity and higher ratios don't do much more. So in the event I get copper in my intake ports a dash of methanol will make it really hum along...

However, many metals and metallic oxides show catalytic activity with ethanol and promote dehydrogenation. Chromium oxide, silicon oxide, and a whole whack of other metals. The rub is that they appear to need the temperature a little higher than typical intake port temperature for the reaction to get going. But if intake ports in most engines are a typical 6000 series aluminum alloy, they DO have a whole whack of other metals in them, some of which may promote catalysation already, albeit very weakly. Even carbon is meant to catalyse dehydrogenation. See here for all the metals that get into various alloys... http://en.wikipedia.org/wiki/Aluminu...8.25_weight.29


So here's where the "Hail Mary" comes in. If one were to add 5% proportion of methanol to the ethanol in the gasoline then one might get some dehydrogenation action happening in the intake port or inside the motor, using metals that are already there as catalysts. This might only happen when the motor is running very warm, it might not happen at all in some motors, and it might work amazingly well in others. Iron head motors may benefit also, the iron is likely an alloy with other metals, and the intake valves probably have metals in that might contribute. The ratio of methanol to try for 5% concentration of the ethanol content in E10 would be 6.5 oz per 10 gallons.

Now the caveats. Methanol is known form weak acids that attack aluminum. This is why it's not a great idea to run straight methanol in aluminum alloy motors. However, the aluminum oxide generally protects the aluminum well enough when only small amounts are run, or if methanol is used as a power adder by 5th injector in boosted motors. Folks who run methanol/water mixes as charge coolant/extra fuelling don't generally have too much problem with modest amounts until they get silly. So as long as methanol isn't used in high concentrations (and remember it's sold as gas line antifreeze) no adverse effects should occur. Since high proportions of ethanol have the same problems, E85 vehicles have protection against undue corrosion in various systems, and thus should be more resistant to methanol, and hence can run an amount appropriate to the proportion of ethanol in the fuel... but the rub is that some of that protection may mean that a catalytically active surface is not available to have a reaction to promote, so while results might be stellar if it works in E85, finding vehicles it works on might be an issue.


I'm throwing this out before I've done any testing myself, because it's hard to tell around here which stations actually are dispensing gas that have ethanol in, and what the actual proportion is. There's a couple of stations that have the "May contain up to 10%" but it's presumed that this varies by season, and the regular may have small to diddly squat amounts in. So to some extent I would be flying blind with that.

Soooo, 6.5oz methanol per 10 gallons of E10 and you either get results like the MIT/Arvin-Merritor plasmatron hydrogen augmentation project of 33% mpg boost, or you're gonna have to wait to see what copper plating the ports does for me. It's probable that on it's own with no dehydrogenation activity that the methanol will have about a 5% benefit on it's own merits, due to high polarity, surface tension reduction, etc.

regards,

RoadWarrior

[cugir321]

That's going to be interesting. So let me see if I understand.... 6.5 oz per 10 gallons should not cause any adverse effects to aluminum parts? Will it effect the burn? Timing? How will it effect emissions? Sensor/computer response??? I'm not an auto mechanic.

[GasSavers_RoadWarrior]

Heet gas line antifreeze comes in 12oz bottles, and the makers of that say up to 12oz/10gallon is fine...
http://www.goldeagle.com/heet/faqs_h...uct=HEET&ID=95

H2 is known to burn very fast relative to gasoline, and a greater part of it's energy becomes expansion pressure rather than heat. The efficiency of engines run on pure H2 appears to be limited by the ability of a reciprocating engine design to capture it. Introducing H2 into an engine primarily running gasoline appears to speed the burn of the gasoline, and enhance cylinder pressure. Ergo more cylinder pressure for less fuel inducted and less heat wasted. It's potentially possible that with the gas mixture as a kind of buffer, very nearly 100% of the energy in the hydrogen portion is converted to mechanical motion. With a cooler faster burn, NOx should be reduced to practically nothing, and since this allows a leaner burn, if one can manage to get the ECU to cooperate or fool it, with excess air then CO should be significantly reduced also. H2 supplementation is known to make engines very clean.

With a faster burn speed, it's probable that best results will be seen with the ignition timing retarded, apparently the BMW test vehicles running pure hydrogen have their timing set at TDC. In combo with gasoline, a couple of degrees retarded may be all that's necessary. It should be possible to run engines on a lower octane fuel, given that the lower octane fuel contains enough ethanol such that the effect still works efficiently. i.e. motors that need premium may be able to run E10 87 octane. The methanol does boost octane by itself, and most engine management systems do compensate for lower octane fuel than optimal these days, they back the timing off, so post ~'95 cars should not suffer any ill effects (Unless you've already messed with fuelling and power output and are a bad tank of gas away from blowing it up already)

TBI and carbed motors will probably see zero to no benefit, due to not having fuel sitting in a hot port. There is little opportunity for any catalysation to take place.

[GasSavers_Erik]

Instead of copper plating the intake, you'd get more surface area if you inserted a copper grid into each intake port- kinda like the honeycomb in a MAF sensor or in a catalytic converter, but made of copper.

The old Briggs and stratton engines had a twisted piece of strap meta in the intake that supposedly swirled the charge- maybe you could make several of those out of copper and insert into each intake port

[GasSavers_RoadWarrior]

Problem with screens is mechanical stability and getting them to absorb enough heat from the head to do anything. I don't think actually they'd do any better anyway, since the ports get wetted with the injector spray while the valve is closed. I am going to have increased surface area and "wicking" ability in my ports because they will be "lynzed" and textured before plating.

[GasSavers_RoadWarrior]

Well, can't seem to find out whether my gas actually has ethanol in or not, there's a legally mandated 5% minimum but it's based on a credit trading system so whether and how much ethanol is in a fuel up here is very hard to determine....

Going on the assumption that this tank has the legally mandated 5% I'm just gonna pour a whole 16oz bottle of "fondue fuel" methanol in the tank and see what happens. I think if it has any ethanol in, and if I manage to promote any catalytic activity from the intake port, valve etc metals, I might see a 10% gain. So I'll call it a win if I see 26mpg on this tank and look harder for 10% ethanol fuels to see if I can push that to 20%. If it doesn't work, it's inconclusive until I know I've really truly got ethanol in there.. I would just go and put Sunoco in it to get ethanol in there for sure, but Marvin never liked Sunoco before, so could see a drop.

[GasSavers_RoadWarrior]

First 50 miles on it... engine sounds slightly quieter and less "rumbly", seems to have lost the muffler resonance at approx 2400 rpm, or is quieter such that it doesn't occur under only light load any more. Seems to have shifted the start of "useful" torque down by 200 rpm. Initially it felt like it had less power, but this might be subjective due to the engine note change and quietening. Got up to highway speed just as quick, just didn't make so much fuss about it. Also apparently was running a little cooler. Was able to slog up a hill at a lower speed than usual while not hearing "pinking". Also felt like I had responsiveness that was not there before on the uphill slog. Usually if I drop below 80kph on that hill it feels like I can't accelerate out unless I drop gears or mash the gas hard enough to kickdown. It felt like I had to use a little less throttle angle to maintain speed. It also seem to hold TC lockup to a slightly lower speed, which I thought was odd.

I have absolutely no idea if these were the effects of methanol by itself or not. On it's own it's used to cool combustion a little, on it's own it improves octane. Better pull uphill and loss of pinking could be due to methanol's octane boost. Perception of reduced throttle angle, reduced engine noise generally, and reduced muffler resonance at 2400ish specifically, appears to suggest it's sipping the gas a little lighter for the same propulsive effort.

Which of course is all highly subjective and speculative....

[kamesama980]

FYI ethanol is also slightly acidic and will horribly corrode aluminum. I saw and article a while back about someone that tested this with a tahoe with an aluminum head by running e85 for 100k miles in one truck and straight gas in another for the same length of time/miles (and at the same time) then tore down the engines. I don't know the exact conditions and obviously they weren't commpletely identical conditions BUT the one run on ethanol ran better and was cleaner inside (intake and crankcase) I wouldn't worry about methanol..especially not in the quantities you're using.

[GasSavers_RoadWarrior]

Yeah, I think the only time you'd really have to worry is if you screwed up an HHO setup and had caustic soda/lye stuff misting in the intake and stripping the protective oxides, such that the ethanoic acid and what have you was able to attack the aluminum directly.

[usedgeo]

I don't want to high-jack the thread but I cannot find satisfaction when searching the net for more information on low temperature conversion of ethanol to hydrogen. The catalysts I see mentioned are not necessarily exotic but are more complex that just copper. Your initial post made me think I could wrap a piece or copper tube around my exhaust manifold and run an ethanol water mixture through that and get a 25% mixture of hydrogen and other things out the other end of the tube. To be sure I have found this link but it is a bit more than you indicate by your plans.

http://www.trnmag.com/Stories/2004/0...en_022504.html

Actually here is a low temp link that even suggests this reaction for fueling an engine using the waste heat from the engine to drive the reaction.

http://pubs.acs.org/cgi-bin/abstract...ef049692t.html

This catalyst sounds more complex than what you suggest. Doesn't the copper require the nickel also to make this reaction work?

Thanks,
Ernie