Distilling Ethanol

[Anthony]

I haven't started this thread in the chemistry section because it's not really about producing ethanol, but more about me being a cheap-skate.

I've long decreed that Her Majesty's Customs and Excise are taking the piss concerning fuel prices. A gallon of petrol costs a little under £4 and will propel me between 30 and 35 miles.

Since I have a little time now and a little spare cash in the near future, as part of setting up a decent lab, I'm going to include my latest hair-brained idea about cheap travel.

The idea being to run the car on ethanol :)

Of the various cheap fuels that a car can be run on, IMO ethanol looks to be the best/simplest.

The plan is to start out with 25% ethanol 75% petrol and 50/50 to test it. Increasing to reap the savings. My goal is 90% ethanol. However, as the ethanol increases, I'll need to make a few adjustments to the engine, such as adjusting the timing, adjusting the fuel mixture with the ECU and enlarging the fuel injectors.

Ethanol is a great fuel :) It has a high octane rating, allowing a typical petrol engine to run at 22* BTDC, tolerates high compression ratio (upto 15:1) burns cleaner than petrol and runs at a richer mixrure than petrol, meaning more power - hence the need for larger injectors.

On top of all that, the cost will be a catering sized drum of sugar, a bunco f yeast, tap water and some electricty.

I intend to build a fractional/reflux still and shoot for 90-95% ethanol. The process being as automated as I can make it, so I can set it going, leave it to do it's thing and a day or several later have ~10 gallons of ethanol.

Looking at the different fractions in a typical mash, I was wondering: "Will it be a waste to use only the ethanol?"

The methanol is a fuel in its own right, but what about the 1 and 2-propanol?

If these other alcohols are suitable as fuels, and represent a significant percentage of the output, I don't really want to throw them away. Unless, either themselves, or in the other nasties that will come off with them will do nasty things to my car. Such as corrode the engine, foul oil, dissolve/persih plastic or rubber components or wreck my catalytic converter.

Anyone have any idea about that?

My second question is about cooling for the condenser/fractioning column:

The mash will be brewed in a wheelie bin/dustbin/45(55)gallon drum etc. The plan is to periodically pump it into a smaller header tank about the still and then gravity feed it into the boiler, controlled by a float valve.

The cooling will be water recirculated by a pump. The original intention was to have another drum of water, but this would take up precious space. So, can I not use the mash? It's a large body of essentially cold water and any warming it gets will mean less energy required to heat it up when it eventually works its way into the boiler. Any comments?

I'll add an explanation about why I don't intend to use pure ethanol as the fuel. Despite having hardened valve seats and the remaining water in the ethanol acting as a lubricant, I have a niggling fear that I still need some of the additives found in unleaded petrol. Also, the presence of a little petrol will make the fuel smell and look like petrol. Plus it will (AFAIK) legally render the ethanol unfit to drink, thus dodging the tax man on two accounts (hopefully!). It might also help in extreme cold weather starting, where the lower volativity of ethanol over petrol can mean improper vapourisation. Although this shouldn't be an issue with fuel injection.

Comments/suggestions/questions welcome :)

[IPN]

Sounds like something very interesting indeed!

The distilling is IMO quite a slow process so it may and probably will need some tweaking to get the ethanol coming with a decent speed.

Also the fermentation is thing it self because it will maximally produce alcohol to about 13-15%
and is also a quite slow process so this will probably stay as an 25% additive to the petrol I think.
But of course if you are being able to make it into a very fast process then it will be very good thing.

[Arkangel]

Plus it will (AFAIK) legally render the ethanol unfit to drink, thus dodging the tax man on two accounts

Not sure about that. Certainly he won't be as interested in it if you can't drink it, but using any fuel on which road duty has not been paid is still illegal - same as using red diesel or paraffin.

When we ran our Triumph Dolomite on paraffin, we used a mix of paraffin and acetone to get it running. Once it was warmed up it ran fine on the paraffin alone.

[zaibatsu]

I'm on a mailing list that was discussing this subject recently, however I've deleted the emails since. The main thing though is that there has to be no more than 10% water. Also it said something about using champagne yeast - higher % alcohol I guess. Just a few little 'gems' (:rolleyes: ) I picked up.

[Anthony]

I must admit that I haven't really read into the mash side of the production yet, as it seemed so simple. From what I have read, fermenttation should take as little as three days, although I certainly haven't verified this.

If fermentation takes a while, I can always have two loads of mash and have one ferment whilst the other is distilling.

I was wondering what the maximum water content tolerable was, thanks zaibatsu :)

For distillation time, I've read one account saying to heat up the still and use a reflux ratio of 3:1 and you'll get 250ml/hr of "pure" ethanol. These instructions accompanied instructions for a still made from 2" copper pipe for the column.

Another account (specificially for high quality drinking alcohol) stated that the still must be allowed to reflux for 20-24hrs and then drawn off very slowly at a reflux rate of 13-15:1. Obviously this would take a very long time!

Arkangel, a piece of US literature stated that =>4% petrol in ethanol is legally denatured, I assumed that UK law would be similar.

Apparently, some petrol companies add a percentage of ethnol to petrol as a cheap non-lead octane booster...

[Felonous Monk]

A couple thoughts on the distillation of Ethanol, Turbo Yeasts can be ordered from companies such as Gert Strand AB in sweden, and some others over the internet. The benefits are reduced brewing times typically taking 3-5 days to produce a brew that can have alcohol of upwards of 20%, as well generally producing less high alcohols. However for my money Lalvin's EC 1118 gives good results and isn't to fussy (as mentioned in earlier in this thread it is a champagne yeast).On another note perhaps a used car radiator cooling the condenser water (or mash) before it returns to a small reservoir prior to being returned to the condenser. I don't know what tap cost in Britain but here in Canada I hook my condenser to the tap and the return goes to the drain. In terms of determining a reflux rate this site has some calculator that can help with alot of different aspects of reflux or fractionating column design.

[J]

The last time I was looking into brewing my own booze I found the following sites helpful:

http://www.moonshine-still.com/page5.htm
http://homedistiller.org/
http://lorien.ncl.ac.uk/ming/distil/distil0.htm

The law will almost certainly make running a car on un-taxed alcohol illegal, just as running a diesel engine on vegetable oil is illegal unless you pay the duty. But since it's a petrol engine, who's going to find out? Even if they did stop you for some misdemeanour, they wouldn't dip the tank! You can't buy 'red petrol', so they have no reason to suspect.

[zaibatsu]

Yeah, I read something about that too Anthony, that seemed to confirm 3-4% of petrol to ethanol makes it disgusting to drink. But what difference that makes in the UK...

[DBSP]

I remembered that I had seen something on fuel alcohol on homdestiller.org a while ago, I had a look and found the page:

http://running_on_alcohol.tripod.com

might be useful..

[Anthony]

Thanks for the links everyone :)

I'll look into these special yeasts, they sound good as long as they aren't too expensive.