E10

I had to fill the car with petrol the other day. I also filled my 20 litre jerrycan for all the petrol driven things around here – generator, mowers and the brushcutter (AKA The Petrol Driven Bastard). The only unleaded petrol available here now is the new E10 – ten percent ethanol.

The car’s fine with it, almost all Toyotas have no issue with this silly diluent. Saving emissions? You really need a bit of chemistry education – what do you get when you burn ethanol? The generator and mower are also fairly new so I don’t expect them to have problems. My little tractor – the ride on mower – might, and the Petrol Driven Bastard (PDB) certainly will.

So I’ll have to get the ethanol out or at least reduce it for those things. It’s not difficult but it will reduce the octane rating of the remaining petrol by, as far as I can find out, 3 points. It’ll drop from 97 to 94 octane, I doubt the old engines will notice that.

I am not going to do it for the car because I’d have to deal with 50 litres at a time and the car doesn’t need it anyway. The PDB declares alcohol-free petrol essential and I expect the old engine in the tiny tractor will need it too, but I only have to deal with a couple of litres for both.

It’s very simple. Ethanol is soluble in water. Most of the hydrocarbons in petrol are not. So you mix the petrol with water (for E10 I’d say 1 part water to 9 parts petrol), shake the hell out of it and leave it overnight. You’ll have the water (and hopefully most, if not all, of the ethanol) at the bottom and the petrol at the top. Oh and… don’t be tempted to have a smoke around it. Shaking it is going to release a lot of explosive fumes. Probably best to not do it in the kitchen, eh?

This is easier if you have a garage full of lab equipment including a separating funnel and stand but you can do it in any petrol resistant container. If you can tap off from the bottom, take out all the water and a bit of the petrol just to be sure, and dispose of it without killing anything that matters to you. Do not attempt to drink the ethanol/water mix, you don’t know what else got extracted. Dump it. Ideally not into the sewage system and certainly not into your septic tank. I have a lot of weed-strewn waste ground here that would be improved by a treatment with something horrible, you have to find your own way.

No separating funnel, you could carefully pour or siphon the cleaned up petrol into another container. Make sure you only get petrol and sacrifice the last bit, don’t try to get it all or you’ll get water in there again.

This works if you only need a litre or so for an old, small engine. It’s not viable for a very old car engine. That would need a whole industrial scale fractionation column and I don’t think many people will have space for that – or sufficient training to use it without blowing themselves into mince.

This E10 is not about saving the planet. Burning ethanol produces carbon dioxide, same as pretty much every chemical compound on the planet. It’s about getting rid of old cars. They want you to drive electric dodgems that won’t work in winter or in floods.

There is a solution, if you have the equipment and knowledge. Unfortunately modern education has ensured that few people have that knowledge.

I am increasingly convinced that this has happened before.