Ethanol
by Peter J. Sumner
With fuel companies considering adding ethanol to petrol, I have a few reservations about this. I don't claim to be a chemist or a petroleum expert of any kind, but call it intuition, I have bad feelings. First, I recall the few facts that I know of regarding ethanol, and here we are talking about the pure stuff, not wine! It is used by dentists as a nerve killer - pretty dangerous stuff! It is never 100% ethanol but 91 per cent by weight with nine per cent water. When standing in the open it attracts water thereby diluting itself.
The country most famous for fueling cars with ethanol is Brazil. The majority of cars in Brazil are Volkswagen Beetles (the old design) or old American gas-guzzlers, both having low compression, slow revving engines.
In my youth, I had experience of cars both as a regular driver and as a race driver. The car that I remember most in this context was a typical American gas-guzzler - a Ford Galaxy. In spite of many warnings before buying this car, I didn't heed the advice concerning fuel consumption. I was quite happy to find that I was getting an average 20 miles per gallon which, though not good, was much better than I had been expecting due to the previous advice. This was also using the cheapest available grade of petrol. It wasn't long before someone in the racing team suggested that I mix kerosene with the petrol. So, one gallon of kerosene in four gallons of petrol went in, and apart from a little extra smoke on starting, there was no noticeable loss in performance. It became quite clear that even the worst grade of petrol was too good for this car. On the other hand, the race cars (HotRods) had high compression cross-flow engines and after we had tweaked them a little, refused to run on anything except the highest octane rating petrol available, and only then with sustained burn ignition systems. We would gladly have added Nitro if only the rules had permitted it.
So against this background, I would have to believe that ethanol, which has far fewer combustible atoms than petrol, is only suitable for old cars. The same applies to the use of compressed natural gas (CNG). This has even less combustible atoms! I have heard many drivers commenting on how CNG just doesn't have any "Go" compared to petrol.
A visit to the chemical market was instructive. Ethanol presently sells for Rs.400 per litre! So don't expect ethanol/petrol mix to be cheaper. Further, I have serious doubts concerning its production - I don't think Pakistan can produce enough of it. The major source of ethanol will come from sugar mills. It will be distilled after fermenting molasses, which is the dark brown uncrystallizable remains of sugar production. I really don't know what product would be left behind after that process - perhaps some chemist can tell me! Apart from the appalling record of sugar mills for artificially causing sugar shortages, there is the risk that they may find it more economical to use sugar itself in the fermentation process. Either way, the prospect of both sugar and fuel shortages isn't appealing.
The more practical aspect of using any non-petrol fuel is seen in reduced engine life. Both CNG and ethanol lack the lubrication qualities of petrol. Ethanol in petrol would cause a similar lubrication loss as it is a solvent. The volkswagen engine is relatively easy to disassemble, so is more suited to ethanol fuel if one takes extra wear and tear as a natural consequence. But on a modern engine which seems to have more valves per cylinder than actual cylinders, the maintenance costs could be extremely high.
I can only hope that we will have the option to buy pure petrol as well as the 'mix', but I expect it will be forced upon us. Then everyone will be looking for Volkswagens!