All about Ethanol fuel
A great sidekick to good old gasoline, but could it carry the torch forward?
The hunt for a new type of fuel has been in motion ever since the advent of petrol engines in the early 1900s. Fossil fuels are inherently limited by nature, and at the current rate of consumption we will completely run out of dinosaur juice in 47 years. It's almost impossible to believe that in the 200 years or so since we discovered gasoline and all its magical applications, we have managed to deplete a shocking majority of these 600 million year old natural reserves. The situation is starting to become dire now. Countries are not able to keep up with fuel demand and have to rely on imported fuel at high prices to satisfy demand. In the specific case of India, we have to import 80% of the fuel we consume (as of 23 June 2021) which means that our fuel prices have been skyrocketing lately. A litre of fuel costs Rs 100 (at the time of writing) which converts to about $1.36 or £1. Exorbitant prices. The British government has even enforced a ban on the sale of all petrol and diesel powered cars in favour of EVs from 2030, which is just 9 years from now. So with the situation becoming this serious, what alternative fuels do we have which could save the piston engine from extinction?
Diesel is a fossil fuel in itself and diesel engines have a set of their own problems such as a shorter lifespan, narrow rev range, high carbon build-up in the exhaust runners, and high NVH levels so that's out. Hydrogen fuel is still hard to find and not to mention, very expensive. Electric motors and batteries are looking more and more like the sole successors to the conventional engine, which is a future I dearly hope not to witness. However, there is another option.
A biofuel is basically a type of synthetic fuel that's mixed with a percentage of gasoline to be used in engines. The most common biofuel is ethanol which has been in use since the early 2000s. The first production car to be powered entirely by ethanol was the 1978 Fiat 147. These days, ethanol is sold in mixtures with gasoline such as E10 (10% ethanol, 90% gasoline), E25 (25% ethanol, 75% gasoline), E50, E85, and so on. Cars that can be powered by E85 and above are known as flex fuel vehicles. As a rule of thumb however, cars manufactured before 2002 shouldn't be used with ethanol-gasoline mixtures since their engines weren't designed to handle anything else except petrol. On the other hand, cars manufactured after 2011 are completely safe to fill up with ethanol mixtures. 2002-2011 is a grey area with some cars supporting ethanol and some not. With all that out of the way, let's dive into the specifics.
So where does ethanol come from? The answer may not be what you think. It's corn. Ethanol is synthesized from what is basically the same process of making beer, albeit with some extra steps. Corn is processed and chopped up into a powder. Then it's all dumped into a vat with water and enzymes, heated to 185 deg C, then cooled down to 92 deg C. This is when the cornstarch breaks down into fermentable sugars. After that, yeast is added to the mixture and left alone for 50-60 hours. The yeast ferments the sugars and releases a lot of carbon dioxide to create what we call 'beer' with an alcohol percentage-by-volume of less than 20%. The beer is then passed through a process called distillation which separates the alcohol in vapour form which is then passed through a condenser to finally synthesize 99% pure alcohol or as we know it, ethanol. It can also be synthesized from sugarcane and even yield higher amounts, but sugarcane only grows in specific regions so it's more viable to use corn.
Now that we know how ethanol is made, let's discuss why it was chosen to be used in our engines. The most obvious answer here is that ethanol is made from a renewable resource which means there is theoretically no limit to how much of it we can produce. Moreover it comes from corn, which is cheap and easy to grow. On the availability front, ethanol scores full marks. Compared to gasoline, ethanol has an energy equivalence of 1.5 which means you would need to burn 1.5 litres of ethanol to produce the same amount of power as 1 litre of gasoline. This means using a mixture of predominantly ethanol (such as E85) would drop fuel efficiency by around 25% but since ethanol's chemical composition consists of oxygen by default, you wouldn't need as much air in the cylinders as a regular engine, which results in cleaner combustion and emissions. A remarkable drop in carbon monoxide and carbon dioxide emissions was observed in E10-powered vehicles compared to a gasoline engine.
Unfortunately though, like everything else, ethanol has its drawbacks. First and foremost being its corrosive nature. You might have wondered why ethanol is mainly sold as a mixture with gasoline. The first reason is that pure ethanol would corrode the fuel tank, fuel filter, fuel lines, and anything else it goes through over a period of time. The second reason coincidentally leads into the second drawback. Ethanol by itself doesn't have as much molecular energy as gasoline as stated before, so it will always develop less power and deliver lower fuel efficiency unless it's mixed with gasoline. The third drawback comes from the low vapour energy of ethanol due to its high enthalpy of vapourisation. In layman's terms, that means ethanol by itself will struggle to perform a cold start in weather less than 11 deg C. This is the reason US and Europe legislations limit the highest percentage ethanol blend to E85. However, in Brazil you can buy ethanol grades of up to E100 because their temperature conditions don't get cold enough to make cold starting a problem. Very convenient for them. The last two drawbacks are actually concerns but I feel they should be shared. The first being the impact of ethanol production on space for growing food crops. Ever since ethanol became mainstream, there has been a slight reduction in the amount of land available for food crops. Not enough to make a significant dent of course, but with more and more countries making ethanol fuel blends mandatory, it could become a problem as it scales.
My second concern warrants another paragraph because this could be a hurtful one for petrolheads. I stated before that vehicles manufactured before 2002 weren't made to handle ethanol fuel. If (and it's a big if) pure gasoline is outlawed in the near future, that could be the end for the retro cars we've loved growing up. Everything from the Mk4 Supra to the 1964 Mustang will be reduced to the status of 'garage queens'. I cannot begin to describe how dystopian a future that sounds to me as an enthusiast, knowing that the cars of those era which are unmatched even today will face the risk of being obsolete.
To conclude, I will say that while ethanol does show promising results when used as a fuel blend, it doesn't seem to be the one to take the baton forward from gasoline. However, it still does a fantastic job of being a sidekick. Lately, a lot of countries (including India) have pledged to aid in the production as well as widespread sale of ethanol mixtures by 2025. In the long run, ethanol will not only save millions of litres of petrol for posterity, but also lower the impact of harmful emissions on the planet. Just not as a petrol successor. That being said, the story for biofuels hasn't ended yet. Porsche claims to have developed a biofuel that is as clean as an EV and I'll write about it as soon as I'm fully caught up on it. Until then, goodbye and thanks for reading!