With the price of gasoline escalating nearly every day, we get all sorts of inquiries about alternative fuels and power sources. Some of the most common inquires are about bio-diesel and the use of alcohol in gasoline engines.
Technical challenge: Burning bio-diesel, a blend of petroleum diesel with a bio-fuel, or even straight bio-fuel "vegetable oil" in a diesel engine is pretty straightforward. Diesel engines operate on a completely different principle than gasoline engines. Diesel engines do not require a spark plug or electrical ignition system. Rather, they operate at such high compression ratios that the fuel combusts spontaneously when it is injected. The only real challenge with using non-petroleum is getting it to flow as a liquid at lower temperatures. There are many ways to skin that cat, but the main thing is that the engine itself does not need any type of major modification.
Gasoline (spark ignition) engines are a completely different story. Running 100% alcohol in an engine designed to operate on gasoline is not straightforward. It is not just a matter of installing a simple, inexpensive “conversion kit.” For the engine to work properly, changes in the engine’s compression ratio, camshaft profile, and ignition timing would have to be made. Beyond that, there are legality issues with emissions standards in various states. “But I've heard that alcohol burns so much cleaner that gasoline," you say. Unfortunately, when it comes to laws and such, logic does not necessarily have anything to do with it. The law states you cannot alter ANYTHING in the emissions control system, and the fuel used is part of the overall emissions control system. This technically applies to diesel powered vehicles, as well, but the law does not have a mechanism to monitor them (no smog checks), so they slip by more easily.
Legal issues: Then we have emissions standards in various states. “But I've heard that alternative fuels burn so much cleaner than petroleum," you say. Unfortunately, when it comes to laws and such, logic does not necessarily have anything to do with it. The law states you cannot alter ANYTHING in the emissions control system, and the fuel used is part of the overall equation. So, before jumping on any alternative fuel band wagon, consider the laws in your area.
Practicality / Wisdom: Beyond the technical challenges, and legal issues, I question the wisdom of using bio-fuels instead of petroleum. There is no question that the extensive use of petroleum since the industrial revolution is taking a toll on our planet and threatening our future as a species. The question is what to do about it. With the technology currently available, it just does not seem to make any sense to make a mass move to bio-fuels. And even if a technology was devised today that could turn biomass into alcohol with no energy consumption to do so, there have been studies that show it may be MORE harmful to the planet when one considers the amount of land and water that would be required.
Indeed, it can make you feel better to quit running petroleum in your vehicle; it may even seem like the politically correct thing to do, too. But is it? “You gotta start somewhere—it won’t happen until we make it happen," you say. While that logic does make some sense, it does not ALWAYS apply. For example, nobody thought we would actually land on the moon in 1963 when President Kennedy challenged the scientific community to make it happen. But it was possible, and those in the know knew that. If President Kennedy had asked to land on the sun, nobody would have even begun to work in that direction.
This issue about energy is similar: those in the know understand the total picture. The amount of water and land needed to feed even half of the current demand for energy makes that concept impractical. In my view, petroleum and its abundance of energy has been too cheap for too long, and it has been wasted. Consider the striking fact that—after over 100 years since it was invented—the best internal combustion automotive piston engine available is less than 50% efficient. That's right, over half of the energy available in each gallon of petroleum is WASTED, and that is for a really REALLY efficient engine, in a super-efficient vehicle. When it was cheap, it didn't matter. And while it may have been cheap, that certainly doesn't mean it was not valuable… Not to mention all the negative side effects we are experiencing from having used so much of it up so quickly.
I look forward to the next 10-20 years. Now that a gallon of petroleum is approaching in cost to what it is really worth, to include the negative implications to climate, it will be really interesting to see all of its energy extracted instead of being pumped into the atmosphere as wasted energy. This will most likely take the form of burning petroleum in huge power plants that operate at 90+% efficiency to produce electricity that can be distributed all over the place to power electric cars. I grew up around internal combustion engines, understand them inside and out, and have made a good chunk of my living fixing them and improving them. But the writing is on the wall: we will see an end to the internal combustion engine. It is just a matter of when, not if…