In my last column, Ethanol and aircraft: Just say no, I answered some questions about ethanol and its effect on aircraft.
In this column, I would like to address some follow-up questions about ethanol. Specifically, if ethanol causes so many problems with engines, why is it added to fuel and why is fuel with ethanol cheaper than conventional auto gas?
Ethanol was added to auto gas primarily to reduce the amount of carbon monoxide (CO) exhaust emission. The secondary reasons were to reduce our dependence on imported oil and to help the farm community.
The science behind reducing emissions is based on the fact that ethanol contains oxygen, giving it a lower stoichiometric air/fuel ratio. This mean an ethanol blend will lean out the air/fuel mixture.
But if an engine is operating on the lean side of stoichiometric, there should not be any CO produced because there is excess oxygen and all of the carbon atoms are converted to CO2.
The problem is that every car produced since 1968 has operated on the lean side, except when the accelerator squirts in a shot during acceleration or during super high loads when enrichenment kicks in. With all of the new injection engines and feed back systems, there is almost no CO produced.
I have not seen any data that shows that ethanol fuels have a significant effect on CO production in new direct injection modern engines.
On the other side of the coin, with increased prices for corn, many farms are digging out trees and plowing up highly erodible pasture land and planting corn, which has a negative impact on the environment.
Ethanol producers claim that adding ethanol to our fuel has reduced oil imports and caused a drop in crude prices.
One of the problems in today’s world is that people only give half of the story, often leaving out the down side of any solution.
If you look at the benefits of ethanol production, you also must look at what the energy cost is for each gallon. When you add up the amount of fuel it takes to produce the seed, till the soil, plant it, spray it, harvest it, ship it to market, and refine it — plus the energy to produce the fertilizer and all of the other inputs — you find that it takes almost as much energy to produce a gallon of ethanol as the ethanol produces.
The lower crude costs are a result of reduced usage and increased production from areas like North Dakota and Canada.
As far as helping family farms, the ethanol plant near me sold shares for $25,000 each. Even before it started producing any ethanol, the shares were almost worthless. A large ag company eventually bought all of the shares for pennies on the dollar.
In addition, with higher prices, the cost of seed and fertilizer went way up.
Bottom line, if farmers analyze all of the factors, it has not been a great boost for the average family farmer.
Lower Prices
As far as the price is concerned, that is another story. To get ethanol usage up, the federal government initially subsidized it for 50 cents a gallon, but that program has ended.
Now there is a new scheme: Lawmakers passed a clean air act that states that all oil companies must blend in a certain percent of ethanol for all of the conventional auto gas they sell. To be able to sell the needed volume of ethanol, they need to reduce the price so that people will buy it.
Now before you write that I am against clean air, I am very much in favor of efforts to clean the air and our environment.
I just have that dumb idea that we need to work on solutions that really make a difference, not ones that do nothing but make a few people richer and others feel good.
This is like the move to get lead out of 100LL. It will not affect the health level of anyone, will not improve the environment in any way, but it does make a few people think that they have done something.
And since they do not ever look at the down side to their actions, nor care, they do not see the risk and costs that they are imparting to the general aviation community.
Care to comment on the main by-product produced by the distilling process used to make ethanol from corn? (Tons of CO2!) Then there’s the amount of water used in the distilling process….
Ethanol and wind generators are both “feel good” programs that do not actually have a positive impact on the environment. Certain individuals make lots of money. Taxpayers get the bill.
There are better solutions but the unintended consequences need to be evaluated before spending millions or billions on a scam solution.
Ummm…. no.
Ethanol is a giant subsidy to big agribusiness in Iowa, who wanted guaranteed markets (since feed corn isn’t that profitable)
Wind turbines, on the other hand, are the single cheapest way to generate power, which is why Mid-American Energy is replacing ALL its power generation with wind turbines right now. To make money.
The university of Minnesota did a study on ethanol witch showed it was a net loser it was retracted after pressure from the corn growers association and farmers union and others.they said they would cut the research funding if they didn’t. We are pawns of the greenies..
Actually, even most “greenie” groups have finally come around to admitting that there is no benefit to ethanol. At this stage we’re pretty much being held hostage by the ethanol lobby’s ownership of Washington D.C.
“Green” groups were opposing ethanol as early as the 1990s. It’s entirely the damn midwest farm lobby…
I have to take exception to your second to last paragraph regarding getting the lead out of 100LL. Even small amounts of lead in our environment are harmful. But what’s even more attractive about unleaded avgas are the benefits to engines. Unleaded fuel means no lead fouling of spark plugs, cleaner oil (and therefore longer intervals between oil changes) and fewer deposits on valve seats and valve guides, meaning lower chances of exhaust valve related engine failures. Unleaded avgas is long overdue and I am looking forward to a viable replacement becoming available and keeping my engine running cleaner.
“Even small amounts of lead in our environment are harmful.”
How harmful? Let’s not forget that lead in fuel is a lubricant. And most, if not all, small piston aircraft engines were designed with that in mind. Remove the lead and another form a lubricant needs to replace it.
Making one change often leads to the need to make another, which leads to another, which leads to another, and so on and so on. Is the level of harm that may be, or may not be, done to our environment, from the minute amount of lead in aviation fuel, worth the hassle and expense?
Or is it being done solely to placate the fringe element of the environmentalists movement?
According to the CDC, there is no known “safe” level of lead in the blood stream. The only reason TEL was added to gasoline in the first place was that it was a cheap way to boost octane rating and reduce detonation and pre-ignition in lower quality gasoline. An added benefit was discovered that led to reduced wear of exhaust valve seats which would often succumb to micro-welding under the high inner-cylinder temps produced during combustion.
Todays engine use hardened valve seats and no longer require lead to provide this cushion against wear. In fact, in todays engines, lead is more of a nuisance, leaving dirty, sticky deposits on valve guides while providing no additional protection for valve seats. And with newer, safer ways to boost octane, TEL is an anachronistic technology that is obsolete.
Regarding environmental concerns, as I mentioned earlier, there is no safe level of lead in the blood stream. And lead has a very long half-life and takes months to years to exit soft tissue and bones. It is a highly toxic substance and should be avoided. Lead pipes for drinking water should be completely eliminated and TEL in gasoline leads to small particle lead in the air that we breath. You can go on blaming “fringe elements” of “environmentalists” all you want. But you are ignoring known scientific fact that lead is not only harmful in any amount, but that it’s also not the best stuff for our engines. Then of course, you could complain that, “what if we are wrong and we end up creating a better technology and make the world a better place for nothing?”
Lead is super ultra nasty.
Childhood lead poisoning in the 1950s and 1960s is the cause of the crime wave of the 1980s in the US. Seriously.
http://www.ricknevin.com/
Gasohol is best described as the use of tractors to convert diesel fuel into ethanol. When you balance the equation, there is no net gain in energy. Since we buy energy in the form of gasohol, and it contains less energy by volume, the consumer is getting screwed. Since it is stillborn as a viable product, it needs either a subsidy to reduce the cost or laws that mandate oxygenates. Regardless, mileage suffers. In the case of Stihl and Husky small engines, they have been a boon, because it has destroyed millions of old engines, but their warranty is void if more thatn 15% is used on new engines.
In the case of aircraft, once converted to viton, carbs and hoses are fine with it. The water issue is the same for cars and planes, but it discloses itself in planes with what is called a phase change. This is where lots of water is present, the alcohol absorbs it, and at some cold temp at altitude it separates and falls to the bottom of the tank. The engine cannot burn it.
In normal ops ethanol is a water scavenger and beneficial. My 1968 Cessna OM specifically calls for adding up to 10% isopropyl alcohol if water is present to ‘burn off’ the water. How it differs from ethanol isn’t apparent. Ditto how it promotes corrosion vs a puddle of water sitting in a tank of 100LL.
It may be a hazard in Lycomings with the carb bolted to the hot sump. Mogas in general has a low vapor pressure and vaporizes rapidly in a hot carb, creating a rich condition. How alcohol affects that is not clear to me. If all the fluid boils out the float sinks and on high-wing planes the engine gets a dose of raw gas. Pulling the red knob to idle cutoff gets it running again, but the fix is to get it running so there is enough flow to cool the carb with fuel.
As far as detonation: Alcohol is an octane booster, so at proper fuel flows it should reduce the chance of detonation. For 2 stroke engines that are not properly jetted it apparently leans the fuel enough to cause detonation and rapid melting, enhanced by pieces of rubber clogging the main jet.
Very well stated, Ben. We need to wean off of ethanol rather than increase the ethanol mandate. If ethanol fuel can stand on it’s own without subsidies, and people want it, fine. But that has not been the case.
“This is like the move to get lead out of 100LL. It will not affect the health level of anyone, will not improve the environment in any way, but it does make a few people think that they have done something.”
Exactly. When was the last time someone got sick from lead poisoning? Like the lead-in-paint scam (lead was removed from house paints back in the late 1970’S.) the health risk of leaded aviation fuel is miniscule. And efforts to eliminate 100LL do nothing except make people feel good.
The last time someone got sick from lead poisoning? Duh….Flint Michigan. Wake up.
Yea? And how much did 100LL pay into that fiasco?
Blood lead levels in preschoolers living under GA airport flight paths are higher than blood lead levels in normal preschoolers living in normal places. This is entirely the fault of 100LL.
Any level of lead causes brain damage to babies. It’s cumulative, so it gets worse with more lead, but the studies say there’s no safe level.
Please fly unleaded. Otherwise you are actually causing brain damage to babies. Surely you don’t want to do that.
Practically all GA planes can fly on unleaded gasoline anyway; unless you’re running some obscure historical military aircraft, you really don’t need leaded gasoline. Please make the extra effort to get the fuel which isn’t causing brain damage to babies.
Childhood lead poisoning is the cause of most criminal activity.
Not kidding here. Just start scrolling down the page.
http://www.ricknevin.com/figures.html
There is no safe level of lead for babies. It stunts the brain.
From a practical standpoint, ethanol is terrible fuel if you are running anything not specifically designed for it, ie: your carbureted lawnmower, snow blower, pre-fuel injected car or aircraft. And we all know that. The end of season ritual is to empty out your fuel tank and run ethanol free gas through the system (like 100 LL Avgas). Better yet, run your mower, motorcycle or classic car on Avgas all the time. Ethanol attacks the seals and metal bits in carbureted vehicles and severely degrades their performance. It may have been a good idea when corn prices crashed a few decades ago, but right now it seems to be a scam – defended by the folks who get paid to defend it. (Note I didn’t mention ‘Bradley’s’ name,)
I bypassed my lawnmower’s carb. and directly injected fuel into the cylinder, but it has to be metered.
FWIW, at this point (2017) you should just get battery-electric lawn tools. It’s now dumb to use fuel in inefficient small engines when there’s a perfectly good battery model for every size category, even the riding mowers.
There’s even a battery-powered two-stage snowblower now, though on that one I’d wait for next year’s model.
Ben is correct that adding alcohol to the fuel has not been a good answer in the long term. The government has caused the market to be distorted by choosing winners and losers.
Because alcohol has about one half as many BTUs per pound as gasoline the fuel mileage is reduced by 5% when you add 10%.
In addition the mixture will not keep as well as straight gasoline. That’s is why your lawn mower, garden tractor and boat will not start in the spring unless you purge the system with new fuel or use non-alcohol gasoline.
Now with the US nearing self sufficiency in oil production it is time to stop putting alcohol in the gas.
This distorts the fuel market and does more damage than good to the environment.
Well said, Ben. Thank you for revealing, once again the scourge that is ethanol and the scourge that those politicians who support the ethanol fraud in America.
Absolutely ignorance and falsehoods!!!! This is a false “article” by Shell Oil. Shame on General Aviation News! This article is based on NO science or data. Does he really think people drive cars with Carbs? The last production car sold in the us was the Grand Wagoner. Cars don’t “normally run lean”. That increases NOx gases. This article is complete propaganda.
Bradley, I think if you are going to criticize an article as being “based on NO science or data,” you should back up your argument with…well…some science or data of your own, which you haven’t. Also, Ben’s background is clearly stated at the end of each of his articles, and so whether or not I agree with Ben, I see he has some foundation on which to stand. What is your background and training that gives you the authority to say he’s wrong?
Shut it Bradley. Do you work for an ethanol producer?
Ben was addressing carbed airplanes, which are still in production. Nowhere in Ben’s article does he address automotive carbs or NOx: He addressed CO, which is produced by running rich.
It’s been fun . . .