The United States faces two problems when it comes to transportation: getting fuel and the by-products of burning it.
The United States imports over 2/3 of the petroleum we use for transportation, primarily because most of the easily accessible oil isn’t located in places we control. Easy sources of U.S. petroleum are being exhausted, which forces us to look for and extract oil from less-convenient places, like deep underwater. Accessing these oil reserves is more expensive – companies are willing to do it only because oil prices have risen so much. As we’ve seen in the Gulf, going further and deeper for oil presents greater potential hazards if something goes wrong. Being dependent on other countries for energy is bad, so developing energy sources that we have greater local control over is a good goal.
The second is that combusting any fuel containing carbon creates carbon dioxide and/or carbon monoxide. Both are greenhouse gases that contribute to increasing the global mean temperature. Every gallon of gasoline combusted produces 19.4 lbs of carbon dixoide. In 2009, the US consumed about 138 billion gallons of gasoline, which means we produced 2.7 trillion pounds of carbon dioxide last year. One small comfort about the economic decline is that people in the U.S. are driving less: we consumed less gas in 2009 than in 2007, when we used 142 billion gallons of gasoline. If you simply calculate how much the world’s population will increase in the next 30 years, and how many more people will demand access to the standard of living we enjoy in the US, you ought to be worried. Even if you don’t believe in global warming, the health consequences of pollution from cars are scary – ask anyone who lives in LA.
NASCAR announced Saturday that they will be introducing E15 as the official fuel for 2011. E15 is a mixture of 15% (by volume) of ethanol and 85% gasoline. NASCAR’s fuel, which is provided by Sunoco, uses corn-based ethanol. Why only 15% ethanol? Because ethanol is tough on engine components. It eats away certain types of polymers and can be very corrosive on cast iron and some aluminum alloys. The government is planning on approving up to E15 for cars manufactured after 2007, but there are some serious issues being raised that may delay this change. For example, small engines (like those in weed whackers and lawnmowers) may have series problems with E15. If you’re like me, you fill those devices with the same gas you put in your car. On the other hand, I guess if people need to replace a lot of things, that would help stimulate the economy. Also, ethanol is more flammable and doesn’t work well with fuel gauges that use capacitance measurements (not an issue on NASCAR cars, which only measure fuel pressure).
Ethanol is a type of alcohol. Alcohols differ from hydrocarbons (the molecules that make up gasoline) by an oxygen atom that forms an “O-H” link. The molecule shown below is ethanol (a.k.a. C2H5(OH)). Ethane is C2H5(H) – exact same thing, but without the oxygen.
In contrast to petroleum, which we’ve discovered relatively recently, humans have been producing (and using) alcohols for a very long time. Drinking alcohols are made by fermenting the sugars in hops, grapes, rice, potatoes, corn, rye or just about any other carbohydrate. The particulars of the distillation process are dictated by the taste of the final product. Taste is obviously not a criterion for automobile fuel, but you still have to choose what you ferment carefully.
Fermentation is essentially yeast “eating” simple sugars and excreting alcohol and carbon dioxide. The simpler the sugar, the easier it is to ferment. Corn kernels, wheat, milo, sugar cane and sugar beets all have a lot of simple sugars –think high fructose corn syrup!
Of course, the preponderance of simple sugars in these foods is also why we like eating them. Corn was the first fermentable material in this country to raise enthusiasm for ethanol as an alternative fuel to to gasoline; however, ethanol is not a perfect solution and corn ethanol (in particular) is not being considered seriously as a viable sustainable fuel for the future.
To evaluate how ‘good’ a fuel is, you have to analyze how much energy it takes to produce, ship and use the fuel, and then compare it to the amount of energy it produces. This process (called ‘well to wheel’) has been modeled by the Argonne National Laboratory – but even their complex models are approximations. The energy balance of a fuel (the ratio of energy in to energy out) depends heavily on the particulars of how that fuel is produced. In the early days of corn ethanol, some processes actually used more energy than was contained in the fuel they produced.
Mike Lynch, NASCAR’s green czar in an interview in NASCAR.COM
Q. Doesn’t ethanol production consume a lot of natural gas, diesel fuel and other inputs that produce CO2?
Lynch: Advances in technology, science and engineering in farming and ethanol production have substantially reduced the amount of CO2 emissions related to ethanol. Today’s grain ethanol is a low-carbon fuel — up to 59 percent cleaner than conventional gasoline. [The entire well-to-wheel Life Cycle Analysis, from production to consumption, can be found in Yale’s peer-reviewed study in Journal of Industrial Ecology]. With further developments in farming, ethanol production and ethanol marketing, this American fuel will get only cleaner.
It is very difficult to find anyone in the energy field who will argue that corn ethanol is a sustainable fuel or a wise choice for the future. It is, at best, a good choice to dilute our dependence on foreign fuel. The journal article Lynch cites is from 2006 and the scientific literature is full of contradictory assertions; however, most studies from the last two years emphasize that corn ethanol should be considered, at best, a stopgap measure and not a solution. Take a look at the following from the American Association for the Advancement of Science, or Challenges in Scaling up Biofuels Infrastructure, Science, vol 329, no 5993, pp 793-796, August 2010. The economics are of great concern when you consider how much energy goes into corn production: fertilizer, cultivation, processing from corn into fuel, etc. Corn is a high-maintenance energy source and virtually no one not associated with the corn lobby is arguing that making corn production more efficient will make enough of a dent in the problem to be worthwhile.
The effort focused on developing ethanol as a transportation fuel focuses almost exclusively on cellulosic ethanol. Almost anything with starch can be fermented. That makes cardboard, wastepaper, sawdust, weeds and plant waste all potential sources of ethanol. There’s a catch, of course: the complex starches these materials contain are harder to extract and ferment than the simple sugars in food. Cellulosic ethanol is made from complex starches contained in the cell walls of hard, stalky (and mostly inedible) plants like switchgrass, as well as in plant parts like corn stalks. These cell walls contain cellulose – a polysaccharide with several hundred to tens of thousands of linked glucose molecules–and hemicellulose, a starch composed of many different types of simple sugars linked together.
Before cellulosic molecules can be fermented, they must be separated from the lignin and pectin holding the plant wall together. Once the binders are gone, challenges remain. The structure of cellulose makes it hard to break down into simpler sugars. Hemicellulose is easier to break down, but the sugars into which it decomposes are harder to ferment completely. The range of treatments being explored to make this conversion feasible and , but right now, it is still very difficult to produce cellulosic ethanol in an economically and energetically efficient way. Yes, in the future, NASCAR cars may run on fuel generated from stuff we would otherwise throw away, but we are far from being there yet, and there are serious concerns about the viability of scaling up the production process in an economically efficient way.
Producing ethanol isn’t the only problem. One gallon of ethanol contains only 2/3 the energy contained in a gallon of gasoline. E15 contains about 95% of the energy contained in gasoline. That’s going to create a small change in fuel mileage if any, depending on how much latitude teams get in changing engine parameters. I predict that there are a lot fewer teams willing to chance winning races on fuel mileage unless they truly have nothing to lose if they run out of fuel.
Now let’s look at the argument that ethanol is a cleaner burning fuel. Ethanol produces less carbon dioxide per gallon than gasoline; however, since ethanol only contains 2/3 the energy (gallon for gallon), you have to use more ethanol than gasoline to go the same distance. By the time you factor in those two issues, pure ethanol actually produces more carbon dioxide than pure gasoline when you compare carbon dioxide produced per energy. At only 15% in the E15 blend, it’s a small difference one way or the other. But it is disingenuous for NASCAR to throw around the 59% number – that is how much less carbon dixoide pure ethanol burns relative to pure gasoline, not how much cleaner the E15 will burn.
The horsepower an engine produces is more dependent on engine parameters than the fuel. The fuel provides chemical energy, but the engine transforms the chemical energy into motion. How much fuel do you allow each cylinder to combust on each cycle? How fast do you allow the engine to run? E15 requires a different air:fuel ratio than gasoline. Pure ethanol runs cleanest at compression ratios more like those used in diesel engines. Ethanol is higher octane, which means only that the fuel is less likely to detonate instead of combust.
The fuel and the engine work together and the power – and emissions – produced depend on that combination. NASCAR engine builders build engines to make torque and power, not to be environmentally friendly because speed wins races in NASCAR. The current engines spew out a lot of uncombusted fuel and don’t run at the ideal 14.7:1 ratio.
The fuel will be brought in in tankers and distributed. Ethanol is hygoscopic, which means that it absorbs water, so E15 will absorb water more readily than the current gasoline. Tankers will do a better job protecting the fuel.
Mike Lynch, NASCAR’s Green Czar says
“A benefit not visible to the human eye is reducing greenhouse gas emissions, based on the EPA’s classification of corn ethanol as a renewable fuel in the Renewable Fuel Standard-2 released earlier in 2010.”
Being a renewable fuel has absolutely no correlation with emissions. Renewable means that we can make more. Petroleum takes millions of years to form, and we are using it faster than it is being replenished. We can plant more crops from which to make ethanol, but that has nothing to do with emissions. E15 may emit less carbon dioxide per gallon, but you need more of it to go the same distance, so it is questionable as to whether the amount of carbon dioxide is reduced. The term ’emissions’ includes not only carbon dioxide, but other gases, like nitrogen-oxygen compounds. There is absolutely no agreement that ethanol generates less emissions of those gases
NASCAR takes a poke at IndyCar because IndyCar uses sugarcane ethanol, which is produced in Brazil. NASCAR will use American-produced corn ethanol. The energy balance from sugarcane ethanol is much more favorable than that from corn ethanol. Some sources cite sugar cane ethanol as being four times more efficient in terms of energy used in producing it. Corn, of all the known ethanol sources, has the least reduction in emissions relative to gasoline at 10-20% whereas sugarcane is about 90%. (That is for pure ethanol vs. pure gasoline.)
Another exchange from NASCAR.COM
Q. Does using corn for ethanol raise the price of food?
Lynch: We are not the experts on the very complicated issue of food pricing. We are standing behind American farmers, who are growing significantly more corn than is needed for food, and will benefit from having a new market for extra corn.
When you disseminate information to millions of people, you have a responsibility to be informed. If you’re going to get into the issue of alternative fuels, especially if you’re going to snark Indycar for using a more energy efficient version of fuel just because it’s not produced here, you ought to be ready to talk honestly about the positives and the negatives of your choices.
Cited by an article by Nate Ryan at USA Today:
NASCAR couldn’t provide many specifics about ethanol. France said the move would reduce the carbon footprint of a race (“we’re not exactly certain, but there is a benefit”).
If the president says “We know that there will be a reduction in taxes as a result of our legislation, but we’re not exactly certain how much”, would you place much credence in that statement?
From the transcript of the press conference
Q: Do you know about the miles per gallon, is this going to impact that much? And there was a study done what the study called alarmingly high decibel levels associated with NASCAR racing, are you concerned that you might have to address that in the future also?
ROBIN PEMBERTON: The mileage, if there’s any change whatsoever, I don’t think that you’ll notice it, remember, it’s just 15 percent blend. All of our feedback has been positive. The horsepower’s been great, reliability’s been good.
We’ve had several hundred miles runs at racetracks, and everything looks to be great as far as performance goes. Probably better than we had first anticipated.
The mileage, it will be seamless. You won’t even know if there’s a difference. I think after our experts, meaning in the garage area, they get ahold of it, they’ll take that opportunity and more than likely make gains with it.
BOB OWENS: And the decibel rating is negligible, I think.
BRIAN FRANCE: Decibel reading is something we do monitor periodically through the year, and if there’s any big changes, obviously, we would address them.
Robin Pemberton is (as usual) the voice of reason. The energy density of the fuel is changing by less than 10%. In ALMS, teams running E85 have a 11o-liter gas tank, compared to 90 liters for E10, so that the energy carried by each car is the same. If NASCAR increases the tank size so that you have the same energy contained, it’s going to increase by about 5% in volume. The average fan isn’t going to notice a change in gas mileage, just like they wouldn’t notice if the sound intensity level of a racecar decreased by 20 deciBel (dB).
You don’t need a study to know that NASCAR engines are loud. Just look at how many people over 50 in the garage wear hearing aids. Personally, I like loud. My favorite thing about being at the track is being able to feel the sound of the engines through my bones – but I do it wearing earplugs because I sort of like being able to hear the rest of the time. I measured about 120 dB 15 feet from a car, and 115 dB or so during a race in the grandstands. If you go, wear earplugs. But I get the same thrill at an ALMS race, where the noise output is limited. (Sorry, I can’t tell you limited to what. I seem to remember 11o dB, but my IMSA rule book is coming tomorrow on the moving truck.)
The sound coming from an engine is generated by the pressure waves created by combustion. The chemical composition of the fuel is negligibly important compared to the carb jetting, the rpm of the engine and other parameters (the same ones that are related to the power produced). You can get more information about sound on this video.
If you really want an understanding of green racing issues, take a look at issues of Circle Track from this year. Here’s a great example of motorsports journalism. The hard core racers at CT decided to do their own investigation of greening up racing, looking at ethanol in engines, mufflers, and catalytic converters. They surprised themselves, finding that you could still race hard and fast (and pretty loudly) while implementing some of these technologies. Great journalism, great writing and great reading. Solid scientific content and the authors are really upfront about their own biases. They show you the data and let you come to your own conclusions.
And if you want to see a racing series that is really committed to greening up motorsports, take a look at the American Le Mans Series. NASCAR is doing some positive things, like employing Safety-Kleen, which has a huge impact on recycling automotive fluids, and the track recycling programs that are attempting to capture the huge numbers of beer cans and water bottles that amass during a race weekend. ALMS has gone full throttle green. Tire manufacturers, fuel suppliers and manufacturers are developing new ideas for the passenger car market that they test on the track. Low rolling resistance tires, cellulosic E85, gas-to-liquid diesel (made from throwaway vegetation), even teams experimenting with hemp composites instead of carbon fiber. Porsche introduced an electric E-10 hybrid racecar at the Petit Le Mans that was one really nice looking car. We did a series of videos explaining the Michelin Green-X challenge, which rewards speed and greenness in the ALMS. They touch on some of the ideas about energy density and energy dependence relevant to the present discussion.
I’ll warn you right now that I’m not approving any comments that are lacking arguments based on fact. “Global warming is a liberal conspiracy” or “NASCAR are too right wing and stupid to understand what it means to be green” are equally stupid statements unless you have evidence to back them up. This blog is focused on the science of ethanol and not whether racing should be concerned about green, whether NASCAR fixes the races, or whether global warming is a sham, etc. This blog focuses on science, so if you have a scientific point, please feel free to contribute. If you are one of those people who is willing to be told what to think, there are plenty of other places for you to contribute.
I apologize for touching on some of the more complicated issues in a cursory way, but I am getting bombarded with questions and I wanted to get this up quickly. If you have other questions, please ask, as I have conversations scheduled with a number of engine builders tomorrow. My passion for this issue is partly because I am in the research phase for my next book, which focuses on — surprise — the future of transportation, alternative fuels, new propulsion mechanism and cultural attitudes.