Long touted as a renewable fuel emitting 20 percent fewer greenhouse gasses than gasoline, ethanols’ emissions may be 24 percent higher.
https://insideclimatenews.org/news/16022022/corn-ethanol-gas...
https://link.springer.com/article/10.1007/s11053-005-4679-8
Don't even need the article, the abstract says exactly the same as this result from 17 years later. What are we doing...?
Ethanol Production Using Corn, Switchgrass, and Wood; Biodiesel Production Using Soybean and Sunflower, March 2005
"Ethanol production using corn grain required 29% more fossil energy than the ethanol fuel produced."
The only difference is that now switchgrass, which was known 17 years ago to have this advantage over corn if cellulosic ethanol is working, has this advantage over corn now that cellulosic ethanol is working...
If you make cellulosic corn ethanol, by the way, that 29% doesn't apply either. It's an apples and oranges to compare sugar based corn ethanol to cellulosic based switchgrass ethanol.
Corn subsidies were created as part of a national security measure. Corn is somewhat unique in that it can be both food and fuel, both of which contribute to national security. When you subsidize something, you get more of it. This creates a glut of corn, so what do we do with it? Ethanol was part of that answer.
So the question isn't "What makes the best biofuel?" but what do we do with the glut of corn? If your answer is to stop subsidizing it to avoid the glut in the first place, then you need an answer to the national/food security problem.
Thus, this simply isn't surprising, we should obviously do this if cellulosic ethanol works well enough now.
But some grasses, grown intentionally, grow extremely fast (giganteus miscanthus was the big one at the time I was researching actively).
https://en.wikipedia.org/wiki/Miscanthus_%C3%97_giganteus
I'm certain there are better ones now, this is very dated information about the details. But from the Wikipedia there's some exciting stuff to me:
"Miscanthus is unusually efficient at turning solar radiation into biomass, and its water use efficiency is among the highest of any crop. It has twice the water use efficiency of its fellow C4 plant maize, twice the efficiency as the C3 energy crop willow (Salix viminalis), and four times the efficiency as the C3 plant wheat."
and check out just how tolerant this species is --
"Miscanthus × giganteus is either moderately or highly tolerant of heat, drought, flooding, salinity (below 100 mM), and cool soil temperatures (down to −3.4°C, or 25°F). This robustness makes it possible to establish relatively high-yielding miscanthus fields on marginal land, for instance in coastal areas, damp habitats, grasslands, abandoned milling sites, forest edges, streamsides, foothills and mountain slopes. 99% of Europe's saline, marginal lands can be used for M. × giganteus plantations, with only an expected maximum yield loss of 11%."
It's pretty amazing, and is already grown for fuels according to the wikipedia page so it's not like it's a novel concept.
And in a way, isnt the way our farming is a national security tool kind of a secret? Like, “merchants of grain” is a niche book thats borderline conspiracy territory, and politicians dont talk about farmers as national security.
https://www.amazon.com/Merchants-Grain-Profits-Companies-Cen...
Plus Iowa has a senator and early primaries, I don't think you should discount the straight up "federal government gives my state a bunch of money for this, let's not touch it."
there are other octane boosters that don't raise the price of food.
editing to add that other octane boosters don't drop mpg efficiency nearly as much as ethanol does. ethanol also has a much lower energy content, meaning a much lower mpg.
Yes, there are some other octane boosters. The main ones today are 3: ethanol, MTBE and ETBE. MTBE and ETBE are derived from methanol and ethanol respectively [1]. I don't know if there is anything wrong with MTBE or ETBE, but the ethanol lobby managed to push the idea that ethanol is good, so it is widely mixed in gasoline in the US.
According to the DOE [2]:
Lower-octane gasoline is blended with 10% ethanol to attain the standard 87 octane.
> and so less efficient engines, and fewer mpg
ethanol, while providing a higher octane rating (which if you drive a car that requires a higher octane rating for its immediate power might matter), actually lowers the mean mpg quite a bit, since it has much lower energy density.
that, and the fact that we're literally burning food, are some of my issues with ethanol.
I drive a car that knocks if I put less than 91 octane in, but if that octane is obtained from ethanol, it reduces the mpg by 25% (for 10% ethanol, higher if the ethanol percentage is raised). that's a problem. sure, I too want to get off of hydrocarbons that produce co2 for energy, but making that energy less efficient is not the way to do it, especially when we're burning our food and destroying the soil to achieve that.
Wikipedia has a handy table with the energy density of various fuels used in tranportation [1]. The net energy density per liter of regular gasoline is 32.2 MJ (megajoules). For gasoline with alcohol (which they call gasohol) it is 31.3 MJ. So gasohol has an energy density about 2.7% lower than regular gasoline, not 25% lower.
[1] https://en.wikipedia.org/wiki/Gasoline#Comparison_with_other...
This isn't correct. It does make a huge difference in 4-stroke and an even larger difference in 2-stroke. Any engines that are being used for capacity / load will showcase the differential in a very significant way. Even according to the US Department of Energy they state that: "Denatured ethanol (98% ethanol) contains about 30% less energy than gasoline per gallon." [0]
If you've never towed in a vehicle that can use E-10 or E-15 and compared, I'd suggest you give it a shot. Be prepared for upwards of over 25% difference in gas mileage alone, not to mention reduction of power.
"Due to ethanol's lower energy content, FFVs operating on E85 get roughly 15% to 27% fewer miles per gallon than when operating on regular gasoline, depending on the ethanol content. Regular gasoline typically contains about 10% ethanol."
"Standard" E-10 gasoline contains between 0% and 10% ethanol. E-15 is 15% ethanol. So E-15 has at most 4.5% less energy density than standard gasoline. You would not see a 25% decrease in gas mileage between standard gas and E-15.
I'm not sure what you mean by E-10. Basically all gasoline that is sold in the US is E-10. You have to look hard to not get E-10. I doubt you have performed the experiment you described, for the simple reason that it's hard to find gasoline that's not mixed with ethanol. I just googled, and apparently gasoline without ethanol is called "recreational gasoline", or REC-90 [1].
It's not really productive to make assumptions. Where I live I can buy non-oxygenated gas at almost every station. And, yes, I actually do this experiment all the time given I'll drive to places with a trailer where I'm forced to run an ethanol blend.
I realize my comment conflated two things: the reduction of performance and the difference in power per straight gallon. My point is that even with a minimal blend you can lose significant mileage / power. The easiest layman's way to measure that is in MPG. And, yes, there is a significant drop in both power available and MPG.
And for reference [0]: "Due to ethanol's lower energy content, FFVs operating on E85 get roughly 15% to 27% fewer miles per gallon than when operating on regular gasoline, depending on the ethanol content. Regular gasoline typically contains about 10% ethanol."
The above is in normal driving. So, no, I'm not making my statement up.
Hell, just read the first sentence of the second paragraph of that wikipedia page:
> Unlike most stations in the plains states which carry ethanol-free 87 octane unleaded alongside 10% ethanol 87 octane unleaded, ...
As a midwest resident of a non-plains-state, I can confirm that there are plenty of gas stations that sell no-ethanol gas, either 87 or 93 octane (usually the higher, since it's a premium product anyway).
I've never seen "REC-90" and had never heard of it before your posting. clear gas in my area is 92 octane, with up to 110 available in select locations.
most everyone I know who drives a performance vehicle, or a motorcycle can tell you where their closest gas station that sells clear gas is.
> I doubt you have performed the experiment you described, for the simple reason that it's hard to find gasoline that's not mixed with ethanol.
I've performed it many times over the last 17 years I've owned my current car. the results are always the same: 25% better gas mileage with the clear gas.
I keep track of my mpg, and am able to quickly see any difference between gasoline grades. I typically drive in my car's "power band", staying between 5000 and 6700 RPM.
And that's why we don't quantify energy efficiency using just MPG. You adjust for the density to get some sort of mile per gallon-energy-equivalent.
> Making that energy less efficient
I have no idea at all how this could happen, except to say that your very rough numbers do suggest a reduction in energy efficiency. EtOH is supposed to have 34% less energy per volume, so for E10 the reduction should be around 3.4% (IGNORING VOLUME CHANGES WHEN MIXING). This matches well with the "up to 2.8%" claim of Wikipedia citing[1], but certainly not what your engine is doing.
[1]: https://web.archive.org/web/20070609142818/http://www.raa.ne...
> the fact that we're literally burning food
We are all minions of corn. The hope has for a long time been on grass and other stalks full of waste cellulose digestible only by microbes in ruminants and fermentation plants, but these just keep on not delivering.
Isobutanol was supposed to be a more gasoline-like biofuel too. Nobody figured out how to make it cheaply enough to burn either.
There are also some other octane boosters that could be used (which aren't environmental disasters like lead, or arguably corn ethanol), like aromatic amines.
It seems that there's a clear anti-biofuel agenda when a few comments apart we get "biofuel is replacing food crops causing people to starve" and "biofuels should have land use change carbon emissions counted against them".
You think so? How much carbon do you suppose is stored per hectare in a mature woodland versus tall grass prairie versus a corn field? Consider the cornfield after harvest or ploughing. How much carbon is stored aboveground? How much below? I don't know the numbers, but it's hard to believe that that rutted dirt and stubble is storing more carbon than the woodland or prairie it replaced.
The prairie does not accumulate more carbon each year; it is roughly carbon neutral as decaying matter balances new photosynthesis. The corn field has a large part of the biomass carbon removed from it each year. Within a few years the destruction of the prairie has been cancelled out.
This is true even for most woodland, although of course the break-even is much much longer. I'm not arguing in favor of cutting down first-growth forest to grow ethanol though, and I don't think that is the typical case in the United States.
Some praries burn regularly and some don't. Most (as I said above, most land types) do not have significant ongoing accumulation of carbon in the soil. Obviously there are some biomes that do. Citing the fact that prairies burn as proof that they aren't long-term carbon neutral just seems to me like a low-quality argument if you are trying to challenge what I have suggested here, that land use changes are a one-off carbon cost which is paid off by biomass being used in fuels which replace fossil carbon.
You're also replying to someone who completely ignored the difference between the amount of carbon biomass and the change over time of that amount.
If I am completely mistaken and land types which are plausibly converted from unmanaged to biofuel crops are in fact accumulating significant stored carbon on an ongoing basis then tell me so and I stand corrected.
> Various studies of the potential for tallgrass prairie carbon storage have shown that the storage rates vary between .30 and 1.7 metric tons per acre per year. This storage ability is cumulative over time
> Ironically and sadly, because they produce the best, deepest and richest soils, grasslands have been their own worst enemy as they have been rapidly converted to agriculture.
Pretty much at odds with your whole point of converting to farmland being net neutral.
Prairies in the Midwestern United States (where we grow most of the corn for Ethanol) do burn (or rather, did), and do have significant long term accumulation of carbon in the soil - it's literally why our soil is so good for farming (for now). Like, where on earth do you get the nonsense idea that they're carbon neutral ecosystems? Tallgrass prairie has crazy deep roots that over time can place a lot of carbon in the ground, not even accounting for the persistent char layers that accumulate after periodic burns. Thousands of years of accumulation adds up, and converting it to farming:
1. Removes that service 2. Has one off costs 3. Has ongoing costs, in that biofuels are not (currently) carbon neutral at all 4. Has other negative impacts.
Assuming that biofuels have a one-off cost and then become carbon neutral just isn't supported by the evidence - it's a simplistic argument that is so at odds with the literature that I have a hard time taking it seriously.
Also, it might be true that prairies do long term accumulation of carbon, but not true that this represents more carbon than that which is removed from the environment by biofuel crop growing and harvesting. That was my original claim and I don't think you've shown quantitative evidence that it should be dismissed.
It's not a rosy picture at all.
It would even be viable if the total amount of carbon generated by the farming, processing and transportation of biofuels without including burning but subtracting the carbon taken from the air by plant growth, was a net positive by itself, as long as the excess was less than the corresponding total for fossil fuel production, including all the carbon involved in its production.
I accept the validity of what you said about land use in the sister thread, but I don't think you've established that this criterion isn't true (and making the much weaker claim above suggests that you aren't able to).
I also believe that many types of impact on the environment (for example what you mentioned about topsoil and water quality) should be treated with much lower priority than the greenhouse effect. If biofuels, or some other strategy for reducing emissions such as solar or wind power generation has a devastating but localized impact on some ecosystems, it might be worth it to forestall the wider effects of global warming. This is a matter of opinion though, and I do not live in an area which could be sacrificial in this sense.
No, I'm saying it's of dubious climate benefit (compared to fossil fuels), and has outsized environmental externalities besides.
https://www.reuters.com/business/environment/us-corn-based-e...
Not to mention that your goal posts are so incredibly, unbelievably far from where the industry started. Corn-based ethanol was pitched as a bridge fuel to get us to cellulosic, and was supposed to have real, tangible environmental benefits. This also doesn't touch on the fact that the subsidies involved have distorted several climate-relevant markets, most importantly the consumer market for inefficient vehicles in the US. When gas prices go up, demand for inefficient vehicles goes down - US biofuels are giving inefficient cars a huge boost.
> I also believe that many types of impact on the environment (for example what you mentioned about topsoil and water quality) should be treated with much lower priority than the greenhouse effect.
In some cases I agree - see mining of minerals for batteries. It just happens to turn out that if you look at the whole system, biofuels are a scam from a climate perspective, as well as an environmental disaster in their own right.
> This is a matter of opinion though, and I do not live in an area which could be sacrificial in this sense.
I live in Iowa, one of the most modified ecosystems on the planet, and ground zero for biofuels.
At least not until you manage to convert the whole plant to Ethanol, stalk and all
(I mean it's not a secret, more than the US being overly invested on corn)