Grass makes better ethanol than corn does (2008) | Hacker News Reader

Grass makes better ethanol than corn does (2008)

scientificamerican.com

128 pointsdmbche164 comments

Corn-Based Ethanol May Be Worse For the Climate Than Gasoline, a New Study Finds (2022)

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://www.pnas.org/doi/full/10.1073/pnas.2101084119

In reality ethanol is not used as a renewable fuel, although it is touted as such. It is simply used to increase the octane rating of gasoline. Without ethanol we'd need lead. Or some stuff that would be worse. Or, we'd put up with the lower octane rating, and so less efficient engines, and fewer mpg, and more CO2 emissions.

I was at least 20 before I realized the 87, 95, etc weren't release years (I think at least in part because I only became aware of them when NZ banned leaded gas in 96, and at the same time "unleaded 95" became something being advertised as the advertisers started advertising fuel grades like super)

Unleaded 98 SE was the best gas.

If only there were a DLC version :D

I always consider DEF (diesel exhaust fluid) is basically DLC for diesel.

that doesn't make sense. there is clear gas with 110 octane, and most clear gas is 92 octane. clear gas does not have ethanol nor lead.

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.

Petroleum contains many hydrocarbons, with chains of different lengths. Octane (C8H18) is one. Refineries separate various hydrocarbons. In principle a refinery can separate pure octane. If sold at the pump, that would be by definition gasoline with 100 octane rating. The majority of the hydrocarbons are worse than octane, but some are slightly better. So you could have gasoline without any additives that has an octane rating slightly higher than 100. The problem is that most chains have octane rating significantly lower than 100. What do you do with them? You throw them? Of course not. People create different blends, and add some additives so they can sell as much of the original petroleum as gasoline with a decent octane rating.

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.

[1] https://en.wikipedia.org/wiki/Methyl_tert-butyl_ether#Altern...

[2] https://afdc.energy.gov/fuels/ethanol_fuel_basics.html

it's not the hydrocarbons or the fact that ethanol provides higher octane that I'm disagreeing with, it's this:

> 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.

No, ethanol has a lower energy density, but not that much lower as to make a huge difference.

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...

> No, ethanol has a lower energy density, but not that much lower as to make a huge difference.

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.

[0] https://afdc.energy.gov/fuels/ethanol_fuel_basics.html

Well, as someone else replied in the thread, if pure ethanol (98% is basically pure) has 30% less energy density than gasoline, then a mix of 90% gasoline and 10% ethanol has 3% less energy density.

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].

[1] https://en.wikipedia.org/wiki/REC-90

IME, the gas stations that sell ethanol-free gasoline seem to exist around farms or places where people use off-road gas powered equipment, though I don't have many data points. It stores for longer than ethanol blends (which absorb water over time), so it's better for filling up gas cans used to fill equipment, or infrequently used vehicles.

Around here every station has non-oxy premium but only one station has ethanol free regular unleaded 87.

Ethanol also has a nasty tendency to eat various portions of the fuel systems in older vehicles that don't have gaskets and hoses made of material specifically formulated to withstand it.

REC-90 is a very specific blend, which isn't sold in many states for the simple reason that they have others available.

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'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.

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.

[0] https://www.fueleconomy.gov/feg/ethanol.shtml

it's called "clear" gas around here. there's a website that tracks places to buy it in all 50 states: https://www.pure-gas.org - but I've noticed that it doesn't track every location and is often wrong about prices, at least in my area.

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.

If roughly pure ethanol has has 30% less energy than gasoline, going from a blend of 90/10 gasoline/ethanol to a 85/15 blend shouldn't decrease mileage by 25%.

It does [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."

[0] https://www.fueleconomy.gov/feg/ethanol.shtml

That link is about E-85. E-85 is 85% ethanol (actually 60%-85% depending on the season and the gas station). Ethanol has 30% less energy density than pure gasoline, so E-85 has 0.3*0.85=0.255 less energy density than pure gasoline. That is why E-85 gets 25% lower gas mileage.

"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.

> lowers the mean mpg… energy density

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.

MBTE is a persistent ground water contaminant. Ethanol is definitely a better oxygenate.

You’re missing the chemistry involved, refineries don’t just separate out the constituents of oil as their name suggests. They manufacture the specific hydrocarbon blends using heat, catalysts, steam, and solvents that maximize the value of that oil.

EX: https://en.wikipedia.org/wiki/Cracking_(chemistry)

MTBE/ETBE is banned in many places due to groundwater contamination. But ethanol-less gasoline wouldn't be a disaster either, it would mean the refiners would have to do more processing (alkylation, reformation etc.) to increase the octane of the gasoline, which would increase costs. But OTOH without an ethanol mandate there might be less cost via agricultural subsidies etc., so it wouldn't surprise me if the total cost to society would be less.

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.

But how much octane 110 fuel can you squeeze from a barrel of oil?

"In the new study, Lark and his colleagues found that after the RFS took effect, farmers expanded corn production on nearly 7 million acres each year, causing the conversion of lands to cropland “such that the carbon intensity of corn ethanol produced under the RFS is no less than gasoline and likely at least 24% higher.” The policy, the study said, also resulted in increased fertilizer use, water pollution and habitat loss."

This seems suspicious. Converting land to be used for crops doesn't reduce the utility of that land as a carbon sink. It's generally the opposite. Most wilderness does not steadily accumulate carbon biomass, but stays at a steady mass in a cycle of plant growth and decay into the atmosphere. Crop land, on the other hand, has lots of the carbon removed each year to be used as fuel.

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".

> Converting land to be used for crops doesn't reduce the utility of that land as a carbon sink. It's generally the opposite.

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.

Yea, prairie is burned converting some fraction of accumulated bio to char which stays in the soil more or less permanently.

Pretty sure that burning things generally leads to a lot of carbon emissions..

See your previous comment about carbon neutrality of that biomass, except less methane is produced through burning, which also produces long lasting char... Are you commenting in good faith?

Sorry, but this is a frustrating topic full of double-counting and apples-to-oranges comparisons (arguably on both sides).

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.

From https://tallgrassontario.org/wp-site/carbon-sequestration/

> 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.

> Some praries burn regularly and some don't.

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.

I accept your point about tallgrass prairies but you're back to the double-counting. The argument that 3 - biofuels are not carbon neutral, is established based on 1 and 2.

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.

Did you read the next sentence after the two you quoted? The point is not how much carbon is stored in the prairie but how much it changes by each year.

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.

Plowing absolutely releases carbon, particularly as a source of methane.

Again, that's more or less a one-off effect of land use conversion, and further biofuels agriculture does not indefinitely continue to release carbon into the atmosphere.

It just (in its current form at least) uses a net positive amount of carbon to plant, fertilize, spray, harvest, dry, ship, process, and finally burn in our cars. In addition, the impacts on land use (and correspondingly on our water quality and topsoil) of things like the RFS are clear now.

It's not a rosy picture at all.

Sorry, but read literally what you are claiming is totally acceptable and does not indicate that we shouldn't be using biofuels. You seem to be saying that biofuel generation including burning as fuel using a net positive amount of carbon. There is no reason it shouldn't. It is a viable strategy if it uses less than the fossil fuel alternative. Note that the way to measure the alternative here is not the emissions from burning a unit of fossil fuels, but that plus all the emissions involved in extracting, refining and transporting the fossil fuel. For example, this includes flaring (~1% of all global C02 emissions).

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.

> Sorry, but read literally what you are claiming is totally acceptable and does not indicate that we shouldn't be using biofuels. You seem to be saying that biofuel generation including burning as fuel using a net positive amount of carbon. There is no reason it shouldn't. It is a viable strategy if it uses less than the fossil fuel alternative.

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.

You also know they plow more than once, right? Like, they're doing no till a bunch now (by using more herbicide), but still plow when rotating crops.

Yeah, and the sad thing this is definitely not news.

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.

I think a lot of this discussion is missing the context of the problem. The problem is not simply "What makes the best biofuel option?" but multi-dimensional.

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.

For some additional critical context here, switchgrass can be grown in "marginal" soil that is too salty or otherwise can't handle food crops well. In this case it really doesn't need to be a trade-off, and we've known that for decades too. It barely even needs fertilizer because it contains little nitrogen.

Thus, this simply isn't surprising, we should obviously do this if cellulosic ethanol works well enough now.

Yes, there's other comments here addressing the marginal soil aspect. My understanding is that marginal soil that is used for agriculture is generally used for cattle grazing. So I'm not sure that there's a free lunch here. People aren't generally buying plots of marginal soil for agricultural purposes, but maybe this changes that.

I'm out of the loop, I don't know much about grazing pastures.

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.

You’re right but this context is lacking from most citizen’s understanding of corn, and especially from ethanol marketing.

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...

I don't think it's a secret, but rather something that most people don't have the inclination to dive into. The use of subsidies for national security is displayed on federal websites and in Congressional bills.

Definitely not a secret, totally agree that food security and making sure that our farmers stay in the black are the actual reasons for the corn ethanol thing.

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."

Of definitely the latter as well. The congressional bill I saw was sponsored by an IA congressman, for obvious reasons.

But doesn't the corn fields suck that back up?

Some. Not enough.

Here's the secret: don't make it from corn.

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)

Stop using fertile land to produce fuels for energy hungry cars and energy for industry. Use fertile land for FOOD.

Then, use all the rest of the land for energy production: roofs, parking lots, infertile land.

Question, don't we have enough food production[0]? Basic search says we're doing well enough in that regard.

[0] https://news.thin-ink.net/p/we-produce-enough-food-to-feed-1....

We could easily feed everybody. We just choose not to.

And we could feed even more if we just ate less beef.

One reason is a lot of food grown is used as animal feed. It's a lot more efficient to take soy beans and process them into tofu and other foods, like they do in Japan, than to use it as cattle feed (which is where most soy goes)

It's also an issue of distribution and local production, eg countries making food for export rather than to feed their own population. Like in Honduras the people grow strawberries and cattle for export rather than beans and corn for local use.

I hear you. I live in the Midwest and see endless monoculture fields dedicated to mostly corn and soybeans. It’s very disappointing.

I think the tough part is finding crops fit for human consumption that actually grow in these areas and can be farmed efficiently at scale.

Soy is not a great example IMO because it is difficult for humans to digest without fermentation.

Soy has so many uses, in Japan they find 101 uses for it. In fact I like it just as it is, soaked and boiled and cooked in a curry.

The US throws out tons of food so we probably need less here, actually

Nuclear power plants use of land is almost zero compared to wind farms and solar parks.

It's good that we started building an insane number of said plants 20 years ago.

I'm a fan of nuclear but it just takes too long to deploy compared to wind/solar and that is an absolute killer for ROI (and the climate). We should be building out but only as a secondary/support not as the main source of energy.

The slow building times are more due to regulatory overreach. Wind/solar are more expensive overall, as Germany shows.

>I'm a fan of nuclear but it just takes too long to deploy compared to wind/solar and that is an absolute killer for ROI (and the climate).

Unless you build it like Koreans.

But if something goes wrong they will grab this areas and several Km around, for thousands of years, banning people to live there.

In Fukushima most of the area is safe now:

https://blog.japanwondertravel.com/fukushima-exclusion-zone-...

So the only large permanent contamination seems to have happened in Chernobyl.

If you take mining and the fact that solar power can be installed on top of existing infrastructure into account, the comparison of land use is still in favor of nuclear, but definitely not "almost zero".

Extensive power like wind and solar also relies on mining; it would be interesting to see a comparison per joule delivered, my guess is this would favor nuclear.

If "surface area used per megajoule" is 100x lower for nuclear than for, say, solar, I would be comfortable calling this 'almost zero', there are plenty of rhetorical situations where 1% is almost zero, this strikes me as one of them.

> If "surface area used per megajoule" is 100x lower for nuclear than for, say, solar, I would be comfortable calling this 'almost zero'

The problem is these kinds of numbers are usually comparing apples to oranges. Like comparing the size of the nuclear building, or just the site (maybe also the exclusion zone in rare cases), with the planning area for the wind/solar power plant.

If you count like this, the area counted for a wind turbine put next to a farm field would imply that the areas used by the farm is lost. Which it's clearly not.

Wind power area usage doesn't exclude all other uses of the land. Solar power doesn't either. Sometimes the use of the area can be improved with solar, by providing shade. There's a growing sector called agrovoltaics exploring the benefits of combining solar power with farming.

With off-shore wind power we're also starting to see that there could be benefits to having the wind turbines there, by acting as artificial reefs. The area used by off-shore wind will generally exclude fishing. This could be seen as a good or a bad thing, but from nature's side, the artificial reefs and protected area for fish is clearly a huge positive.

So you need to add some kind of factor on the wind/solar side of the equation to account for the fact that the area is only partially consumed by the power plant, or that they even improve the value of the land. Nuclear proponents NEVER do this, which is pretty much just lying.

You need to mine in order to produce solar power as well. If you take mining into account solar power uses more than 73 times land than nuclear per MWh produced[0]

[0]: https://ourworldindata.org/land-use-per-energy-source, Numbers from UNECE 2021

If your goal is maximizing acreage for farming, a pretty good idea would be to get rid of land dedicated to our number one crop: grass that gets mowed. We spend over 40 millions of acres in lawns, as farms get replaced with subdivisions that are well over 50% lawn, and most of the rest is asphalt.

Your typical American metro area is very low density, but not because it has a lot of land dedicated to farming, or old growth woods, but because we dedicate so much space to very low density development that erases whatever was in that land in the first place. The trees are not local, the plants aren't local, and neither is the concrete.

Maybe there could be a business idea in AI-powered semi-automated(remote oversight) lawnmowing that pays for itself by collecting the grass for ethanol production.

This video is an interesting look at this whole issue:(Engineering Explained - America Was Wrong About Ethanol) https://www.youtube.com/watch?v=F-yDKeya4SU

Especially his summary, where corn creates 20 percent less GHG than gasoline and ''breaks even'' after 28 years, while switchgrass creates 94% less GHG and breaks even in it's first year.

Switchgrass farmers don't vote enough. The whole ethanol thing was just to prop up corn prices and production during election runs.

How practical is it really? They’ve been talking about ethanol from cellulosic biomass since at least the 1970s but progress seems about as fast as fast breeder reactors.

The idea looks sound, but cellulose is hard to break down. If it wasn't bacteria would have figure it out long ago (before the dinosaurs ago)

There's a number of animals called Ruminants that do it regularly no?

They all use bacteria.

... why wouldn't we use those then?

No, that’s not right. Cellulose decomposition is easy. You are probably thinking about lignin decomposition, which is typically done by fungi, not bacteria.

And to make things worse, corn farmers are concentrated in Iowa which was one of the first states in the presidential primary. So they had outsized influence over who gets chosen as president and what campaign promises they have to make in order to get elected.

one of the first? Don't they literally have laws requiring them to have the first presidential primary?

Who do you mean by “they” here? I believe the parties themselves choose when to have their primaries.

Yep. And the Democrats are changing the order this year. The plan is South Carolina will be first.

https://www.pbs.org/newshour/politics/democrats-vote-to-chan...

States can choose when their primaries happen by law, and the parties can choose when and where their primaries should happen. Entertaining things happen when they differ. The Democratic party cannot force Iowa and New Hampshire to not have their primary and caucus later in the year, but they can threaten not to count their delegates if they go at the wrong time.

The sobering thing is, this is not nearly the dumbest part of the American electoral system.

How is this not a breach of the constitutional protection for the right to freedom of assembly? A caucus, in particular, is literally an assembly. Surely for elections to be free and fair, the private associations who put forth candidates should be able to freely determine who those candidates are.

Not counting the delegates isn't preventing the assembly.

The constitution doesn't ensure free and fair elections, unfortunately, as is demonstrated by the fact that states can pass laws regarding primaries that are mutually inconsistent. States A and B can both pass laws saying they have to have the first primaries in an election.

Going a step further, the constitution doesn't require states to have their citizens vote on the delegates to the electoral college. The state (Legislature) could decide that the Electors are actually always for one party's candidate and that no state wide election is necessary.

> [1] Each State shall appoint, in such Manner as the Legislature thereof may direct, a Number of Electors, equal to the whole Number of Senators and Representatives to which the State may be entitled in the Congress: but no Senator or Representative, or Person holding an Office of Trust or Profit under the United States, shall be appointed an Elector.

[1]: https://constitution.congress.gov/browse/article-2/section-1...

There was an attempt to do this at some point in Alabama. I can't find it right now but a group made up a bunch of "Who decides your X? The party or the people?" with hammer & sickle logos on it.

I'm always surprised there aren't troll billboards in the south of "Vote Red for Socialism" overlayed on a Soviet flag.

> The state (Legislature) could decide that the Electors are actually always for one party's candidate and that no state wide election is necessary.

There is plenty in the constitution and in case law that would apply if a state effectively tried to prevent citizens from exercising the franchise. It's not like the topic has never come up before.

I welcome you to quote from the constitution that applies.

The case law uses the 14th amendment which also does not mention the word voting anywhere so again, strictly looking at the text of the constitution, states do not need to allow their citizens to vote on the president.

The case law is also strictly only focused on can you deny voting to some but never the question of to all.

> [1]: All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside. No State shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States; nor shall any State deprive any person of life, liberty, or property, without due process of law; nor deny to any person within its jurisdiction the equal protection of the laws.

[1]: https://constitution.congress.gov/browse/essay/amdt14-S1-8-6...

I think it is New Hampshire with the law, but they may not be alone now. Nevada passed a law of their own as I recall.

First caucus, which is like a primary, but worse.

If you want to see a good (fictional but pretty much on the money) depiction of this, check out the episode “King Corn” from season six of The West Wing.

Even then it was blatantly obvious that corn ethanol was all about subsidising corn farmers, but the state’s political importance made it impossible to do anything about.

Thanks for that summary, the video doesn't say much more other than repeat these things over and over.

One thing that wasn't clear is why does tilling the land release so much carbon into the atmosphere?

Tilling the soil in conventional farming creates large air pockets which fill up with oxygen, where microbes then turn carbon in the soil into CO2.

Also when you convert forest into farmland and cut down the trees, the root systems of the trees will, over a period of time, decompose. Annual plants have much smaller root systems.

It was never about GHGs, always about subsidizing corn farmers.

This.

And also reducing US reliance on foreign energy. Farmers make 10x the corn that we can eat, why not make renewable, albeit kinda dirty fuel out of it? Still better than importing arabian oil on a supertanker 10,000 miles, right?

At what opportunity and environmental cost? For what we spend, we get increased reliance on subsidized fuel instead of investing in renewables, all while fucking our water quality and destroying fisheries in the gulf. There are much better ways to decrease our reliance on foreign oil - starting with reducing the demand for it through better MPG standards and investing in clean energy and transportation infrastructure.

If you want something that is more up-to-date and covers this topic, here's a good podcast: https://www.volts.wtf/p/whats-going-on-with-biofuels

Most important fact: All these promised second generation biofuels technologies, from which switchgrass was one, didn't happen.

why didn't they happen? im not in a place to listen to a podcast

Switchgrass is a natural solar panel that converts sunlight into chemical energy. It has many benefits, like improving soil quality, storing carbon, and reducing emissions. It can also be burned with coal in existing plants, which is convenient. Switchgrass is a promising biofuel that can help us transition away from fossil fuels. It has a lot of potential to grow in various conditions and produce high yields with low inputs. It also has a positive environmental impact by sequestering carbon and reducing greenhouse gases. Switchgrass is not without its challenges, but they are not insurmountable. It needs more research and development to make it more efficient and cost-effective. It also needs more support from farmers, scientists, and policymakers who are working to make it a viable option. I think switchgrass is a great idea, and I’m excited to see how it evolves in the future.

Who didn't already get that ethanol was about corn subsidies and not the environment?

Probably a lot of people the same way many don't get what so many other climate change initiatives are about

Corn is a type of grass. So is sugarcane. (The article is about switchgrass, not generic grass)

I know attempts have been made to use more than just the corn seed into ethanol. The big disadvantage is that you take away a lot of nutrients from the soil forever. Sulphur for example doesn't go back, and so the more of the plant you take away, the more you have to add back as fertilizer .

If only there were at thick black viscous substance rich in sulfur that was present in the Earth's crust we could harvest easily, then extract the sulfur, & then use to create fertilizer.

seems like the waste from digesters could be returned back as fertilizer.

I don’t know switchgrass, but with miscanthus another perennial grass, at some point the nutrients mostly get taken back to the roots and what you harvest has a very low mineral content.

Just take the CO2 from the atmosphere, concentrate it to a 100% pure CO2 stream, then generate a 100% H2 stream from water, blow off one O to make CO (carbon monoxide), now we're into well-characterized Fisher-Tropsch and Sabattier processes...

https://en.wikipedia.org/wiki/Fischer%E2%80%93Tropsch_proces...

https://en.wikipedia.org/wiki/Sabatier_reaction

Why on earth would you devote a scrap of quality agricultural land to ethanol production? You might as well just compost lost crops, get better production later. Seriously, biofuels are like raising seals in pens so you can kill them and get lamp oil from their blubber, it's just stupid.

Yes. Another variation on this scheme (which AFAIK the Porsche synthetic fuel plant in Chile is doing) is producing methane from atmospheric CO2 and H2 from electrolysis, then converting methane to methanol (how most methanol is produced today, albeit from fossil methane (natural gas)), and finally converting methanol to gasoline with the methanol-to-gasoline (MTG) process.

But in the context of corn ethanol in the USA, none of this has anything to do with the environment or sane economics, it's all just an agricultural subsidy scheme.

Switchgrass farming would be no-till farming, and on net would probably increase (and stabilize) the carbon content locked in soils. Another respect in which it would be much better than corn for ethanol.

The exact effect appears to depend on soil quality, e.g. https://www.nature.com/articles/s41396-021-00916-y

I still find it crazy that we are capturing solar energy on plants, growing them, and then burning them to get energy to move our cars…

It seems so much more intuitive to just capture solar to electricity and use an electric car…

BTW, I live in Brazil where ethanol from sugarcane is widespread

Yes, I assume in regions with an ideal climate, sugar cane crops average around 50 tonnes/acre or roughly 125 t/Ha. [Note ^1 - average over all in Brazil this year is 70.5t/Ha] Using this lower average, if the yield averages around 14 ccs (roughly 1/7 sugar) the 70.5 tonnes translates to about 10 tonnes of sugar. Going the ethanol route under ideal conditions would derive around half that weight as ethanol, but ethanol is relatively easy to handle as a fuel source since the petro industry already has much of the infrastructure in place, as well as letting older engines that don't have much use remain in service. (I suspect that older pre fuel injection engines would be fine with 80% ethanol, 20% water.) However since electric cars are now not the stuff of science fiction, it maybe makes more sense to investigate and use sugar to power a fuel cell instead.

[1]https://www.statista.com/statistics/742523/sugar-cane-yield-...

It's a lot less work per Kwh to harvest the energy that plants store than what would be needed to make and maintain solar panels to make the same amount - I assume

I doubt it. solar panels are much more efficient per volume than corn, don't require pesticide spray, aren't nearly as weather dependent, and last 20 to 40 years.

It's indirectly solar power, and ethanol can hold more energy per volume than batteries. However all of the other inputs that go into growing ethanol cancel that advantage out. If we were using Nuclear or maybe pure solar to produce the fertilizer perhaps the math may work out.

Literally everything except nuclear and maybe geothermal is indirectly solar power. Nuclear is indirectly dead-star power; fossil star fuel. Unless of course the abiogenesis theory is correct, in which case oil and at least some natural gas are also dead-star fuel.

> Unless of course the abiogenesis theory is correct, in which case oil and at least some natural gas are also dead-star fuel.

I don't see how whether abiogenesis theory is correct or not matters here. The energy trapped in oil and natural gas is not from "life" but from the sun. Of course it wouldn't have accumulated without life, but that is not the source of the energy.

Abiogenesis means oil and gas are primordial matter. Trapped sun energy in the form of biomass is biogenesis.

Ah thank you for the clarification.

I was not aware that it was used in that meaning too. The only meaning I did know is in the context of origin of life.

The energy density of fuel is much much higher than electricity, which makes using fuel to transport energy to where it is needed is much easier, and it makes the effective range for gas much higher because in those cases where you need it you can always just take extra gas (even taking into account the relative engine efficiency, to the worst possible degree gas is more than 10x the miles per kg than current battery tech).

Add to that speed of refueling vs. recharging, the many areas where power is not available at all, let alone super chargers (absent specialized charging hardware charging an EV takes days), etc fuel still has real value.

There are vast swathes of the world where grid power is not available, so the only available power is via diesel generators, which are generally around 40% efficient. At that point using an EV is not only slower, but at that point the best case efficiency (watts/kg) is less than 34% vs a diesel car engine's 43% energy efficiency.

If you have the right environment you might be able to use solar to charge the car, but I think for that you need something like 6kW of solar panels per car you want to use each day, and an additional car worth of batteries to store power during the day because you're presumably using your car at during the day. That's not a trivially portable system, so still doesn't fix the "I am driving a long distance where there aren't super chargers".

Depends on the use case. I live semi rurally and an EV would be a tough sell for most people here. I do see a few of them, but these are households with multiple vehicles where the EV is a runabout, and work is done using diesel or petrol, often a 4x4 from the 80s or 90s with the better part of a million kms on the body.

Well we can store corn and oil and can't really store electricity.

  "It's a prediction because right now there are no biorefineries built that handle cellulosic material" like that which switchgrass provides

so.. nobody can ferment it but it gives a higher ethanol yield than corn.. how does that work

Fermenting on a tiny scale in a lab is fundamentally different than fermenting on a commercial production scale. Basic calculations of energy density + small experiments support the assertion, but without a working larger scale production that can consistently yield ethanol (i.e. preventing the bacteria responsible from being displaced by wild strains, yeast or other fungi, ensuring batches run to completion, etc) it's nothing but a prediction.

The issue is not so much that it's cellulosic as that it's lignocellulosic; we have a pretty good grasp these days on cellulose (and hemicellulose, but we can handle that too so I'll skip over it). Lignin is (oversimplifying, but not by too much) what makes the difference between soft paper pulp and hard woodchips. The lignin crosslinks the (hemi)cellulose and makes it much harder to access for the enzymes we'd use to break down the cellulose, while itself being very difficult to break down (it's thought that the whole reason we have coal is due to how long it took for fungi to evolve the enzymes needed to break down lignin effectively in order to degrade wood).

You need a bunch of equipment and/or biochemical processing to break down lignocellulosic plant matter into something that can be efficiently fermented (keyword: "lignocellulosic biomass pretreatment"), so while thay may be available at a lab scale, it's not necessarily possible on an industrial scale (yet).

As one example, there's a method called "steam explosion" where you apply very hot (around 160-260 °C) and high-pressure (tens of atmospheres) steam to the biomass, then release the pressure relatively fast. The hot steam causes chemical reactions like hydrolysis, and the pressure release breaks down the material physically as the steam expands. Imagine the sort of equipment you'd need to do that on an industrial scale. Nowhere out of reach for modern chemical engineering, but someone has to build it.

Now, as you might imagine from how relatively non-woody switchgrass is, it doesn't have a ton of lignin compared to trying to ferment woodchips, but it still has enough to be problematic, and in fact there's research being done on how to reduce its lignin content, such as by genetic engineering.

The article is from 2008. What happened in the 15 next years on this front ? Is any biofuel actually produced this way ? How many cars can use it ?

Or is the submission a troll on modeling ?

https://www.eia.gov/energyexplained/biofuels/ethanol-supply....

https://www.eia.gov/tools/faqs/faq.php?id=27&t=4

https://www.eia.gov/tools/faqs/faq.php?id=90&t=4

https://apnews.com/article/ethanol-e15-gasoline-midwest-epa-...

Coincidently, increasing EV sales threatens ethanol production, so there are calls for increasing ethanol in fuels to compensate. Subsidies typically don't die quietly, unfortunately.

> Coincidently, increasing EV sales threatens ethanol production, so there are calls for increasing ethanol in fuels to compensate.

I already have to search out "clear" gas to gain back the 25% mpg loss I receive when I use ethanol (currently 15% I believe in Oregon?).

I fear what adding more will do. if I don't use clear gas, I have to run my car a lot more often, which is also not good.

I accidentally got ethanol free gas one time and was baffled at the sky high fuel economy I was getting for that whole tank.

I noticed a massive difference in L/100Km when i filled up in the US vs Canada. It was unquestionably cheaper to fill up though.

it is more expensive to buy clear gas, but the savings in gas mileage usually makes it worth it.

at least until the clear gas went up more quickly than the ethanol gas:

  $4.79/gal for premium
  $4.99/gal for clear

that was a no-brainer.

  $4.79/gal for premium
  $5.99/gal for clear

that is a little different calculus. that's about break-even for me - if those prices diverge further, then I will just need to stop driving as much. currently, I am managing about 50 miles/week at most.

25-30% is roughly the difference I see between E10 and E85. I'd be very surprised if E0 and E10 had the same difference in mileage.

Well, this happened for one: https://www.clarionledger.com/story/news/politics/2017/07/30...

Algal biofuel boom-bust of the early 2010's: https://www.greentechmedia.com/articles/read/lessons-from-th...

Isn't part of the idea that corn makes more sense to subsidize because it multi-use? I.e., it can be food and fuel?

>"This is an energy crop that can be grown on marginal land,"

This seems like the lede and comparison to corn is missing point and opening itself up to counterpoints that detract from the value of using grass on land that would otherwise probably only be used for grazing.

The land-conversion from forest or grassland into farmland is a surprisingly large effect on the environment.

Making Ethanol from natural grasses and keeping the land natural is one of the best things we can do for the environment, as well as creating an alternative means of capturing solar energy.

You know... if we can get it to be commercially successful. If we can't sell the darn thing, then it'd never happen. But the theory is sound and enough prototypes have been created that we know how this works.

How much current grassland is used for grazing? Works there be any potential pushback from, say, cattle ranchers who would be otherwise using the land or is there a plentiful amount of otherwise land unused for agriculture?

> there a plentiful amount of otherwise land unused for agriculture?

More like land that "shouldn't" be converted into agricultural lands (or ranches for that matter)

I'm not sure if "grazing" is an issue, because the argument is what should we be encouraging our private farmers to be doing. (While "Grazing" questions tend to be a question on public lands IIRC) If you own 100 acres of wilderness, you can cut down all the trees and replace the grass with corn... or maybe you can leave the natural grass and harvest it instead.

Natural grass grows wildly, its perfectly suited for the wild environment to grow quickly. Learning how to take advantage of the natural state of American land is a good idea.

The question at hand is "is this a _profitable_ idea?" and that remains to be seen. I know they've been working on various chemistry, biofuels, etc. etc. to try to take advantage of natural grasses for a few decades now.

Sorry, I wasn't very clear. My question is more about the grazing on public lands. Meaning, it's already being used for agricultural purposes (ie cattle ranches). But your point makes sense when we're talking about privately held farms and encouraging specific behavior.

I’m having a pedantically tough time with this headline. It’s like saying “pork makes better lard than ham”, or “grain makes better whiskey than rye”. Maybe that’s true, the superset might have better properties for the purpose than the subset? But it’s a really strange distinction to make.

That article was 15 years ago, back in 2008. If it was a better alternative, we'd have seen it by now.

You are correct that there's no better alternative.

But that's not according to emissions or energy density. It's about Politics.

Politically, there's no better alternative to corn ethanol.

Maybe it's because corn is subsidized.

Yes but corn makes better campaign donations than grass does.

Meanwhile as part of the process of making plastics, we're flaring off enough propane and butane to run millions of cars.

LPG is reasonably popular in some places.

I run both my Range Rovers on it, which in the grubbier parts of cities where you get a lot of diesel buses and taxis means that strictly speaking it's not just a "Low Emission Vehicle", it's a *Negative* Emission Vehicle.

I'm trying to understand - why is it negative emissions? I'm unfamiliar with LPG (Liquefied Petroleum Gas), it's a byproduct of something else? It just seems like it's produced like gas normaly is, it's just cleaner by 30ish%. Could you tell me more or direct me somewhere?

Edit: https://newatlas.com/materials/catalyst-mixed-plastic-waste-...

I think this is it

Corn-based Ethanol is used to curry favor with Iowans who hold (for Republicans) the first in the nation presidential primary contest (actually a caucus, but it’s the first voting event on the primary calendar).

It was also the first in the nation voting event for Democrats until the IA Democratic Party thoroughly botched the 2020 caucuses.

Corn is a grass so without saying which species of grass do this, the title is useless.

Would this work with regular lawn grass? if so, you could think of having huge amount of this raw material for ethanol production worldwide.

I used to mow lawns. We would dump the clippings into a pasture to feed the cows. They absolutely loved it, and would come running when they heard our truck. The rancher told us to stop after one of them died of a weird illness. There's a a lot of nasty shit people spray on their lawns to make them look nice and green.

Just nitrogen for the green part. The nasty chemicals are for weed and pest control.

Yes, but the corn growers lobby makes more "donations" to politicians than the grass growers lobby does.

https://archive.is/sWTQJ

what is "better ethanol"? seems like grass can be used more efficiently than corn for making ethanol is what it means.

I recall among the early 2000s the right wing push to slow down adoption of electric vehicles with President Bush giving some sort of pro-ethanol push in front of some switchgrass. It seemed bizarre to me that corn kept on being pushed when a non-food option was available. But obviously none of this was ever about what “made sense”

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