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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 ga

by myshpa 3y ago

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-gasoline-climate-change/ https://insideclimatenews.org/news/16022022/corn-ethanol-gas... https://www.pnas.org/doi/full/10.1073/pnas.2101084119 https://www.pnas.org/doi/full/10.1073/pnas.2101084119

raverbashing 3y ago
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)
sproketboy 3y ago
[dead]
credit_guy 3y ago
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.
- olliej 3y ago
  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)
  - bombcar 3y ago
    Unleaded 98 SE was the best gas.
    - olliej 3y ago
      If only there were a DLC version :D
      - bombcar 3y ago
        I always consider DEF (diesel exhaust fluid) is basically DLC for diesel.
- jerrysievert 3y ago
  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.
  - credit_guy 3y ago
    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#Alternatives_to_MTBE_as_an_anti-knock_agent https://en.wikipedia.org/wiki/Methyl_tert-butyl_ether#Altern... [2] https://afdc.energy.gov/fuels/ethanol_fuel_basics.html https://afdc.energy.gov/fuels/ethanol_fuel_basics.html
    - jabl 3y ago
      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.
treeman79 3y ago
[flagged]
dmbche 3y ago
"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."
- lifeonlars 3y ago
  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".
  - DFHippie 3y ago
    > 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.
    - peteradio 3y ago
      Yea, prairie is burned converting some fraction of accumulated bio to char which stays in the soil more or less permanently.
      - lifeonlars 3y ago
neltnerb 3y ago
Yeah, and the sad thing this is definitely not news. https://link.springer.com/article/10.1007/s11053-005-4679-8 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.
- bumby 3y ago
  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.
  - neltnerb 3y ago
    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.
    - bumby 3y ago
wodenokoto 3y ago
But doesn't the corn fields suck that back up?
- empyrrhicist 3y ago
  Some. Not enough.

by myshpa 3y ago

raverbashing 3y ago

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)

sproketboy 3y ago

[dead]

credit_guy 3y ago

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.

olliej 3y ago
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)
- bombcar 3y ago
  Unleaded 98 SE was the best gas.
  - olliej 3y ago
    If only there were a DLC version :D
    - bombcar 3y ago
      I always consider DEF (diesel exhaust fluid) is basically DLC for diesel.
jerrysievert 3y ago
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.
- credit_guy 3y ago
  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#Alternatives_to_MTBE_as_an_anti-knock_agent https://en.wikipedia.org/wiki/Methyl_tert-butyl_ether#Altern... [2] https://afdc.energy.gov/fuels/ethanol_fuel_basics.html https://afdc.energy.gov/fuels/ethanol_fuel_basics.html
  - jabl 3y ago
    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.

treeman79 3y ago

[flagged]

dmbche 3y ago

"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."

lifeonlars 3y ago
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".
- DFHippie 3y ago
  > 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.
  - peteradio 3y ago
    Yea, prairie is burned converting some fraction of accumulated bio to char which stays in the soil more or less permanently.
    - lifeonlars 3y ago

neltnerb 3y ago

Yeah, and the sad thing this is definitely not news. https://link.springer.com/article/10.1007/s11053-005-4679-8 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.

bumby 3y ago
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.
- neltnerb 3y ago
  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.
  - bumby 3y ago

wodenokoto 3y ago

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

empyrrhicist 3y ago
Some. Not enough.