6 ms·

It seems to me that it serves no environmental or pragmatic purpose, and may increase the corrosiveness (and decrease the stability) of fuel.

thescriptkiddie 9y ago
Please take your pro-oil astroturfing elsewhere.
nhorob67 9y ago
Growing one acre of corn takes approximately 8 gallons of diesel fuel (directly) and produces enough corn for 485 gallons of ethanol.
- mullingitover 9y ago
  I'm curious how much fertilizer is used in that acre, and how much fuel was needed to crack the atmospheric Nitrogen to produce the fertilizer.
  - nhorob67 9y ago
    300 lbs of urea or .65 boe of NG (1 bbl of oil = 20 gallons of gas and 11 gallons of diesel). So let's just say 20 additional gallons of fuel to account for the N Edit: the land would be planted to wheat if not planted to corn. Wheat uses approximately 80% of the N as corn. The land wouldn't sit idle.
- microcolonel 9y ago
  The direct combustion emissions can be about half in the right powertrain, but ethanol fermentation produces CO₂ on its own, as does the distillation process, as does the machinery involved in cycling and drying (possibly actively, consuming more energy to heat them, or passively, consuming more energy to transport them) the molecular sieves used to separate the azeotrope of H₂0 and ethanol. Furthermore, Ethanol is, gallon for gallon, about half as energy dense as gasoline.
  - kbutler 9y ago
    Not a fan of ethanol production, but CO2 released fermenting and burning bio fuels is carbon neutral - the CO2 was bound in the plant by photosynthesis, then released by these processes.
    - TrinaryWorksToo 9y ago
      Wouldn't the CO2 be absorbed over a period of time, which the combustion would do it all at once, being a net positive as far as the environment is concerned? Or perhaps I don't understand how CO2 harms the environment well.
      - baddox 9y ago
        Yes, but on a time scale of a year or more (disregarding corn reserves, which probably do exist but are probably too small to matter), we can only emit the CO2 from corn ethanol at the same speed we absorb it. This is unlike fossil fuels, which took millions of years to form but which can be used much faster.
    - mirimir 9y ago
      Some of it is, yes. But some of it depends on nitrogen fertilizer, which is made using energy from petroleum. CH4 + H2O → CO + 3H2 CO + H2O → CO2 + H2 3H2 + N2 → 2NH3
      - Robotbeat 9y ago
        As your homework shows, nitrogen fertilizer comes from hydrogen which comes from natural gas, not petroleum. Maybe if we were all aware of this, we'd be setting up clean hydrogen to be converted into ammonia instead of just burning it in hydrogen cars.
        mirimir 9y ago
        > hydrogen which comes from natural gas, not petroleum That's a rather subtle distinction ;) I mean, natural gas is just a natural cracking product of petroleum, which gets captured under impermeable geological formations.
- mdorazio 9y ago
  Source? I'm more familiar with this info [1]. [1] http://news.cornell.edu/stories/2001/08/ethanol-corn-faulted-energy-waster-scientist-says http://news.cornell.edu/stories/2001/08/ethanol-corn-faulted...
  - nhorob67 9y ago
    My farm. 6 gallons in tractor fuel and 2 gallons in truck fuel. If we didn't raise corn, we'd raise wheat which has similar fertility requirements as corn. Maybe a bit more urea on corn, 50 pounds or .11 barrels of oil equivalent.
    - microcolonel 9y ago
      Good of you to have a grasp on the fuel inputs on your fertilizers. How much land do you tend? I'm interested to see what brings a farmer to HN.
      - nhorob67 9y ago
        We have a small North Dakota farm (500 acres) but I work with some larger farms (10,000+ acres). Farm management consulting and software is my full time gig
    - deleted 9y ago
      [deleted]
    - mdorazio 9y ago
      Awesome. Glad to have a first-hand source.
- mkj 9y ago
  How much fertiliser?
  - nhorob67 9y ago
    300 lbs of urea or .65 boe of NG (1 bbl of oil = 20 gallons of gas and 11 gallons of diesel)
perl4ever 9y ago
I thought ethanol was an alternative to MTBE, which was a problem because it was contaminating groundwater in many places.
- microcolonel 9y ago
  Right, but people are talking about replacing more of the fuel with Ethanol than would help as antiknock. I can understand this if you want race fuel, but it isn't an environmental endeavor in itself to operate vehicles on E85 (or simple denatured ethanol) vs. common gasoline with ethanol for antiknock. I'd be for it if people were talking about it as an economic effort, because that's where it can shine.

thescriptkiddie 9y ago

Please take your pro-oil astroturfing elsewhere.

nhorob67 9y ago

Growing one acre of corn takes approximately 8 gallons of diesel fuel (directly) and produces enough corn for 485 gallons of ethanol.

mullingitover 9y ago
I'm curious how much fertilizer is used in that acre, and how much fuel was needed to crack the atmospheric Nitrogen to produce the fertilizer.
- nhorob67 9y ago
  300 lbs of urea or .65 boe of NG (1 bbl of oil = 20 gallons of gas and 11 gallons of diesel). So let's just say 20 additional gallons of fuel to account for the N Edit: the land would be planted to wheat if not planted to corn. Wheat uses approximately 80% of the N as corn. The land wouldn't sit idle.
microcolonel 9y ago
The direct combustion emissions can be about half in the right powertrain, but ethanol fermentation produces CO₂ on its own, as does the distillation process, as does the machinery involved in cycling and drying (possibly actively, consuming more energy to heat them, or passively, consuming more energy to transport them) the molecular sieves used to separate the azeotrope of H₂0 and ethanol. Furthermore, Ethanol is, gallon for gallon, about half as energy dense as gasoline.
- kbutler 9y ago
  Not a fan of ethanol production, but CO2 released fermenting and burning bio fuels is carbon neutral - the CO2 was bound in the plant by photosynthesis, then released by these processes.
  - TrinaryWorksToo 9y ago
    Wouldn't the CO2 be absorbed over a period of time, which the combustion would do it all at once, being a net positive as far as the environment is concerned? Or perhaps I don't understand how CO2 harms the environment well.
    - baddox 9y ago
      Yes, but on a time scale of a year or more (disregarding corn reserves, which probably do exist but are probably too small to matter), we can only emit the CO2 from corn ethanol at the same speed we absorb it. This is unlike fossil fuels, which took millions of years to form but which can be used much faster.
  - mirimir 9y ago
    Some of it is, yes. But some of it depends on nitrogen fertilizer, which is made using energy from petroleum. CH4 + H2O → CO + 3H2 CO + H2O → CO2 + H2 3H2 + N2 → 2NH3
    - Robotbeat 9y ago
      As your homework shows, nitrogen fertilizer comes from hydrogen which comes from natural gas, not petroleum. Maybe if we were all aware of this, we'd be setting up clean hydrogen to be converted into ammonia instead of just burning it in hydrogen cars.
      - mirimir 9y ago
        > hydrogen which comes from natural gas, not petroleum That's a rather subtle distinction ;) I mean, natural gas is just a natural cracking product of petroleum, which gets captured under impermeable geological formations.
mdorazio 9y ago
Source? I'm more familiar with this info [1]. [1] http://news.cornell.edu/stories/2001/08/ethanol-corn-faulted-energy-waster-scientist-says http://news.cornell.edu/stories/2001/08/ethanol-corn-faulted...
- nhorob67 9y ago
  My farm. 6 gallons in tractor fuel and 2 gallons in truck fuel. If we didn't raise corn, we'd raise wheat which has similar fertility requirements as corn. Maybe a bit more urea on corn, 50 pounds or .11 barrels of oil equivalent.
  - microcolonel 9y ago
    Good of you to have a grasp on the fuel inputs on your fertilizers. How much land do you tend? I'm interested to see what brings a farmer to HN.
    - nhorob67 9y ago
      We have a small North Dakota farm (500 acres) but I work with some larger farms (10,000+ acres). Farm management consulting and software is my full time gig
  - deleted 9y ago
    [deleted]
  - mdorazio 9y ago
    Awesome. Glad to have a first-hand source.
mkj 9y ago
How much fertiliser?
- nhorob67 9y ago
  300 lbs of urea or .65 boe of NG (1 bbl of oil = 20 gallons of gas and 11 gallons of diesel)

perl4ever 9y ago

I thought ethanol was an alternative to MTBE, which was a problem because it was contaminating groundwater in many places.

microcolonel 9y ago
Right, but people are talking about replacing more of the fuel with Ethanol than would help as antiknock. I can understand this if you want race fuel, but it isn't an environmental endeavor in itself to operate vehicles on E85 (or simple denatured ethanol) vs. common gasoline with ethanol for antiknock. I'd be for it if people were talking about it as an economic effort, because that's where it can shine.