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How much electricity to produce gasoline?
- Thread starter Brent
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Wall St Journal article about Valero building solar and wind farms to meet the 50MW (!) power needs of their Sunray, TX refinery.
Valero Harnesses Wind Energy to Fuel Its Oil-Refining Process - WSJ.com
Valero Harnesses Wind Energy to Fuel Its Oil-Refining Process - WSJ.com
Maybe so, but for me the importance of the article is that it provides further evidence of the vast amount of electric power needed to make gasoline. While it's not exactly secret, it's far, far from being common knowledge.
If the power consumption of refineries was well known, we would never have to hear the long tailpipe argument again! It tilts the environmental benefits equation so heavily in favor of EV's that the anti-EV enviro arguments will wither and die.
Norbert
TSLA will win
I think the existing environmental benefits equation already is heavily enough in favor of EV's.
The long tail pipe argument is (of course) incorrect by a large margin, for at least three reasons:
1. Solar PV, just for example, is well on its way to grid parity, apparently in about the same time frame as EV's will be mass produced (coincidence or not). Clean energies will be able to more than cover for any additional demand in electricity (be it on your roof or as a power plant). Clean energies can, must and will happen, in any case. And that is also what we want, in any case, isn't it?
And even if clean energy were to come later than EV's, we won't have to buy new cars when it does come.
2. Even today, since the efficiency of electric motors is so much higher, no matter how the electricity is produced, EV's (significantly) improve the situation in any case.
3. Even today, electricity doesn't depend on foreign oil.
So, in so far as the long tail pipe argument is pointing out that our electricity is not as "clean" as EV's are, it is not an argument against EV's, but an additional argument in favor of clean energy.
I'm not aware of any scenario from anyone, short-term or long-term, in which EV's wouldn't significantly improve our energy problems.
The long tail pipe argument just isn't what perhaps to some it seems to be.
But you already know that. Thanks for reading.
JRP3
Hyperactive Member
Even in the face of all the conventional arguments for EV's there are still those trying to muddy the waters and convince people they are no better than ICE's. For that reason we need all factors that point out the inefficiencies of ICE's to make a crushing argument. It's an interesting reaction when you tell people it takes electricity to make gasoline, they often seem deflated, along with their arguments :biggrin:
Norbert
TSLA will win
The long tail pipe argument just isn't what perhaps to some it seems to be.
But you already know that. Thanks for reading.
Of course it isn't, but I continue to see it come up, over and over, with just about every article on the enviro benefits of EV's.
It's wrong and I'm tired of seeing it, want it to just go away!
And they were going to convert that hydrogen to helium with or without your use of the resultant energy produced.
JRP3
Hyperactive Member
Electricity use of Refineries
If you really want to do some calculations using total electricity use, try the folowing:
Here you get an idea of consumption of Californian refineries: Electricity Shortage in California: Issues for Petroleum and Natural Gas Supply
Now as an example, I took Torrance (Los Angeles), the first refinery listed in the above report, with 160 mbpsd (kilobarrels per stream-day).
I assumed that this particular refinery produces about 20% of its intake as gasoline (without checking the figure for this refinery):
Using the 94MW listed and 24 hours operation: 94*24=2256 MWh per stream day
Output 160*42*0.2=1344 thousands of Gallons (US) of gasoline per stream day.
Resulting in about 1.7 kWh per gal of gasoline.
For doing some averages there are more data in the same reference and also some explanations of the role of electricity.
If you really want to do some calculations using total electricity use, try the folowing:
Here you get an idea of consumption of Californian refineries: Electricity Shortage in California: Issues for Petroleum and Natural Gas Supply
Now as an example, I took Torrance (Los Angeles), the first refinery listed in the above report, with 160 mbpsd (kilobarrels per stream-day).
I assumed that this particular refinery produces about 20% of its intake as gasoline (without checking the figure for this refinery):
Using the 94MW listed and 24 hours operation: 94*24=2256 MWh per stream day
Output 160*42*0.2=1344 thousands of Gallons (US) of gasoline per stream day.
Resulting in about 1.7 kWh per gal of gasoline.
For doing some averages there are more data in the same reference and also some explanations of the role of electricity.
Norbert
TSLA will win
To focus solely on the electricity would be more for the fun of the argument. I do think the more relevant number is the energy used to refine a gallon of gas, as Tdave suggests:
According to this apparently careful study:
http://www.transportation.anl.gov/m...dfs/energy_eff_petroleum_refineries-03-08.pdf
The energy used to refine a gallon of gas is around 10% of the energy content of the crude oil used in refining it. Of course one has to consider that this produces not only gas, but also diesel and other products. It seems in the US, at the top production level, gas and diesel are the driving factors. If one distributes the 10% energy input on gas and diesel, without doing the exact numbers, I think one gets quite close to the number which Nissan has made public. The energy used to produce the gas would have to be added.
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Refineries are short on hydrogen
Excellent find! The report also shows how hydrogen short those refineries are! The benefit in energy terms of reducing then the gasoline share should be very noticeable, but as i said before: You have to run the LP models to find realistic figures.
Excellent find! The report also shows how hydrogen short those refineries are! The benefit in energy terms of reducing then the gasoline share should be very noticeable, but as i said before: You have to run the LP models to find realistic figures.
Norbert
TSLA will win
I'd expect that by the time it will actually happen, many other things will change as well, and changing just one variable in the equation would be just for theoretical interest.
The electricity mentioned in these documents seems to be just the electricity purchased externally, and we don't know yet how much of the fuel "loss" comes from using it to produce electricity. In my view, that only part of the energy loss comes from purchased electricity makes things worse: it means that a larger part comes from burning fuel, and so that even more CO2 is emitted than if it were all purchased electricity.
When Doug posted the news about that recent refinery explosion, I learnt that hydrogen was needed for the production of ultra-low sulphur diesel. Does anyone have any data on how much and what that does for the overall CO2 emissions for producing a gallon of such diesel?
In other words, there are emissions to produce the diesel, emissions to produce the hydrogen used to removed the sulphur and then still more emissions in burning the end product in your car.
It'll be interesting to see what that does to Audi's claims in this new ad.
In other words, there are emissions to produce the diesel, emissions to produce the hydrogen used to removed the sulphur and then still more emissions in burning the end product in your car.
It'll be interesting to see what that does to Audi's claims in this new ad.
I believe this number used to be 100 to 1. That's it's now 10 to 1 may be largely a function of the difficulty of finding new crude sources -- we have to use more energy to find them. It's a compelling number, but I don't know that the increase also means more energy to refine a gallon of gasoline, unless perhaps it also reflects more usage of lower quality crude.
Norbert
TSLA will win
I have also read somewhere (perhaps a common source) that some relationship went from 100:1 to 10:1. At the time I read it, I interpreted that as an increase in the difficulty in refining the crude oil, as the quality of crude oil went down by that much, as apparently the high-quality sources are no more. What would that mean?
However, I'm quite certain that the energy loss of 10%, in the study I referred to above, refers to the loss in refining itself, and only that. The loss in finding and producing the crude oil (which appears to be a larger number) is additional to those 10%.
In many places production of crude oil involves flaring off natural gas. I'm fairly sure that's not included in the calculation of energy loss, since it is purely byproduct. But if you want to know the total CO2 emissions, then it's got to be included.
Production of crude from bitumen requires much more energy. I understand that energy loss could be as high as 50%.
Production of crude from bitumen requires much more energy. I understand that energy loss could be as high as 50%.
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