Like the illusion of Wall Street, with its vast and powerful investment banks, now shuttered, China too is an illusion perpetuated by the Globalists that gave us the 15,000 mile Caesar salad, poisoned cat food and lead based paint on babies' pacifiers. Like the illusion that money would come from thin air to always push housing prices higher, China has spent a generation pursuing its illusion. Pursuing an unattainable dream to be like the West, while 6000 years of its carefully shepherded top soil blows into the sea.
Posted: Tue Aug 12, 2008 7:40 am Post subject: Energy, entropy, exergy, and EROEI. (Part 1)
A comment by another poster got me thinking about the whole EROEI of oil and it's supposed superiority to other energy sources.
Quote:
First of all they have to compete against petroluem that is still relatively cheap and abundant given its superior EROEI.
The one thing I couldn't figure out was why exergy wasn't included since an energy source w/ less entropy would be preferable to one w/ greater entropy, que no?
I'd like to begin with a line from a TOD article.
Quote:
A 5:1 EROI may not be enough to power our society.
What's interesting is that if we look at California's oil inputs, we find that "Annually, the oil extraction industry uses 3,846 million KWh of electricity 2,910 million Therms of gas." and "Petroleum refining is the number one consumer of energy in California's manufacturing sector. In 1997, the industry consumed 7,266 million KWh of electricity and 1,061 million Therms of natural gas." This corresponds to roughly 310 million bbls/year produced, and twice that amount refined. A barrel of oil is ~1,700kWh, so the EROEI of extraction in California is roughly 89,110 million Kwh of natural gas and electricity used to get 527,000 kWh of oil. This means the EROEI of extraction is roughly 5.9:1 in CA (California). Now we go to refining. To refine 620 million bbls, or 1,054,000 million Kwh of oil per year we use about 38,353 million kWh of natural gas and electricity, which corresponds to an EROEI of ~27:1. The overall EROEI of oil so far is ~4.5:1. Now, since not all of oil's refined products are used for energy, we look at the ratio of those. Since only four out of every five units of oil are used for energy, the ratio of energetic to non-energetic products is 4:1, and as such oil's EROEI drops to a pathetic ~1.9:1. We haven't included distribution from refineries yet, however we do know that it would only reduce the EROEI of oil in CA further, so we can safely say that the EROEI of oil in CA is less than 1.9:1.
So, w/ an EROEI approaching unity, how can the transportation used by civilization in CA even function? Fortunately for us, the answer to that question, and the reason why CA hasn't fallen off and sunk in the Pacific yet is the definition of EROEI. It's merely the ratio of energy input to energy output for a given energy source. What it does not do is discern between whether or not an energy form is usable or not. So, even though oil has an EROEI of less than 2:1 in CA, not all of it's energy inputs may be usable in anything but oil extraction/refining given current demand/trends. This explains why the EROEI of oil can be so low, yet CA can still function. While they may be using up one unit of energy in order to get two units of oil, if they didn't use that one unit of energy to make oil they may not have been able to use it for any other reason. In short, in order to be more useful as a measure, EROEI needs to include the concept of "opportunity cost", since some of the energy inputs may not be usable for anything but oil extraction. In other words, if we didn't use significant amounts of natural gas for oil, we may have not used it at all, so in this case from the point of view of energy, having an EROEI of about two to one is better than having no energy at all. That being said, if there is a market for natural gas, using it to make gasoline instead of directly as a transportation fuel could very well result in a lower EROEI/efficiency of use. _________________
Joined: Aug 03, 2007 Posts: 4590 Location: Boston Suburbs
Posted: Tue Aug 12, 2008 8:04 am Post subject: Re: Energy, entropy, exergy, and EROEI. (Part 1)
yesplease wrote:
What's interesting is that if we look at California's oil inputs, we find that "Annually, the oil extraction industry uses 3,846 million KWh of electricity 2,910 million Therms of gas." and "Petroleum refining is the number one consumer of energy in California's manufacturing sector.
This has the be the most under-reported aspect of oil as an energy source. It sure makes the idea of electric cars sound ever more appealing as a way to use that electricity more directly that would otherwise be used to refine oil that is destined for transport anyway.
yesplease wrote:
This explains why the EROEI of oil can be so low, yet CA can still function.
$ROI vs. EROEI. If electricity is much cheaper per BTU then you'll make a profit refinining oil even with a negative EROEI. It's not good for the planet, but it's still good for business. _________________ http://doomsteaddiary.blogspot.com/
Posted: Tue Aug 12, 2008 9:15 am Post subject: Re: Energy, entropy, exergy, and EROEI. (Part 1)
mos6507 wrote:
yesplease wrote:
What's interesting is that if we look at California's oil inputs, we find that "Annually, the oil extraction industry uses 3,846 million KWh of electricity 2,910 million Therms of gas." and "Petroleum refining is the number one consumer of energy in California's manufacturing sector.
This has the be the most under-reported aspect of oil as an energy source. It sure makes the idea of electric cars sound ever more appealing as a way to use that electricity more directly that would otherwise be used to refine oil that is destined for transport anyway.
Fer sure! The US DOE has the RAV-4 EV at ~430Wh/mile with NiMH batteries. I doubt they would be used since LiFePO4s are looking damn good, so it'd probably be closer to ~300+Wh/mile for a current production vehicle. According to fueleconomy.gov the automatic 98 RAV-4 is at 23mpg so with a gallon of gas having ~37kWh, that means the gasser version uses ~1,600kWh/mile. For the EV, toss in electricity generation in a combined cycle power plant/transmission efficiency at ~50% and it'll end up using ~600Wh/mile. With the ~2:1 EROEI of oil that means that roughly speaking even if CA stopped extracting/refining it they would have enough excess electricity and natural gas to power the same vehicles in EV format 30% farther than they did w/ gasoline around 2000 (Maybe even further now). This means fewer Carbon emissions, and way, way less pollution.
Granted, even if EVs do cost the same or less, given the much higher entry costs, consumers would probably have to go w/ way more efficient vehicles to see "acceptable" range, and in that case the difference would balloon! A fleet of vehicles similar to the Aptera would allow drivers to go five times as far as they go in RAV-4 equivalent vehicles.
mos6507 wrote:
$ROI vs. EROEI. If electricity is much cheaper per BTU then you'll make a profit refinining oil even with a negative EROEI. It's not good for the planet, but it's still good for business.
Win! Well, for the groups making bank anyway. Since oil and natural gas production tends to go hand in hand, it's easy for certain groups to figure out which is the most profitable. Buy a few elected officials, work some "demand" magic via financial institutions, and before we know it they're bringing in big bucks. IMO of course. _________________
Posted: Tue Aug 12, 2008 9:41 am Post subject: Re: Energy, entropy, exergy, and EROEI. (Part 1)
Yesplease, your work is fine and I appreciate the results. ~4.5:1 is useful number, however it ignores the energy-cost of infrastructure amortized over the life of the well, collection, refinery, delivery pipeline, etc. and the cost to house and feed the labors. Such measures are daunting and thus net-energy analysis is in its infancy. You went off track though.
yesplease wrote:
The overall EROEI of oil so far is ~4.5:1. Now, since not all of oil's refined products are used for energy, we look at the ratio of those. Since only four out of every five units of oil are used for energy, the ratio of energetic to non-energetic products is 4:1, and as such oil's EROEI drops to a pathetic ~1.9:1.
This is not correct, and in fact reverses conventional measures. If the asphalt and other non-energy products were not freely available as a consequence of petroleum production, they would need to be manufactured (with another industrial process) at an extra cost in energy. So this stuff is credit, and in fact increases the eroei according standard net-energy analysis. _________________ ree rah rip ram. sunofabitch godamn. hidey didey christ almighty. rah rah crap
Posted: Tue Aug 12, 2008 12:15 pm Post subject: Re: Energy, entropy, exergy, and EROEI. (Part 1)
pstarr wrote:
Yesplease, your work is fine and I appreciate the results. ~4.5:1 is useful number, however it ignores the energy-cost of infrastructure amortized over the life of the well, collection, refinery, delivery pipeline, etc. and the cost to house and feed the labors. Such measures are daunting and thus net-energy analysis is in its infancy. You went off track though.
The thing w/ infrastructure is that it tends to last a while and for the most part doesn't incur much of a specific resource's energy contribution. If you have anything that shows otherwise I'd love to see it, but AFAIK infrastructure for the oil industry is roughly equivalent to distribution. Not that either is inconsequential since they would both reduce the EROEI, just that they're relatively small compared to the other energy inputs.
pstarr wrote:
This is not correct, and in fact reverses conventional measures. If the asphalt and other non-energy products were not freely available as a consequence of petroleum production, they would need to be manufactured (with another industrial process) at an extra cost in energy. So this stuff is credit, and in fact increases the eroei according standard net-energy analysis.
It can't increase the EROEI if we don't get any energy out of it. Some activities, for instance agriculture for our current food mix, simply end up being net energy losers. The same goes for roads. I suppose the closest we could come, assuming we're looking at net energy and not EROEI, is to assume that instead of asphalt roads we have concrete, and in that case it would take ~1/20-80th of oil's available energy in the states to account for that, not that other energy sources besides oil couldn't fill in this gap for the most part. _________________
Posted: Tue Aug 12, 2008 1:15 pm Post subject: Re: Energy, entropy, exergy, and EROEI. (Part 1)
yesplease wrote:
pstarr wrote:
Yesplease, your work is fine and I appreciate the results. ~4.5:1 is useful number, however it ignores the energy-cost of infrastructure amortized over the life of the well, collection, refinery, delivery pipeline, etc. and the cost to house and feed the labors. Such measures are daunting and thus net-energy analysis is in its infancy. You went off track though.
The thing w/ infrastructure is that it tends to last a while and for the most part doesn't incur much of a specific resource's energy contribution. If you have anything that shows otherwise I'd love to see it, but AFAIK infrastructure for the oil industry is roughly equivalent to distribution. Not that either is inconsequential since they would both reduce the EROEI, just that they're relatively small compared to the other energy inputs.
This is simply wrong. Notice the energy cost for infrastructure:
Pimentel and Patzek wrote:
Table 3. Average Inputs and Energy Inputs Per Hectare Per Year
for Switchgrass Production
----Inputs----------------------------Quantity----kcalx1000
Labor----------------------------------5 hr-----------------20
Machinery---------------------------30 kg----------------555
Diesel------------------------------100 L ----------------1,000
Nitrogen---------------------------50 kg ----------------800
Seeds-----------------------------1.6 kg ----------------100
Herbicides------------------------3 kg ------------------300
Total 10,000 kg yield ----------------2,755
40 million input/ 1:14.4k
kcal yield output ratio
Table 4. Inputs Per 1000 l of 99.5% Ethanol Produced From U.S. Switchgrass
----Inputs----------------------------Quantities----kcal x 1000
Switchgrass------------------------2,500 kg---------694
Transport, switchgrass------------2,500 kg-------300
Water-------------------------------125,000 kg-------70
Stainless steel---------------------3 kg---------------45 Steel--------------------------------4 kg----------------46 Cement-----------------------------8 kg---------------15
Grind switchgrass------------------2,500 kg-------100
Sulfuric acid------------------------118 kg---------------0
Steam production------------------8.1 tons----- 4,404
Electricity---------------------------660 kWh------1,703
Ethanol conversion to 99.5%-----9 kcal/L-----------9
Sewage effluent-------------------20 kg (BOD)-----69
Total-------------------------------------------------7,455
Inputs per 1,000 liter of ethanol: 7,455,000 kcals. Outputs per 1000 liter of ethanol: 5,130,000 million kcal.
You can see that the energy embodied in the farm equipment (Machinery from table 3) is quite significant (20%) because (I assume) this machinery is worn and requires regular maintenance and replacement. It would be analogous to the drilling rigs.
Whereas the equipment used in the distillation process (stainless steel, steel, and cement from table 4) is not under stress (other than heat and pH) and does not wear. (like oil pipelines, and less so, refinery columns and tanks) and so accounts for smaller percentage (<2%) of the total energy costs.
yesplease wrote:
pstarr wrote:
This is not correct, and in fact reverses conventional measures. If the asphalt and other non-energy products were not freely available as a consequence of petroleum production, they would need to be manufactured (with another industrial process) at an extra cost in energy. So this stuff is credit, and in fact increases the eroei according standard net-energy analysis.
It can't increase the EROEI if we don't get any energy out of it.
This is a somewhat contentious issue and is at the core of an ongoing debate over corn ethanol. Shapouri et. al. contend that the biofuel has a positive EROEI specifically because byproducts of ethanol production (the protein waste called 'distillers grain') are replacements for normal cattle feed and therefore represent fuel not spent (in the production of the replaced cattle feed). To a point this is a reasonable argument but I have always contended that the energy cost to actually deliver the distiller's grain from the fermentation facility (to dry, containerize, and deliver the stuff) must also be measured. So Shapouri et. al. proffer a minimal positive energy return of 1.34:1, whereas Pimentel figures a net loss (see above in his summary paragraph).
So by the same logic (useful agriculture byproducts increase net energy by replacing fuel not spent) that is used to justify ethanol production, the tar that comes out of petroleum refineries also increase the EROEI of petroleum production because cement is not used.
So in your attempt devalue EROEI you have simply misrepresented the definition of the term, the methods used to arrive at net-energy figures, and the implications to the most current pressing EROEI debate, biofuels.
yesplease wrote:
Fortunately for us, the answer to that question, and the reason why CA hasn't fallen off and sunk in the Pacific yet is the definition of EROEI. It's merely the ratio of energy input to energy output for a given energy source. What it does not do is discern between whether or not an energy form is usable or not.
This is nonsence, not the accepted definition of eroei and misrepresents the methods and the value of such analysis. I will tell you right now, that this conversation will stop unless you act honorably and enter into a useful scientific debate. I am about done with people who feel entitled to redefine terms and methods at their leisure. Yes net-energy analysis is confusing, technical and is a very new discipline but has become a defining study in this declining energy world we are entering.
yesplease wrote:
Some activities, for instance agriculture for our current food mix, simply end up being net energy losers. The same goes for roads. I suppose the closest we could come, assuming we're looking at net energy and not EROEI, is to assume that instead of asphalt roads we have concrete, and in that case it would take ~1/20-80th of oil's available energy in the states to account for that, not that other energy sources besides oil couldn't fill in this gap for the most part.
Of course agriculture and road building are net-lose activities. They are not primary energy production systems. _________________ ree rah rip ram. sunofabitch godamn. hidey didey christ almighty. rah rah crap
Joined: Nov 24, 2007 Posts: 140 Location: Christchurch, New Zealand
Posted: Tue Aug 12, 2008 2:31 pm Post subject: Re: Energy, entropy, exergy, and EROEI. (Part 1)
This is perhaps a rather simplistic question, but it's the first thing that jumps to mind.
You've shown that California has a low EROEI rate for the oil that it produces. But California is also consuming oil that comes from other parts of the world, right? Oil from Texas and OPEC that has a much higher EROEI, for example.
So it seems to me that you can't say "see, CA hasn't imploded and become a mad-max world because the EROEI is less than 5", because when you consider the average EROEI of oil used in the state, it could easily be much greater than 5. Even if you say that CA is only consuming 100% CA oil with a EROEI of 5, its trading partners are still using oil with a higher EROEI, so in effect they would be subsidising CA.
Now compare this to a situation where all oil in the world has an EROEI of 5 or less, and that is quite a different kettle of fish, I would think.
Posted: Tue Aug 12, 2008 3:12 pm Post subject: Re: Energy, entropy, exergy, and EROEI. (Part 1)
Lanthanide wrote:
This is perhaps a rather simplistic question, but it's the first thing that jumps to mind.
You've shown that California has a low EROEI rate for the oil that it produces. But California is also consuming oil that comes from other parts of the world, right? Oil from Texas and OPEC that has a much higher EROEI, for example.
So it seems to me that you can't say "see, CA hasn't imploded and become a mad-max world because the EROEI is less than 5", because when you consider the average EROEI of oil used in the state, it could easily be much greater than 5. Even if you say that CA is only consuming 100% CA oil with a EROEI of 5, its trading partners are still using oil with a higher EROEI, so in effect they would be subsidising CA.
Now compare this to a situation where all oil in the world has an EROEI of 5 or less, and that is quite a different kettle of fish, I would think.
Similarly high-eroei petroleum from yesterday built the road, pipelines, rigs, etc. we use today to produce low-eroei petroleum. We subsidize today's expensive energy with yesterday's cheap petroleum. Problem, is we spent the rest of our high-eroie energy on crap asphalt roads, McMansions, and endless vacations. Should have used it to repair the corroded energy-delivery system. _________________ ree rah rip ram. sunofabitch godamn. hidey didey christ almighty. rah rah crap
Posted: Wed Aug 13, 2008 6:40 am Post subject: Re: Energy, entropy, exergy, and EROEI. (Part 1)
pstarr wrote:
This is simply wrong. Notice the energy cost for infrastructure:
Pimentel and Patzek wrote:
Table 3. Average Inputs and Energy Inputs Per Hectare Per Year
for Switchgrass Production
----Inputs----------------------------Quantity----kcalx1000
Labor----------------------------------5 hr-----------------20
Machinery---------------------------30 kg----------------555
Diesel------------------------------100 L ----------------1,000
Nitrogen---------------------------50 kg ----------------800
Seeds-----------------------------1.6 kg ----------------100
Herbicides------------------------3 kg ------------------300
Total 10,000 kg yield ----------------2,755
40 million input/ 1:14.4k
kcal yield output ratio
Table 4. Inputs Per 1000 l of 99.5% Ethanol Produced From U.S. Switchgrass
----Inputs----------------------------Quantities----kcal x 1000
Switchgrass------------------------2,500 kg---------694
Transport, switchgrass------------2,500 kg-------300
Water-------------------------------125,000 kg-------70
Stainless steel---------------------3 kg---------------45 Steel--------------------------------4 kg----------------46 Cement-----------------------------8 kg---------------15
Grind switchgrass------------------2,500 kg-------100
Sulfuric acid------------------------118 kg---------------0
Steam production------------------8.1 tons----- 4,404
Electricity---------------------------660 kWh------1,703
Ethanol conversion to 99.5%-----9 kcal/L-----------9
Sewage effluent-------------------20 kg (BOD)-----69
Total-------------------------------------------------7,455
Inputs per 1,000 liter of ethanol: 7,455,000 kcals. Outputs per 1000 liter of ethanol: 5,130,000 million kcal.
You can see that the energy embodied in the farm equipment (Machinery from table 3) is quite significant (20%) because (I assume) this machinery is worn and requires regular maintenance and replacement.
Speaking of simply wrong, look at the amortization rate Pimental assumes (~10 years), at least compared to this.
Quote:
A national survey in 1993 found the average age of tractors used on farms was approximately 23 years.
Which is beside the point, since I never stated that it wouldn't contribute, just that is wasn't as significant as other factors. There are other differences between assumptions and for the most part, as shown by ANL and MIT is right around 1:1, a little more or little less not including the co-product credit.
pstarr wrote:
It would be analogous to the drilling rigs.
How so? You need quite a bit of information to show that the energy cost of farming equipment is analogous to the energy cost of drilling rigs. Furthermore, you also need to compare the energy/infrastructure costs of drilling rigs to the industry as a whole. Back of the pad indicates that even applying Pimentals assumption of a decade lifespan, there is at least an order of magnitude difference in the impact of farm machinery energy costs on Ethanol production compared to rig energy costs on oil production.
pstarr wrote:
yesplease wrote:
pstarr wrote:
This is not correct, and in fact reverses conventional measures. If the asphalt and other non-energy products were not freely available as a consequence of petroleum production, they would need to be manufactured (with another industrial process) at an extra cost in energy. So this stuff is credit, and in fact increases the eroei according standard net-energy analysis.
It can't increase the EROEI if we don't get any energy out of it.
This is a somewhat contentious issue and is at the core of an ongoing debate over corn ethanol. Shapouri et. al. contend that the biofuel has a positive EROEI specifically because byproducts of ethanol production (the protein waste called 'distillers grain') are replacements for normal cattle feed and therefore represent fuel not spent (in the production of the replaced cattle feed). To a point this is a reasonable argument but I have always contended that the energy cost to actually deliver the distiller's grain from the fermentation facility (to dry, containerize, and deliver the stuff) must also be measured. So Shapouri et. al. proffer a minimal positive energy return of 1.34:1, whereas Pimentel figures a net loss (see above in his summary paragraph).
So by the same logic (useful agriculture byproducts increase net energy by replacing fuel not spent) that is used to justify ethanol production, the tar that comes out of petroleum refineries also increase the EROEI of petroleum production because cement is not used.
Like I said before, I'm not looking at co-product credits/EROEI, just EROEI. And when looking at just EROEI, we would not include/remove production credits.
pstarr wrote:
So in your attempt devalue EROEI you have simply misrepresented the definition of the term, the methods used to arrive at net-energy figures, and the implications to the most current pressing EROEI debate, biofuels.
I'm not attempting to devalue EROEI, just present it as per the definition. If you want to look at co-product credits, that's fine, but not what I'm talking about, barring of course my responses to your statements regarding it. That being said, EROEI does not include co-product credits, and if anyone here is devaluing it's you by mixing it up with them.
pstarr wrote:
yesplease wrote:
Fortunately for us, the answer to that question, and the reason why CA hasn't fallen off and sunk in the Pacific yet is the definition of EROEI. It's merely the ratio of energy input to energy output for a given energy source. What it does not do is discern between whether or not an energy form is usable or not.
This is nonsence, not the accepted definition of eroei and misrepresents the methods and the value of such analysis. I will tell you right now, that this conversation will stop unless you act honorably and enter into a useful scientific debate. I am about done with people who feel entitled to redefine terms and methods at their leisure. Yes net-energy analysis is confusing, technical and is a very new discipline but has become a defining study in this declining energy world we are entering.
If anyone is redefining EROEI here it's you by including co-product credits, that do not result in energy out from a system, in EROEI. All I'm stating is that as a measurement, if, according to supposed "experts" on the subject, we probably can't get by on less then 5:1, yet seem to be fine with less than 2:1, looking at the EROEI (or decline) of a specific portion of a process cannot be the end all be all of energy analysis. Why? Probably because it doesn't account for whether or not an energy source is stranded w/o another energy source and the lack of available data on the available energy mix, how much energy is available in the long run, and the exergy of the energy supplied wrt it's use.
pstarr wrote:
Of course agriculture and road building are net-lose activities. They are not primary energy production systems.
Shoot, they aren't even secondary energy streams. Because of this, they are not included in EROEI. _________________
Posted: Fri Aug 15, 2008 3:53 pm Post subject: Re: Energy, entropy, exergy, and EROEI. (Part 1)
Lanthanide wrote:
This is perhaps a rather simplistic question, but it's the first thing that jumps to mind.
You've shown that California has a low EROEI rate for the oil that it produces. But California is also consuming oil that comes from other parts of the world, right? Oil from Texas and OPEC that has a much higher EROEI, for example.
According to shortonoil, the average EROEI of oil production in the US is less than or similar to that in CA. So unless CA happens to be getting oil from Alaska or foreign sources that has an EROEI much much greater than ~20-30:1 for production, there won't be a significant difference. Odds are the EROEI of imported oil is lower or the same since it has to travel even farther than oil from Alaska.
Lanthanide wrote:
So it seems to me that you can't say "see, CA hasn't imploded and become a mad-max world because the EROEI is less than 5", because when you consider the average EROEI of oil used in the state, it could easily be much greater than 5. Even if you say that CA is only consuming 100% CA oil with a EROEI of 5, its trading partners are still using oil with a higher EROEI, so in effect they would be subsidising CA.
Now compare this to a situation where all oil in the world has an EROEI of 5 or less, and that is quite a different kettle of fish, I would think.
I really doubt that. Even if oil from foreign imports/Alaska had a very high EROEI, lets say ~1000:1, or for all intents and purposes it's at ~100% efficiency, because half of CA's oil is at less than 2:1, the total EROEI of CA's oil use still wouldn't reach 5:1. Odds are the EROEI of oil from Alaska/foreign imports is pretty close to the EROEI of oil from CA. Even if it was double what CA's oil was at, the EROEI would still be less than ~2.4:1. _________________
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