Posted on 06/08/2007 1:08:55 PM PDT by Red Badger
Comparing life cycle CO2 emissions from plug-in hybrids, coal-to-liquids gasoline, and conventional gasoline.
A study from the Carnegie Mellon Electricity Industry Center (CEIC) concludes that while enacting policies to subsidize the production of coal-to-liquids transportation fuel would enhance national security by lowering oil imports, encouraging plug-in hybrids powered by coal-generated electricity is a less costly policy that also reduces oil imports and does more to lower greenhouse gas (GHG) emissions.
CEIC produced the paper in the context of the current work by the US House Committee on Energy and Commerce on transportation energy legislation, the current draft of which includes significant support for CTL. (Earlier post.) The CEIC paper compares GHG emissions of CTL gasoline to the emissions of plug-in hybrid vehicles powered with electricity generated from coal on a full life cycle basis.
Although CTL conventionally produces more diesel than gasoline, the process can be altered with catalysts to upgrade some of the diesel and waxes produced in the standard F-T process to gasoline, with an overall efficiency of around 52% (HHV).
The CEIC team used CTL inputs and outputs derived by Bechtel in 1993, and allocated the total emissions factor among the various CTL co-products using the method in the GREET model (by energy content of the co-products).
The allocated worst-case well-to-plant emission factor (no carbon capture and sequestration, current electricity generation mix) is 190 pounds CO2 equivalent per MMBtu of CTL gasoline, and 50 pounds CO2 equivalent per MMBtu of CTL diesel. With 80% CCS and zero-carbon electricity, the allocated factors drop to 50 pounds CO2 equivalent for gasoline and 15 pounds for diesel.
Adding in the other complete lifecycle factors (transportation for distribution, combustion in the engine) resulted in complete well-to-wheel CTL lifecycle emissions of 360 pounds CO2 equivalent per MMBtu of gasoline in the worst-case scenario and 220 pounds CO2 equivalent per MMBtu of gasoline in the best-case scenario.
CEIC then used a fuel consumption figure of 34 mpg and an annual driving distance of 12,000 miles to calculate the annual CTL gasoline emissions: 1.18 lbs/mile (536.7 g/mi) in the worst case; 0.72 lbs/mile (325 g/mi) in the best case.
For plug-ins, the CEIC researchers calculated the impact of both electricity and gasoline. For electricity generation, they used two scenarios: bituminous coal in a pulverized coal power plant and bituminous coal in an integrated gasification combined cycle power plant with carbon capture and sequestration (IGCC w/ CCS).
For a vehicle, they assumed a plug-in hybrid built on a Toyota Prius platform in a parallel configuration with an all-electric range of 60 miles. To determine the fraction of vehicle travel powered by electricity or gasoline, they used the percentages resulting from the cumulative distribution function of daily vehicle miles traveled constructed in another paper from CMU (Samaras and Meisterling, “Decarbonized Electricity Needed for Plug-in Hybrids” 2007). The CEIC distribution estimates electricity would power about 85% of average annual vehicle travel for a plug-in hybrid with a 60-mile electric range, assuming vehicles are charged once per day.
The results: total well-to-wheel emissions of 264.6 g/mi for the conventional coal-generated scenario; 105.8 g/mi for the scenario with advanced IGCC with CCS). The conventional gasoline baseline in the study was 344 g/mi.
It can be seen that gasoline derived from CTL plants with no CCS could increase GHG emissions from vehicles by almost 60%. If CCS is available, then a reduction of less than 6% could be obtained. It is important to note, once again, that in this best-case CTL scenario, not only is there CCS at the CTL plant, but also a low-carbon electricity source is used for CTL production. This might not be a very realistic assumption, but is presented here to show that at best we could only obtain a very small reduction in GHG emissions following a path of increased CTL production.
Plug-in hybrids look more promising as a pathway for reduction of GHG emissions. Even if coal electricity without CCS is used, plug-in hybrids could lead to a GHG emissions reduction of almost 25%. This demonstrates the worst case for plug-in hybrids, as GHGs would be further reduced with a low-carbon electricity portfolio. It is important to note however, that this analysis does not include the emissions from manufacturing the storage battery used in plug-in hybrids. If GHG emissions from lithium-ion batteries for plug-in hybrids are included, total annual GHGs from plug-ins would increase by about 800-1,500 pounds of CO2 equivalents, depending if a twelve or eight-year vehicle life is assumed (Samaras and Meisterling 2007). Battery technologies are difficult to predict, but even when emissions from current battery production are included, plug-in hybrids result in substantially lower emissions than CTL pathways.
The Carnegie Mellon Electricity Industry Center (CEIC) was established in August 2001 as one of 20 centers of excellence in different industries that the Alfred P. Sloan Foundation has established at 13 universities. CEIC’s core funding comes jointly from Sloan and from the Electric Power Research Institute (EPRI).
Resources:
“For energy security and greenhouse gas reductions, plug-in hybrids a more sensible pathway than coal-to-liquids gasoline”; Paulina Jaramillo and Constantine Samaras; CEIC Working Paper CEIC 07-04 – June 2007
Really ? The last time I checked, they spewed radioactive reaction material. The shielding needed to prevent that was too heavy for aircraft. There was a project in the 50’s & 60’s that was deemed a complete failure.
Did you have a link to the successful projects ?
If it were possible, how do you explain the B2 not being built that way ? Eliminating the need for refueling and the unlimited range provided by a nuclear reactor would be a precious military advantage.
Uranium.
Actually, I have no problem with using coal and natural gas either. Both are found in abundance in North America.
I am shocked I tell you, shocked to think their may be some bias in this report! :)
In reality this report is biased against anything that will produce CO2, thus they pick the mode that produces the least CO2 according to their models which are slanted against hydrocarbon fuels.
Please note, that they completely and totally ignore nuclear power as a source of electricity. That is all you need to know about this report. It is political crap with a preordained agenda and outcome.
We may be in a global warming period that will melt the ice caps and we may not be. If we are it does not have a damn thing to do with CO2 levels. CO2, levels lag global temperatures by a few hundred years. The level of CO2 in the atmosphere is a function of global temperature.
It is as simple as a bottle of coke. Open a hot bottle or can of coke and it will spew out gas. The gas is CO2. The reason is the solubility of CO2 is a function of the temperature of the liquid. There is a layer of liquid that cover 2/3s of the earth and averages 5 miles deep it is called the oceans. That is where the vast majority of the CO2 in the world resides. If the earth warms due to solar and cosmic influences the water gets warmer and releases CO2. I wish someone would mention this to Al Gore. What I would really like to mention to Al Gore is the fact that that damn graph he uses showing CO2 levels and temperature is so damn compressed that you can not see the fact that the CO2 levels lag the earths mean temperature. The very data he used to support his beliefs destroys his beliefs if subjected to true scientific analysis. He knows this. He is a liar.
Actually I think the polar caps are melting and will melt. I do not know if this is a slight warming in glacial period or a true end of the last glaciation of which we are still in.
I would hope that we are actually at the end of a glacial period and over the next few thousand years the polar icecaps will melt. During these temperate times in the geologic past life flourished on the earth. During truly glacial times, life was hard, very hard on this earth.
If the sea levels rise many coastal cities will move inland over hundreds of years. The buildings will fall down from age long before the sea claims them and Al Gore will be less than an iota or em in history before one drop of seawater enters Central Park in New York.
Forgive my grandstanding but the best solution is the market place that will deliver the maximum power to the drive train at the cheapest cost. Today that is Diesel, perhaps in the future we can figure out how to convert lefties, hippies (I was one in the 60s but grew up) and eviromentalist to pure diesel or cognac. You can burn the diesel and drink the cognac. :)
I’ll go down to the station and fill up then, woops.
The simple fact is that we cannot produce enough vegetable oil to make any impact on the fuel market. It is very similar to the current ethanol situation.
There is some real potential for biofuel in the future but it relies on currently unrealized, more efficient technology, both in fuel production and vehicle efficiency.
Currently, biodiesel is a good hobby for the self sufficient. However, if you could divert enough vegetable oil to the fuel market to add a couple percent of our fuel needs, you would send the market into a speculation nightmare.
Adding just bit of battery to allow the flexibility of plug-in augmentation seems the way to go.
It doesn't have to be that way. 70% of Earth's sun absorbing surface is unused saltwater. Most people don't know this but all the energy in petroleum originally comes from saltwater algae. With bioengineering it should be possible to create super-algae that can be converted efficiently into bio-diesel and alcohol fuels. It's a bit silly to consider but the oceans are so vast we could breed whales to eat the algae/plankton mix then swim their oily selves to the coasts for conversion to fuel. Most of our transportation fuel use is near the coasts. The good thing about making our own petroleum is it would create a CO2 closed loop system allowing nearly unlimited economic expansion. Saltwater algae or some kind of saltwater plant seems to me to be the most promising direction.
About plug-in hybrids: why not embed electric lines in the road beds of highly traveled freeways and use induction to transfer the power? The hybrids then would not need heavy batteries which would noticeably increase mileage. When the car brakes it could sell the power back to the grid. These cars could be hooked up into virtual trains boosting freeway lane capacity by 10. We'd get all the benefits of commuter trains with the personal freedom of automobiles.
Ice only melts where the temperature shifts just above 32 degrees. If we induced man-made clouds to cool the surface a degree at just this narrow latitude the polar caps cannot melt. These man-made clouds in cold air eventually snow out adding freshwater ice mass to the edge of the polar caps.
Saltwater algae oil is much more promising than ethanol from corn and sugar cane that require consumption of limited farmland, fertilizers, pesticides, and freshwater resources but I haven’t heard of anyone trying to use the open ocean to grow algae yet, they always try high capital cost/high efficiency methods. With the free open ocean high efficiency isn’t an issue since even 1% efficiency would capture huge amounts of energy. It would be hard to harvest but there’s probably a high oil fish that could do that for us.
I may be wrong but I believe when you fill up with “biodiesel”, you are getting between 85% and 95% petroleum.
Shale oil facilities were impressive also.
Once again, biodiesel is good as long as it is small scale enough to not interfere with the food market. Vegitable oil production per acre is not enough to sustain any significant contribution to our fuel needs.
I once thought of doing a spoof of the "Global Warming" so called data that shows how GW has increased ever since the invention of the Internal Combustion Engine. Since the carbonated soft drink industry started at about the same time as the IC engine, and has steadily increased in popularity ever since, you could, truthfully, make up some charts and graphs and all sorts of sales figures for Coke, Pesi and all the others that showed a direct link between Carbonated soft drinks and GW. It would be just as valid and honest as An Inconvenient Truth and just about as scientific........
The original DIESEL engines ran on COAL DUST!.............
I think I’ve read about that being tried but it didn’t work. They considered genetically engineering algae to be grown at sea, but there are some who are legitimately worried about super hardy mutant algae getting loose and taking over and causing us all sorts of problems. There has been a fair amount of experimentation with growing algae as a fuel crop in open ponds, and that didn’t turn out well. It’s too hard to control variables like temperature and competing wild algae and other contaminants in open ponds. Now most experiments are with closed systems growing salt water algae, algae that grows in brackish water, and fresh water varieties. None have produced anywhere close to the theoretical yields and none have come even remotely close to producing algae at a cost that would make it a commercially viable feedstock. This technology is not ready yet. It may work out someday and we may all be driving algae-diesel vehicles, or the idea may just fizzle out.
It depends on the blend. If you get B100 you are getting straight non-petroleum based oil. A lessor number means you are getting a blend of petroleum-based oil and a non-petroleum based oil. B80 is pretty much standard here.
Biodiesel is great fuel, but it’s too expensive to make and it takes way too much land to make a little fuel. Per gallon, biodiesel is a lot more subsidized than ethanol. Blenders get a one dollar tax credit for every gallon of biodiesel that they blend with regular diesel compared to the fifty one cents blenders get for every gallon of ethanol they blend with gasoline. Most all biodiesel sold in this country is made from soybeans, a subsidized crop just like corn. (With current high corn prices very little corn subsidies are being paid by the way.) Biodiesel needs the bigger tax credit because it’s so expensive to make. It’s so expensive to make because it takes a whole lot more land to produce a gallon of biodiesel from soybeans than it does to produce a gallon of ethanol from corn. This makes feedstock prices are really high for biodiesel. You only get something like 50 gallons of soy oil per acre of beans on average, if that, and you don’t get a full 50 gallons of biodiesel from 50 gallons of vegetable oil. No biofuel concoctions we make for our cars are going to do much to reduce our dependence on foreign oil until we can figure out how to make one cheap enough to compete with petroleum based fuels on a cost basis and be able to make enough of that fuel from every acre we devote to it to supply several drivers. Maybe something like biodiesel from algae or cellulosic ethanol will pan out, maybe not.
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