First off - Many commendations to Gov. Schweitzer for his efforts to do something for Montana's residents, and also the U.S., with regards to the current energy debacle.
But the "sin-fuels" (liquid fuels from coal) ideas that he is talking about need a tweeking or two. And maybe a touch of science to put some common sense in it. And remember, burying CO2 is going to be an expensive process, so "sinfuels --> sun fuels" will NOT be cheap. Which is good, because large scale uses of coal derived fuels would not be good for the world. Why ? Right now, in one word - WILMA. Shout it like Fred Flintstone would.
More below.
I think he gets it mostly right. I like his idea to tap the huge wind resource of Montana - probably equal to at least one fifth of the current total U.S. delivered electricity supply, and maybe more, if 80 meter towers and big units are used (= modern wind turbines). And liquid fuels made from crops makes lots of sense - home grown, with little net CO2 pollution. Especially if the ammonia used to grow these crops is naturally made or made from wind turbine derived hydrogen. After all, hydrogen is only as clean as the source of energy used to make this hydrogen.
Here is a discussion on how you can power a Harley (or any other internal combustion engine needing liquid fuels) from a wind turbine. There are a few different routes here. And this is using KNOWN techniques/technologies. And no need for fuel cells, with the resulting skyrocketing in the price of platinum, which is already pricey enough.
In case you want a quick answer, syn-gas is basicly a mixture of carbon monoxide (CO) and hydrogen (H2), often with methane and carbon dioxide in there. You do not need coal to make this mix - just H2 and CO2 will do. And if you have wind turbines making electricity, you have H2 - vais electrolysis of water. You do not need a lot of water to make lots of H2 - just lots of electricity. You need about 45 MW to make 1 ton of H2 per hour, using the most efficient units (Norsk-Hydro 5000 amp modules) on the market, which are 85 % efficent, although other models are close to this level, with differing features. And this all gets down to price. It is true that you can also make syn -gas from coal and water (= "sin-gas") which is reasonably cheap (about equal to crude oil at $40 to $50/bbl), as long as the coal is cheap, and you do not have to dispose of the CO2 produced from either the sin-gas production plant, or from the fuels made from the coal-derived fuels.
But I guess having some fuel is better than none. The wind-only syn-gas approaches are actually VERY similar to the coal based sin-gas preparation, especially when ALL costs (such as global warming effects) are included. One other thing to consider - the wind appraoch makes more jobs/dollar invested, and thus more jobs/gallon of fuel produced.
So here is the long version:
Powering a Harley with the Wind
Introduction
The Harley-Davidson motorcycle (HD) has become associated with many things in the last century, but one of these is the sense of "riding with the wind". These road machines can get over 60 mpg, and the rider feels the elements much more directly than is the case for an automobile. Needless to say, HD's require a liquid, high octane fuel - they don't run on electricity, yet, and a quiet electric ride would be a very different experience that is the current situation, even for an "Electra-Glide" model.
Unfortunately, as of 2005, much of the fuel for our country's car and motorcycle transportation needs is currently derived from imported crude oil and/or refined products. In some instances, the source for these hydrocarbons are foul, corrupt and decidedly nasty governments, which often resemble criminal extortion organizations - some examples are the current regimes controlling the countries of Sudan, Spanish Guinea, Nigeria, Iraq, and Columbia. Choosing between support of such governments (and the likes of "Osamma Bin Forgotten") or no transportation is obviously not a desirable state of being. And it is quite possible for this country to produce our own transportation fuels/energy, provided there is a will to do so, and at costs similar to slightly above to what is currently being charged for gasoline ($3/gallon). After all, the most important part of the transportation equation is $/passenger-mile, not necessarily $/gallon. Switching from a SUV getting 10 to 15 mpg for a single person using gasoline at $3/gallon to a HD getting 60 mpg would be cost equivalent at $12/gallon for the HD. While fuels priced at the equivalent of $12/gallon of gasoline ($9.60/gallon of ethanol) may be a scary concept, a phenomena known as Peak Oil (and related Peak Natural Gas) may force such a situation upon us in the very near future.
Discussion
One energy source with which the United States possesses in great abundance is wind. The estimated amount of electricity which could be produced by modern wind turbines from winds averaging more than 6.9 m/s at 80 meters above the land surface is estimated to be more than 1800 gigawatts (GW), or four times our current electrical consumption (which averages about 450 GW). When offshore wind resources and lower speed wind resources (such as 6 m/s) are considered, the usable wind energy potential is significantly higher than the factor of four estimated for the fast wind sites only. The 6.9 m/s cutoff was chosen to keep generating cost low (such as near 5 cents/kw-hr), but when late 2005 electricity prices are considered, the "cut-off speed" seems far too conservative. Due to the rapid rise in natural gas prices following Hurricanes Katrina and Rita, electricity prices for the manufactured component of electricity (not counting distribution and other prices, fees and taxes) is now nearly 10 cents/kw-hr in Western New York (September, 2005), which is one of the least expensive zones for electricity pricing in the state.
So our country has plenty of wind resource. We also have plenty of land area, coastline and shallow water within our territorial limits. This will allow the varying nature of wind at any given location to be buffered into a fairly constant supply (a 400 x 400 mile area is required to achieve such a situation, or about the size of New York and the remainder of New England). Thus, the potential replacement of all polluting and/or environmentally destructive electrical generation sources (specifically coal, oil, natural gas, nuclear, some hydroelectric) with wind turbines is quite possible, and at prices/costs similar to what is currently being charged for electricity. But this does not put fuel in the gas tank. However, there are some ways to redirect/convert wind energy into liquid fuel energy in a manner compatible with the present ways that we use to move people and things - such as cars and HD's.
Liquid fuels are best defined as stored chemical energy, which can be readily liberated and utilized by combustion (alias oxidation reactions), using the oxygen present in air. If the fuel is made using renewable energy, combustion of this fuel will not dump additional net quantities of carbon dioxide into our atmosphere. This will avoid stressing the climate control system and the entire biosphere of our planet via the process best described as "global warming", where the increased concentration of CO2 in the air leads to lower emission rates of heat energy from earth out into space. If the fuels are derived from the remains of earlier activity (fossil fuels), global warming potential is worsened by combustion of such fuels. Burning fossil fuels dumps the sequestered carbon from thousands of years of prior times in one year at our current consumption rate, which is obviously not a sustainable activity of the long term. The only way our planet can eventually maintain a stable carbon dioxide level in the atmosphere given the huge fossil fuel consumption level is by absorbing CO2 into the ocean, and "burying" it in deep ocean waters or on the seabed. However, the consumption rate of the oceans is limited by a number of factors, so stable atmospheric CO2 levels are only going to be achieved by lower net CO2 emission rates into the air, when viewed from the "short-term" perspective of the 21st century.
Fuels from Wind Turbines
Obviously, electric cars, busses, trains and other vehicles are one way of directly using wind turbines as energy sources for transportation. However, most existing personal transportation, as well as all trucks, trains and ships, use liquid fuels to power internal combustion engines, turbines or boilers. These fuels are a compact way to (usually) safely store a lot of energy, and the infrastructure of preparing and distributing these fuels is already in place. Existing cars, trucks, trains and ships represent trillions of dollars of investment, and are generally a fairly universal way of moving people and/or goods between various locations. If a new mode of engine (for example, hydrogen powered fuel cells) were adopted, all of these vehicles would need to be replaced - in effect, trashed and recycled. If H2 fuel cells were the selected choice, the replacement vehicles would be more expensive than the replacements, and the fuel cost in terms of $/mile traveled will also be considerably higher. However, this is not an immediate option, since such fuel cells are still in the developmental stage, and may never be as cost effective as battery cars and trucks, for a variety of reasons.
Some existing, readily employable liquid fuels, which can be made from electricity, include ethanol, methanol, gasoline and diesel, by various indirect means that usually start with hydrogen. The hydrogen is prepared (along with co-product oxygen) by alkaline electrolysis of water, at efficiencies of up to 85%. This H2 represents stored energy, which can be used to directly or indirectly make fuels. At present, almost all H2 used in the U.S. is prepared by partial oxidation of methane (natural gas) or hydrocarbons (for example, cracking ethane to ethylene and hydrogen, or partial oxidation of residual oils). The replacement of hydrocarbon derived H2 with wind derived H2 represents a net replacement of oil and gas, with many associated national security, economic security and environmental benefits.
The best indirect way of using wind turbines to replace gasoline and diesel oil is by replacing the methane used to make the H2 that is used to manufacture ammonia (NH3, made by the reaction of nitrogen and hydrogen). Ammonia is either used as is or derivatized (to ammonium sulfate, ammonium phosphates, ammonium nitrate, urea) and used as a fertilizer (plant food). The ammonia and derivatives drastically stimulate plant growth rates, and are required by plants to produce proteins (which are made from amino acids). In general, plants do not care whether their nitrogen is supplied by compost, bacteria nodules or via manufactured chemicals, they just need soluble nitrogen, in addition to other factors. Obviously, over application of fertilizers is a problem as well as a waste of resources, as is underutilization of "natural" nitrogen sources. However, fertilizer can boost corn yields from the "natural", unfertilized level of about 25 bushels/acre to over 250 bushes/acre, and in addition to allowing the plants to produce higher amounts of proteins, significant amounts of carbohydrates (sugars, starches, celluloses) and oils/fats are made.
The oils and fats from various crops can be extracted to make "bio-diesel" fuels. If fatty acids are also made, these also can be esterified, using methanol or ethanol, into liquid fuels that are also great bio-diesel fuels. The "carbs" - sugars, starches and cellulose - can then be converted into a variety of products, the most famous of which is ethanol, via fermentation. The remainder is a product enriched in minerals and proteins, which can be used in food products (for example, brewers yeast) or for animal feed. As a last resort, it can be used as a fertilizer (a source of fixed nitrogen, after all) - recycling some of the nitrogen used to originally grow the crop. However, there is a limit to this recycling, since some soil bacteria use these nitrogen compounds as an energy source (de-nitrifiers), returning nitrogen molecules to the atmosphere. In modern fermentation plants, even the by-product carbon dioxide is captured and sold. In some cases, the cellulose portions of the crop is burned to power the facility.
Another way to produce fuels from crops/plants/trees is via pyrolysis approaches - this was once a source of "wood alcohol" (methanol), after all. More modern approaches involve heating the "carbs" into a mixture of carbon monoxide, carbon dioxide, methane and hydrogen, known as synthesis gas (or syn-gas). This works especially well for cellulose rich feeds, such as corn stover, straw or wood chips. The syn-gas can then be readily converted into methanol, ethanol, gasoline or diesel, depending upon the reaction conditions and catalysts used. If methanol is obtained, this can be readily converted into gasoline using the Mobil Oil "MTG" process (methanol to gasoline). If diesel oils are made, this would be an example of the Sasol Fischer-Tropsch (FT) process, which is still employed in South Africa, but without the need for coal to make the syn-gas. A recently developed approach (still at the lab scale) involves direct hydrogenation of cellulosics to make a gasoline-like hydrocarbon mixture, with water as a by-product. Despite the wide variety of approaches, all rely on grown crops, which will require some source of fixed nitrogen to be grown in high yields.
A "hybrid" approach is also possible to extend existing oil supplies, and/or prepare liquid fuels from coal, and this again involves H2 production from wind turbine derived electricity. However, these are both "lesser of the evils" approaches, which still involve the net production of CO2 from fossil fuels, via the end use as fuels. In one route, all H2 used in an oil refinery would be supplied by wind energy - about 3.5 million tons/yr of H2 is annually used in the U.S. to remove sulfur from crude oil, as well as prepare usable materials (such as gasoline) from high molecular weight (and lower valued) cuts of oil. All oil refinery H2 is made from the crude oil or related natural gas feedstock, thus "wasting" some of the feed, and dumping more greenhouse gas pollution into an atmosphere already overburdened with CO2. With coal, liquid fuels can be made by directly hydrogenating coal, once the sulfur is removed (also by reaction with H2). Coal is actually a complicated mixture of molecules (many are aromatic polymers), with an empirical formula of "CH", while usable hydrocarbons have formulae of CH4 (methane), CH3 (ethane), towards CH2 (diesel, gasoline). In most coal to liquid fuels processes (and the Sasol process in South Africa), the H2 for the process is made by steam reforming coal, which requires energy provided by the burning of some of the coal. And burning coal produces even more greenhouse gas, in addition to the greenhouse gas emissions made by burning the FT fuel products.
The final way to use the H2 made by wind turbine powered water electrolysis involves the direct reaction of carbon dioxide with H2, to make either methanol, ethanol, or materials such as gasoline and diesel oils via the FT route. To use the FT route, carbon monoxide (CO) is made via the initial reaction of CO2 and H2:
CO2 + H2 → CO + H2O
Once these two products are separated (easy to do) from this exothermic (self-powering and then some) reaction, the CO and additional H2 can be mixed to the desired ratio and this syn-gas can then be used to make further FT products, ranging from gasoline, kerosene, diesel to fuel oils.
Another route is to directly react CO2 and H2 to make methanol (well known chemistry) or ethanol. In the latter approach, a special catalyst (Ru10Se on TiO2) produces a mixture of largely ethanol and CO (the CO can be further hydrogenated to methanol or methane). The overall efficiency of the ethanol route would be nearly 68% based upon the energy needed to make the H2 from water, with process energy readily supplied by the reaction processes.
While the last number may sound depressing (all this wind used to ONLY get 68% back to feed an internal combustion engine), it is actually very good compared to the alternative fuels. Many of the other approaches offer similar efficiencies. After all, there is no free lunch in thermodynamics - and any time one form of energy is converted into another, a price gets paid (the "No Perpetual Engine" concept).
In Conclusion
And remember the fuel cell approach mentioned earlier? Fuel cells, at present, are lucky to get a steady 60% efficiency from H2, and if this process is back-tracked to the electricity, the overall efficiency drops to 46% (85% electrolysis efficiency and a 10% loss due to H2 compression and storage, which may be optimistic).
Besides, the fuel cell engine only lasts for 2000 hours before it needs to be replaced, they are expensive (they still need a touch of platinum to operate efficiently), and we still don't know if they will survive a decent Lake Superior (or more intensive) grade of winter weather. And then there is the problem of the un-reacted H2 from a fuel cell engine causing grief in the stratosphere, making ice crystals in regions where that is not a good idea. Needless to say, H2 fuel cells as car engines are still in the "not ready for prime time" realm.
And they will not do any good to the Harley, where this story started off...... So if you want to take the Harley for a drive, it needs high octane fuel for food, for starts.
Anyway, happy cruising, if you must, whether it's in a Harley or merely a Ford Escort that gets by on 40 mpg, or a car of the future that takes that mileage a step further. Maybe in our near future, these will be powered by the winds - after all, it beats going to war and stealing somebody else's hydrocarbons.....
If you want more details, zap me a line at dbradley@LakeEffectEnergy.com
Dave Bradley
Buffalo Wind Action Group
October, 2005