Synthetic Fuels
Posted in Unfounded Speculation
on May 8th, 2011 by
Stephen DeGrace
Topics:
Crystal Ball,
Energy
Human survival at our present population level absolutely requires vast reserves of energy, to produce and transport food for our immense population if for no other reason. Particularly if we want to maintain anything like a comfortable and pleasant lifestyle for significant numbers of people, affordable and plentiful energy is a must. While there is a lunatic fringe in geology which proposes that oil is being continuously generated in the earth by microorganisms and essentially limitless, and others who favour an abiogenic origin of petroleum and much higher reserves available than conventional geology predicts, the safe money is on the hypothesis that fossil fuels are a finite resource, and that further, in the case of conventional oil, we are actually at or near a peak in production. Hence, curiosity about what, if anything, humanity will do when fossil fuels become scarce enough that running our civilization on them is prohibitively expensive leads one to the consideration of synthetic fuels.
Fossil fuels are going to run out if society continues to use them. It is a logical necessity in that they are finite. Before they ever ran out, of course, they would become so prohibitively expensive that they would not effectively be affordable as an energy source for a mass technological civilization, or else the effects of their rising price and changing geographical distribution as they were consumed (or the effects of climate change, but let's leave that aside for a moment) would create political instabilities so great that civilization would tear itself apart (thereby taking the pressure off the remaining fossil fuels - silver lining, anyone?). Even assuming that we can fall back to being a mostly coal-powered culture (I'll return to this point later) and assuming generous estimates of over 200 years of coal reserves at energy consumption levels comparable to the present, 200 years is still small potatoes in the scope of human history. Then what? This again leaves climate change out of it.
Right now, the lion's share of our energy comes from fossil fuels. Significant contributions come from hydroelectricity and nuclear in some countries for electrical generation, and comparatively minor but growing shares from wind, but for a variety of reasons, fossil fuels enjoy a hefty dominance. For one thing, electricity is not a universal energy coinage with our current technology. At our present level of technology it is possible to to run short-haul personal automobiles on electricity, for example, provided you don't mind waiting for them to charge between uses, and this has the benefit of providing cleaner air for cities. But a mass conversion to electricty for personal transport would require installing an epic amount of new generating capacity, as transportation takes approximately 28% of all energy use in the United States.
Fossil fuels and equivalent substances, on the other hand, are highly versatile, capable of being used for electrical generation or to directly power a wide range of devices including heavy trucks, planes, and container ships. For reasons I have stated elsewhere, I am very skeptical about the scope that wind, solar or nuclear fusion will ever be able to play in our energy mix, hydroelectric and geothermal have inherent geographic limits, and that doesn't leave a lot. Plus, these sources of energy all rely on the electric energy coin. I think that our technology can adapt to be nearly exclusively electrically driven if it needs to, but that will be an economically and socially difficult transition.
For reasons of versatility and technical, social and economic ease of transition, I think that society will actually turn to synthetic fuels as conventional oil becomes permanently expensive, as appears to be already the case. The technology already exists - it was used extensively by oil-poor but coal-rich Nazi Germany and Apartheid-era South Africa to convert their abundant coal to a range of useful liquid fuels, from gasoline to diesel to jet fuel. The Fischer-Tropsch process and water gas shift technologies allow practically any carbon-containing feedstock, from natural gas to coal to biomass to be converted into very pure forms of all our conventional fuels. The process is quite expensive and generates a lot of greenhouse gases (if Carbon Sequestration and Storage, or CSS is not employed) relative to refining conventional oil, but if the proponents are to be believed, at present oil prices, synthetic fuel is profitable for many different versions of the process. According to the Mar. 19, 2011 Globe and Mail Report on Business, the energy company Talisman is already looking at building such a plant in western Canada to take advantage of abundant natural gas reserves and present low North American prices.
Tar sands such as the Alberta oil sands can also be mined and processed to produce synthetic crude. In fact, synthetic crude from the oil sands is already achieving real prominence, not to say notoriety. The price of oil needed for synthetic crude from oil sands to be profitable is similar to the price needed for synthetic crude from coal and natural gas via the Fisher-Tropsch process. This is a sure sign that the latter will also rise to prominence, given the ubiquity of coal deposits around the world and the strategic interest countries have in energy independence.
Let's put it this way... if synthetic fuel can be manufactured profitably with conventional oil trading at $100/BBL in today's dollars and ignoring inflation, then it is a virtual guarantee that more and more capacity will be installed to take advantage of abundant coal reserves and apparently abundant shale gas reserves (if you're not too worried about polluting the water table, that is), effectively holding the price of hydrocarbon fuel indefinitely at the profitable price of synthetic hydrocarbons. At that price, economic growth will be limited but civilization can still manage comfortably. Under those circumstances, we could conceivably put a very large fraction of the fossil carbon in the earth into the atmosphere before coal, the last good fossil feedstock for synthetic fuel, finally peaks and itself begins rising in price to a level that creates a final energy crisis.
If the presently accepted theory of global warming due to carbon dioxide were untrue in a way that favoured the deniers, the situation would be bad enough, because 200 years sounds like a long time, but it isn't. Anyone interested in posterity needs to look for longer term sustainability than that. In the much more likely event that climate change is a real thing and is going to get us into very deep trouble, however, technology that allows us to economically put a large percentage of the fossil carbon on earth into the air is an extraordinarily dangerous thing. This technology exists, it is well-established, it is evidently affordable at realistic oil prices, and it will therefore be used.
The greenhouse gas toll from the synthesis of liquid fuel hydrocarbons from gas and coal can be mitigated by employing CSS, but that will invariably make the product more expensive and will only be employed in the event that there is the political will on a global scale to put a price on CO2 emissions, which at the moment does not seem to be the case. Furthermore, while some sources seem to treat the usability of CSS as a foregone conclusion, it's not. Certainly carbon capture is possible, but storage is a different matter. Geological storage is essentially unproven, and oceanic storage is insane. CSS might conceivably pan out and should be worked on, but it's one of those things you don't have to bet the farm on. Furthermore, CSS just mitigates the greenhouse gas problem, it doesn't address the problem that fossil fuels must eventually run out.
The only source of energy that is massive and constant enough to maintain human civilization other than the solar energy captured and stored in fossil fuels is present day solar energy. Schemes to directly generate electricity from solar energy so far have not shown themselves to be up to the scale needed and perhaps may never, and furthermore suffer from the same problem as wind - electricity needs to be generated at the precise moment that it is used, and nothing that can only be used for part of the day and only at full capacity in ideal weather is going to be able to provide base load. However, solar electricity, like wind, could be used to generate hydrogen from seawater by electrolysis, which could be used to feed into the synthesis of hydrocarbons from carbon dioxide taken from the air, or directly used for energy storage, and might have some utility.
The really good long-term solution, however, may be capturing solar energy and turning it into liquid hydrocarbon fuels that work with our present technology without modification through biomass. This might be accomplished by growing oil-rich algae in sea water and then directly refining the oil in basically conventional refineries, or from more generalized biomass, again hopefully grown using seawater so as not to use up agricultural capacity for food or fresh water supplies, which can feed into Fischer-Tropsch style hydrocarbon synthesis in a similar manner to coal. The latter process takes advantage of known technologies and would definitely be refined if used on a large scale. In theory, these technologies could be carbon neutral, as the biomass is made from carbon taken from the air and the process of burning just returns the carbon. The energy needed to raise, harvest and transport the biomass and run the chemical processes would have to take a cut from the output of the process, so the key thing is whether there is a net gain in fuel supplies if the whole cycle has to be self-sustaining. With CSS added in, the cost goes up that much more, but on the other hand, it could actually lead to a net reduction in greenhouse gases.
I would go out on a limb and say that synthetic fuel made from shale gas or coal, and synthetic crude made from tar sands, are probably always going to be more cost-effective than biomass-generated fuels. Biomass should be pursued further to see whether the needed volumes are even feasible and if the price can be brought down, but if I'm right about this, a lot hinges on whether we place a price on carbon. Without some kind of carbon tax or cap and trade system to subsidize non-fossil-fuel energy sources, we are probably not going to turn to these sources of energy until we hit peak coal, many decades hence.
What I think will happen is in the very near future, with conventional oil unmistakably into its gentle decline such that even the most diehard oilmen have to admit that we are past peak oil, society will be firmly embarked down the path of using synthetic fuels from a variety of sources (mainly coal and natural gas) and will be adjusting to the permanent end of the era of cheap energy. We are presently so wasteful, that in an era of moderately expensive energy that we're entering, we'll have some room to adjust. Globalization will begin to reverse as Jeff Rubin predicted under the tariff-like pressure of high transportation costs, we'll be forced to conserve energy more, and economies will shift to being more local in orientation, but we'll survive and probably manage quite well.
The thing that I think will be a gamechanger is that in the not too distant future, the early affects of climate change will become unmistakable, and the earliest things hit will be food production and water supplies in the global south, and some of the countries hit will not be poor and helpless. Furthermore, tightening food and fresh water supplies (which we're already seeing), more expensive transportation making evening out global supplies less affordable, and growing populations to feed in many of the countries which will be the hardest hit will put great pressure on social systems. Granted, in theory, there are many ways to squeeze more food out of the global system by reducing waste, eating less meat, cancelling biofuel projects that sap agricultural production, and improving farming techniques in many poor countries, but some of these things will be politically or logistically extremely problematic, and the required lifestyle changes will not be received well by the societies undergoing them. This will lead to serious social unrest, which is potentially extremely destructive, especially if it leads to military confrontations between advanced countries.
The clear effect of climate change overall will be to halt or reverse economic growth worldwide, which will itself lead to unemployment and more social unrest. However, anemic or non-existent economic growth will take a lot of the pressure off of energy reserves. This could be a good thing or a bad thing, especially if it sabotages the economics of synthetic fuel from biomass.
If we respond to the global warming crisis becoming undeniable by finally putting a meaningful price tag on CO2 emissions (a definite case of too little, too late, but never mind that), I think we'll probably go through a phase of relying heavily on synthetic fuel from biomass, provided we find a good source for a huge amount of biomass that doesn't hit our food or water supplies, as we have a huge infrastructure which can be run conveniently without modification on synthetic fuels. Depending on what other technologies pan out, this may truly prove to be a transitional phase to a very different infrastructure, maybe on the scale as the shift from wind to fossil fuels to power shipping over the water.
I think the problem, though, is that there are a lot of vested interests that will want to keep fossil fuels on top basically forever and which have convinced themselves that this proposition is actually viable, and they have recruited a horde in the general public which is ideologically dug in against any measure to combat global warming. Take Canada - the best case scenario that I've sketched out would suck for us, because countries with a lot of hot, sunny coasts will be the best at growing huge volumes of biomass using brackish water and will be at a clear geographical advantage to process the material. Canada will become a major net energy importer and Alberta and Saskatchewan can kiss the good times goodbye. Look for Canada to play a big spoiler role. I predict we will continue to be climate change bad guys in a big way.
By the time the truth is too obvious for even the most hardened skeptic to deny, it will already be too late to do much about it. While I think the existence of technologies to extract energy on a large scale from biomass potentially guarantees us a serious long-term future as a civilization without requiring any speculative technological advances which may never pan out, I think that population pressures, shortages of food and water in many countries, and the various early effects of climate change (forget about the late effects like massive sea level increases - I figure we would destroy ourselves well before that would be a serious concern to civilization) combine to make that congenial future unlikely, or at least difficult to achieve.
It gives us a potential blueprint to move forward, though:
- Drop the corn ethanol immediately and focus energy now on how we are going to maintain food and water supplies to the whole world. Everyone has to be able to eat and drink or the political fallout will be literally deadly for the whole world, not just those who go without.
- Put an enormous amount of money and resources into various biomass-based schemes to produce hydrocarbons and to operate them entirely on a portion of their own output, so we have the theoretical means to maintain our energy requirements without ramping up greenhouse gases further.
- Put a price on CO2 emissions.
- Find a way to get down the birthrates in countries which still have high fertility. If coersion is not practical, it may be necessary to try to improve their standards of living and push the birth control hard. This is perhaps the most difficult problem at all, but population is at the heart of all of humanity's other problems with food, water and energy, not to mention to destruction of biodiversity. We have no future if our population is not in steep decline by the end of this century - which it will be, one way or another, but let's just hope not the hard way.
- Seriously consider geoengineering solutions like injecting sulfate particles into the stratosphere to reflect sunlight - we don't want to have to go there, but if we have to, it would be nice to have some solutions ready to go.
- Figure out some way to begin to draw the atmospheric carbon dioxide back down.
This is all theoretically doable, but whether we are able to go down this road I seriously have my doubts.
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