First Question: Ask About the Energy Balance
Over the coming months and years, you are going to see a ton of stories like this for somehow storing or reprocessing CO2:
If two scientists at Los Alamos National Laboratory are correct,
people will still be driving gasoline-powered cars 50 years from now,
churning out heat-trapping carbon dioxide into the atmosphere "” and yet
that carbon dioxide will not contribute to global warming.The scientists, F. Jeffrey Martin and William L. Kubic Jr., are
proposing a concept, which they have patriotically named Green Freedom,
for removing carbon dioxide from the air and turning it back into
gasoline.The idea is simple. Air would be blown over a liquid solution of
potassium carbonate, which would absorb the carbon dioxide. The carbon
dioxide would then be extracted and subjected to chemical reactions
that would turn it into fuel: methanol, gasoline or jet fuel.This process could transform carbon dioxide from an unwanted,
climate-changing pollutant into a vast resource for renewable fuels.
The closed cycle "” equal amounts of carbon dioxide emitted and removed
"” would mean that cars, trucks and airplanes using the synthetic fuels
would no longer be contributing to global warming.Although they have not yet built a synthetic fuel factory, or even a
small prototype, the scientists say it is all based on existing
technology.
You are going to see a ton of stories like this from academia because academics respond to incentives like everyone else -- faced with billions of dollars available for funding research into carbon-neutral technologies, they are going to publicly promote their ideas in an attempt to garner this funding.
The first question you should always ask is about the energy balance. I am sure that this is technically possible. Today we can create hydrogen fuel from sea water, but it is atrociously expensive from an energy standpoint. The problem, then, is whether it makes any sense from a cost and energy balance point of view. This is a good hint that it does not:
Even with those improvements, providing the energy to produce gasoline
on a commercial scale "” say, 750,000 gallons a day "” would require a
dedicated power plant, preferably a nuclear one, the scientists say.
We have to be suspicious that the carbon benefits come from the nuclear plant they require, not the process itself. In fact, one is left to wonder why we would go through so much effort at all rather than just charge electric cars directly from the nuclear plant. My sense is we are much closer on battery technology than on this stuff.
Kevin Dick:
A buddy of mine made an interesting observation on this. You have to distinguish between technologies that are energy _sources_ and ones that are energy _transports_. It's common to confuse them because petroleum is currently both.
All this technology is doing is using petroleum as a transport. Once this is clear, it becomes obvious to ask how it will compare to alternative transports like batteries in terms of its efficiency, density, etc.
As you note, the real challenge for the carbon neutral folks is coming up with a scalable carbon neutral energy _source_ other than fission.
February 20, 2008, 3:35 pmFrederick Davies:
Kevin is right: oil is not the World's fuel of choice because of its great heating value, but because it comes "pre-made" from the ground; only when competing with other fossil fuels does the high heating value of oil matter. Hydrogen has a heating value almost three times greater than gasoline, but there are no free sources of it, so much help Hydrogen cars are going to be.
Just a few numbers for the next Climate alarmist you come across:
Energy density of a nanowire battery: 7 MJ/kg
Energy density of ethanol: 30 MJ/kg
Energy density of gasoline: 47 MJ/kg
Energy density of U235 fuel: 80 _million_ MJ/kg
Energy density of H (fusion): 600 _million_ MJ/kg
If that does not show them where the future lies, they are a lost case.
February 20, 2008, 4:15 pmJason Rennie:
On the upside the scientists seem to understand that they are making the petrol into a energy transport.
Plus I suspect a plus of a scheme like this ultimately is that it works with the "installed user base".
Even if electric is more efficient on some level, this would work nicely as a stop gap measure if they can make it work.
February 20, 2008, 5:41 pmAl Fin:
They claim that when gasoline prices reach $4.60 a gallon, the process will pay for itself. I suspect they really mean $14.60 a gallon, after paying for the nuclear plant.
The whole idea is wrong-headed. They are chasing CO2 reprocessing when they should be looking for economical energy sources that are relatively neutral, CO2 wise. CO2 reprocessing, recycling, sequestering, burying, etc. are all a waste of time and money unless they can pay for themselves.
CO2 in oil wells, for example, to raise pumping pressure. Or biomass to energy, using 2nd and 3rd generation technologies.
February 20, 2008, 6:26 pmDavid B:
To be a bit of a contrarian, I've got to say that I'm in favor of this line of research: power sources and power transports other than fossil fuels are worth investigating, because I'm certain that there's something we treat as gospel which will be shown to be incorrect in 20 years. I'd rather not cut off any of the lines of inquiry...
February 20, 2008, 10:39 pmFrederick Davies:
David B,
Not if the opportunity cost of this research is higher than other more useful research; there is no money for researching all available lines of enquiry, so they should spend their money in things that are likely to give a useful result.
February 21, 2008, 1:11 amDaniel:
To my mind, the question isn't the energy balance but the cost balance of the different forms of energy. It wouldn't necessarily be a problem to put more energy into the process than you get out if you get energy out of the processes in a more usable form. But the real question is--at what cost? As noted above, that cost is really high.
February 21, 2008, 8:15 amDaniel:
To my mind, the question isn't the energy balance but the cost balance of the different forms of energy. It wouldn't necessarily be a problem to put more energy into the process than you get out if you get energy out of the processes in a more usable form. But the real question is--at what cost? As noted above, that cost is really high.
February 21, 2008, 8:15 amJoeH:
Lest you believe the 750,000 gallons of gasoline a day is significant, consider that it would only replace between 38-40,000 barrels per day of crude oil and U.S. refineries are currently processing on the order of 15,000,000 barrels of crude a day. My first question is how many watts per barrel so we can estimate the size of the nuc's that provide the power.
February 21, 2008, 12:21 pm