The New and Improved CTL Scheme

“In theory, there is no difference between theory and practice. But, in practice, there is.” – Jan L. A. van de Snepscheut

A very short paper (two pages) appeared in the latest Science detailing an improvement on coal-to-liquids (CTL) technology. A couple of people have e-mailed me to ask for my take on it. You can get the executive summary from the quote at the top, or from my version, which is:

“In the world of energy, people sometimes have trouble distinguishing make-believe from reality.” – Me

Wired Magazine weighed in on the (subscription-only) Science report – Producing Transportation Fuels with Less Work – a few days ago:

Bad News: Scientists Make Cheap Gas From Coal

If oil prices rise again, adoption of the new coal-to-liquid technology, reported this week in Science, could undercut adoption of electric vehicles or next-generation biofuels. And that’s bad news for the fight against climate change.

The new process could cut the energy cost of producing the fuel by 20 percent just by rejiggering the intermediate chemical steps, said co-author Ben Glasser of the University of the Witwatersrand in Johannesburg, South Africa. But coal-derived fuel could produce as much as twice as much CO2 as traditional petroleum fuels and at best will emit at least as much of the greenhouse gas.

“The bottom line is that there’s one fatal flaw in their proposed process from a climate protection standpoint,” Pushker Karecha of NASA’s Goddard Institute for Space Studies wrote in an e-mail to “It would allow liquid fuel CO2 emissions to continue increasing indefinitely.”

The Wired story has spread like wildfire. I have seen numerous references to it. It has spawned lots of debate over whether it is desirable to increase our usage of coal. But one important detail seems to have been overlooked: It’s not real.

So what’s the story? Here is a clue, from early in the paper:

We outline reaction chemistry and processing designs that could dramatically reduce these energy inputs and minimize the amount of CO2 emissions that would be emitted or mitigated by other costly strategies, such as carbon capture and sequestration.

This is a ‘process’ only in that it has been drawn up on paper. This isn’t even at the stage of lab scale. This is Step 1: You have an idea. Next comes the step where you try to economically evaluate the implications, and then if they are favorable you start doing some laboratory experiments. This is the stage where probably upwards of 90% of all ideas that were thought to be good fail because the theory overlooked something that turns out to be a problem in the lab.

However, if the lab studies look good, you go on to build a pilot plant to demonstrate the concept at a larger scale. Again, the majority of the ideas that make it past the lab stage get weeded out at this stage. You have situations like CWT building a pilot plant only to find out that they have an odor problem that didn’t seem all that bad in the lab. Or you find out that while the front end of the process works well in the lab, and while the back end works well, when the front is connected to the back there is a problem. Maybe the front end produces a trace impurity that is a real problem for the catalyst in the back end. In the lab, this wasn’t a problem because you were simulating the back end with gases from a cylinder. However, those gases were of a higher purity than what you are producing now in the pilot plant. The list of land mines is endless.

None of this suggests that this is an idea without merit. But an idea is not a process, and so Wired got a little carried away with their description. In fact, the Science paper heavily references Sustainable fuel for the transportation sector (PDF) by Rakesh Agrawal et al. at Purdue. Theirs is another proposed process. It is called the H2CAR ‘process,’ and is another idea in need of some laboratory testing. For a layman’s explanation of H2CAR process, see:

H2CAR could fuel entire U.S. transportation sector

For a more detailed technical (and skeptical) view see:

H2CAR: Another blind alley

In that essay Engineer-Poet (of The Ergoshpere) concludes that this idea is doomed to die once the economics are considered fully.

But the bottom-line here is that it is important to distinguish between what is real and what is make-believe. A process that has survived lab tests or that is successfully being piloted is real. A process that only exists on paper is make-believe, and should be recognized as such. That’s not to say that the make-believe process won’t some day turn into a real process, but the lab has an uncanny ability to kill a lot of seemingly great ideas.

16 thoughts on “The New and Improved CTL Scheme”

  1. RR,
    Perhaps you can comment on the similarities and differences between CTL and BTL. In theory this breakthrough (assuming it survives the various stages of testing) could help BTL. Then the greens would be thanking this guy for saving the planet.

    Seems like these guys at Wits do a lot of high level, theoretical Chem Eng. A few years ago, I read one of their researchers had figured out a way to optimize chemical conversions. Sounded impressive, even though I couldn’t quite figure it out…

  2. Can H2CAR or a similar scheme work if the carbon source is coal and the H2 (and O2) source is nuclear?

    Too often, these ideas are dressed up with wind and solar derived H2, and biomass soure carbon, to satisfy those who follow the religion of environmentalism. Those who will crucify any idea involving coal and nuclear.

    If you had side by side, a large nuclear powered hydrogen plant, feeding H2 and O2 into a coal to liquid plant, what would be the downside? How much capacity could you gain by adding the Hydrogen source? Could you turn nearly all of the Carbon into a liquid hydrocarbon fuel?

  3. In practice, practical is where engineers are able to get the tasks done. This is followed by a process of continuous improvement.

  4. Nice find, Anon!

    RR, I do believe you stand corrected. If the Mining Weekly article is right, the pilot plant (14m tall is a hell of a pilot plant) has been in operation for about a year.

  5. Dear Mr. Rapier

    Glad to see your recent appearance on Bill Moore”s EV World Blog.


  6. Does the paper describe what they used in this Chinese plant, or is it something different?

    Wow, that really confuses matters. If it is an operating plant, I have to believe it is different, because what they describe in the Science article is purely theoretical. There is no discussion of piloting or results. However, most of the authors of the Science article are mentioned in that story.

    This may explain it:

    China’s Yitai starts making oil products from coal

    It says that China suspended all but a pair of CTL plants last year. So it could be that the work is theoretical, they went straight from theoretical to pilot plant, and they have still not started up the plant. I have searched, and I can’t find any reference to actual results. But as Optimist said, “Nice find.”


  7. Perhaps you can comment on the similarities and differences between CTL and BTL.

    The major difference in all of these is that C or B or G is merely the feedstock that is gasified. Whether coal, biomass, or natural gas they all are gasified to synthesis gas. At that stage, they can be converted into a variety of different liquids, but typically diesel via the Fischer-Tropsch process is the ‘L’.


  8. Can H2CAR or a similar scheme work if the carbon source is coal and the H2 (and O2) source is nuclear?

    Not coal directly, because it is hydrogen deficient. But I have seen schemes floated for using excess nuclear power to electrolyze water to produce hydrogen. Not efficient from a thermodynamic point of view, but if you have excess power it would be a way to put it to use.


  9. Glad to see your recent appearance on Bill Moore”s EV World Blog.

    Thanks for the heads up, John. I didn’t actually know about it (although I give permission to anyone to grab any articles they wish – as long as they are attributed). I had to Google to find it.


  10. I tried to post yesterday but was having browser problems.

    Using hydrolsis makes little thermodynamic sense. I can break hydrogen and oxygen bonds using heat at better than 80% efficiency or I could take the same thermal energy, run it through a power plant at 50% efficiency (at best) to do the same thing.

    So which is better, using natural gas to heat your hot water or turning the natural gas into electricity and then using the eleccricity to heat the water.

    Using wind or solar to make hydrogen and oxygen might make you feel better about CTL or BTL but that is about all.

  11. King,

    How do you split water using heat and get better than 80% efficiency? What is your opinion on using nuclear (high temp thermal hydrogen production)and CTL to make liquid fuel. Could you increase volume and decrease CO2 footprint enough to make it pay. Assuming that reducing CO2 footprint is worth something.

  12. There are many 200 thermochemical cycles which can be used for water splitting but I am not aware of any that are close to 80%.

    Using a HTGC reactors to make H2 & electricity is in the R&D phase. It will not be until 2030 at the earliest that the practicality is known.

    What needs to be done is to fill all available land in Texas with wind turbines to supply hydrogen to Texas refineries. Since the Texas refineries could then claim to renewable energy, California could be charged more money.

  13. So you can take nuclear heat and turn it into electricity, then store that energy in a battery and then use that enegy to run an electric car.

    Or you could use nuclear heat and turn it into Hydrogen and Oxygen and feed those gasses into a liquid fuel production process, which stores the energy in chemical bonds of the fuel, then put that fuel in your tank and run your car.

    What’s the difference?

  14. Not much difference at this point. Dennis wait 50 years and see what happens.


  15. You mention that few theories prove out in pilot plants.

    Additionally, few pilot plants (maybe a few percent) ever justify the first small scale commercial plant.

    After that a few percent of the first small scale commercial plants justify a larger commercial plant.

    After that there are still many failures due to unexpected problems with the technology.

    In other words, a theory is worth the paper it is written on. A pilot plant has a small amount of additional value. The first commercial plant is still a risky investment.

    GTL is one of the technologies with a few successes and a whole lot of failures.

    But we keep on trying and successes do come.

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