Technical Feasibility is the Easy Part

A couple of people have now written to ask for comments on the story from Green Car Congress about the Polish CO2 to methanol scheme. Here is the story:

Report: Polish Power Plant and University to Cooperate on CO2 to Methanol Trial

Here is the bit I immediately focused on:

Nazimek says his “artificial photosynthesis” process is based on the photocatalytic conversion of water and carbon dioxide under deep ultraviolet light. Synthesis of 1 kmole (32 kg) of CH3OH from CO2 and H2O requires 586MJ of energy, according to Nazimek’s calculations. (Methanol has a HHV of 22.7 MJ/kg, or 726 MJ/kmole).

So the implication there is that you are getting more energy in the form of methanol than you put into the system (input of 586 MJ for an output of 726 MJ), for a positive net energy. However, like the Steorn system, this interpretation would unfortunately violate the laws of thermodynamics. Perhaps something has been lost in the translation. Otherwise, either all of the energy into the system is not being measured, measurements are being done inconsistently, or there is some other error.

Here is one problem. Methanol’s high heating value (HHV) is quoted above. However, when considering energy that you can practically get out of a system one should not use HHV. Why? Because that presumes that you have condensed the water from the combustion products and taken everything back down to room temperature (25 C). That doesn’t happen in practice. Just feel the exhaust coming out of your auto.

So the comparison of energy input into the system to HHV for the output can be misleading. If you consistently use HHV for input and outputs, then you should get a consistent answer for the net energy, but if you mix lower and higher heating values you could easily conclude that you are creating energy when in fact you are simply subtracting apples from oranges.

Having said that, I think artificial photosynthesis has great potential for energy production. I have often speculated on this. Natural photosynthetic efficiency is very low, but it does result in captured solar energy in plants all over the world. Plants do take CO2 in and convert to biomass. The trick is that they do take in more BTUs in the form of solar energy (and maybe also energy in the form of fertilizer) than are found in the the biomass they produce.

So I am in no way trying to diminish the work. This sort of work needs to be done. I just want to inject a dash of reality into the energy balances. It’s like I tell people all the time – you can in fact run a car off of water. You can turn combustion products like CO2 and water back into fuels of all sorts. The catch in both of these cases is that you must always input more energy into the system than you can get back. That’s how the laws of nature unfortunately work.

So while technical feasibility can often be easily demonstrated, there are many more hurdles that must be jumped before you would operate a scheme like this in practice. For instance, what is the source of energy? If you are using sunlight, then it may be perfectly acceptable to input 100 BTUs of sunlight and get back 10 BTUs of liquid fuel. But it wouldn’t be a good idea to input similar quality fuels and get back fewer BTUs.

A second consideration is energy required to purify the final product. The story above indicates that the product is in water at a 15% concentration. This is quite similar to the concentrations of ethanol that corn ethanol producers make and then have to purify. The water has to be removed, and it takes energy to do that. So even if I had a perfect conversion of 1 BTU of energy input to 1 BTU of energy out, the net energy will fall as I input energy to purify the final product. (A 3rd major consideration is the capital costs, which keeps many fine ideas in the lab).

So in conclusion, technical feasibility of so many of these schemes is not in question. (Of course as was the case with Steorn or (possibly) with Cello, sometimes technical feasibility itself is the problem). But beyond technical feasibility are all sorts of considerations that can render a seemingly wondrous invention into something that never escapes the lab. If you hone in on the mass and energy balances of the system (a chemical engineer’s bread and butter), you can often see why a promising experiment in the lab won’t work in practice.

40 thoughts on “Technical Feasibility is the Easy Part”

  1. I worked with the Midrex process (iron ore direct reduction) for many years. Midrex & HYL of Monterey, Mexico were the only two viable processes for many years.

    US Steel, Davy McKee/Exxon, Purofer, Krup, Allis Chalmers, Lurgri and many others had processes which were technically feasible but failed at the first commercial plant stage. Billions of dollars down the toilet in the 70's & 80's.

    There is one hell of a difference between feasibility in the lab, feasibility at the pilot plant stage and the feasibility of a commercial plant.

  2. "You can turn combustion products like CO2 and water back into fuels of all sorts. The catch in both of these cases is that you must always input more energy into the system than you can get back. That's how the laws of nature unfortunately work."

    Natural laws that Big Ethanol and Corn Belt politicians too often either ignore, or are ignorant of.

  3. Wise words again from RR. There is world of difference between technical feasibility (which makes sense often in military applications) and commercial viability.
    Unfortunately, I think the words "commercial viability" may spell the death knell for many types of biofuels. The change in natural gas markets, thanks to shale gas, is a new daunting obstacle.
    Motor vehicles can run on natural gas, or they can be PHEVs. Thus, biofuels not only have to be as cheap as crude oil, they must also make sense in light of CNG vehicles, and even PHEVs. (I suppose one must add CTL and GTL processes).
    I admire those people with the smarts to honestly investigate biofuels. I suspect palm oil, and perhaps pongamia pinnata will emerge as commercially viable supplies of liquid fuel. (Obviously, palm oil already has).
    I wonder about any other source of liquid biofuels. There just doesn't seem to be enough "oomph" or calories in biomass, and then you have the problems of collecting and then converting the biomass.
    I suppose there are locales where biomass is collected incidentally, such as dumps. Thus collected, it may make sense to place a biofuel plant at a dump.
    The good news is that we are centuries away from the need for biofuels. We have plentiful supplies of NG, and can generate electricity at will (see Kinu's commentary on nuke plants).

  4. RR nails it again.

    BTW, you should add that HHV/LHV is part of what kills hydrogen-from-water schemes: you start with a fuel and liquid water, which you proceed to convert into hydrogen [angelic music, please]. Not a very efficient process, but technically feasible. Then after use, the combustion product from the hydrogen is water vapor. So, for all those "look, I drink the tailpipe emissions!" stunts, you have paid the penalty of converting liquid water into water vapor.

    Much more efficient, and greener, to supply the original fuel directly to the consumer.

  5. "Much more efficient, and greener, to supply the original fuel directly to the consumer."

    Exactly what the ethanol crowd has never learned with respect to all the diesel fuel and natural gas they consume.

  6. Another stumbling block in a lot of biofuel schemes is insolation, which places an upper bound on the energy production with a given size of solar collector.

    Given an energy production rate, and the efficiency of the conversion process, you can then work out the size of the collection area needed. Run the numbers sometime, and you'll understand why solar power is such a small part of our energy generation.

  7. "Alomg the same vein but perhaps more practical?"

    From that link:

    "Comparatively speaking, little research has been performed applying CO2 as the carbon source in synthetic fuel production…"

    The reason is the same reasoning I applied in this essay. For instance, to turn carbon dioxide into gasoline necessarily takes more energy than you get from combusting the gasoline. It would be like eating food that contains fewer calories than it takes to digest it. You could eat until you are stuffed, but you would eventually starve to death if you stuck with that diet.


  8. "For instance, to turn carbon dioxide into gasoline necessarily takes more energy than you get from combusting the gasoline."

    That's exactly the situation with ethanol from corn, and hydrogen from water.

  9. "That's exactly the situation with ethanol from corn"

    Are you forgetting that the energy to grow the corn came from the sun?

    Yes it does take fossil fuels to make ethanol, but it is energy positive. This study puts the energy ratio at 1.24, and up to 1.7 if you factor in the distillers grains:

    With anaerobic digestion of the thin stillage of an ethanol plant, natural gas use can be nearly eliminated…and effluent from digesters can be land applied to lower synthetic fertilizer usage.

    With these energy inputs eliminated or reduced, the net energy balance or corn ethanol can be over 3.0.

    p.s. I'm a chemical engineer that has spent the last 2 and a half years on site at ethanol plants running anerobic digesters (pilot plant-10,000 gallons) processing thin stillage.

    We are trying to keep corn ethanol alive until the day when everyone realizes that cellulosic ethanol is a mirage…will never happen (economically that is).

  10. Nick, I recognize that what you are doing is the future. However, since nat gas IS, albeit temporarily, the present, have you ever looked into how far a car can travel on 10,000 btus of nat gas vs 10,000 btus of ethanol?

  11. "Are you forgetting that the energy to grow the corn came from the sun?"

    No, I'm not forgetting that, and I know the best estimate for the EROEI of corn starch ethanol is now about 1.2 to 1, so I shouldn't have said that's "exactly the situation with corn ethanol." I should have instead said, "Pert' Near" instead of exactly.

    If you think* solar energy is the only energy input into corn ethanol, lay some seed corn on your driveway in the Sun and let's see what happens. I don't think you'll get much w/o lots of water (pumped by diesel or electric pumps if your in Nebraska, Kansas, or South Dakota); lots of synthetic fertilizers, herbicides, insecticides, and fungicides all made from fossil fuel feedstock; and diesel oil for cultivation, harvesting, and transportation.

    For all that solar energy that beats down on a corn field, getting only a 20% return over unity is not very good. Making corn ethanol is a lousy way to convert solar energy and fossil fuels into a liquid transportation fuel.

    We are trying to keep corn ethanol alive…

    Yes, through the use of subsidies, tax credits, mandates, and protective tariffs. (Remember, one person's subsidy is nothing but another person's tax.)

    * Actually, I know you don't think that since your a CE.

  12. I'm, particularly, interested in the fact that Scania is producing ethanol-powered engines that achieve 43% efficiency on E95.

  13. Wendell, don't you realize that 96% of corn ethanol is made with Non-Irrigated Corn?

    BTW, it takes about 5 gallons of diesel fuel to grow enough corn for 700 gallons of ethanol.

    And, I suppose you ignored the part about the effluent being a very good organic fertilizer.

  14. Also, as far as I've heard, we have no plans to move the 5th fleet (stationed in Dubai,) and 150,000 ground troops (and, their attendant fossil fuel usage) to Iowa.

    That should drive a lot of "John Deeres."

  15. Blogger rufus said…

    Also, as far as I've heard, we have no plans to move the 5th fleet (stationed in Dubai,) and 150,000 ground troops (and, their attendant fossil fuel usage) to Iowa.

    That should drive a lot of "John Deeres."


    You are right. When you consider all the true costs of gasoline, the bio-fuels look like a bargain.

    The true cost of a gallon of gasoline has been estimated at between $8 to $15 dollars in cradle to grave studies.

    Check out the recent Boeing Newsletter. They flew one of their jets using bio-kerosene and were impressed with the results and encouraged the Government to approve the fuel.


  16. RR,
    Thanks again for the detailed analysis. None of these problems are trivial. Damn Thermodynamics Laws.

    Perhaps we should be spending more time,dollars and energy looking at increasing efficency on the demand and generation side.

    Engineers that would find ways to make existing coal plant 1% more efficent and our political and economic will to make it happen most likely would save a hell of alot of money and CO2.

    Interesting to see the gov putting in some money for CHP research. This is one of the few energy areas that the free market has driven as business like to save expenses.

    Thanks Jim Takchess

  17. "BTW, it takes about 5 gallons of diesel fuel to grow enough corn for 700 gallons of ethanol."


    How can that possibly be when a big John Deere tractor uses about 25 gallons of diesel fuel per hour?

  18. Mr Rufus continues his denial of current corn ethanol water use, and how much irrigated corn there is in the US – it is not 4%, but probably at least 3x of 4x more. There are many water issues to think about besides just how many acres of corn are irrigated, but there is no doubt that far far more than 4%.

    The Corn Growers themselves (NCGA) in their '10 myths' says 13% in 2006. See Apr 2009 NCGATenMyths

    DoE Argonne rpt: Consumptive Water Use in the Production of Ethanol & Petroleum Gasoline (January 2009)
    ArgonneWater says that the 2002 data average for Regions 5,6 & 7 (Corn Belt States) is 12%.. .

    And from the Il Corn Growers: based on the USDA NASS 2002 Census of Agricultural and the 2003 NASS Irrigation Survey, " . . . about 14 percent of the corn land area harvested for grain is irrigated. Because irrigated land has a higher average yield per acre of corn, the irrigated acres account for about 20 percent of the nation’s corn production." ILCorn

    Let's use these values as a starting point for discussing corn ethanol and water use. Not the goofy 4%.

  19. BTW, oil sinking again. The globe is producing 2 mbd more than it uses, even after OPEC cutbacks, and every every major oil-producing nation being mismanaged by thugs for decades.
    On top of that, we have epic gluts and supplies of natural gas.
    I am beginning to wonder if the whole Peak Oil scare was…well, just that, a scare carefully manipulated and amplified by interested parties.
    Imagine how much oil there would be if Mexico, Venezuela, Iran, Iraq, Saudi Arabia, Russia, Nigeria, Libya et al were well-run countries, open to investment?
    Really, politics trumps geology, so in the U.S. it probably behooves us to go ahead with domestic sources of energy, which we can easily do, especially with natural gas and nuke plants.
    I sure would like to know who finances The Oil Drum.

  20. Robert,

    Have you heard of this coal to liquids process, it sounds promising.

    Rather than using gasification to obain liquid fuels the are using supercritical water to separate the products. They claim this allows for a more direct conversion that is more efficient and cleaner. I don't understand the process enough to know if their claims are valid, just wanted to get your input.

  21. "Rather than using gasification to obain liquid fuels the are using supercritical water to separate the products."

    Thanks for linking to that. I am digging now. On the surface, it sounds quite interesting. I am digging through some of their presentations. I have seen a few potential areas that I would quiz them on, but nothing so far that would convince me that this isn't real.


  22. Rufus,

    Yes, I've seen a 24-row planter. But planting is far from the only thing farmers do with those big John Deere tractors.

    And what about the "embodied energy" in that big John Deere — and in the 24-row planter?

  23. Reading comprehension is important. I said, "4% of Ethanol is made from irrigated corn."

    That's not the same thing as saying, "4% of corn is irrigated."

    Again, even in the "irrigated" areas (Nebraska, et al) most of the irrigation is NOT from the deep glacial reservoirs. Most is from shallower river valley water. It's taken out of shallow well's, sprayed over the corn, and goes right back into the water table. Or, it's transpired, and falls on the next county/state over.

    Besides, a barrel of oil requires about 1,500 gallons of water. Divide that by 21/42 (well, multiply, actually) and divide by 21. About 37 gallons of water per gallon of gasoline.

    Look, the water is cleaned, and introduced back into the biosphere (just like most of the water from the oil refinery.) It's not a very big deal.

    Oh, an ethanol refinery that supplies enough fuel to drive 100,000 Cars for a year, uses, cleans, and returns about the same amount of water as an 18 hole golf course.

  24. Wendell, most corn is now raised no till/low till. They make a pass in the fall to lay down fertilizer. One to plant. One to side dress, one for herbicide/pesticide, one to harvest.

    Anyway, modern equipment is a marvel. So are modern seeds. Your farmers are using less fertilizer, less pesticides, less fertilizer, replanting less often. And, getting higher yields. Erosion is down. Water usage is down. Quite a deal, really.

    And, you can buy all the corn you want, Today, for $0.06/lb. $0.06

  25. Wendell, that tractor over its lifetime could account for 25 Million Gallons of Ethanol. The embedded energy would have to be infinitessimal figured on a per/gallon basis.

  26. More and more NG, from the Horn River in Canada. Bigger than Haynesville?

    Exxon is most encouraged by the exploration of 250,000 acres it has leased in the Horn River Basin, in northern British Columbia. Mr. Cejka said results from the first four wells lead the company to conclude that each well will produce between 16 million and 18 million cubic feet of gas a day.

    That's five times the size of average wells in Texas's Barnett shale and comparable to big wells in Louisiana's Haynesville shale, two major shale-gas fields that already have moved the U.S. natural-gas market from scarcity to abundance.

    Though Exxon is better known as the nation's largest oil company, "We are really interested in shale gas," Mr. Cejka said, detailing the company's push into the energy-exploration business, which was once dominated by scrappy independent companies."

    I admire biofuels, and the people who develop them.
    But really, can biofuels compete with epic supplies of natural gas? This Canada strike suggest we have gas for centuries…..

  27. Ah, Benny, we'd better keep our options open on both. Remember how the "Bakken" was going to make us "Energy Independent?"

    I certainly hope we have a kazillion, kadoodle of Nat Gas. That would be wonderful. However, we do see confusing numbers coming out of the shale plays (rate of depletion, much less potent wells as you leave the core, etc.)

    Hopefully, our grandkids, and great-grandkids will be here a long time. We're not going to leave them much oil, It'd be nice to leave them a little nat gas, and coal.

    I'm willing to keep an open mind about gas. The only thing I won't keep an open mind about is sending a couple of billion/day to Saudi Arabia, and Jihad, Inc.

  28. Optimist said Much more efficient, and greener, to supply the original fuel directly to the consumer.

    Are you sure about that?

    Do you want some electricity and some gasoline?

    No, I'll have a big pile of coal, a handful of uranium ore and a couple barrels of crude oil.

    All energy sources need to be processed and transported, and that always costs you some energy but you also gain in getting the energy or fuel in a form that can be used.

    Fuel to heat to steam to mechanical energy to generator means you lose energy. But what you gain is a home with instant on lighting and appliances.

    Pumping and refining crude oil requires many steps with energy loses and inputs along the way, but what you gain are a variety of fuels that all serve specific purposes.

    So whats the point? Finding ways to convert energy into a liquid fuel energy carrier is a reasonable thing to pursue.

    Consider one popular solution, the electrification of cars. What is the best way to do it? I prefer nuclear, so should we go nuke heat to steam then through a turbine then into electricity into a battery which drives the car? There are energy losses, technical challenges and inconveniences along the way.

    Or would a better solution be to use nuke heat driving a CO2 + H2 reaction to produce a liquid fuel that can go into a vehicle. There would obviously be energy losses, and different technical challenges, but for me, it is too early to pick a winner just yet.

  29. Rufus-
    Despite the naysayers, energy independence seems quite doable, and I suspect would be a huge boon to our economy.
    I deeply admire the biofuels movement. I hope ethanol can be made to pan out, purely on a commercial level. I still wonder if a separate ethanol-only system makes more sense. In other words, cars that run on ethanol pure, using higher compression ratios.
    I do think some level of subsidy is okay for domestic energy sources. Hell, after spending a trillion dollars in Iraq, and after — as you point out– sending a few trillion to thug states, I would support any and all domestic energy sources.
    The one hope I have for ethanol is that corn yields have been rising for generations, while inputs have been falling. So, at some point corn ethanol "makes sense" on a EROEI level. Or even more sense.
    In the U.S. we cannot grow palm oil trees (except perhaps in Florida), although we can grow pongamia pinnata, which may offer even higher yields, per acre.
    I will keep an open mind on corn ethanol, if you will keep an open mind that there may be superior crops to corn. I especially like tree oil crops, as you do not have to plant and plow seasonally. With tree oil crops, you plant once, wait a few years, and collect for 40 years.
    I enjoy your posts, Rufus.

  30. Natural Gas ?

    By Paul Foy, AP Business Writer

    "Troy Anderson was at the gas pump and couldn't have been happier, filling up at a rate of $5 per tank. Anderson was paying 63.8 cents per gallon equivalent for compressed natural gas, making Utah a hot market for vehicles that run on the fuel.

    It's the country's cheapest rate for compressed gas, according to the Natural Gas Vehicle Coalition, and far less than the $3.56 national average price for a gallon of gasoline.

    "I'm totally celebrating," crowed Anderson, a 44-year-old social worker, who picked up a used Honda Civic GX two months ago. "This is the greatest thing. I can't believe more people aren't talking about it. This is practically free."


  31. Anon-
    What a great post! That story should be on the cover of every newspaper in the country–no, the world.

    OPEC: Are you reading, you greedy thug bastards?

    We have NG in North American coming out of our rear ends, and will for decades and decades. And we can run our trucks and cars on it. Shove that up your oily asses.

  32. "So the implication there is that you are getting more energy in the form of methanol than you put into the system"

    But,the water and CO2 already contain energy. Suppose their process used photosynthesis to split the hydrogen atoms contained in the water. It would produce a lot more energy than was put in,right?

  33. Again, I'm with you, Bennie. I don't care if it's nat gas, cow methane, geothermal, pongamia, Jerusalem artichoke, sweet taters, or corn.

    If they can find more oil off the coast (or, in the Bakken) they should drill it.

    I'm "Positive" on anything you can find EXCEPT sending Hundreds of Billions of Dollars to Thugs that would like to see us Dead.

    I'm building a Still.

  34. "Suppose their process used photosynthesis to split the hydrogen atoms contained in the water. It would produce a lot more energy than was put in,right?"

    It could produce more energy than the fossil energy you had to put in, but it will always produce less energy when you sum up the energy inputs. If you are using the sun as an input, as I pointed out that may be fine. But if you are using "deep UV light", which may mean they are using artificial lighting, then you will always get less back than you put in.


  35. But,the water and CO2 already contain energy.

    No. Think of water and CO2 as the lowest energy state of carbon hydrogen and oxygen. If you want to rearange the atoms into a fuel that will burn, you need to add energy. It doesn't matter if you are making methane or methanol or a hydrocarbon.

    As Robert has pointed out, you always need to add more energy than you get out.

    There are many ways to split the water into H2 and O2 and to split the CO2 into CO and O2, but it always requires some form of energy, be it heat or light or electricity. The cost of that energy and the efficiency is the key.

    If the energy is free, like sunlight, the problem is that that energy is very low density, and you need to concentrate the energy from a very large area to have enough to make the process work.

    If you start with something like nuclear fission which has a very high enrgy density, then you need to build a reactor at a very high cost. And you have to ask if that energy would be more valuable as electricity.

    The key to this type of research it to make the fuel as efficiently as possible and to compare the cost to other fuels and forms of energy. And to scale up.

  36. Thanks guys. Now I understand why burning saltwater isn't a panacea either. I always thought the two hydrogen atoms contained in a molecule of water was energy just ready to be tapped. Dangit….

  37. Maury,
    The key is that the energy does not reside in the atoms, but in the chemical bonds that hold the molecule together.

    For carbon based fuels we want C-H and C-C bonds, they have energy that can be released. Adding oxygen (O2) releases the energy. The O-H and C-O bonds are more stable and therefore, you can't get any energy out of them.

    Consider methane and methanol. Carbon will make 4 bonds. methane is CH4, one carbon and four C-H bonds. Methanol is CH3OH, one carbon with three C-H bonds and one C-O-H. Methane contains more energy per molecule than methanol.

    But that O-H group in methanol is why methanol is a liquid while methane is a gas. Therefore, sometimes it is better to sacrifice some per molecule energy density to get a fuel that is easier to handle, as opposed to one that needs to be compressed and contained.

    Sorry about all the chemistry.

  38. "If the energy is free, like sunlight …"

    Fossil fuels are "free" too, just like sunlight. After all, fossil fuels are lying around. All you have to do is go & pick them up.

    Ah, you say, but you have to pay the guy/country who owns the property on which those fossil fuels are found.

    Do you imagine that the people who own the land on which the sunlight is currently falling will let you have the use of their land for nothing? Look at the wind power scam, where the subsidy hogs have to pay landowners so that they can put up turbines to collect energy from "free" wind.

    Well, you say, but you have to drill wells at great cost to get that oil which is just lying around.

    Yes, just like you have to build solar panels at great cost to collect "free" sunlight. Just like we have to build dams at great cost and flood useful land to get "free" hydro-power.

    In physical terms, there is really no big difference between using the energy the sun puts out today and using the energy the sun put out millions of years ago.

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