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Science

Using Enzymes to Help Fight CO2 Build-Up 163

A reader writes to us: "There is a story in the New Scientist that details efforts to use enzymes that destroy ethanol as catalytic converters, turning noxious carbon dioxide into methanol. " The enzymes in question are actually those that are found in the liver - the same one that helps break down alcohol. Cool application of it, if this ever becomes reality.
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Using Enzymes to Help Fight CO2 Build-Up

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  • A couple of points...

    Methanol can more efficiently be used as a fuel in fuel cells than by simply burning it. Yes, they won't be released commercially until 2004 but they've been independently predicted to take over a hefty slice of the market pretty soon.

    Methanol can more efficiently and easily be obtained a load of other ways such as from the natural gas that's burned off (read 'gone to waste') at oil rigs everywhere or from domestic and agricultural waste.

  • by Chemical Serenity ( 1324 ) on Thursday January 27, 2000 @05:04AM (#1331497) Homepage Journal
    I would imagine that, aside from sucking down excess CO2 from the oxygen here on earth (which I personally can't see being all that effective in comparison to the diverse and highly efficient ways that nature has already developed), there would be other handy uses for this technology.

    Basically, they're advocating using CO2 as what amounts to a chemically-based energy storage unit. Methanol may not be the most human or environmentally friendly substance, but it IS easily convertable back into energy, stable and easy to transport, etc. I could see this technology being used (in conjunction with solar or other more convential power systems) as a method of extracting portable energy to fuel rovers and such on Mars, where there's an abundance of CO2 in the atmosphere waiting to be harnessed.

    All very 'blue sky', of course. I'd expect that there's other fuel source methodologies that would be more efficient than this process too.

    --
    rickf@transpect.SPAM-B-GONE.net (remove the SPAM-B-GONE bit)

  • Not to mention that global warming causes ocean levels to fall and not rise. This is the biggest misconception they try to pullover on you. take a glass with 3 or so ice cubes and mark the water level. cover it and let it set a few hours. When you come back you'll find the level has sunk. "Well gee Mr. Wizard, why is that?"

    A glass? Evaporation!
    Floating ice won't change the water level at all. Sure - the ice shrinks as it melts, but the shrinking is exactly the part of ice that was above water before melting.

    So melting the north pole ice won't change the water level at all. Melting glaciers resting on land, such as the south pole icecap, will definitely raise the seas, but nowhere near a "waterworld" scenario.
  • by jd ( 1658 )
    I'm going to be childish and quibble that vapour isn't really a gas. :)
  • No, our bodies certainly don't need any methanol. The stuff is quite poisonous, and has a nasty habit of making you blind. The stuff you drink is ethanol (C2H5OH), not methanol (CH3OH). The metabolism of which still takes quite a toll on your liver in the long term.

    Not to mention, this has absolutely nothing to do with the article, which was about converting CO2 to CH3OH.

    Sorry to rant, but I get annoyed when people post stuff they don't know anything about, which has nothing to do with anything.

  • by Tau Zero ( 75868 ) on Thursday January 27, 2000 @05:22AM (#1331510) Journal
    Step 1: CO2
    Step 2: CHOOH
    Step 3: CH2O
    Step 4: CH3OH

    I can't be the only person who noticed that the step from 1 to 2 added 2 hydrogens, step 2 to 3 deletes an oxygen, and step 4 adds 2 more hydrogens... without any mention of where these things are coming from and going to! I'm not a biochemist so I don't know anything about the chemistry of NADH, but a science article ought to at least explain how the equations are balanced.
    --

  • A bit offtopic... but...

    Said SO2, NO2, and H2O all combine in the atmoshere to form H2SO4 and HNO3 and promptly rain down on some forest somewhere, killing it. CO2, is much less water soluble, and accumulates in the atmosphere much easier. CO2 does have the distinction of being the primary control of pH in most bodies of water on the planet.

    The problem with burning fuel in an air atmosphere is that you can't exclude nitrogen from the combustion chaimber (I.C.E., not a fuel cell) and always seem to end up with a teeny bit of NO2.

    Temkin

  • I think I recall that some of the fuel cells being developed use methanol as fuel. I know there has been talk of 'hybrid cars' using plain ol' electric batteries and combustion engines. I wonder if the same could be used for fuel cells:

    1) CO2 scrubber produces methanol
    2) Methanol is used to provide more power to a fuel cell...

    (Obviously, not in violation of the 2nd law of thermodynamics, just squeezing out a little more fuel efficiency..)

    I *don't* know if this would be practical (i.e. use more energy to power the CO2 scrubber than the fuel cell would produce... That would be kind of pointless...)

  • coral reefs are much more important as carbon sinks.

    That makes sense, since coral reefs build upon themselves, so the removed carbon is accumulated in lower levels of the reef. Trees, on the other hand, have a relatively fixed level (you do build up soil, but I doubt at the same rate), and as trees die they decompose and the CO2 gets released.

    My favorite alternative energy generation technique is off-shore wind generators, as there's plenty of ocean room for them (even on the shelves), and they would provide residences for waterlife. It seems like they would also provide bases for coral reefs, at least in the right water conditions, making them even better environmentally.

  • how many people would use a computer when they're drunk
    *holds hand up high*
    Yep. Pissed out of my tiny mind. Had to type with 2 fingers, and close one eye, because depth perception of vision had gone.
    Doesn't sound too hard? I was on call overnight for a trading system at a _large_ international merchant bank at the time.....
    Fixed the problem, the got a free taxi home !!! Hehehehe!!!! :)
    Anybody else got tales of drunken support?

    Strong data typing is for those with weak minds.

  • Water vapor causes 98% [vehiclechoice.org] of the Earth's greenhouse effect. Carbon dioxide gets called "major" [senate.gov] because environmentalists love water and can't do anything about it. Imagine what the next ice age will do to the present environment.
  • 'cos I sure hate fish
    .oO0Oo.
  • Hmm, actually with the proper filtering in place, you would be able to repeatedly use the same batch of fuel, but it wouldn't last forever as only a portion of the byproduct of the reaction is CO2, the rest being useless crap as far as this cycle goes. This would be an awesome method to use on a CO2-rich planet to provide power, though, as fuel wouldn't be an issue. :)

    Deosyne
  • The New Scientist article is baffling because it seems to have things backwards. Our livers (in the unhappy event anyone is foolish enough to consume methanol - not ethanol) in fact convert methanol into formaldehyde and formic acid, not the other way round.
    You are essentialy correct with regard to the action of alcohol dehydrogenase in the liver.
    I know the article waves its hands and says, oh, the process is reversible. Maybe...
    Nothing handwavy about it. Remember that enzymes are catalysts. They do not alter the energetics of a reaction, only the kinetics. ALL catalysts (enzymes) Increase the rate of reaction equaly in both directions. This is fundamental to the way the universe works. If you ever took a basic chemistry class, think back to something called Le Chatlier's Principle. As long as you keep the concentration of methanol low in the reaction vessel, there is no problem having the reaction proceed in a "backward" direction. Many, many,many reactions in the cells of your own body use the same enzymes to proceed in both directions, depending upon the imediate need. An obvious example comes to mind: carbonic anhydrase in red blood cells, which, in most tissue, catylizes the conversion of carbon dioxide and water into carbonic acid, and then in lung catylizes the reverse reaction of carboic acid into carbon dioxide and water. Nothing hand wavy about it. Another example involves most of the enzymes involved in glycolosis ("forward") and gluconeogenisis ("backward"). And so on and so on.
  • by Josh Guffin ( 43687 ) on Thursday January 27, 2000 @03:42AM (#1331522) Homepage
    There is a story in the New Scientist that details efforts to use enzymes that destroy ethanol as catalytic converters, turning noxious carbon dioxide into methanol.

    Enzymes that destroy ethanol... noxious CO2 -> methanol...

    So basically they're the kind of like me. I break down ethanol with my liver,
    and then produce noxious methane (you know what i mean)

    =D
  • On the other hand, if you made yourself an -edible- Silicon-based life form, it could be open-sauced. :)
  • I'd like to think that a rather large number of trees and other assorted foliage would disagree with that comment.

    Carbon Dioxide is not 'noxious', any more than our exhaled breaths are. The threat it represents is that of a greenhouse gas, effectively operating as a heat retainer for our planet.

    Although, now that I think about it, some people's exhalations are pretty noxious... ;)

    --
    rickf@transpect.SPAM-B-GONE.net (remove the SPAM-B-GONE bit)

  • A glass? Evaporation!

    I said cover it. Earth is a closed ecosystem.
  • The morning after tying one on, you could now help your liver out with ''hair of the CAT'' :)
  • . But pretty much every credible scientific organization now agrees that warming is happening.

    With due respect, qualifiers like "pretty much every" and "organization" do not take into consideration WHICH organizations there are out there supporting it. I have seen a a paper denounching GW theory signed by 15,000 scientists, independant and otherwise, all qualified in this field. The problem comes from the scientific method and not following up on the last few steps. These days, they make a theory, sign a treaty and gather no further evidence of impact. Its quite painful to be honest.
  • They go on about how great this is, and how you can cut down on the amount of C02 into the aptmosphere, and it sounds perfect. Until they get to the fact that you need a lot of electrons to make this work. Hess's law states that you can go through any pathway for a reaction, but that the amount of energy is the same in the end. This means that whatever you are burning to create this CO2 must release more energy than the ethanol that you are producing. Seems to me that ethanol releases a lot of energy when it burns. I want to know what type of fuel's CO2 they plan to convert.
  • You assume that all the ice on Earth is floating at sea level.

    ~70-90% of bergs are sub-surface. I know that. Scientists refer to the atmosphere warming the oceans, where most of the ice in the world resides. At a height of 14,000 to 29,028 feet or so, no matter how much "global warming" occurs, the ice on top of mountains generally either sublimates, or stays put. Go on top of Everest in the middle of its warmest season, and look at all the lovely snow and ice. Now think of raising the temperature 5 or so degrees. And think about the ice still being there.
  • Well, from what I remember from Biology, NADH is one of the cellular energy transport chemicals. Its energetic form is NADH2... I think you get that by adding the electrons that they were talking about. Anyways, 2NADH2 -> 2NADH + H2.

    Note: I'm not a biochemist, and my organic chem is really rusty. But if I had to hazard a guess, this would be it.


    --Fesh

  • Although, now that I think about it, some people's exhalations are pretty noxious... ;)

    Yeah, but I'll bet those exhalations contain more than just carbon dioxide!
  • Hey, if we put this together with that methanol based fuel-cells we'd have batteries that recharges when you breath on it!

    Now would that be useful! Humm, I wonder if I could get a patent on the concept...

  • by jd ( 1658 ) <`imipak' `at' `yahoo.com'> on Thursday January 27, 2000 @03:53AM (#1331534) Homepage Journal
    CO2 is far from being the worst of the greenhouse gasses, and it's already being converted quite nicely into O2 by trees and plants. (Mind you, humans seem to have a habit of turning said trees and plants into lots more CO2 by burning them, to make way for McDonald ranches, in the area formally known as the Rainforest.)

    By far the nastiest gasses are NO2 and SO2. These give you that icky brown and yellow smog, which you can see over many industrial cities and major roads during a temperature inversion. They are also the predominant gasses on Venus and are the primary cause of the hellhole nature of that world. They also contribute FAR more to the greenhouse effect than carbon dioxide.

    Now, if the enzymes could do something useful with those, I'd be impressed. Clean up smog AND remove the greenhouse effect in one easy sweep. Anyone want to develop a sulpher-based life-form?

  • So basically, you've managed to engineer it so cars can run on coal via an intermediate process, but you've done nothing to reduce the net CO2 emissions.

    Actually, now you're essentially just burning coal in order to create electricity AND run a car (by capturing the CO2 that would have ended up in the atmosphere anyway) instead of burning both coal and gasoline.

    Yeah, you still burn methanol, and the energy to produce that has to come from somewhere (so I guess the above statement is a bit misleading, kind of like saying that electric cars are ZEV's since they don't burn anything), but if the energy required to create the methanol is significantly less than that required to create gasoline, then you have reduced the net CO2 emissions. If I read the article correctly, that is the thing they still need to find out.

    "... message passing as the fundamental operation of the OS is just an excercise in computer science masturbation."

  • Back in 1994, there was much discussion on usenet about introducing a bill to outlaw internet usage while under the influence. My reaction was such an idea was absurd, but those people seemed serious enough to try and push for it. Laughable now, but you should see some of the laws on the books.

    Oh yes, drunken surfing! Sure, what you see when drunk might cause your eyes to bug out, but the only thing that might crash is ill written code or operating system. Back in the old days when the pooter crashed, one could often see pretty colored characters dancing across the screen. And that was fun.

    Coding while drunk often brings out the most lines of code and arguably the most productivity. I once wrote 200 lines of daring assembly language for a Z80 GUI with mouse and keyboard support [attaway.org] on such a binge. The rest of the weekend was spent just to get the damn thing to work!
  • Methanol is not ethanol. Methanol is toxic when drunk, toxic when the vapor is breathed, toxic when absorbed through the intact skin, and really bad news if you squirt a couple of drops in your eye.

    Don't forget 100% miscible with water. Spill the stuff and any ground water or reservoir it gets into is going to be poisonous....

    Methanol is a perfectly fine chemical, as long as you take good care of it. As a large scale fuel, its toxicity makes it Right Straight Out.

    Ideally, they could do the same thing to produce ethanol, which is essentially harmless. Unfortunately, that attracts the attention of Mister Tax Man.
  • The whole reason for using living enzymes is to be able to get energy from natural resources and restore it to the combustion/by-product system. Where do plants get the energy needed to convert CO2 into O2? It comes from the energy of the sun being transfered into ATP which is used later during the process of chemical conversion. Hess' law isn't wrong, nor is the idea wrong. Rather your thinking is dead wrong. But its nice to know on the other hand that readers are thinking.
  • by Anonymous Coward
    ..run a methane powered fuel cell battery (as referenced in /. recently, developed by Motorola I believe). The components of it could be build into the enzyme holding structure, and could react with just enough of the methane to recycle an appreciable amount of the NADH.

    Someone run with this idea.. please..

    --
    Sean Dunn
    DigitalAnvil.com
  • I believe your logic behind weather prediction is somewhat flawed. Short term weather prediction is extremely flawed through chaos theory (sensitive dependent on initial condiitons). It is impossible to absolutely predict what will happen tomorrow, but using sophisticated mathematical models general trends can be established. The difference between being able to predict snow in winter and being able to predict the amount of snow in a given winter is an example of this. Although long range climate forecasting is by no means perfect, advanced mathematical models and computing power allow it to be much more accurate than the nightly news.
  • Water vapor causes 98% of the Earth's greenhouse effect.
    This is Yet Another Reason that we should Ban Di-Hydrogen Monoxide NOW! See the DHMO site [dhmo.org].
    --
  • The Co2 that is in the atmosphere is a tiny fraction of the CO2 that is dissolved in the ocean, and the ocean is not ven close to being saturated (think carbonated water :-)

    So, the real problem is that because the contact surface between the ocean and the air is too small, (and the temperature too cold?) and the air is above the ocean ;-) oceans are absorving CO2 too slowly.

    Solutions:

    What, you thought I actually had one? ;-)

    Who knows, maybe when the CO2 concentration in the air rises, oceans will start absorving quicker (I am no chemist) and it will all self-regulate in such a way that Siberia is a nice place to live, and we can open resorts in Antarctica (the peninsula must have some nasty surf waves!)
  • Well, temperatures are higher now that in the "Mini Ice Age" several hundred years ago. Look it up, and then see if your favorite environmentalists started measuring temperatures from that known extraordinary low point.

    Yes, I recognize the satire of the posting I'm replying to.

  • No, Earth is not covered and is not a closed system. The top of our atmosphere leaks, and we're venting gases just as Mars did. Fortunately we've got more gases, have greater gravity so leak more slowly, and might be reabsorbing more snowballs (if we are indeed getting hit by ice from space...some of that would be our own leakage). Warmer gases will expand the atmosphere and more will leak away more quickly (in addition to dragging more on Mir). Not a problem as long as we've got enough water to keep making enough water vapor to keep us above the freezing point (where we'd be without the water vapor greenhouse).
  • Methanol can more efficiently be used as a fuel in fuel cells than by simply burning it. Yes, they won't be released commercially until 2004 but they've been independently predicted to take over a hefty slice of the market pretty soon.
    This is of course true - but retooling car plants for electric+fuel cell is a lot more complex and involves more commitment than doing a petrol engine>>methanol engine swap.

    Methanol can more efficiently and easily be obtained a load of other ways such as from the natural gas that's burned off (read 'gone to waste') at oil rigs everywhere
    This is of course true, and I firmly believe it is a crime to throw valuable resources like that away just because it was mixed with the oil - why destroy a dwindling resource?
    but more importantly, I read the aim of this technology as wishing to reduce dependence on fossil fuels, and to reverse the CO2 increase caused by that - just changing the flavour of fossil fuel you use can't really help that.

    or from domestic and agricultural waste.
    Definitely - this is going to be produced anyhow, so should be used.
    --

  • I don't know if global warming will cause an overall rise or decline of sea level, but I find it hard to believe it will fall for the reason given above. Since an object floating in water displaces its weight in water, if you remove an ice cube (or iceberg) from the water and replace it with its weight in water, the level of the water should not change (ignoring the changes that happen while doing the removing and replacing). When an ice-thing melts, it essentially replaces itself with its weight in water, so there should be no change in water level. The expansion is seen in the ice that rides above the water. I've never done the icecube experiment, but if it does, indeed, work as described, there must be some further explanation than the expansion of water as it freezes.

    Also, don't forget that all the ice that's sitting on land (e.g. on Greenland and Antarctica) will end up in the oceans if it melts. The ice will go to the seas, the land masses will rise because of the removal of the weight of all that ice. Will that cause a net rising or lowering of sea level? I sure don't know.

    Always and inevitably everyone underestimates the number of stupid individuals in circulation
  • There's a lot of speculation as to whether (weather? ;) or not we're having an effect on climate AT ALL. While I don't have the urls to studies on hand, I have come across more than one environmental researcher who adroitly points out that a volcanic eruption pours out enormous amounts SO2, Methane, and other nasty nitrates, hydrates, and just about every other -ates one can think of, not to mention a boatload of particulate matter... some speculate that humans have thus far produced as many of these nasty chemicals in our entire existance as a race on this planet as the equivalent of a couple of pompeii-grade volcanic explosions.

    If that's the case, then we're really just along for the ride and the planet's at the wheel. We know the earth has undergone radical climatic changes in her past (egypt was relatively fertile back 6000 years ago, for example). Perhaps our latest climatic changes are just symptomatic of the 'next big swing'.

    When it comes to weather on a geological time scale, we are pretty clueless. Good theories may abound, but unless someone can tell us with certainty when the next ice age is coming or when we're gonna go venusian most people will ignore the situation until it's "too late"... particularly when we can't even say with certainty that pollution we generate is the deciding factor in it all. In that case, is there such a thing as "too late" when really you don't have a significant ability to control it anyways?

    --
    rickf@transpect.SPAM-B-GONE.net (remove the SPAM-B-GONE bit)

  • Not to mention that global warming causes ocean levels to fall and not rise. This is the biggest misconception they try to pull over on you. take a glass with 3 or so ice cubes and mark the water level. cover it and let it set a few hours. When you come back you'll find the level has sunk. "Well gee Mr. Wizard, why is that?" "well Timmy,(or Tommy or whichever one he didn't blow up last week) that is because water expands when it freezes.

    But like the above post states the greenhouse effect is what keeps us alive!

    that and they keep saying global waming over and over. Last year was the 15th warmest on record for the 21st century. If GW were a serious problem, the last 50 years would be the warmest in a slow progression upwards.

    Besides, I think the article is likely incorrect. CO2 is not noxious, CO is.
  • by Tau Zero ( 75868 ) on Thursday January 27, 2000 @06:48AM (#1331554) Journal
    Said SO2, NO2, and H2O all combine in the atmoshere to form H2SO4 and HNO3 and promptly rain down on some forest somewhere, killing it.
    One little problem for your assertion there... HNO3 dissociates in water to H+ and NO3-. NO3-, otherwise known as nitrate, is an essential nutrient for plants. It isn't plant-killer, it's plant food. (H2SO3 and H2SO4 have no real uses in that regard, save perhaps for changing the pH of excessively alkaline soils.) The real problem with NOx production is its contribution to photochemical smog.

    Nitrate is also produced by lightning, and IIRC the fertilizing effect is well-known. Adding too much puts it into rivers and lakes (promoting eutrophication and algal blooms), but that's once removed from the main issue.
    --

  • Well, I don't remember much from Organic chemistry as far as the reactions go, but I'll give it a shot...

    Step 1: C02 + H2 -> CHOOH
    Hydrogen cleaves one of the C=O bonds, with one H attaching to the C, the other attaching to the O.

    Step 2: CHOOH + H2 -> CH2O + H20
    One H and the OH group combine to form H20, other H attaches to the C.

    Step 3: CH20 + H2 -> CH3OH
    Hydrogen Cleaves the C=O Bond, with one H attaching to the C, the other attaching to the O.

    This balances the equations, but I'm not sure which reacions would need to be done. Needless to say, without the enzymes, they're probably pretty hairy. This particular synthesis was very likely not practical before they started using enzymes as catalysts.
    --Fesh

  • Shessh!

    Last time I checked, Animals had a nice symbiotic relationship, we breath O2, and exhale CO2, Plants breath the CO2 and "exhale" O2...

    Until we invented automobiles that burn hydrocarbons...

    Our lovely vehicles spew out Carbon Monoxide(CO). Thisis both deadly to plants and animals.

    Yeah, this article is nice, but it's not the levels of CO2 that we should be trying to reduce from our cars, it's the levels of CO. (Of course, reducing CO2 would help reduce the greenhouse effect, but that's a different story..)

    H.
  • The New Scientist article left a lot out, but filling in the blanks is suggestive.

    Suppose you have a fuel-cell hybrid car. The fuel cells run at high pressure, so you can store the CO2 in tanks (perhaps along with the water, all dissolved as soda water). You can either dump the soda-water and buy more methanol (expensive, perhaps, if carbon taxes are imposed) OR you can hook up to the wind genny, solar panel or wave-power machine somewhere and use the CO2/NADH reaction to regenerate methanol and oxygen from the CO2 and H2O. This effectively puts the exhaust back into the fuel tank. You wouldn't necessarily have to do the regeneration in the car; you could dump the soda water into a tank at home or a station and regenerate it there.

    This is equivalent to a battery-powered car, but without any effective daily-range limitation and "recharging time" of a few minutes.
    --

  • CO2, on the other hand, is food for plants.

    Only during the daytime. CO2 is used in conjuction with sunlight to produce O2+energy. During nighttime, plants consume oxygen just the same as you and I.

    The above equation may be greatly overgeneralized but it's been quite some years since my Biology classes.
  • . He just said that the hydrogen in the fuel was itself derived via electrolysis.
    I found the original post to be incoherent, but that assertion is untrue. The hydrogen used by space probes is obtained by reforming natural gas (methane, CH4) in a chemical reactor. You put CH4 and O2 in, you get CO2 and H2 out.
    --
  • Comment removed based on user account deletion
  • The article doesn't mention chemical H2, it mentions NADH. I'm assuming that NADH can be regenerated at the cathode of an electrolysis cell, but the article (and your description) still leave me in the dark as to the exact role played by NADH and how it is altered in the process.
    --
  • In fact, it has to require exactly as much energy to convert CO2 into methane as would be released by converting the methane into CO2 (eg by burning). Your perfectly efficient methane-burning engine would have to use all its energy to reconvert the CO2 to CH3OH. So your typical 20% efficient modern engine would be able to reduce its "greenhouse gas" emission by 20% when sitting at a red light with the A/C & radio off.

    Big Deal

  • Here's a theoretical pathway (the real mechanism will certainly be a lot messier, involving enzyme-substrate intermediates):

    CO2 + H20 <==> H2CO3
    (occurs without catalysis, but can be sped up by carbonic anhydrase)
    H2CO3 + NADH + H+ <==> HCOOH + NAD+ + H2O
    (catalyzed by formate dehydrogenase)
    HCOOH + NADH + H+ <==> HCHO + NAD+ + H2O
    (catalyzed by formaldehyde dehydrogenase)
    HCHO + NADH + H+ <==> CH3OH + NAD+
    (catalyzed by alcohol dehydrogenase)

    Net reaction: CO2 + 3NADH + 3H+ <==> CH3OH + 3NAD+ + H2O

    I think that's balanced. Biochemists are often lax about mentioning hydrogen ions and water molecules in a reaction because it's generally assumed that they're present in abundance in biological conditions.

  • Don't forget 100% miscible with water. Spill the stuff and any ground water or reservoir it gets into is going to be poisonous....
    Also biodegradable. There are bacteria which produce significant amounts of methanol in the process of fermenting carbohydrates. There are other bacteria which eat the methanol. No biggie, just put the right bugs to work. Besides, there are trace amounts of methanol in all kinds of things, including grape juice. Unlike carcinogens such as benzene and MTBE, it does not appear to be at all dangerous below a certain threshold.
    --
  • By combining different enzymes within a fixed structure these scientists have been able to bubble in a combustion end product -- CO2 -- and produce useful commercial feedstock out the other. It works without moving parts (except for the pump to bubble air through the cell). Getting this to successfully work is pretty clever.

    New Scientist is kind of crazy to talk about this as being any possible solution to global warming because the energy requirements are excessive and most likely would have to come from a source that dumped CO2 into the atmosphere. And we may or may not need another source for producing methanol. But having shown that their technique works one can assume that other combinations of enzymes will be tried until something really useful is produced.

    This reminds me of the proposal to use CO2 in the Martian atmosphere (and liquid hydrogen shipped from Earth) to generate rocket fuel. (CO2 + H2 = CO + H2O. CO + H2 + catalyst = CH4 + O2 (rocket fuel). Elctrolysis the excess water to extend the process.) It was clever, used largely off-the-shelf products and solved an formitable problem.

    Having demonstrated that they can produce organics from raw materials, there are any number of possibilities one could speculate on that they could do next. One possibility would be to combine this catalytic converter with efforts to develope artificial chloraphyll. (I believe there was a slashdot article on that) Chloraphyll traps solar energy to liberate an electron, and this catalytic convertor needs a lot of free electrons. If one could successful pair the two processes together the result would be a methanol producing solar panel, which could be organized into farms out in the desert. Solar energy stored as methanol would be more transportable than electricity from solar panels and be available for a wider array of uses.

    Brian Brown (beb01@sprynet.com)

  • i'll be the first to admit i don't fully understand the chemistry involved here, but i agree with you, solar energy was my first thought when they said they needed electrons to complete the reaction. i wonder, would it actually be feasible, though... i don't seem to remember anything ever being said about solar panels being efficient energy converters (or whatever they technically are). would it be possible that to produce enough energy, there would have to be some impractical amount of panels? and solar panels atop a power plant seems a little silly to me... :)
  • Crap. Preview box managed to lose my correction to that formula. The correct reaction is

    CH2OH + NAD <---> CH2O + NADH
  • THIS is the missing chemistry from the New Scientist article! Thank you, sir, for the enlightenment. (Someone ought to moderate the parent post up.)
    --
  • The key point here is the energy efficiency of the first two reduction steps. If they can't get that efficient enough (i.e. less than the energy difference between the original fuel and methanol), then the process will lose energy. That is, you would need battery to run your gas-powered, zero-emission car. At the very least, this process would eat up a very significant amount of your fuel.

    Anyway, what happens to the methanol? Is it burnt? That releases the carbon into the atmosphere anyway. Given that both burning processes (fuel->MeoH, MeOH->CO2) are less than 100% efficient (closer to 30%), you would burn more fuel this way, not less.

    This only makes sense if you do something to sequester the methanol, like make it into plastic, which costs more energy. Of course, this is at the cost of making burning hydrocarbons considerably more expensive. I'd guess that you would use at least two to three times the fuel you do now.

    Kind Regards,
  • Sorry.

    Adding more steps just makes the process less efficient. The point you're forgetting is that you don't get the CO2 for free; it takes considerable energy to drive the enzyme reaction in bulk.

    It looks seductive, but you're falling into a "perpetual motion" trap here.

    Kind Regards,
  • Try this for size:
    1. Precipitate carbonates (calcium, magnesium) from seawater.
    2. Roast carbonates to oxides, capture CO2.
    3. Dump any undesired oxides back into the ocean, raising the pH, converting bicarbonate ion to carbonate ion, and helping absorb more CO2. (MgO may be worth saving for conversion to metal.)
    4. Convert CO2 to CH4 or MeOH using whatever process is desirable. Use as fuel elsewhere.
    If you have enough cheap energy, this might actually be feasible.
    --
  • Why don't they just couple this with, say, glycolysis or the electron transport chain so they can regenerate NADH as much as they want? Couple these to photosynthesis, and you could cut CO2 emissions even further. Use the enzymes out of some archaebacteria, and you could filter out nitrogen or sulfur byproducts as well.
  • Some points:

    1. Precipitate carbonates (calcium, magnesium) from seawater.

    There is not enough salt in the world to do this, but I suppose the salt could be recycled at a higher energy cost. This isn't the real problem though.

    2.Roast carbonates to oxides, capture CO2.
    The real problem is the energy cost of doing this.


    No kidding. It's not as expensive as preparing the metal ions for you first step though. But this isn't the real problem either.

    3.Dump any undesired oxides back into the ocean, raising the pH, converting bicarbonate ion to carbonate ion, and helping absorb more CO2. (MgO may be worth saving for conversion to metal.)

    You've got this step more or less right; use the CO2/CO3[2-](aq) equillibrium to drive CO2 out of the atmosphere into seawater. You could, in principle, do this.

    4.Convert CO2 to CH4 or MeOH using whatever process is desirable. Use as fuel elsewhere.

    This is the step that makes no sense at all. The energy requirements will be big, but probably not as much as the salt processing in your steps 1 and 2. No, the real problem is what you do with all the methanol. You know you'll have to produce enough to fill the Great Lakes to make a difference, right? Every decade or so?

    Methanol is not the worst chemical in the world to handle, by any means, but it is toxic to almost every form of life on the planet.

    Never mind that you would need horrific amounts of energy (probably more than the world currently produces).


    Kind Regards,
  • spineless polyps

    Actually some of those polyps are quite brave! They leap into the water, and hope that the currents will take them into a new area suitable for growth.

  • For use on earth this seems to be limited by the fact that you need to
    put energy in to the system, and most of our energy generation
    involves the production of co2.

    However, energy is one of the things which is not in short supply when
    you're in orbit, but carbon is. This might be a useful part of the
    life support system of a space habitat. Allowing co2 to be recycled
    as methanol using plentiful solar energy.

    The next questions is: what do you do with the methanol?

  • here: http://www.mbari.org/itd/news_center/news/may_07_1 999.html

    with cool videos here: http://www.mbari.org/ghgases/deep/release.htm

  • Compared to suggestions of industrial processes, ecological processes have a lot higher chance of actually making a dent in CO2.

    Since photosynthesis removes CO2 from the atmosphere, The Iron Solution [msu.edu] to the global warming problem proposes to radically expand photosynthesis on the planet by fertilizing high nitrogen, low phytoplankton regions of the ocean with the element that limits phytoplankton growth in those regions: iron.

    A side benefit of this sort of agriculture is that it would tend to lessen agricultural demand for land-based ecosystems that are currently being slashed and burned for agricultural production, such as rain-forests. Phytoplankton is at the base of the food chain for high protein organisms like fish. People would have to get used to eating less pasta and more halibut -- a small price to pay for the salvation of millions of species, except maybe for Italians.

  • Well if you solar or wind powered this reaction it would seem like a fairly nice idea; the question is how much would be needed to make any noticeable difference?
  • Actually to anyone with a biochemistry or organic chemistry background the answer is obvious. The oxygen comes from the water in which the rxn takes place (actually probably in a step 0 where C02 + H20 -> CO3H2 which is carbonic acid). The reducing potential to take the oxygen off comes from NADH being oxidized to NAD+. The actual hydrogen atoms/ions coming from NADH and/or water. Typically the statement that NADH is a co-factor in the rxn is enough to make the above clear to the audience of the New Scientist.
  • Now I could look up the respective thermal stabilities of the enzymes mentioned here, but I'm lazy :-) What I want to get at is that enzymes are proteins and as such have a finite lifetime at room temparature. They have a nasty habit of denaturing (losing their 3D shape) and thus losing activity. You can store them at 4 degrees C but they don't have much activity then. So you might not want to power your phone with an enzyme-dependent fuel cell.

    A solution to this might be to use enzymes from deep-sea vent bacteria, they have evolved to stay active under thermal stress. But they still have a finite lifetime, eventually they will lose activity. In living cells, enzymes have very short lifetimes before they are broken down into amino acids and recycled.
  • Actually the solubility of CO2 (and most other gasses) is lower in warmer water than it is in colder water (that's why warm pop fizzes so much more than cold and why the bubbles form so well in your warm mouth). That means that if the oceans do warm then they are likely to release more CO2 thereby accelerating any warming that is occuring.
  • If carbon dioxide was primarily affected by natural processes, I'd expect it to stay fairly steady over a long period of time. However, in the last 250 years this has not been true. Since 1750 atmospheric CO2 has gradually increased from about 280ppmv to 366.70 ppmv in 1998.

    Up until 1750 it was the pattern I'd expect to see in a steady system, more or less steady with random variations about the mean.

    Unless you can give a reasonable explination for a steady increase since 1750 (When the industrial revolution dramatically increased the amount of fossil fuels being burnt), your theory doesn't hold up.

  • AP, Curitiba, Brazil

    A team of scientists working on studying the interaction between tropical frogs on rain forest plants may have made an important unexpected discovery.

    Dr. James Tertweiller, who has been living and working all over the state of Parana in Brazil for the last 3 years, said there's some indication that plants -- from the mighty, thick vegetation of our rainforests, down to your household cactus -- appear to be constantly converting carbon dioxide into oxygen.

    "The implications are enormous," he said. "We've been so worried about the rising CO2 levels in the atmosphere. But if the plant life biomass of the planet is large enough -- and I think we might be able to acheive this in the forseeable future -- we can actually sustain a fine balance of atmospheric gases."

    Policymakers around the world greeted this news with enthusiasm, but expressed some doubts about the economic viability of the plan.
  • Would be better to quibble that clouds don't contain water vapor, they contain liquid (or frozen) water droplets.
  • I must admit I haven't done the experiment yet, but I always thought the level was the same (if you assume the starting and finishing temperature of the water is the same). Objects that float in water displace an amount (mass) of water that equals the mass of the floating object. Thus when the ice melts it exactly fills in what it had displaced before. As far as any analogy to to global warming goes, the reason that there might be a problem with sea levels has nothing to do with floating icebergs. I believe it has to do with 1] temperature expansion of water (water expands when it gets warmer too) and 2] melting of ice that is supported by land (e.g. Antarctica). - dara
  • I know the CO2 doesn't come free, (niether does the methanol) but was throwing out the idea that prehaps this process might grab a little energy from the waste product.

    Example: Car produces a few liters of C02 that can be processed into methanol with 15 joules of energy.

    Methanol is converted by a fuel cell to produce 17 joules of energy: net gain: two joules..

    The problem with this: I have no idea what the energy amounts involved are. It just may be that it takes 17 joules to convert enough methanol to produce 5 joules (net loss: 12 joules)

    You obviously can't run a car forever; but such a process might improve the mechanical efficiency...

  • Now if they will just create a enzyme that will clean my bathroom.
  • One little problem for your assertion there... HNO3 dissociates in water to H+ and NO3-. NO3-, otherwise known as nitrate, is an essential nutrient for plants. It isn't plant-killer, it's plant food.

    Close, but wrong, here's why.... NO3- is indeed plantfood, as is SO4--. But it's the hydrogen you have to worry about. pH is proportional to log[H+], or the activity of hydrogen ions (hydronium ions actually, H3O+) in solution. So while the anions are plant food, they exist in concert with highly reactive hydrogen ions, which lower the pH of water enough to cause damage to plant tissue. In most natural waters, this effect is buffered by CO2. CO2 forms carbonic acid when disolved in water and has a couple stages to its disassociation that resist the drop in pH. As pH drops ([H+] activity increases) the disassociation reaction shifts equilibrium towards H2CO3, which is volitile, and causes CO2 to exit the solution. Once the CO2 is gone the pH drops below 4 towards the really acid range.

    This is why you see farmers put ammoinum nitrate and ammonium sulfate on their land rather than nitric or sulfuric acid.

    Temkin

  • Actually, plants breath O2 and exhale CO2 as well. They use the O2 to oxidise the sugars they produce as photosynthsis, pretty much the same as we do.

    If you want to kill a plant, then putting it in a O2 less atmosphere will do it much quicker than a CO2 less atmosphere, the difference between suffocating than starving.

  • 1. Precipitate carbonates (calcium, magnesium) from seawater.

    There is not enough salt in the world to do this, but I suppose the salt could be recycled at a higher energy cost. This isn't the real problem though.

    You don't do it with salt, you do it by concentration of seawater until the minerals precipitate. Or you do it electrically; there is a hint about artificial reef-building here [ser.org] (I've been unable to find any papers on the web). Unless I'm mistaken, pretty much all of the magnesium used in the world is "mined" by precipitation of MgCO3 from seawater.
    4.Convert CO2 to CH4 or MeOH using whatever process is desirable. Use as fuel elsewhere.

    This is the step that makes no sense at all. The energy requirements will be big, but probably not as much as the salt processing in your steps 1 and 2.

    The energy requirements are entirely involved with producing the hydrogen (at least for the conversion to CH4); with common industrial catalysts, the reaction 4H2 + CO2 -> CH4 + 2 H2O runs all by itself.
    No, the real problem is what you do with all the methanol.
    You ship it to where you need energy, and you burn it. If you want to sequester the carbon you'll have to get fancy, but if you just dump the CO2 back into the air it'll replace the CO2 being consumed by the CaO and MgO you dumped.
    Never mind that you would need horrific amounts of energy (probably more than the world currently produces).
    Absolutely. It assumes a situation where energy is cheaper than fossil carbon. There are a number of scenarios which might bring this about, such as some of the Solar Power Satellite schemes or a breakthrough in Ocean Thermal-Electric Conversion (OTEC); one of the biggest problems with OTEC is that electrical transmission from generators in the middle of the ocean is impractical, and this converts the problem into one of transport of bulk liquids. Stiff carbon taxes would change the economics in favor of schemes like this overnight.
    --
  • Some anonymous coward dun said:

    >Anyone want to develop a sulpher-based life-form? One of my profs (a bio-resource engineer) was studying sulphur-munching bacteria. I don't recall exactly what form of sulphur it ate (or produced) though. She was studying it for wastewater treatment for stuff like mines, so I don't know how applicable it is to gaseous SO2...

    If I remember right, most sulfur-eating "bacteria" use hydrogen sulfide as an energy source. (They're delightfully weird critters in any case--more on that below.) Most of the sources of HS2 where sulfur-eating "bacteria" live are underwater "hot vents"--basically small underwater thermal springs and volcanoes--so MAYBE it could be applicable if you put them into smokestacks. ;)

    Yes, there is a reason I use quotes around "bacteria". Most of the sulfur-eaters aren't true bacteria, but in an entirely different domain of life altogether (aka superkingdom) called Archaea, which actually has more in common with eukaryotes (like us and most stuff with mitochondria) than "true" bacteria. (As a neat aside--it's also thought that at least one branch of Archaea might well have become mitochondria. :)

    Most of the Archaea live in what we'd term extreme environments. Many of the environments are thought to be similar to those of Earth when she was younger, and one big source of Archaea are in ecosystems around "hot vents" which--oddly--are also some of the only ecosystems on the planet which are not dependent on the sun in one form or another. Studies of these ecosystems (which also include big animals, like tubeworms and blind-crabs) have actually given scientists some ideas on how extraterrestrial life might survive (especially on places like the moon Europa--it's thought Europa has water under ice, and it's entirely possible that if the core of Europa is hot enough you might have hot-vents and maybe life)...especially since those animals live in areas that have been traditionally thought of as "dead zones" because surely NOTHING terrestrial could live there :)

  • This further reinforces my opinion that the New Scientist contains too much sensationalism, and not enough fact.

    The entire article is about Carbon Dioxide, yet in their graphic of the chemical reaction, they show a nuclear power plant in the background as the generator spitting out "greenhouse gasses"...

    ... despite the fact that the "smoke" seen coming out of the cooling towers is harmless steam (though arguably water vapor is a greenhouse gas, as pointed out by another poster) and nuclear plants are often touted for their lack of emissions of any kind (barring the rare distaster, that is)

    Maybe I'm just picky because I grew up 3 miles from the Limerick Nuclear plant in southeast PA, and was forced to learn about it in HS, or maybe its because I work for a utility company. ;)

    -- Scott

  • Last I heard the greenhouse effect / global warming theory was just that - a theory. It's not for certain that earth'll warm up because of CO2 gasses. And from what I remember it's not the trees and plants that convert most of the CO2 back into O2 - 90% of it gets converted by planctons in the oceans, and I doubt the capacity has reached it's max.


    My theory: incr CO2 -> more food for plancton -> more food for fish -> more fish in the ocean -> more food for humans -> more humans -> more CO2 -> etc.


    I do on the other hand think we should try to limit it somewhat - but not go overboard like the media has (they just love armageddon stuff).

  • ...when I first learned about the wonders of hydro-electrolysis, and found out about the perfect closed fuel circle that could result from the simple seperation of hydrogen and oxygen in water.

    My mind spun with all the things you could use it for. Well, I'm a little older, a little less enthusiastic, and maybe a little more efficient. Now I know it's just another way to move energy around, like batteries or gasoline.

    If it's as efficient as they make out, combined with the new cheap methanol fuel cells, this could be the clean, portable energy solution of the next century. It has every advantage of the hydrogen energy system (well, maybe it loses a little in simplicity of generation), plus the extremely important bonus of how easy it is to move methanol around. There are plenty of other ways to get methanol, too. Forget solar power plants: fermentation of vegetable matter into methanol is simple; you could fuel your cell phone out of your compost bin.
  • Just think of what we can do with all that formaldehyde [anime.net].

    O_o
  • Tough luck:

    1. Thermodynamics say that in order to convert CO2 into CH3OH you have to use quite a lot of energy. So whatever you burn like that will be bloody inefficient

    2. The only productive thing you can actually do with the CH3OH is burn it so back to CO2. It can be converted into some plastics and stuff but the overall demand for such material is not high to satisfy a massive generation of CH3OH.

    3. Better stop cutting the brazilian forests. I actually check the labels on all the stuff I buy and try not to buy anything that is not:

    3.1. Made of recycled paper (this technology is dirty as well but still better than nothing).

    3.2. Made out of planted forests in scandinavia or somehewhere else where they plant at least as much as they cut.

    In btw: these labels are almost standard on anything sold in the EU.
  • by QuMa ( 19440 ) on Thursday January 27, 2000 @03:59AM (#1331605)
    Can someone please change em so they make ethanol? Please? (Not that I mind the taste of methanol, it just makes you go blind a lot quicker, and if that happens I can't find my glass).
  • by DaveHowe ( 51510 ) on Thursday January 27, 2000 @04:00AM (#1331606)
    They go on about how great this is, and how you can cut down on the amount of C02 into the atmosphere, and it sounds perfect. Until they get to the fact that you need a lot of electrons to make this work. Hess's law states that you can go through any pathway for a reaction, but that the amount of energy is the same in the end. This means that whatever you are burning to create this CO2 must release more energy than the ethanol that you are producing. Seems to me that ethanol releases a lot of energy when it burns. I want to know what type of fuel's CO2 they plan to convert.
    *I* wonder how high a percentage of CO2 the mix bubbled through the converter really needs. The problem with electrically powered cars has always been that not enough stored power could be carried for the speed of the motor you want - Motorway speeds will eat all the power you can load onto a mobile base fairly fast. *however*, if you have roadside petrol(gas) stations doing this conversion, you can have the following process:
    1. Electricity is produced in non-polluting manner (difficult, I know)
    2. At petrol station, electricity+atmospheric CO2 is converted to methanol and stored (continuous process)
    3. Cars refuel as normal at station
    4. Cars burn fuel, returning the original CO2 to the atmosphere it came from
    As far as I can tell, this gives you "clean" electrically powered cars, but indirectly.
    --
  • by Anonymous Coward
    Okay, let's get something straight. Greenhouse effect and Global Warming are NOT the same thing. We need the Greenhouse effect (a misnomer anyway) because the earth doesn't receive enough energy from the sun alone - some of the heat reaching our planet is actually radiated to us from our own atmosphere. Check this URL for more information: http://www.ems.psu.edu/~fraser/Bad/BadGreenhouse.h tml Also, trees are NOT the be-all and end-all of CO2 consumption - coral reefs are much more important as carbon sinks. Unfortunately, spineless polyps don't make good press, so the enviro-lobby has taken up tree hugging as a sport.
  • How do they want to recycle NADH?
    NADH is a very important substance of the energy managment in living beings. Nature has invented a way of recyling it, it's called Life. I'd be really amazed if they found a way of recyling it synthetical. (ok, they will, but probably not in my lifetime). My best bet is genetically manipulating bacteria to do this for us.
  • We all know our bodies don't need any methanol floating around in them, but I can't help but wonder whether this is another step along the way to finding the holy grail of alcohol metabolism: a pill that speeds up the process of alcohol metabolism. The financial reprocussions would be enormous both for the manufacturer and for society at large which would benefit from increased productivity with saying good bye to hangovers. On the other hand, alcohol consumption would skyrocket and we'd become an even greater society of alcoholics than we currently are, not to mention all the idiots who would still manage to induce alcohol poisoning in themselves.

    But just look at how societies have always grown up around the simple fact that it takes hours for people to sober up, and imagine a world without that. My cynical mind wonders what hell might replace it.
  • In your .sig:
    >Important Proir cases effecting DECSS, a must read

    affecting, not effecting is correct here...

    (this particular mistake is one of my pet peeves - really makes people sound/look uneducated. Almost as bad as "your/you're" problems)
  • by Tower ( 37395 ) on Thursday January 27, 2000 @08:58AM (#1331620)
    Actually, this is part truth and part myth...
    Plants do produce much less O2 during the nighttime, but they do not consume it - they do actually continue the process. Without the added energy of the sun/light source they can only keep this up for so long, but if you check out a book that does a good in depth analysis of photosynthesis and the Kreb's cycle, you should be able to get all of the info there.

    Though it used to be common practice in hospitals to remove plants from the patients rooms at night for the very reason you mention - the newer, more accurate research has led to the repeal of these actions.
  • Typically the statement that NADH is a co-factor in the rxn is enough to make the above clear to the audience of the New Scientist.
    If you've ever read New Scientist (and especially looked at the pictures they run with their stories) you'd know that it's aimed at a very popular audience, not expected to have all that much education. A magazine like Nature would never have run a picture of a hooker's buttocks with an article on sampling and population estimating techniques; New Scientist did (and got a lot of indignant letters over it).

    New Scientist does not even bother captioning most of their pictures, which is probably appropriate because few of them are very relevant to the stories in which they are placed. It is not even in the league of Scientific American in that respect. On the other hand, it is a weekly, and it is fairly thick. I've subscribed to it and found it expensive (in US$) but about as worthwhile for the money as Science News (burden of glitz outweighed by volume of coverage).
    --

  • by / ( 33804 )
    The big-assed coal plant doesn't matter 'cause you're just making car fuel anyway? And what are you going to do with that car fuel -- drink it? No, you're going to burn it, releasing CO2 back into the air. So basically, you've managed to engineer it so cars can run on coal via an intermediate process, but you've done nothing to reduce the net CO2 emissions. That doesn't have too many useful applications.

    As for your second idea, that's pretty much how rocket propulsion is done, and you can imagine that what's appropriate for rockets is perhaps not appropriate for cars, and in any event it's expensive and still requires a "big-assed" power plant to provide the electricity for the original electrolysis, because your idea of a closed internal combustion engine by definition couldn't do any work on the outside world (which is what driving cars is all about). Heck, you wouldn't even be able to idle the damn thing, since there's still some friction and you wouldn't get 100% yield if you tried.

    Maybe you should patent it anyway, since the USPTO seems to deserve patents like that.
  • So you can have solar panals generate the electricity for these reactions. Who cares if you need lots of power, the sun supplies more than enough.


    This produces methanol which you can then use to power those methanol, air breathing fuel cells that are in developement.


    The fuel cells actually burn cleaner than Internal Compustion Engines so you get less nasties in the emmisions, and of course you take the CO2 and start it all over again.


    Of course you can also burn it in Gas turbines, which have a nice clean exhaust as well.

  • Carbon dioxide is a major contributor to the global warming effect. For that reason, a lot of people equate CO2 with global warming. There are, of course, a lot of other atmospheric effects that effect total heat absorbtion and retention, but bringing up details like that tend to confuse people. Easier for the media to use simple words, like "Too much CO2 = Global Warming. Global Warming BAD!" I always thought that a majority of the worlds CO2 gets fixed into Limestone, but it's been a while since I've done geology stuffies. Of course, the difference between calcification and trees is that trees spit out what we need as fast as they take up what we spit out. Gotta love the symmetry of that. Not to mention that most people have had personal contact with trees (skiiers especially ;) whereas few people will have the luxury of being up close and personal to, say, the great barrier reef outside of a Jacques Cousteau video rerun. BTW, you CAN use <A HREF=...> tags in your comments, like on that Bad Greenhouse Link. [psu.edu]

    --
    rickf@transpect.SPAM-B-GONE.net (remove the SPAM-B-GONE bit)
  • Okay, nice responses on water ice. But you're forgetting evaporation of frozen methane [bbc.co.uk] can make sea levels go down when the water warms. Of course, then we've got a bunch of methane in the air too. Got all that in your climate models [llnl.gov]?
  • Sulphur-munching bacteria. Just what we need to seed Venus with. Convert some of sulphur and carbon in the atmosphere into piles of bacteria...odd soil, but better than what they've got now.
  • We'll be needing all the carbon dioxide in the air we can get our hands on soon, so that nanotech can built all our gadgets and mansions and personal trans-continental pipelines for us.

    Leave all that automotive carbon alone --- it's our future feedstock!
  • by fnj ( 64210 ) on Thursday January 27, 2000 @04:40AM (#1331652)
    This is a joke, right? I mean, no one could be so stupid as to think that changing massive quantities of comparatively harmless CO2 into highly toxic methanol is desirable on a large scale.

    Methanol is not ethanol. Methanol is toxic when drunk, toxic when the vapor is breathed, toxic when absorbed through the intact skin, and really bad news if you squirt a couple of drops in your eye.

    Besides, methanol's only uses are as a fuel and as a raw material for making other compounds. When you burn or catalyze the Methanol as fuel, you get the CO2 back again, and when those other compounds are eventually consumed or destroyed, you get the CO2 back again (and other noxious compounds, by the way).

    CO2, on the other hand, is food for plants. If you "cleaned" the atmosphere entirely of CO2, all plants would die, no more O2 would be produced, and eventually all O2 would be consumed and all animals would die. Yes, we are animals, and we would die too.

    The New Scientist article is baffling because it seems to have things backwards. Our livers (in the unhappy event anyone is foolish enough to consume methanol - not ethanol) in fact convert methanol into formaldehyde and formic acid, not the other way round. It is this formaldehyde and formic acid that account for the toxic effects - notably permanent blindness and destruction of the nervous system and cerebral cortex (not real fun). I know the article waves its hands and says, oh, the process is reversible. Maybe...
  • by radja ( 58949 ) on Thursday January 27, 2000 @04:44AM (#1331654) Homepage
    Just go to hospital, first aid department. Wait til you're first in line. and have some methanol handy...

    Nurse: what's the matter sir?
    you: I'm about to go blind because of methanol poisoning.
    (Now is the time to drink some methanol)

    The usual way to cure methanol poisoning: saturation with ethanol. Up to the point of getting poisoned by the ethanol.

    Disclaimer: If you actually try this you're pretty stupid, so don't come complaining to me (if you can find me on sound and smell)

    //rdj

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