Putting a lid on carbon dioxide

Abdul Alhazred said:
Kidding aside, if we really need to reduce CO2, why not plant a lot of trees?
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Where? Where do we find enough land to off-set the trees being cut down other places?

Rolfe.
 
Abdul Alhazred said:
Kidding aside, if we really need to reduce CO2, why not plant a lot of trees?
Click to expand...

I remember from my high school environmental class that trees are actually the least efficient at converting CO2 to O2. The most efficient I think might have been plancton.

I'm going to sit here and wait for a life sciences expert to smack me upside the head for spreading misinformation, and then tell everyone the real story...
 
In the USA forestation has been increasing for quite some time.

Enough? I don't know.

Plankton may be a more efficient converter of CO2, but adding more plankton is problematical.
 
I remember from my high school environmental class that trees are actually the least efficient at converting CO2 to O2. The most efficient I think might have been plancton
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I seem to remember a report saying that if the whole Brazilian rainforest were eliminated, it would not make a big difference in CO2 concentration. It would be a disaster but not in the CO2 part of it.

CBL
 
Abdul Alhazred said:
In the USA forestation has been increasing for quite some time.

Enough? I don't know.

Plankton may be a more efficient converter of CO2, but adding more plankton is problematical.
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The vast majority of biomass is, at best, a temporary carbon sink. When the organism dies and decomposes all the carbon is returned to the atmosphere. You can actually see this effect (called the carbon cycle) by looking at seasonal trends in CO2 atmospheric concentrations.

Regarding plankton, deep-ocean carbon sequestration via fertilization of phytoplankton is a very active field of study. Here is a list of some abstracts:

http://cdiac2.esd.ornl.gov/ocean.html

Oh, and Bruce, nature has been sending carbon deep underground for billions of years, using no more than the power of the sun and the miracle of photosynthesis. Heard of limestone? You know, calcium CARBONate? ;)
 
I would take all of this nyuk-nyuk winking and BWAAAHAHAHAHAHAHAHAH!!!!!!!!-ing more seriously if the US Dept. of Energy was also laughing at the idea, if the Norwegian company Statoil wasn't already doing it in the Utsira sandstone formation and if a team of organizations including the US Department of Energy and BP Energy weren't also doing it at the Frio Brine Pilot experimental site in Texas.

If you examine the USDoE website, you'll see that other carbon sequestration technologies are also being studied, including pumping CO2 to the bottom of the sea.

Now throw in the fact that coal powered electric plants are terribly inefficient, the logistical problems of degining a low energy CO2 trapping and compressing system, scale it all back up to real-world, then ask who is going to pay for all of this. Doesn't this proposed system sound an awful lot like a perpetual motion machine? It's taking more energy to trap the CO2 than what is generated from the coal.
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It could be that it would take more energy to trap the CO2 than what is generated from the coal, but it's not immediately obvious to me that this is true. It would only sound like perpetual motion if the claim was that the CO2 was going to be returned to a coal-like state. Recapturing CO2 is more difficult than sweeping up ashes after a fire, but cleaning up waste products is not equivalent to claiming the existence of a perpetual motion machine.

MattJ
 
Till <-- not a chemist.
Wouldn't it be feasible to use an artificial carbon cycle 1 engine instead of stack scrubbers at industrial sites. The waste is 02 and sugar , yes? I'm not sure of the energy or volumetric constraints in RE efficiency and speed, but I would think you could do some fancy molecular footwork and use the sugar with other compounds to supply ( as an adjunct ) the energy to breakdown the CO2 ?
 
TillEulenspiegel said:
Till <-- not a chemist.
Wouldn't it be feasible to use an artificial carbon cycle 1 engine instead of stack scrubbers at industrial sites. The waste is 02 and sugar , yes? I'm not sure of the energy or volumetric constraints in RE efficiency and speed, but I would think you could do some fancy molecular footwork and use the sugar with other compounds to supply ( as an adjunct ) the energy to breakdown the CO2 ?
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Bruce <--- not an engineer.
What is an artificial carbon cycle 1 engine?
 
An electrochemical cell or a passive catalytic cell , both would use energy ( UV? Electricity? regents ? ) to chemically separate the carbon from the O2 with sucrose as a waste product. I have seen some reaction vessels that do this a long time ago, so I was just wondering at the scale since the concept is viable. ala fuel cell or catalytic convertor.
 
TillEulenspiegel said:
An electrochemical cell or a passive catalytic cell , both would use energy ( UV? Electricity? regents ? ) to chemically separate the carbon from the O2 with sucrose as a waste product. I have seen some reaction vessels that do this a long time ago, so I was just wondering at the scale since the concept is viable. ala fuel cell or catalytic convertor.
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Do you have any links? I did catalyst research in graduate school. That sort of catalyst has been discussed as the "dream" catalyst by my colleagues, but to my knowledge, no one has ever discovered one.
 
So many chemists... :p



KC<-------Wants to be a chemist (and is in both organic and inorganic chemistry this semester)
 
Bruce said:
Do you have any links? I did catalyst research in graduate school. That sort of catalyst has been discussed as the "dream" catalyst by my colleagues, but to my knowledge, no one has ever discovered one.
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I've seen working fuel cells with methanol, but nothing with anything more oxidized.

CO2 is a huge thermodynamic sink. I'd like to know the other reagent that might be used. For example, CO2 + water to give sucrose and oxygen is endothermic by 100 kcal/mol per CO2 If I try other alternatives, something like methanol needs 190 kcal/mol per CO2. Probably the best thing you could imagine, methane, still requires 27 kcal/mol per CO2. That's a lot of energy that has to be overcome.
 
pgwenthold said:
I've seen working fuel cells with methanol, but nothing with anything more oxidized.

CO2 is a huge thermodynamic sink. I'd like to know the other reagent that might be used. For example, CO2 + water to give sucrose and oxygen is endothermic by 100 kcal/mol per CO2 If I try other alternatives, something like methanol needs 190 kcal/mol per CO2. Probably the best thing you could imagine, methane, still requires 27 kcal/mol per CO2. That's a lot of energy that has to be overcome.
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That's the thing that astounds me about plants!

There were some interesting dissusions related to this subject on the skeptical community board. I'd like to invite you and anyone else that is interested for comments.

http://www.skepticalcommunity.com/phpbb2/viewtopic.php?t=4585
 
Abdul Alhazred said:
Kidding aside, if we really need to reduce CO2, why not plant a lot of trees?
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Some people are planning to do just that, eg, I think Australia plans to do that to meet it's Kyoto obligations. It hasn't signed up for Kyoto, but it is going to do it anyway. Talk about having an each way bet.

Of course, if you are going to do this, you need space, water, etc. Australia has cleared a lot of land in it's brief history, so that won't be a problem. Getting the water to the trees so they grow could be a problem.
 
Bruce
I guess I was talking about lithium hydroxide as the catalyst. Most prevalent are Biological reaction vessels that use bacteria..
I had no idea that this is a holy grail of chemistry, that's why I was asking questions. Since this appears to me to be a strait forward chemical process (Carbon cycle) Is there no way to craft an emulation of the bio breakdown mechanism seen in plants?
 
TillEulenspiegel said:
Is there no way to craft an emulation of the bio breakdown mechanism seen in plants?
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There probably is, but to this day, scientists have been unable to even come close to mimicing the remarkable and efficient ability of plants to to harness sunlight and use it's energy to reduce carbon dioxide into sugars or other organic products. It really is a holy grail.

One of the research projects I was working on in graduate school was a platinum catalyst that appeared to oxidize water to O2 and H+ without the use of electricity. This is another holy grail. It would have got me a Nobel Prize. Unfortunately, it turned out that the oxygen was oxidizing the phosphine ligand on the platinum catalyst rather than being released as O2. Nine months of work down the drain, but I still got a publication out of it in Inorganic Chemistry.

Another catalyst holy grail was discoverd several decades ago. I believe it's called the Wacker process. It's a process were you expose N2 and H2 to a platinum catalyst and you get ammonia, NH3. If there is a catalyst that can do this, then there is probably a catalyst for the other two.

I really wanted to be a catalyst researcher when I entered college, but nobody appears to be hiring catalyst researchers anymore. It's probably because nearly all catalysts are discovered by accident. Discovery happens on its own time. It's hard to make money on something like that. :(
 
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