CO2 Capture solution?

Burning such weeds or algae will simply release CO₂. Is this what you really have in mind?

Tornado,

It simply means we get energy without generating extra CO2, the weed or plant will re-absorb back the CO2, that's why it is called renewable energy. If we burn fossil fuel to get energy, we get more and more CO2, that's is the problem, go watch Al Gore presentation: An Inconvenient Truth, very educational.

Agreed, if the next generation of biota can absorb the CO₂ released by burning the previous generation, this would be sort of a net-zero-effect loop. (And better than burning "banked" fossil fuels.)

Plants by nature use CO2 to grow and burning them is as old as fire. Agriculture and forestry are already supplying labour opportunities.

The actual problem today is that Forrest and agricultural land is consumed to satisfy the need for land to accommodate the growing population.

The situation can be rectified if the population can be reduced (Any volunteers?})

or humanity should be trained to require less energy.

Desalinating sea water is expensive and the energy needed to transport it to the places where needed would at this stage be more that can be produced.

Please also remember that a burning process will produce CO2.

I like your way of thinking, and some people are working in directions like that. I'm trying to remember some things (as I'm always forgetful)--a crop that can produce a large amount of matter (by dry weight) for burning in such a scheme is hemp. There are political problems with growing hemp, especially in the US.

(There may be a few crops that can produce more per acre on a dry matter basis--but I forget what they are--maybe sawgrass is one--oh, and there's one that is native to some part of Africa--when I read about it I've only ever seen them mention the latin name, which I have no chance of remembering or relating to--I mean, it could be poison ivy, poppies, coca plants, or whatever for all I know.

Other people are experimenting with growing algae in tanks, with the intent that the algae can easily be converted to oil or similar liquid fuels.

The reason I'm commenting though is to comment on the following statement.

Re: Sahara is good choice since it is hugh and just beside the sea, so water supply is no problem.

I wouldn't exactly call it no problem. I don't know how many dry land plants can grow in water with salt concentrations like you'd find in sea water. Plus, salt would build up in the "soil" (sand) of the desert and eventually there would be enough salt in the sand to prevent or severely inhibit growth.

OTOH, seaweed can grow in salt water--maybe an approach is to flood large areas of the Sahara with sea water (to shallow depths for convenience)--but that has problems--I'd expect much of the water will seep through the desert sands, and just be lost, and might also contaminate ground water supplies in the area.

And, of course, I assume the Sahara is generally above sea level, so either water would have to be pumped from sea level to the higher elevations, or excavation would have to be done to create lower elevation channels and "seabeds".

Still, there is a lot of solar energy impinging on the Sahara--finding ways to make better use of that would be good.

There are other thoughts about making use of large deserts like the Sahara--I've read about large scale plants to place solar photovoltaic or solar thermoelectric installations there. (The thought of windmills also crossed my mind, but the thought of the blades enduring sandstorms needs some consideration. (As does the effect of sandstorms on the surface of photovoltaic cells or mirrors used for thermoelectric installations.)

So, what do you plan to do to get efforts actually moving in one (or more) of those directions? (I'm not trying to be--what would the word be--I'm not trying to discourage you, or hint that you can't do anything. Instead, I'm tryhing to encourage you, because I believe that you, the same as everyone else on earth, both can and should get involved in finding the right directions for us to head in, and then pushing (or pulling) to get us moving in those directions).

Hmm, flooding the Sahara with Seawater. I guess it would be a good way to sterilize the Sahara against any future plant growth as the salts build up. Seaweed can tolerate high levels of salt, but even they can not grow in the dead sea or great salt lake.

GA

Re: Hmm, flooding the Sahara with Seawater. I guess it would be a good way to sterilize the Sahara against any future plant growth as the salts build up. Seaweed can tolerate high levels of salt, but even they can not grow in the dead sea or great salt lake.

If my post #5 left the impression that I was advocating flooding the Sahara, that was not my intent. The more viable answers (imo) are those I mentioned in the 2nd last paragraph--solar photovoltaic or solar thermal voltaic.

(PS: I intended to respond yesterday, but apparently encountered the limit on number of posts allowed in a 24 hour period, and, it appears, had to wait a full 24 hours before being able to post again.)

There are already several commercially viable processes that convert CO2 into biomass using algae. The biomass can be used as animal feed, converted to diesel for fuel or burned for a net zero gain in CO2. Right now its just the economics that hold it back.

Adding iron and phosphate to sea water would increse very much algea growth.

Who will pay for it?

by turning the deserts of the world into farms, will alter the worlds weather systems, therefore negating the effects of capturing CO2 using the methods you suggest.

As it happens, only last night on the Discovery Channel (UK) they covered CO2 capture. Two Americans called the Wright Brothers (no relation to the flyers) have invented a synthetic material that will catch CO2 but requires washing to remove the CO2, the next problem is what to do with the CO2 laden water, and thats another topic.

I was of the opinion that methane was more of a problem than CO2!

If we change the Sahara into farm, we may also solve the unemployment problem of youths in Arab world, we may also solve the world terrorist problem !

Re: by turning the deserts of the world into farms, will alter the worlds weather systems, therefore negating the effects of capturing CO2 using the methods you suggest.

Would the world's weather system be altered for good or bad? Does anybody know?

Is it April 1st today?

I have a simple concept for you to grasp. Think of a tree, crude oil or coal. All three of these are something that contain carbon. Some took years to accumulate the carbon, some took centuries. When you burn a fuel that SAME carbon is returned to the atmosphere. Your suggestion to burn algae or weeds is no different. It isn't so much about the fuel or how fast it grows. It's all about fuels that release carbon in the burning process.

I wish I could see the problems of life as simply as you do Fill the Sahara with seawater, why didn't I think of that???

Re: Your suggestion to burn algae or weeds is no different. It isn't so much about the fuel or how fast it grows. It's all about fuels that release carbon in the burning process.

I think posts #2 and #4 address your first point.

I confess I never read the entire thread. I was just trying to keep it simple. If I understood him right he didn't seem to understand that there isn't "new" carbon.

that there isn't "new" carbon.

That's is the whole point of growing weeds/plants and burning them, there isn't new CO2 added, but we get energy .

Like I said, I was trying to keep it simple....where do you think the carbon the plants consumed has disappeared to? When you burn the algae or weeds the carbon you captured is released AGAIN. I can't make it anymore basic than that.

Fill the Sahara with seawater, why didn't I think of that???

Hi Fredski,

I was not suggesting filling Sahara with seawater, but using hydroponic to grow weed or plant, and Sahara provide hugh land space.

First of all, Co2 is not a problem!

And to try and solve a non-problem by introducing a un-natural plat into our ecosystem is IMHO foolish.

Look at history;

Water hyacinth has been widely introduced throughout North America, Asia, Australia and Africa. They can be found in large water areas such as Louisiana, or in the Kerala Backwaters in India. In many areas it, particularly E. crassipes, is an important and pernicious invasive species. First introduced to North America in 1884, an estimated 50 kilograms per square metre of hyacinth once choked Florida's waterways, although the problem there has since been mitigated. When not controlled, water hyacinth will cover lakes and ponds entirely; this dramatically impacts water flow, blocks sunlight from reaching native aquatic plants, and starves the water of oxygen, often killing fish (or turtles). The plants also create a prime habitat for mosquitos, the classic vectors of disease, and a species of snail known to host a parasitic flatworm which causes schistosomiasis (snail fever). Directly blamed for starving subsistence farmers in Papua New Guinea, water hyacinth remains a major problem where effective control programs are not in place. Water hyacinth is often problematic in man-made ponds if uncontrolled, but can also provide a food source for gold fish, keep water clean and help to provide oxygen to man-made ponds.

Re: First of all, Co2 is not a problem!

What is your basis for saying that?

It's not as much of a scientific issue as it is a issue!

Political? "When Scientists and politicians get in bed together, pay close attention!

CO₂ is about 0.0387% of the atmosphere... I will not accept that this small percentage is having such a major affect on climate! Consensus is not scientific!

But mostly I see people positioning themselves to benefit from carbon tax and other shady schemes!

While I agree that introduction of non native species can be problematic, I wonder why it is not obvious that we face the same, but far more serious problem, of assimilating modern humanity into the global environment without reeking environmental destruction.

Co2 is a problem. Smog is a problem. Mountaintop removal is a problem. Freshwater depletion and pollution is a problem. Over population is a problem. Pesticides and herbacides that injure micro ecosystems are a problem. Overfishing is a problem. They are all the result of introducing un-natural "plats" into the world. We can deal with them, but to sit in a hole and deny that we have created problems that are less serious than introducing non native plants is a little crazy. (IMHO)

Aside: I gave you a GA.

But, what do you mean by "plats"?

plants

Re: plants

Well, maybe, but I didn't (and don't) see how all of:

Co2 is a problem. Smog is a problem. Mountaintop removal is a problem. Freshwater depletion and pollution is a problem. Over population is a problem. Pesticides and herbacides that injure micro ecosystems are a problem. Overfishing is a problem.

... are

all the result of introducing un-natural plants into the world.

??

Ahh, now I see--I guess you're right--the "plat" originally came from a typo in post #18--I thought PFR introduced it in post #20.

Fredski, you are the man! He points out below that RHK meant "plants" Honestly, in my thick head, I had guessed that "plats" was a reference to the outline of a real property, and while it did not strike me as the best use of the word, I was not going to focus on that. So of course all of those issues I raised were not all caused by plants, but by the general concept of environmental domination.

Thanks, good articles. I would note that the article says the offset cooling effect from aerosols is a short term thing while CO2 can remain in the atmosphere for 100s of years.

So, what do you think the chances are of most of us becoming vegetarians?

And then, what happens if beans become a staple part of our diet? (This last is somewhat tongue in cheek, but not entirely.)

I wish some could explain the paranoia that CO2 remains in the atmosphere for 100s of years. Of course it does. CO2 has been in the atmosphere for thousands, hundreds of thousands of years. Without CO2 in the atmosphere no plants would have grown since the Garden of Eden. CO2 is essential to the growth of green plants.

The question is not how long the CO2 remains in the atmosphere, it is a question of the relative rates of production by burning carbonaceous materials and the rate of consumption by photosynthesis.

Re: CO2 has been in the atmosphere for thousands, hundreds of thousands of years.

Of course you're right!

Re: The question is not how long the CO2 remains in the atmosphere, it is a question of the relative rates of production by burning carbonaceous materials and the rate of consumption by photosynthesis.

Do you (or somebody) have any figures. AIUI, the CO2 level in the atmosphere is increasing, so the relative rates or production and consumption are not in balance.

And the related point in the article is that aerosols do not remain in the atmosphere that long, so they're offsetting cooling effect is only in the short term.

Methane is a BIG problem.. there is a methane glacier in Canada that releases thousands upon thousands of tonnes of the gas EVERY year into the atmosphere.. but not a lot of people know about it or even care..

NOW that is a problem, that and the exhaust gases of the world population of cows.. and now you want the human population to become bean freaks??

Gas..Gas..Gas!!!

So, what do you think the chances are of most of us becoming vegetarians?

Not likely, but those who do will live longer.

what happens if beans become a staple part of our diet?

If you are referring to getting gas from beans, there are ways of dealing with that. You get B vitamins form beans which helps, so the more you eat them the less problem you have.

Re: ways

Thanks, good article!

Dear friends:The problem is not only to be or not to be vegetarians, because producing milk requires cows,and Chaina is now encouraging milk production!

There are many research projects going on right now to use algae for CO2 sequestration use.

See:http://www.biofuelsdigest.com/blog2/2008/08/21/carbon-dioxide-sequestration-via-algae-biofuels-an-overview/ for one

And another: http://www.biofuelsdigest.com/blog2/2008/08/21/carbon-dioxide-sequestration-via-algae-biofuels-an-overview/

And there was a recent story on "60 Minutes" I believe concerning this: http://www.exxonmobil.com/Corporate/energy_vehicle_algae.aspx

There is a lot of work going on since coal is still very plentiful and by use of coal gasification, combined cycle plants and fuel cells it can be used cleanly and the relative ease of Co2 capture compared to coal burning plants makes use of algae to act as the carbon sequestration (CO2) method along with the warm water given off from fuel cells

What do you want to do with the algae to maintain the carbon sequestration?

Not sure of the answer you're looking for from the way your question was poised or phrased. Obviously the algae is there to absorb the CO2 the way all normal algae does and grow and multiply through photosynthesis. Research now is to come up with super algae, if you will, to absorb more CO2 and proliferate more. Some avenues of research are going for algae that will actually produce a bio-oil or bio-fuel as an output of the algae(Exxon project working with DNA researcher Craig Venter). Others are tending to grow the algae to become a bio-mass to be utilized as a feed stock for ethanol production like many other bio-masses are (sugar cane in Brazil, switch grass in USA etc.. Instead of shipping coal back to power plants in 200 car trains they can ship the bio-mass either dehydrated or partially treated and liquefied as a biomass feed stock to ethanol plants or plants could be built on site. The old coal burning power plants instead of burning coal could switch over to the syn-gas produced as an output of the coal gasification plant.

This would reduce dependence on foreign oil, create jobs in engineering, foundries, steel mills, manufacturing,turbines, pumps, motors, generators, etc. plus all the mom & pop stores that provide food, lunches, work clothes et. al.

Algae doesn't maintain the CO2, it gobbles it up and converts it to more algae which then becomes the source of more power and less oil used up or used for areas where it is more needed or less replaceable like home heating or gasoline production. Perhaps this is more germane as a specific answer to your question.

Hmm, seems simple enough asking how you would sequester the carbon. In a very obscured manner you answered the question. Since biofuel only sequesters carbon during the period between biological capture and the use as fuel, which is a relatively short period. So in essence you are only sequestering the carbon emission for a weeks, before it finally does get dumped on the atmosphere, effectively loading the atmosphere the same as burning the coal would have originally without the intemediate steps (and added cost). This is not a net neutral effect (such as natural capture by plants/algae/bacteria of atmospheric CO2), but always the same positive carbon loading effect that would have always been there witht he coal burning as the original source. While this recyles the carbon and makes use of it, it really doesn't address any carbon loading issues from coal. Coal in and of itself is a very long term carbon sequestering process, much like limestone and dolomite are. This is comparable to using a plastic bottle twice before dumping it into the landfill instead of once. So there is no real atmospheric pollutant gains (though some marketing attempts may try to spin it as such), then the question becomes is the cost benefit ratio there without adding on some unrealizable pollution reduction benefit. If they were really going to gain from the carbon sequestration, then they would dry and bury the algae, effectively removing it from the atmosphere.

As far as the claim that burning coal would build a stronger US economy, well that is highly speculative.

Unless you are proposing either eradication of the human specifies or total elimination of the use of all fossil fuels say thru the use of nuclear power there will be some "carbon" release. By the use of the term "carbon" I am presuming that you are referring to the release of CO2 into the atmosphere.

Eliminating all human and animal existence would cut down on the production of CO2. Converting all building heating units to electrical with the electricity provided by nuclear with some provided by wind and solar would do much to drop the release of "carbon" into the atmosphere.

Part of that should also be the strict rationing of power to all surviving humans. No matter how wealthy or how big a house they only should be allowed x number of kilowatt hours per day or per month. How they chose to use it is their problem. The poorer can use it for heat and light and refrigeration and the wealthy can sit in their cold entertainment rooms watching their 60" TV's and listening to their 1000 watt stereo units.

I suppose we could just pump all that CO2 down some deep holes at some high pressure. Then we have to hope that it doesn't seep into the molten core and cool parts of it off creating some sort of imbalance of the earth's axis sending Earth totally off kilter so that the Sahara ended up where the North pole used to be and the Artic ending up at the Equator. Because then the polar ice cap would end up melting and raising the sea level a good 10 feet not to mention what would the polar bears eat up in there in the Sahara.

As to plants being a net neutral that claim is not entirely true since trees are cut down for firewood and saw mills that produce lumber do burn some of the saw dust and chips to produce heat and power for their operations. Hay is grown and cows, horses and other animals eat the hay and produce a lot of methane which is worse than the CO2.

If you have a good or better idea on utilizing the CO2 that gets produced keeping man alive, fed and comfortable I think we would all like to hear it. Just saying "No, don't produce CO2" however, doesn't cut it with most engineers.

Actually all I am doing is shining a light on your original efforts to make coal appear like it can be a green technology in which carbon sequestration will occur through the use of algae.

Eliminating life would not cut down on the CO2, just the opposite it would likely increase it vastly initially as everything decayed eventually the plants would reach a equilibrim again (close to current levels because low levels would impede plant growth).

In truth, you are selectively interpreting the term sequestration to make it seem like a few weeks longer of retention before release to the atmosphere would be any different than the carbon release directly from coal. Then you defer the carbon load off onto another industry, thereby showing a near net 0 impact from coal, with all the imapct showing up as a fuel (with an added cost associated with the refining and processing to make fuel). It is simply cooking the books like the banker were doing a few years ago with toxic mortgages, transferring temporarily the bad mortgages onto a spin off corporation right before the quarterly reporting was conducted so they could show a profit on their books. This would be fine if they included spin off corporation in their accounting.

While it is true humans emit CO2, all the CO2 present in the atmosphere is in a psuedo equilibrium between the oceans, and life forms on the planet. Plants, animals, bacteria, and the ocean represent a generally net neutral carbon balance. Coal, limestone and dolomite are unavailable sources from outside that carbon cycle that just increase the carbon dioxide in that cycle when thermally oxided. Coal, limestone and dolomite also, represent extremely long duration sequestrations (removal in effect ) of carbon from that carbon cycle. So there is actually no carbon sequestration benefit to what you have suggested, unless we generate huge quantities of biodiesel and pump it back down oil wells or bury the algae collected and bury it in the coal mines (and seal to minimize decomposition, which would have to be accounted for then) effectively removing it from the system.

So as it would not represent a true carbon sequestration process, where in carbon is removed from the atmospheric pool, then the real value is in the financial profitability of utilizing the carbon a second time as a liquid fuel before it enters the atmosphere.

Of course I can see how coal interests might lobby for coal to be considered as a green technology under such a premise, so they can benefit from the government funding programs and tax reductions (this kind of funding benefits on the books would definitely make it profitable then, with all the risk deferred off onto another industry). Afterall, congress just needs a cover story they can sell the news organizations who will present it in simplest possible concepts to the public (as soundbite and such). Then the congressmen can take the large campaign donations for their support of the coal lobbies, without major public scandal.

In trying to follow your train of reasoning I find that it zigs and zags to so many directions at dizzying speeds that whatever your point is it becomes obtuse midway through.

I have no "coal agenda" which I believe was one of the points you were accusing me of. I do know that the US Government through the Dept. of Coal Research started spending billions of dollars back in the 70's when the first oil crisis hit so the money has already been spent so now is the time we should start recovering that investment by using the "clean energy" that some of that research showed is possible. The current research into algae should enhance those processes by adding a dimension that was not available back in the 70's & 80's.

There will be CO2 added to the atmosphere by most of the current carbon based power generation units. I feel that those units should be replaced by these other technologies.

Oh, please don't tell the dinosaurs that a lush planet full of CO2 is what actually will kill them off. They might sell off their Fanny Mae and Sallie Mae stocks.

Hmm, it is always good to start off with a attack against the commenters or structuring of comments (especially if they are direct responses to previous comments above). This is a good red herring method to deflect analysis into an attempt to rebrand a questionable proposal in friendlier terminologies.

Dinosaurs? Are you proposing that it would be acceptable outcome to raising CO2 levels to the point they were at 65MY? Bear in mind CO2 is also in a psuedo-equilibrium between our blood and the atmosphere. The CO2 in your blood occupies activity sites where oxygen would be adsorbed. Changing the CO2 to O2 ration would effect oxygen uptake.

I believe you may be confused about the terminology. No one is (or should be) suggesting that algae is a good place to sequester Co2. To the contrary, coal is a very good place to sequester Co2. Sequestering Co2 is applicable to the continuation of fossil combustion, or devising a way to hold Co2 levels steady.

The scheme most people are envisioning with algae is to harness its prolific growth, and minimal nurturing requirements to provide organic oils or sugars for fuel production. These in turn reduce the requirement to burn fuels that have sequestered carbon. As you noted, the Co2 is not affected in any great way. The benefit is that Co2 is recycled, steady levels are the status quo, rather than liberated from coal or oil, which is a net gain format, with steadily increasing levels.

Look at his post #43 and I think you would see very explicitly where he is talking about sequestering CO2 from coal burning plants in algae, not sequestering CO2 in coal. He has proposed to burn the coal, capture the CO2 in algae and then use the algae to generate bio-fuels all under the term sequestering, thus liberating the CO2 from the coal and passing it through algae as a treatment once for reuse of the carbon as a fuel. He has already indicated in Post #52 above his misconception in coal as a "clean energy", and this is leading to the idea of coal being a "Green Energy" source.

Admittedly some people are envisioning using algae in a equilibrium with the atmosphere to generate fuels, then some people are trying to find schemes to get their existing nasty energy line to incorporate some back end treatment that involves a green source for treatment so they can make claims to be green energy and grab some of the benefits (tax breaks, even more government research grants, public support). This is a marketing pitch to spin coal in a better light through some sleight of hand.

I see now based on this response how you got off a such a tangent from my posts and that on a quick review of my posts I see that I hadn't clearly referred to using coal to produce syn-gas and electricity through the coal gasification process. I thought that it perhaps had been self evident to those more familiar with the processes based on the comments made.

I have NEVER advocated using coal as an energy source for direct fired coal burning power stations either through pulverized coal burning, liquefied coal burning or fluidized bed processes. Direct fired coal plants even with the best stack cleanup devices are poor for the environment.

So you are wrong that I am proposing "very explicitly" to "burn" coal, capture the CO2" and here I would assume that you meant from the stack gases and not "the coal". I really don't think that based on the sheer volume coming out of the stack that that would be economically possible .

I would suggest that you refer to the following:http://www.fossil.energy.gov/programs/powersystems/gasification/howgasificationworks.html and http://www.technologyreview.com/energy/24838/page1/

before you deride coal as not a "clean energy".

As far as your theory about pumping a biofuel down a hole or a coal mine shaft as a means of "carbon sequestration" I do not follow or subscribe to whatever that is intended to convey. To the best of my knowledge the intent of "carbon sequestration" is to prevent excess Carbon as CO2 from being released into the atmosphere and that is where the algae would come into play.

Do you by any chance work in the Nuclear Energy field because you seem to have some sort of Agenda aimed in that direction although it would seem strange that someone living in a state with so many fault lines would be pushing that in light of what happened in Japan.

And No, I have NO connections with either the coal industry, the power industry, the oil industry or the government or with any of the "Think Tanks" from the Universities like Berkeley et al who gobble up the taxpayer monies spitting out useless studies at great expense while rewarding Professors with grant monies so they can do research instead of the teaching they should be doing. I just happen to be an engineer who thinks that there is a better way to accomplish getting America back to work without foolish handouts and also clean up the environment at the same time. That is my ONLY Agenda.

"To the best of my knowledge the intent of "carbon sequestration" is to prevent excess Carbon as CO2 from being released into the atmosphere and that is where the algae would come into play."

Are you intentionally being obtuse? How does algae come into play, in the context we have been discussing.

To my mind growing algae from CO2 is not a way of sequestering or storing CO2, it is a method of using the algae and CO2 to produce a useful product i.e. animal feed, or fuel and thereby reducing the use of other products i.e. coal, or fossil fuels. The reduction in CO2 comes not from capturing the CO2 but in the reduction of the burning of other fuels which then produce more CO2.

Unclear as to how I'm being obtuse:

We could simply use the algae as fertilizer and apply it to the fields then you can have your carbon removal.

Enhancing Carbon Removal

All crops absorb CO₂ during growth and release it after harvest. The goal of agricultural carbon removal is to use the crop and its relation to the carbon cycle to permanently sequester carbon within the soil. This is done by selecting farming methods that return biomass to the soil and enhance the conditions in which the carbon within the plants will be reduced to its elemental nature and stored in a stable state.

Key word below (from Wikipedia) I'm referring to is the 5th (so as not to be obtuse) word which is "capture" and not "removal".

Carbon sequestration is the capture of carbon dioxide (CO₂) and may refer specifically to:

• "The process of removing carbon from the atmosphere and depositing it in a reservoir."^[1] When carried out deliberately, this may also be referred to as carbon dioxide removal, which is a form of geoengineering.

• The process of carbon capture and storage, where carbon dioxide is removed from flue gases, such as on power stations, before being stored in underground reservoirs.

You can pump the algae down an old oil well hole or into old coal mines for storage or complete removal or pump it down down as a liquid biofuel as previously proposed. I propose instead to use it as biomass to produce an alternate form of energy. I believe the use of biomass comes under the heading of a renewable energy source as opposed to fossil fuels such as oil and coal which are currently considered limited.

How does one sequester carbon in coal? I thought that would be a rather timely process like centuries or eons or millenniums and that only nature knew the trick as to how it's done.

"Unclear as to how I'm being obtuse:"

ok

"We could simply use the algae as fertilizer and apply it to the fields then you can have your carbon removal."

not true

"not true"

explain

spreading algae on the surface, or into the surface, of farmland, does not remove or sequester carbon on any other but a very short term temporary basis. You will not find short term or temporary anywhere in the discussion of sequestration. It has no net effect. It is merely part of the terrestrial respiratory process.

Coal and most petroleum has permanently sequestered Co2 until it is combusted, which has a net effect.

Wikipedia doesn't seem to agree with you

Enhancing Carbon Removal

All crops absorb CO₂ during growth and release it after harvest. The goal of agricultural carbon removal is to use the crop and its relation to the carbon cycle to permanently sequester carbon within the soil. This is done by selecting farming methods that return biomass to the soil and enhance the conditions in which the carbon within the plants will be reduced to its elemental nature and stored in a stable state.

By the way just what chemical process has enhanced your coal that it sequesters CO2? As far back as I can remember coal was considered a very pure state of Carbon and I never ever remember that CO2 was considered involved in the chemical or physical make up of coal. On the other hand CO2 is made up of Carbon and of course oxygen hence CO2. Coal as carbon would be represented as C and not CO2 or even for that matter CO. So just how do you propose to sequester your CO2 in C (for coal)?

Note below, O is not a major constituent of coal according again to Wikipedia.

Coal is composed primarily of carbon along with variable quantities of other elements, chiefly hydrogen, with smaller quantities of sulfur, oxygen and nitrogen.

"Coal and most petroleum has permanently sequestered Co2 until it is combusted, which has a net effect."

Sounds like a totally bogus claim to obtuse little me.

Net effect ? Removes oxygen from air and replaces it with CO and CO2? That is sort of the definition of combustion or burning i.e. combining with O2. See Wikipedia "Combustion or burning is the sequence of exothermic chemical reactions between a fuel and an oxidant accompanied by the production of heat and conversion of chemical species. The release of heat can create light.

Don't know how oil(petroleum )has sequestered any CO2 either but maybe I'm just being obtuse.

While coal is in the ground, unused, the carbon in it can be considered sequestered. Also, the carbon in that coal will not become CO2 while it is in the ground, unused (usually--barring things like coal seam fires).

If your objective is to avoid CO2, a good way to do that (ignoring energy costs) is to separate the carbon and oxygen--use the oxygen for something useful, bury the coal.

If you consider burying algae as a means to sequester carbon / CO2, it's not very useful, especially in coal mines that you've mined to burn, by volume, (and mass) you're going to sequester a lot less carbon / CO2 than you would by just leaving the coal there in the first place.

Saying not using coal is sequestering it may be a slight misuse of the language, because it is a passive thing, not an active thing, but I think the intent can be understood.

OK, I guess a better way to say it, not burning coal avoids the need to sequester CO, CO2, or C after burning it.

The storage and use of carbon in soils is complex as RCE indicates.

Unless Obama has repealed the laws of thermodynamics, it takes more energy to separate the carbon and oxygen than you got when you burned it the first time. If you use carbon based fuel to create the power to separate them yo needlessly burn more fuel that creates more CO2 etc.etc. etc. If you use nuclear, then you might as well go that route to begin with and not burn the fuel in the first place.

The simplest solution is to use algae and beneficially use their waste products, the biomass they produce. An added benefit is that the algae don't argue, don't have medical benefits, or an unfunded pension plan.

Nuclear would offer definite some benefits over coal with regards to carbon loading in the atmosphere. Though there are some major waste issues and hazards to consider with nuclear. Unless of course you are involved in some manner in the coal industry or a related dependent industry. Of course if there was a ways to deceive the public in to buying into the idea of green coal energy production, and you could get the tax and funding benefits from the government...

Hmm, first off I think I would trust my degrees in chemistry and soil science over a simplistic wikipedia article that is being misinterpreted out of context.

1. Organic Matter returned to soil does not necessarily contribute to soil OM, the portions that contribute to soil OM are the residual organic compounds that are resistant to decay. Algae doesn't contribute to the residuals. Plant tissues do contribute to this soil OM and can remain in the soil stable for many decades, depending on the level of oxygen, moisture and nutrients available. Selecting farming methods that return biomass to the soil, does not mean returnign just any biomass, but rather a biomass that is stable in the soil. In agricultural terms they are talking about plant residues as the biomass.

2. it is a mistatement to indicate that carbon from within plants will be restored to its elemental nature. They probably mean a less complexed structure. It is not returned to elemental carbon in the soil.

3. Rapidly decaying biomass added to soil doesn't provide fertility, it actually creates a competition for nutrients in the soil such that micro-organisms out compete the plant root systems and more nutrients need to be added.

4. Coal isn't even close to pure carbon. Coal is composed of high carbon content ( long chained, polycyclics/aromatics,etc.) hydrocarbons. Diamonds and graphite are nearly pure elemental carbon (though there is a small percentage of impurities, thus the coloration of diamonds).

5. You can equate equivalents in any term, as coal is not pure carbon either. You can equate it in terms of carbon equivalents or carbon dioxide equivalents, depends on how you plan to use it. Carbon per unit mass is a good reference to use for measuring potential energy density. On the other hand for carbon dioxide impacts measuring it in terms of carbon dioxide equivalents per unit mass would be a good way to estimate impacts to the environment. However, neither carbon or carbon dioxide accurately represent the molecular composition of coal.

6. carbon that is not oxidized to form CO2 is sequestered, as coal was originally plant tissues that collected the CO2 from the atmosphere and then were buried before they decayed fully to release arbon back to the atmosphere as CO2. Oil is similar to coal in this aspect of sequestering ancient CO2 collected from the environment in biomass that was retained as the residues we see today (coal and petroleum). The time frame of these sequestrations is in terms of millions of years, not weeks. Limestone and Dolomite are similar but not directly attributed to the biomass organics, though much of it is derived through biological processes.

7. I really do not see any relevence to the definition of combustion, as the most common oxidant used is O2, which is derived from the atmospheric oxygen. What do you think an oxidant is? it is a recombintaion of molecules to forma new molecule , but the aoms are still there

8. BTW exothermic means the reaction releases energy typically in the form of heat. If it absorbed heat it would be endothermic.

Many of your misconceptions are really involve rudimentary chemistry and geology. It sounds much like this marketing guy I met with a few months ago who was trying to convince me that there was strong scientific support for the hexagonal shape of his pipe improving water quality and reducing bacterial loads. He tried to throw in a bunch of psuedo chemistry and microbiology sounding terminology and definitions that he felt augmented his statements.

"Hmm, first off I think I would trust my degrees in chemistry and soil science over a simplistic wikipedia article that is being misinterpreted out of context. "

"4. Coal isn't even close to pure carbon. Coal is composed of high carbon content ( long chained, polycyclics/aromatics,etc.) hydrocarbons."

Funny, I only find those references to"coal tar" and petroleum hydrocarbon products. No one seems to indicate that they are actually present in "coal" itself which it appears you are very insistent upon above. Evidently you have more recent documentation concerning this new finding of yours. Most of the "complex hydrocarbons" that we used do hydro-cracking and catalytic-cracking on to break down into simpler hydrocarbons have all been changed in your textbooks.

Strange too how so much graphite is found in coal. Isn't graphite considered a "pure form" of carbon? Guess I should have tossed my old text books when I stopped going for my Ph.d

Still have to give no better than a D on No. 4

Actually most of the algae will decay when applied as a soil amendment (not really a fertilizer), thus releasing the carbon as CO2. Algae doesn't have the highly resistant carbon compounds you find i higher plants that for soil residual organic matter (which is beneficial for soil structure).

Additionally, the high carbon content applied to soils would actually reduce the fertility as the C:N ration would increase. To maintain fertility for plant growth you would then need to augment the soil with fertilizers particularly nitrogen, which would accelerate decay. Plants depends on a low C:N ratio in their roots for uptake.

Also, carbon in Plants is not in its elemental nature.

Finally any use of a new unavailable carbon source for energy will always equate to a net increase, not a net neutral effect. The only real benefit might be some offset in use of other sequestered carbon sources as fuel, e.g. natural gas or petroleum. however, both of these are environmentally cleaner than coal (even without the CO2 issue). So to clean coal you must also consider all the hazardous waste you must generate (coal has a significant amount of heavy metals and radionuclides, which you don't find in something like natural gas). So then you must consider the cost for the waste generated from cradle to grave for the carbon, including all processing wastes costs associated with the forms the carbon to see if the benefit is really there for coal over some other natural carbon fuel reserve.

Might want to read this article before you push for Natural Gas as a be-all end-all solution.

http://www.technologyreview.com/energy/37390/?mod=chthumb

Original thread posted is below, original line of discussion, original questions posed. Note use of word "algae". If you want to veer off the original discussion you should simply start a new post and not simply throw out snide comments at those who stick to answering the person's question.

Since CO2 is such a big problem, why can't we find or genetic engineer a weed , or plant or algae that grow ferociuosly on land or at sea, harvest them and just burn them for energy.

If we find or genetic engineer this plant or weed that fit or nearly the bill , and if we do not have enough land to grow them , we can use hydroponic method to grow them in desert . Sahara is good choice since it is hugh and just beside the sea, so water supply is no problem.

So, we kill four birds with one stone: capture CO2, provide energy, provide plenty of jobs and possibly de-desertify desert.

Since it was you who went so far off the subject and got nasty when your inaccuracies were pointed out I think you should review the meaning of obtuse below.

Definition of OBTUSE

2

a : lacking sharpness or quickness of sensibility or intellect

b : difficult to comprehend : not clear or precise in thought or expression

thanks. So how does coal-gas Co2 solution you proposed fit here?

See Post #78

direct or indirect, you did advocate using coal. You will still have the waste, even from processes like gasification.

"There is a lot of work going on since coal is still very plentiful and by use of coal gasification, combined cycle plants and fuel cells it can be used cleanly and the relative ease of Co2 capture compared to coal burning plants makes use of algae to act as the carbon sequestration (CO2) method along with the warm water given off from fuel cells"

You just elaborate another process at the front end to make it appear the plant doesn't run on coal, but rather the gassified coal. The waste is still there, whether it is in the front end before the energy production stage or during the energy production stage (as in tradition coal fired plants). Syn gas still depends on coal which has hazardous materials within it that must be disposed of, plus unlike efficiently burned coal, the residues from syn gas production will concentrate the wastes and some of the very durable carbon constituents will remain (some of those that could be dangerous also).

I'd like to request that you give it a rest.

Algae growing schemes can help in carbon sequestration to the extent that they allow us to burn less coal. The carbon in the coal remains sequestered.

There is a slight additional amount of sequestration due to the life cycle of the algae and the subsequently produced fuel, but that is a trivial amount. I don't know why I even mention that.

And, I haven't tried to explain very well what I mean--but just for kicks: Given a steady rate of algae growth (which captures carbon), and subsequent conversion to fuel and then burning (which releases the carbon), there is some amount of carbon always tied up in the process. Only, if you stop growing algae, then convert all of it to fuel, and finally burn it, then no carbon remains sequestered in the process.

But it is, I'm sure, a trivial amount. The big benefit of something like algae comes from not burning fossil fuels, and leaving the carbon sequestered there, sequestered.

Spinco's other point may be that, by using more modern methods of utilizing coal, for example, coal gasification, combined cycle plants, and fuel cells, it may be be possible to burn coal more efficiently, getting more energy for a given amount of carbon release.

Thanks, I'm glad to see that someone got my point.

You have actually identified my point about him playing with the terminology. Yes carbon is sequestered for a few weeks or months, as I stated above in the algae and biofuels until it is used.

You actually have to collect the majority of the algae otherwise they reach a limit for the system they grow in with regard to oxygen and other nutrients and the CO2 jsut passes through without being extracted. To process into a biofuel you must collect and extract the stored carbon, and start a new batch growing. Thus you are releasing the carbon collected in the algae from the coal emissions and convert to a biofuel that then releases it as CO2 when used as fuel (and coal is far more carbon rich per unit mass than biofuels). In general this is not the intent of the term carbon sequestration, to delay the release of new carbon sources. i.e. from coal, into the atmosphere by a few weeks or even months. Now if the algae, or biofuel, was to be buried. So in the end the only sequestered carbon is that bound up in the small amount of algae used to spike and start a new batch, which is insignificant compared to the algae extracted for fuel processing. In general sequestration is about maintaining a store of carbon extracted from the atmosphere, to reduce the effective atmospheric stores.

BTW he doesn't imply we should burn less coal anywhere by replacement with something from algae, but rather we might use less petroleum. So there may be some offset to consider in petroleum. however, it is really a cost issue at that point as no benefit in savings relating to coal emission as those emission still occur, just deferred to somewhere else

So the right way of using algae is , some algae growned will not be burned but permanent buried, thus permanently removing CO2 from atmosphere, while some algae is burned for energy without generating more CO2. THis way, you can restore CO2 to previous level. If we continue burning fossil fuel , we must have in parallel keep burying algae to recycle CO2 back to stored state.

What part of post #43 did you read? Very explicitly see below from that post. Strange no mention of "coal burning plants" that I can see. No mention of burning the coal in order to capture the CO2. No mention of sequestering CO2 in coal because that doesn't exist as a process and no one I know is working on it besides Mother Nature. Suggest you look up what coal gasification is before you denounce it. As far as Green Energy goes it refers to renewable source energy like sunlight, wind and, oh yes, growable feed stocks like for ethanol and bio fuels.

From Post #43

"There is a lot of work going on since coal is still very plentiful and by use of coal gasification, combined cycle plants and fuel cells it can be used cleanly and the relative ease of Co2 capture compared to coal burning plants makes use of algae to act as the carbon sequestration (CO2) method along with the warm water given off from fuel cells"

Fabrication should be done in metal shop not on line.

Re: No mention of burning the coal in order to capture the CO2.

From Wikipedia: Coal gasification:

Coal gasification is the process of producing coal gas, a type of syngas-a mixture of carbon monoxide (CO), hydrogen (H2), carbon dioxide (CO2) and water vapour (H2O)-from coal. Coal gas, which is a combustible gas, was traditionally used as a source of energy for municipal lighting and heat before the advent of industrial-scale production of natural gas, while the hydrogen obtained from gasification can be used for various purposes such as making ammonia, powering a hydrogen economy, or upgrading fossil fuels. Alternatively, the coal gas (also known as "town gas") can be converted into transportation fuels such as gasoline and diesel through additional treatment via the Fischer-Tropsch process.

...

During the reactions mentioned, oxygen and water molecules oxidize the coal and produce a gaseous mixture of carbon dioxide (CO2), carbon monoxide (CO), water vapour (H2O), and molecular hydrogen (H2). (Some by-products like tar, phenols, etc. are also possible end products, depending on the specific gasification technology utilized.)

The coal is oxidized, which is another name for burning. It is only partially burnt (leaving some CO instead of all CO2--if it was completely burnt, the end product would be all CO2). In the process of gasification, the carbon that was sequestered in the coal is released (as CO and CO2 (and perhaps other byproducts like tars)) and adds to the carbon in what I'll call the "carbon cycle" near ground level and above (i.e., the atmosphere, the oceans, soils, plants, animals, etc.).

While the carbon was in the coal, it was not in circulation in the "carbon cycle".

That's more a statement of how the OLD coal gas plants operated rather than the current concept which is currently being built in Pa. and Illinois and throughout the world including China. The modern concept is below. Note the difference stated between the Wikipedia definition as far as by-products and the ability to contain and gather CO2 and the other by-products that are readily collectible. This is more factual than the opinions expressed elsewhere by resident pundits who evidently rank their knowledge as superior to all others and who evidently tag team to give each other "good" answers despite how erroneous they may be.

How Coal Gasification Power Plants Work

The heart of a gasification-based system is the gasifier. A gasifier converts hydrocarbon feedstock into gaseous components by applying heat under pressure in the presence of steam.

A gasifier differs from a combustor in that the amount of air or oxygen available inside the gasifier is carefully controlled so that only a relatively small portion of the fuel burns completely. This "partial oxidation" process provides the heat. Rather than burning, most of the carbon-containing feedstock is chemically broken apart by the gasifier's heat and pressure, setting into motion chemical reactions that produce "syngas." Syngas is primarily hydrogen and carbon monoxide, but can include other gaseous constituents; the composition of which can vary depending upon the conditions in the gasifier and the type of feedstock.

Minerals components in the fuel, which don't gasify like carbon-based constituents leave the gasifier either as an inert glass-like slag or in a form useful to marketable solid products. A small fraction of the mineral matter is blown out of the gasifier as fly ash and requires removal downstream.

Sulfur impurities in the feedstock are converted to hydrogen sulfide and carbonyl sulfide, from which sulfur can be easily extracted, typically as elemental sulfur or sulfuric acid, both valuable byproducts. Nitrogen oxides, another potential pollutant, are not formed in the oxygen-deficient (reducing) environment of the gasifier; instead, ammonia is created by nitrogen-hydrogen reactions. The ammonia can be easily stripped out of the gas stream.

In Integrated Gasification Combined-Cycle (IGCC) systems, the syngas is cleaned of its hydrogen sulfide, ammonia and particulate matter and is burned as fuel in a combustion turbine (much like natural gas is burned in a turbine). The combustion turbine drives an electric generator. Exhaust heat from the combustion turbine is recovered and used to boil water, creating steam for a steam turbine-generator.

The use of these two types of turbines - a combustion turbine and a steam turbine - in combination, known as a "combined cycle," is one reason why gasification-based power systems can achieve high power generation efficiencies. Currently, commercially available gasification-based systems can operate at around 40% efficiencies; in the future, some IGCC systems may be able to achieve efficiencies approaching 60% with the deployment of advanced high pressure solid oxide fuel cells. (A conventional coal-based boiler plant, by contrast, employs only a steam turbine-generator and is typically limited to 33-40% efficiencies.)

Higher efficiencies mean that less fuel is used to generate the rated power, resulting in better economics (which can mean lower costs to ratepayers) and the formation of fewer greenhouse gases (a 60%-efficient gasification power plant can cut the formation of carbon dioxide by 40% compared to a typical coal combustion plant).

All or part of the clean syngas can also be used in other ways:

• As chemical "building blocks" to produce a broad range of higher-value liquid or gaseous fuels and chemicals (using processes well established in today's chemical industry);
• As a fuel producer for highly efficient fuel cells or perhaps in the future, hydrogen turbines and fuel cell-turbine hybrid systems;
• As a source of hydrogen that can be separated from the gas stream and used as a fuel (for example, in the hydrogen-powered Freedom Car initiative) or as a feedstock for refineries (which use the hydrogen to upgrade petroleum products).

Another advantage of gasification-based energy systems is that when oxygen is used in the gasifier (rather than air), the carbon dioxide produced by the process is in a concentrated gas stream, making it easier and less expensive to separate and capture. Once the carbon dioxide is captured, it can be sequestered - that is, prevented from escaping to the atmosphere, where it could otherwise potentially contribute to the "greenhouse effect."

You should really have had a citation / link to the stuff you pasted it. Here it is (I think): DOE - Fossil Energy: How Gasification Power Plants Work

I wish the picture were a little bigger, or had a link to a bigger version, parts of it are very difficult to read. I think, but am not sure, that the word in the dark blue circle (the top circle) on the left hand side is coal. In any event, I assume one of the inputs is or could be coal. My comments apply even if the only fossil fuel input petroleum coke residue (or residual petroleum coke).

I see no significant difference between this description and the Wikipedia description, especially if you focus primarily on the gasifier.

The gasifier takes fuels containing carbon, combines them with steam and oxygen, and produces CO and H2 as combustible gases, and other usable or waste byproducts.

So, if coal or another fossil fuel is one of the sources of carbon for the process, that carbon, which was, for millions of years, sequestered in the coal (or oil), is no longer sequestered.

Absolutely correct. However, again it is not carbon that is being tagged as the bad guy in global warming, it is carbon dioxide and this whole discussion started on removing CO2 and not on removing C from the atmosphere. The only way for complete sequestration of carbon is not to burn ANY fossil fuel, whether it's coal or oil or any carbon containing matter.

Until fusion is developed I see very few alternatives to that not happening to some degree to produce the energy needs of this planet.

Re: However, again it is not carbon that is being tagged as the bad guy in global warming, it is carbon dioxide and this whole discussion started on removing CO2 and not on removing C from the atmosphere.

When you burn carbon, you basically create CO2. (CO may be formed as an intermediate product, burning under stress (i.e., with insufficient oxygen but other impurities may create some gases containing carbon other than CO or CO2--I don't really know--ahh, but some of the tarry byproducts of coal gasification, do, I'm sure, contain carbon.

What I'm trying to say is that it is a common and understandable shorthand to talk about carbon sequestration meaning to remove CO2 from the atmosphere.

Re: The only way for complete sequestration of carbon is not to burn ANY fossil fuel, whether it's coal or oil or any carbon containing matter.

Close enough, I guess. If you tried to be more precise, there would be two points to address:

• the carbon in a fossil fuel is already sequestered, so, in terms of language, rather than sequestering it, you are keeping it sequestered
• if you burn anything containing carbon (fossil fuel or not, e.g., trees, paper, plants, ...) you will put CO2 in the atmosphere. Assuming CO2 in the atmosphere and ocean is a problem, we may have to think about recapturing some of that CO2 and sequestering it.

Based on comments in this thread, I now understand that methane is a bigger contributor to global warming, so maybe we can do the job on global warming my concentrating on controlling methane in the atmosphere, or maybe get more bang for the buck going after methane.

But, I'm not sure that going after methane will help the oceans, which I believe are starting to have a problem with too much CO2.

Unless of course you return the CO2 waste product to the earth or capture it in some manner for a very extended period of time. One method would be capture by plants or algae and removal from the processes of biological decay, such as burial in a contained environment. This is probably a more elegant solution than direct pumping of the CO2 underground, as the Carbon is retained in a solid/fluid form and not a pressurized gas. the other is direct injection of CO2 deep underground (and hope it doesn't leak). Another might be chemical stabilization such as quick lime capture and disposal ina a dry area or deep underground (but then where does the quick like or other chemical reactants come from without releasing CO2).

It is fully possible to capture the carbon in algae, dry the algae and compress it, then bury it to replace the removed coal, or pump a slurry down oil wells to replace the remove oil. This would sequester at least some portion of the cabon, but obviously the algae would not have the same carbon density as the coal or petroleum so you would not get a 100% efficiency. The down side for the industry is it just becomes a cost with no profit to be made from the process.

As stated earlier though their may be some offset value in carbon reuse as a bio-fuel if it offsets use of other coal or petroleum use.

Also, it is possible to design a sequestering system for coal facilities, but it would only use coal initially until the algae grew sufficiently, then it would have to transition to using the bio fuel such that the CO2 waste stream from the biofuel would be captured by the algae and generate a new bath of biofuel. You can easily gasify algae (much like we do with solid waste streams or waste water solids). so in effect all the coal, petroleum or natural gas serve is to get the plant operating and feed the algae, once they mature you transfer waste flows to another batch while harvesting the algae from the initial batch. This would take a lot of land as you would bneed probably at minimum 2 reactor systems (probably 3 realistically or some diversion storage for interim transfer processes) to grow algae in so you could switch between them for harvest. So essentially after the first harvest the plant would be nearly self sufficient on gasification of the biomass from the algae. Once in a while it would need to be augmented for losses. Natural gas would make a better solution for this process though. Gasification of coal still has a waste stream for the remaining solids to consider and brings in more complexities to the process that for the most part is supposed to be psuedo stable on algea biomass for energy. It would take a huge amount of land to get some reasonably high efficiencies, and a CO2 recapture ssytem would need to be installed in the batch reactors to capture the off gas and transfer to another secondary system or route back through the batch reactor. Confound to that is the need for sunlight (which represents the free energy source being used to transform the carbon from CO2 to a organic compound). Simplest version might be a extemely alrge covered ponds with and collection system for off gas, and the covers being translucent so light could reach the algae. (Just bubbling CO2 through a pond will off gas a huge amount of CO2 that the algae won't capture).

I do not understand any possible technology that can "easily gasify algae" which is a solid by nature into a gas. Please do not suggest technology that does not exist unless you have specific knowledge and then share that technology with the world.

Algae is just another solid waste, actually much more like wastewater. Gasifying algae is not different than gasifying solid waste or wastwater. You can gasify wood in solid waste facilities, same process, just algae has less resilient solids than wood. You should google gasification and solid waste, you will fid a lot of information about gasifying organic solids. You can also look at gasification of water water, and you find out it is the dried organic solids they gasify. Nothing complicated about using it on algae, except that it is not mixed solids (much more homogenous than most waste solids used) and algea can readily be shaped during drying for optimal processing. Here is just one of many articles on gasifying solid waste,

http://pubs.acs.org/doi/abs/10.1021/bk-1978-0076.ch007

True but you might be interested in article also:

http://www.emerging-markets.com/biodiesel/pdf/BiofuelsInternational_FeedstockTrends_Algae_March08_WillThurmond.pdf

The gasification of solids like algae is essentially a partial or complete combustion process which then produces CO2 and other than the energy gain which offsets other fuels, what is the point?

As long as the off gases are captured they can be routed through a new batch of algae to be converted back to a more energy rich form of carbon for future processing into fuel. It is not 100% efficient, but you could keep re-capturing some portion of the carbon, and reuse it repeatedly, eventually all the carbon from the initial spike would bleed off through many reuses, but you would get substantially more energy delivered per mole of carboon through the process. So use far less hydrocarbons to get the same amount of energy delivered. Which becomes an offeet for othe hydrocarbons that would have had to have been used to generate the same energy directly. As indicated a offset, or really a more efficient use of the carbon, through repeated re-use before it is released. This does not address the issue of the new carbon from the original spike source eventually reaching the atmosphere though it may reduce new carbon from other sources.

There is no data that I could find anywhere even remotely suggesting that growing algae to absorb C02 then pumping this algae into wells or caverns is a viable sequestration strategy. The C density of algae is not in the same league. Second, it is profoundly unstable in algae. It is profoundly stable in coal. Now you are sounding like spinco.

More importantly, of course there are a lot of energy streams that do not produce Co2 as a byproduct. Solar PV, thermal, wind, hydro, wave, nuclear to name a few.

And that is what I mentioned the carbon density is not the same so there is a loss in efficiency. It is however a process of landfilling, which represents sequestrations if the organics are not decayed. Use of a old oil well or coal mine is just a specific place to landfill where the space would be available due to the removal of the solids that previsouly occupied the space. Once dried and pressed you would achieve a much higher carbon density. You could not sequester the same amount of carbon you withdrew from the mine, but you could sequester some portion of that carbon used. Afterall what is the empty mine beind used for? alternately you could construct dry cell landfills and bury the algae, except landfills a considered a problematic land use amongst certain environmental groups. The use of the oil well or coal mine could serve a similar purpose, assuming the redox conditions had not been substantially changed. It might only equate to a 25% replacement of carbon, but 25% is better than nothing.

Yes there are other sources of energy that can be looked at to replace some portion of the hydrocarbons we use, but probably not all.

Gasification of wastewater solids is another good opportunity, wastewater plants can generate more than enough power to supply their needs and sell some back to the grid. Wastewater solids are either landfilled (in a few cases) or allowed to decay in some manner, and the off gases are just released to the atmosphere. It is all derived from food, which all has its original source at plant extracted atmospheric carbon. So this is a net carbon neutral source of energy also. Solid waste would be similar for the food waste and such, not for the plastics and processed solids. However, right now solid waste is primarily landfilled, which in proper dry cells represents a sequestration process for the carbon (though many do get some water in them which drives the generation of methane from some of the organic materials). Extracting energy from food waste is another opportunity, otherwise the carbon just eventually gets wasted to the atmosphere as the food decays.

I think that both you and RCE should follow this thread before you embarrass yourselves anymore: http://www.fossil.energy.gov/programs/sequestration/capture/

You two are interchanging carbon sequestration with sequestering carbon as if it's one in the same. Unless either of you two can point to something a little more authoritative than you own opinions then I'll stick with mine i.e.your "coal is a very good place to sequester Co2" That rates an F in geology and chemistry not to mention common sense. Totally bogus statement.

As to no one suggesting using algae as a means to capture CO2 again Bogus. As a means to capture Carbon no but then since Carbon is a neutral element why would you. Better look up algae research on Google

As to your last paragraph since you interchange the use of carbon and carbon dioxide (CO2) so frequently it is hard to deduce exactly what your point is much less correct it. Fuels don't sequester carbon in my book, they are either hydrocarbons or carbon matter and when combusted give off CO and CO2 which is what people are trying to capture and sequester and then turn it into something useable such as food for algae. Where you and RCE are getting your facts from doesn't seem to be from the mainstream engineering community.

Hmm, I guess if you are offering your opinion based on your knowledge of geology and chemistry, then maybe you should tell us your educational background in geology and chemistry. I mean who would recognize an F in a subject from someone with no definitive educational background in that subject area. Just to head off your questioning my standing. I on the other hand do hold degrees in chemistry, soil science and civil engineering. I worked as a chemist for some years before becoming a civil engineer (obviously one pays much better than the other, and has less exposure risk).

If you capture CO2 you also capture carbon. Again a little knowledge of chemistry would be helpful here. There is carbon in the CO2. Plant do not just capture and store this as CO2.

What I suspect is fairly straight forward, you are atempting a sleight of hand with the carbon (you know goldman-sachs accounting) and trying to employ terminology in a manner that distorts it to your favor.

You are playing with the term carbon as molecular carbon, but carbon can also be expressed in terms of atomic. You can also discuss equivalents in terms of any molecule or atom that has a atomic relationship to the molecules discussed, e.g it is common to express nitrates or ammonia in terms of the nitrogen equivalents, thus NO3-N or NH3-N.

It seems that there may be another way to reduce CO2 emissions if the following can be done practically. It reduces CO2 while producing methane which can then be burned as part of the ongoing process.

http://web.mit.edu/press/2012/hybrid-copper-gold-nanoparticles-convert.html