h a l f b a k e r yAsk your doctor if the Halfbakery is right for you.
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The idea is as simple as the summary...
Grow algae... probably in open ponds, since it's cheaper than in a bioreactor, and we don't really care what species end up in the product.
Strain the algae out of the water, and compress it into logs to burn in people's fireplaces.
Sure, there are probably
more profitable things to do with algae, but none are as simple as this.
A similar use for algae would be to press it into pellets, similar to those used in pellet stoves.
Sea-weed collection for fuel
Seaweed_20Power
By [worldgineer] [theleopard, Feb 27 2009]
Solar Charcoal Distiller
Home_20Solar_20Charcoal_20Distiller
If the algae pellets are to be charcoalized, this is how it should be done :) [goldbb, Mar 19 2009]
source
https://www.google....swimming+pool+algae
a Lot algae free for the asking [popbottle, Oct 27 2014]
[link]
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I like this idea, but really it should be done with used facial tissues collected from prisons and nursing homes. The tissues would be drier, but not too dry. Plus something needs to be done with them. |
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The pressed logs could be embossed with barklike patterns and sprayed with some brown substance. |
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There's just something that sounds wrong about "used facial tissues". I'm using my facial tissues even while I'm keying this, and I'm not certain that they'd readily convert to kindling. |
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It'd be easier to dry tissues. With algæ, you'd need a lot because they're mostly water, but i can see it would happen in the end. Duckweed would be another option, and maybe carefully quarantined Elodea canadensis, which is invasive here in Britain. Come to think of it, it's another use for invasive plants, so maybe logs made of Epilobium angustifolium or Polygonum cuspidatum would be better. They'd start off drier. |
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I think you'd need to turn the algae logs into charcoal first to make them more flammable. |
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The smell of algae in the air would not be quite the same as a nice oak or maple would be; yay for the sake of crying forests and dwindling woods. I wholeheartedly grant you my wooden bun! |
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I suspect peletized, rather than log would be the most effecient. It minimizes burn dificulty, and the compression technology already exists. The major concern would be ash. Most pellet stoves require very low ash residues, and I don't know what algae (or sea-weed) would leave. |
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Could it be sun-dried? It seems like a REALLY slow conveyor belt system should be able to pull algae off a pool and then sun dry it before it is scraped off a belt to be pressed into pellets. I like the pellets better just because they are generally more efficient and it takes the smell issue out. |
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This is really good and if it could be run with a clock work this could make a real change in the third world.(+++) |
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The ash would depend on the algæ, but if it were kelp, there would be a lot of iodine, and some calcium, chloride, magnesium, sodium, potassium and iron. It would be useful. It's not an alga, but Salicornia ash can be used to make glass. |
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The issue with ash is not content, although useful ash would definitely be good, it's volume. Most current stoves are only designed to handle premium wood pellets, which means less than 1% ash content. Some stoves can handle standard pellets at <3%. Corn stoves can, I belive, handle slightly higher. I'm not sure how much research is being done on flex fuel stoves, but someone must be working on it. |
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So far as i'm concerned, the more ash the better, but i wouldn't be burning it in a stove.
One thing which does make me uncomfortable about this idea is the nutritional value of the algæ. Wood isn't edible, though it could probably be made so. Burning edible plants amounts to wasting food. Therefore, i would prefer "useless" algæ for this purpose, possibly something really poisonous or nasty. Although, would that be dangerous to burn as well, like poison ivy? |
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Regardless, purpose grown algae requires a lot less energy
input than purpose growing many other crops, including
probably wood. Waste materials, sawdust and the like are
definitely better, but limited in quantity. |
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The concern for purpose grown combustible material has
to be less could it be food, but is it the most efficient fuel
that can grown in that space. This is one of the major
objections to corn as a fuel, not because it is food, but
because it is so horribly inefficient. The same is true of
most food to fuel plans. Algae, however, is an efficient
grower in most situations, and can be actually create
cleaner water if grown in ag runoff, for instance, hence
this idea has some real potential merit. |
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I do think it has merit and i think toxins are unlikely to do the poison ivy thing, but a lot of things can be done with algae without burning them, for instance there are a lot of pharmacologically active compounds in them such as antivirals, antibiotics, antineoplastics, anti-inflammatories which don't rely on cyclo-oxygenase and so forth, and they are often nutritionally very valuable indeed, for instance Sargassum fusiforme is totally awesome in this respect. |
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Having said that, not all algae are equal (come to think of it, not all algae are even algae), and there are probably a lot which are neither particularly nutritious nor relevantly toxic. I also wonder if there's a way of reclaiming transition and poor metals from the ash if polluted water is used. |
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I think the derision against using food crops for fuel is valid IF the crops could be used for food. IE Corn kernels are a stupid thing to make alcohol from because they are vaible food. Algae as grown in the open I don't think can make that claim. I know little of this subject but I'd assume it would have the same issues as randomly eating mushrooms found in the forest. I see the value of this idea in it's use of a rapidly reproducible raw material that could be produced in no-tech pools and used in efficient ways. The only real concerns is whether the food for the algae would better be used for food crops or whether the algae itself could be put to better use as fertilizer or something. Also I guess whether burning algae produces any poisonous toxins. |
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The smell is æsthetically the best thing about this idea. On reflection, i think the chances of toxic fumes are pretty remote from most algæ but some red seaweeds contain heterocyclic bromine-containing compounds. I don't know what would happen if these were heated, but they can be quite toxic. Is it easily predictable what happens when such compounds are heated? Would the bromine separate and oxidise? Would they just be volatile? |
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It isn't a case of either/or here. Algæ could be used for another purpose before being converted to logs. Their nutritional value, pharmaceuticals and pesticides could be removed before that happened, then the waste material could be used. What about alginates? Would those stay? Hygroscopic logs would be a bugger to store, particularly because cold weather is likely to be damp round here. |
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Actually, i've thought of another problem. Would the bromine compounds act as fire retardants? Are most bromine-containing organics fire retardant in themselves or do they have to be particular compounds? |
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Do you not find smell to be more of an aide memoire than any other sensory stimulus? |
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Ooh, i wonder if you're synæsthetic, [on_cloud]. |
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[21_Quest], that sounds almost wistful. Probably shouldn't go there. Even a rotting aroma or otherwise unpleasant smell can be good. I reckon that much of the smell of a temperate broadleaved forest in autum/fall is decomposition. You may or may not have had the odd experience of what happens when you visit the little boys' room if you've recently eaten a lot of seaweed. There's the opportunity to develop new associations there. |
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Although many types of burnable things might start off more dry (used tissues, dryer lint, Polygonum cuspidatum, etc.), algae has one important advantage: it's easier to grow and harvest in large quantities. In particular, harvesting can be completely automated, possibly involving only pumps and filters. |
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I think MechE has a good point about it being pelletized... plus, since pellets are so small, they can be dried after being formed... it might take a long time to dry out a 5 pound log of compressed algae, especially if there are no added waxes (other firelogs use wax to hold together... the addition of hot liquid wax obviously boils off any water and displaces the steam.) |
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I don't know how much ash would be produced, but if the algae is grown in fresh water, I would expect there to be very little. |
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The only real concern is alginate making the pellets or logs hydroscopic; the solution is simply to grow species of algae which don't produce alginate. |
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Similarly, bromine can be avoided simply growing the algae in fresh water, rather than sea water. |
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They haven't all got bromine in them in large quantities. Many algæ can grow in either environment, but if they're salt water varieties, they tend to be more watery in fresh. Also, you seem to think i'm saying the ash is a bad thing. It isn't. It means minerals are easier to harvest from the sea. The bromine issue only applies to the Rhodophyta and i'm not even saying it's a problem, just that i don't know what happens when bromated organic compounds are heated, or whether it's predictable. That issue could be avoided by steering clear of the red algæ anyway. |
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A lot more can be done with algæ than just burning them. Once those things have been done, the remnants can still be made into logs and burnt, and after _that_ has been done, the ash is useful. Alginates are nutritionally and medically valuable anyway. |
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What i'm saying is, i like the idea, and i want to add to it. Grow algæ in brine, process it to remove nutritionally and medically valuable constituents, then make the rest into logs and burn them, then use the ash for industrial purposes. The idea is great, and it can also be built on. In situations where the likes of salt were unavailable, they could still be grown, dried and burnt but it would be a pity to do just that, and it would take longer because marine algæ which also grow in fresh water have a higher water content and lower nutritional value. |
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To be pedantic for a second, there are relatively few freshwater rhodophytes and i don't think the marine ones can survive in that environment, but i'm prepared to be corrected. |
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I'm not so sure that growing algae in freshwater for burning is such a waste. Around here, algae tends to grow in freshwater on it's own quite well. |
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In drainage ditches, open pipes, etc, they tend to be a bit of a problem, as they can clog the lines. In standing water, they can choke off fish species, and become an eyesore. |
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I humbly suggest that something similar to the brushes of a streetsweeper vehicle could be used to harvest such unwanted algae in a cotton-gin sort of style without being too distruptive of the overall environment. In the cement channels of my home country, such regular cleanings might be greatly desirable. |
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If you're talking about "blue-green algæ", there's no problem because the toxins are peptides so they can be burnt. You've made me think of something else by mentioning the cotton gin, since that raises the issue of cellulose as a textile, so that makes me think paper and fabric could be made from it. Once that's been done, what's left? No water or polysaccharides doesn't leave too much else to be burnt, but at least the logs can be one of several uses. |
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Paper largely depends on long strand cellulose fibers, algae
would probably not work all that well. Some forms of
seaweed might. |
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Paper doesn't have to be made of cellulose. I wonder what the gels would do made into mats of fibre. It might be as simple as building up layers of spirogyra, dunking them in a solvent and drying them out, or maybe just drying them out and "silaging" them. |
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I've been lumping seaweeds together with other algæ here, as it happens. |
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Is there a benefit to the manufacture of whisky in any of this? |
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Of course there's a benefit to the manufacture of whisky! You have to distill whisky, don't you? Well, use some algae firelogs (or fuel pellets) to provide the heat! :) |
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Nineteenthly, although ash might be economically useful if algae logs are burnt industrially, I doubt that the average homeowner, buying these instead of firelogs made of compressed sawdust (or used coffee grounds) and wax, would not be happy with excessive ash. |
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For that matter, if a homeowner is buying algae fuel pellets to burn in a pellet stove, he would be exceedingly unhappy if there are large amounts of ash. |
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I like this idea. To be worthwhile, I think the drying
would have to be done by the sun. |
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If you used blanketweek (filamentous algae), you
could pull it out of the pond continuously (and
slowly) as a collection of ropes. The machinery could
twist these ropes to squeeze out a lot of the water
and give them some strength, then let them air-dry
as they wound, very slowly, onto a gigantic drum. |
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ugh, for every litre of intracellular volume, you're gonna
have 12-15g of mixed salts, largely KCL. Someone needs to
engineer a strain algae with some form of easily inducible
channel, then we can induce it on it's way out of the water
and perhaps give it a swift wash with fresh water. |
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Actually, the way kerratinocytes deflate and become a nice
dried out protein plate is good, we just need a way to do
that, only with carbohydrate... oh, I've invented the tree. |
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Would the square footage required to grow the algae and dry the algae, be less than that required for solar cells of the same output ? |
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If this were seawater algae, I think there might be an issue with dioxins being created during combustion. It's a problem created by the presence of salt. |
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// Would the square footage required to grow the
algae and dry the algae, be less than that required
for solar cells of the same output ? // |
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Almost guaranteed. However, the cost per square
foot of algae growing area could theoretically be
much less than the cost per square foot of solar
cell. If this could be done in the open ocean, the
real estate cost becomes insignificant. If this has
to be done in enclosed fresh-water ponds, the
real-estate costs might be prohibitive. I don't
know if there are many areas of cheap real estate
left that are in climates favorable for growing algae
that have plentiful fresh water. Solar cells have
the advantage of reusing wasted space (rooftops)
and operating fairly well in areas with poor water
availability. On the other hand, if you could make
this run on either salt water or as part of a sewage
or storm-water treatment system, it might be
possible to make it cost effective. |
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Do you mean KCl (potassium chloride), [bs0u0155]? |
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I'm involved with the commercial production of algae and
the process of separating it from the water and drying it is a
fiddly and expensive process. Drying to the point where it is
combustible could be quite an ordeal. |
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//Do you mean KCl (potassium chloride), [bs0u0155]?// |
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Oh dear. Not on it this week. In fact, I'll be surprised if I
make any progress, in any direction, at all this week. |
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