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Cleaning the Oceans of Plastic

Posted by CTYankee 7 years, 8 months ago to Science
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I have begun a project intended to clear the oceans of the multiple 'Great Garbage Patches' in the East & West Pacific, North & South Atlantic, etc. I would like to get my fellow Gulcher's opinion on the merit and level of interest such a project might inspire.

The prolem of ocean plastic does seem quite remote to my life. This past weekend I made the mistake of watching a documentary which highlighted the plight of ocean animals unfortunate enough to occupy the stretches of ocean which humans have polluted.

Birds, mammals, fish, and the rest of the sea life are ingesting bits of this garbage, and it is becoming lodged in their guts. The animals are starving to death with their abdomens full of this indigestible material. It was disturbing to see.

More importantly, the plastics tend to leach numerous 'toxic' materials (I'll leave the issue of the actual toxicity out for now) which tend to concentrate in the higher animals as we move up the food chain, this is not new science, but long established fact.

Putting all emotional factors aside, I am interested in the general perception here of a project -- INDEPENDENTLY FUNDED -- (of course) which consists of building a fleet of 300 mechanical whales, whose sole purpose if to swim the oceans, eating the garbage.

Scientific reports and commercial observations put the mass of garbage in one of the Pacific gyres at 750,000 tons, spread out over an area the size of Texas 250,000 square miles.

Each of the 'whales' I propose constructing would cost in the range of $500k with a length of ~35 meters (115 ft). These behemoths would 'swim' slowly, just below the surface, constantly sucking in the top two meters of sea water, much like it's biological counterparts.

Putting the whole effort into perspective: Each mouthful of water would on average contain the food equivalent of 280kCal of 'nutrition' meaning the energy that this 'creature' needs to swim into the next mouthful of garbage.

Borrowing from nature, I have done several energy balance analyses. I concluded that the passive technique of filter feeding is the only possible way to make a self sustaining machine capable of processing even these tiny pockets of contaminated oceans.

And here is where the Objectivist in me needs opinions pro & con. These devices will not collect anything during their 15 year missions. they will swim, and they will eat. None of the plastic will be harvested for resale, reuse, recycling, etc, it will be pyrolyzed, and burned as fuel to power the machine.

So unless the benefits of a cleaner ocean can be monetized, this project lacks one of the key factors of an economically viable enterprise.

Of course there is money to be made by the shipworks that builds the fleet. So it's not a total giveaway.

I eagerly await comments from my fellow Gulchers. Either way. Regardless of the consensus of division reached here I will be starting a crowd-funding campaign to build a prototype in the coming days & weeks.

Thank you all.


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  • Posted by evlwhtguy 7 years, 8 months ago
    The "Ocean Huggers" will not like burning the Garbage to power the machine. They will go on endlessly about all the toxins and heavy metals precipitating out in to the oceans from the smoke....net result....nothing gets done!

    Your idea is fabulous.....however I guarantee the biggest polluting countries will not pay for this, and sure as hell the average ocean hugger wont spend one dime of their own money, they will spend their time trying to squeeze money out of the producers because they have omitted the sin of creating wealth.
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  • Posted by 7 years, 8 months ago in reply to this comment.
    It's a valid point, and one I've considered if only superficially. Once again, I'm planning to borrow from nature. When my whale detects an approaching vessel that is not pinging the correct IFF signal, the beast will simply submerge to a depth that takes it out of harm's way.

    I considered this defense mechanism early on, for the simple reason that I don't want salvage vessels to haul the whales aboard and carve then up as a few hundred tons of scrap stainless steel! They're unmanned after all.

    But the primary reason is to escape the worst of the ocean weather. 30ft seas can ruin a 100ft vessel in a very short time. If it dips 140ft below the surface and hangs there, those 30 ft waves are just ripples on the pond.

    Once the danger has past, the ballast tanks are blown, the whale rises back to the surface and it resumes feeding.

    I'm not certain what the specifics in maritime law are regarding blue-water UAV's flying flags, flashing strobes, ringing bells, etc. is, but I don't believe compliance is a huge obstacle. I do know that each whale will be in communication with its fellow behemoths.
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  • Posted by 7 years, 8 months ago in reply to this comment.
    I respectfully disagree. The pollution seems insignificant when viewed from orbit, or even from aircraft.

    But these gyres are well documented. They exist, they are real, they are killing wildlife, and the garbage is working its way up the foodchain.

    If you had asked me this question last week, I'd've been in near agreement with what you stated. Interestingly I still agree with most of your statements. Just not the conclusions.

    My project won't do anything to STOP the new pollution, except perhaps create awareness. But it will reduce the problem which CURRENTLY exists.
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  • Posted by Esceptico 7 years, 8 months ago
    Indeed, the oceans are an unfortunate example of the “Tragedy of the Commons” not only in plastic waste but in over fishing. A real-life example out of Ken Schoolland's book "Jonathan Gullible." I see no way out yet, but as one who loves the sea, I wish you well.
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  • Posted by 7 years, 8 months ago in reply to this comment.
    Unless this chemical can completely oxidize all the garbage to water & CO2 it seems like just another half-measure.
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  • Posted by 7 years, 8 months ago in reply to this comment.
    Hi Upston,

    YES! I'd live to borrow some of your expertise & experience. Is that un Galt-like?

    While I've worked a project that was deployed in geologically active areas (geothermal plant) it was subject to the constant corrosive effects of sulphur bearing gases, but only the occasional (weekly) earthquake. I suspect the sea, with it's constant motion and only mildly corrosive saltwater requires different design choices.
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  • Posted by wiggys 7 years, 8 months ago in reply to this comment.
    I had a dutch built steel hull. it was coated and had I not sold it I was going to have the body putty originally used sand blasted of and redone with ferro cement.
    worms eating plastic is a joke. Italy finding this is a joke.
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  • Posted by 7 years, 8 months ago in reply to this comment.
    Bottom feeding is definitely out of the question. Too much area, too much volume. The gyres are areas where the floating garbage has naturally concentrated. Even with that concentration, the water still appears mostly clean. Much of this plastic waste has been degraded into what is referred to as "micro-flotsam' and consists of sub-millimeter bits of fluff. It's concentration drops off rapidly below two meters. It's still a lot of ocean to clean, but it's the dirtiest 0.01% and the only part where the energy balance is favorable to the task.

    Purification and preparation of the waste prior to processing is an unavailable luxury. That's why I rejected plasma in favor of a fluidised bed.
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  • Posted by upston 7 years, 8 months ago
    Hi Yankee, I live on a 55 ft laminated ferro cement boat and am knowledgeable on it's marine construction applications. I was in southern India last year building large floating barges for a solar project. Concrete whales would have many advantages over steel or GRP and would cost a fraction of "normal" marine materials. If you would like details I would love to get involved.
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  • Posted by shaifferg 7 years, 8 months ago
    Researchers in Italy have discovered a worm that can digest plastic. Investigation continues on discovering what the chemicals are in the worm's gut that do this with hope of developing a chemical that can be sprayed on the plastics to dissolve them.
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  • Posted by wiggys 7 years, 8 months ago
    i pent 15 months as a live aboard sailing the south atlantic and would see the old calypso in fort Lauderdale and NEVR saw the pollution except in new York harbor from where I left. I can tell you live a board's were even in the 70's when I was at sea were very respectful and rarely from what I observed threw much into the sea unless it was edible. just look at the oceans from the satellites that circle the globe and see for your selves that it is not polluted.
    when you look at the rivers that flow through the Asian countries the cleanest water is at the start of the river and as it goes down stream there is significant human waste deposited along the way. you shouldn't eat seafood that is harvested in the mecong delta.
    All of this crap about polluted oceans is directed at the USA and we in the USA are more conscious of eliminating pollution that ANY OTHER COUNTRY IN THE WORLD.. It is time to let the USA rest.
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  • Posted by $ blarman 7 years, 8 months ago
    It sounds like a great idea. I'm not an expert, but one thing is going to be hazard detection and navigation. Something that big at that depth is going to be a hazard to other seagoing vessels. I'm sure you've thought about it, but how are you going to prevent other craft from accidentally colliding with your "whales"?
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  • Posted by $ jbrenner 7 years, 8 months ago in reply to this comment.
    I didn't know that you were considering a plasma to pyrolyze the waste, but that would be how I would do it.

    While my friend whom I compare to John Galt was the inventor of the plasma arc reactor, I was responsible for feed prepurification and all unit operations downstream of the reactor. Indeed removing salt is the first prepurification step.

    The key to the energy efficiency of our plasma arc was a modification that I will not post on the Internet such that the energy required to sustain the plasma after the reaction was started could be lowered considerably.

    The amount of silica is likely to be problematic. This can be solved, but not very cheaply. Electrostatic precipitators are better than standard gas filters in this respect.

    To get most people to buy into this, you may have to make your whale a "bottom feeder". That is where most of the hazardous waste is.
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  • Posted by 7 years, 8 months ago in reply to this comment.
    How did you know I was contemplating a plasma-jet to pyrolyze the waste? Actually, I considered it. However, the salts seem to present a formidable corrosion problem. Also the range of particle sizes will range from a few tens of microns, up to several cm. Feedstock prep would seem to require another $10K machine, and a large fraction of the rather limited available 'food' energy. When you say your plasma arc reactor is a little more efficient than an IC engine, I gotta ask you to expand on what you mean? I'm using the engine to spin a generator, and fans, the exhaust to heat the reactor, then dry the fuel. Even the waste heat from the coolant is used to keep the machinery free of condensation.

    I don't expect that there will be a lot of free metal in the pollution, as most of it will have likely sunk to the bottom. The whales will be equipped with a formidable set of 'teeth' in the form of a shredder which will be able to chew up fishing nets, wooden pallets, and rubber duckies.

    I was actually planning to use a fluidized bed reactor to generate a mixed stream of gasified and liquefiable hydrocarbons. This will run a small 20kW genset. Most of the electric power runs the filters, which also provides the swimming motive force. All of the waste heat goes to drying what was ingested. Up to 10% of the garbage's energy is budgeted to be stored as 'light fat' (oils), to keep the beast swimming through the patches of clean water, like when a storm blows things around.

    P.S. Because of the high energy concentration of the occasional floating solids (treats), the extra energy in these snacks will mostly be stored as partially processed 'chewed cud' within the envelope of the beast. It will also alert its fellows that there is a rich grazing area to be exploited.
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  • Posted by $ jbrenner 7 years, 8 months ago
    1) You provide value to your customers by assuaging their guilt.
    2) They provide value to you monetarily.

    Before it became apparent in 2008/2009 that President Zero was going to finance my solar energy competition with the proceeds of the small, non-cronyist biofuels company that I was director of engineering for, my business partners and I profited by assuaging the guilt of liberals. We even had a guy working with us who, while in Poland in 1958 at age 20, invented a plasma arc reactor similar to Mr. Fusion from The Back to the Future movies. He was as close to a living John Galt as I am ever likely to meet. The ten people in our biofuels company each read AS in 2008, sold the company in early 2009, and shrugged. We had no problem exchanging our value for their value, but were not going to do it with a withering customer base. Likewise, your mechanical whales project, if funded privately and not altruistically, can be morally acceptable if sufficiently profitable.

    The plasma arc reactor my former colleague invented is a little more energy efficient than the internal combustion engine and is more fuel-flexible. Given the variety of hydrocarbon sources your mechanical whales would consume, the plasma arc reactor might be a good choice for your project. What made our plasma arc reactor system better than its plasma arc competitors was the relatively low power it used; this meant that metals were not aerosolized. In your case, any metals ought to remain nonvolatile after pyrolysis, but would have to be removed from the whales during maintenance cycles.

    One of the bigger issues to overcome will be obtaining permissions to approach other countries' borders as a "toxic" garbage seagoing vessel.
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