Vaporizing Garbage to Create Electricity

CaroKann writes "Geoplasma is planning to build a power plant in St. Lucie County, Florida that will generate electricity by vaporizing landfill trash and sewage treatment plant sludge with plasma arcs. It will be the first plant of its kind in the USA and the largest in the world. The power plant is expected to destroy 3000 tons of garbage, generating about 120 megawatts of electricity per day. The plant will also supply steam to a nearby Tropicana juice plant. The landfill is expected to be depleted in about 18 years. In addition, up to 600 tons of melted, hardened sludge will be produced each day and will be sold for road construction."

Mr. Fusion!

[Helmholtz (2715)]

Glad ol' Doc Brown had the right idea .. now when do I get one to stick ontop of the trunk of my time travelling Delorean?

How many AOL CD's?

[phatvw (996438)]

Let me try to brush up on my yank-math...

3000 tons = 6,000,000 pounds
120,megawatts = 120,000,000 watts
A CDROM weighs 1/2 oz.

So you'd need approx 96 AOL CDs per hour to run a 60W lightbulb. I think I have just enough of those to get me through the end of the year...

Re:How many AOL CD's?

[iamhassi (659463)]

"So you'd need approx 96 AOL CDs per hour to run a 60W lightbulb. "

Wait... let me get this straight, someone explain this to me.

I pay money for them to pick up my trash right?

They take my trash, zap it into electricity.

I have to pay for electricity.

So, I'm basically paying to have my trash back? WTF? Why can't I just install a trash plasma zapper under the sink and skip the expensive middle-man? My trash + electricity a month is $200+, I'd love to keep the money in my pocket.

"Hunny, the A/C's not working!"
"Just throw some more AOL CDs at it!"

This is better than solar power if it works! Now bring on those electric cars :)

Re:How many AOL CD's?

[Millenniumman (924859)]

Using "plasma arcs" to "vaporize" garbage sounds vaguely dangerous.

Re:How many AOL CD's?

[GungaDan (195739)]

"Using 'plasma arcs' to 'vaporize' garbage sounds vaguely dangerous."

It's perfectly safe, provided you never cross the streams.

Re:How many AOL CD's?

[Nutcase (86887)]

It would be bad.

Re:How many AOL CD's?

[HotmanParisHiltonKam (944151)]

I'm fuzzy on the whole good/bad thing. Define bad.

Try to imagine every molecule in your body being slashdotted instantaneously...

Re:How many AOL CD's?

[Z34107 (925136)]

According to this article [wired.com], the plant uses 1/3 of the electricity generated to power itself. So, in all due likelyhood, the trash is going to be used to burn more trash.

Re:How many AOL CD's?

[IntelliTubbie (29947)]

I pay money for them to pick up my trash right?
They take my trash, zap it into electricity.
I have to pay for electricity.
So, I'm basically paying to have my trash back? WTF?

Wow ... you mean you'd have to pay for someone to haul away what you DON'T want and give you back something you DO want? I can't imagine why. :)

Cheers,
IT

Re:How many AOL CD's?

[Detritus (11846)]

If your neighbor complains too much, you've got an ideal device to dispose of the body :-).

Byproducts

[Xybot (707278)]

Sounds like a great idea but I'm still a bit skeptical about the composition of the byproducts. Contaminants like mercury don't simply go away, I assume they will be bound into the sludge portion of the byproduct, which is likely to be quite high given the fact that they are re-processing sewage.

What about the Dioxins from vapourised plastics, A plasma arc produces an incredible heat but Dioxins are also very resistant to being broken down in this way.

Sulphur? How is this kept out of the exhaust gases?

Re:Byproducts

[smellsofbikes (890263)]

If you heat things up enough, you'll break down even dioxin. All you need to do is dump in enough energy to start breaking the (fairly stable) molecular bonds. This [websorcerer.com] is what dioxin looks like. A chemist can tell you why it's so stable: lots and lots of alternating single/double bonds. quick chem lesson: lines drawn between atoms, in this case the angles on the outside of the structure, representing a carbon atom at each angle, are single bonds, drawn C-C-C (or in this case /\) while double bonds are drawn as two lines: C-C=C. Something with alternating bonds, C-C=C-C=C, acts as if it has about 1.5 bonds between each, which is tremendously stabilizing. Benzene is a ring of six carbons, with six single and three double bonds: alternating single/double bonds, so it's drawn as a hexagon with a circle in the center, to symbolize its electron structure. This has two benzenes, with oxygens connecting them. Because the oxygens have electron pairs that are unused in bonding, but are in the right place, they can act as, essentially, parts of double bonds, meaning the center section is also alternating single/double bonds -- or, more correctly, the whole works has evenly distributed electron density. Whew. here is some more stuff [chemguide.co.uk] about aromatics and the stability of benzene.
The bond energy of carbon-carbon bonds in benzene is about 200 kJ/mol (as I recall: I may be wrong); dioxin is (I think) going to take more energy to break. But at any given bond energy, a given temperature with large excess of oxygen, over a given time, will break a certain percentage of the dioxins down into smaller (and quickly oxidized) byproducts, so all you have to do is establish what's a reasonable level of dioxin to release into the atmosphere (which a person could justifiably argue is "zero, dammit!") and make sure your flame temperature is high enough that you transfer more energy than that threshhold to the exhaust stream. The temperature of flames is really spectacularly high -- the free air temp of burning oxygen and hydrogen is something like 5500 degrees F -- but you have to guarantee that the mass of the exhaust actually gets that hot, so you have to care about heat transfer, not just temperature. In any case: this is well-known chemistry. It is possible to burn dioxins and destroy 99% (or 99.9% or whatever you've decided is 'enough') of them.

The sulfur would become sulfur dioxide, which would be captured in scrubbers, the way they do in steel plants and coal-fired power plants. They use the captured material to make sulfuric acid, and sell it at a major profit, even considering the initial cost of installing the scrubbers.

That's probably WAY more than you ever wanted to know, but I like chemistry.

Re:Mr. Fusion!

[nuttzy (877548)]

The landfill is expected to be depleted in about 18 years.

Once again, using up all of natural resources!

It's a waste of valuable garbage

[NixieBunny (859050)]

We'll be harvesting landfills in 100 years to get the materials (plastic stuff mostly) that our country is so busy paying China to manufacture, then buying and disposing of in said landfills. If all that fodder is vaporized for energy, we're screwed.

Re:It's a waste of valuable garbage

[gameforge (965493)]

I don't know anything about waste management, but if people care about recycling plastics, shouldn't they be doing that before they throw it in the trash? I think once it's in the landfill, it's "gone"; that means even if we wanted to, there's no way to harvest it out of a landfill that's remotely profitable. I mean, how much would they have to pay you to start digging through landfills for eight hours a day? And that's just the cost of mining the plastic out of the landfill.

People need to worry about recycling these materials (plastic, aluminum, paper, etc.) before they toss them into the trash. Many people (myself included) have signed up for seperate services for recycling stuff like this, and put out a recycling bin once a week with the trash.

Re:

[fm6 (162816)]

Sure, and with today's fuel prices, it would cost us hardly anything!

Sounds like a great plan...

[ossington (853347)]

With minimal impact, good usage of by products and so forth. The only problem is that if we can just zap away our inconvenient little problems (tonnes and tonnes of trash, for example), we will never do anything to curb our overzealous consumption. Doesn't sound like a sustainable idea in the grand scheme of things.

Re:

[Dr. Eggman (932300)]

Well, its not supposed to be the ultimate solution. Anyone looking for a single key that'll fix all our consumption problems is living in a dream world. I don't think letting our garbage pile up beneith us was doing much better at curbing our consumption either. I think that our consumption isn't the real problem; its what we do with what's left over from consuming things. No matter how little we consume, if we can't take the output and make it into new inputs, it will not be sustainable in the end. This ki

Megawatts per day

[by Anonymous Coward]

"The power plant is expected to destroy 3000 tons of garbage, generating about 120 megawatts of electricity per day."

Watt is a measure of energy per second. That is, power. Saying 120 megawatts of electricity per day is nonsense. I think they meant to just say 120 megawatts.

Doesn't slashdot have editors for this kind of stuff?

Re:Megawatts per day

[CastrTroy (595695)]

What's obvious is that the writer didn't have a technical understanding.

Wow, I've never seen that happen. I mean, writers always completely understand the technology they are writing about. I think this is the first time I've ever read an article where the writer didn't understand what he was writing about.

Could happen in the Toronto area soon as well

[ergo98 (9391)]

Here in the Halton region, which is comprised of some suburbs just West of the Toronto metro, there has been some talk of building one of these plants [halton.ca] (although they've tossed around the number $700 million). This is an effort to deal with the reality of garbage, not to mention that reality that Toronto has been giving the entire country a continual black-eye by shipping waste to Michigan [google.ca] (if I were a Michiganer, I'd be pissed to be another regions dumping ground. Even as an Ontarian, the endless row of trash hauling trucks, each leaving a wake of loose garbage, is untenable).

But despite the reality that no one wants to build dumps, and Toronto has been spending millions shipping it to an entirely different country, there are still the head-in-the-sand dreamers who would rather the issue just disappears. A prominent Toronto city bureaucrat [torontosun.com], for instance, has poo-poohed the idea, decrying the vile idea of "burning" waste. They'd rather drive it 500 miles in transport trucks to dump it somewhere else.

Attempted before...unsuccessfully

[PreacherTom (1000306)]

This has been attempted before. I used to work in the waste industry, and one of my clients had a plan to develop this kind of technology. The problem was that, despite predictions, the waste simply did not burn hot enough. If they've managed to overcome this obstacle, this is going to be huge. The cost-effectiveness still concerns me, but government subsidies can take care of that.

The people of St. Lucie County won't go for it

[BeeBeard (999187)]

This will never get built. Let me explain: People near the Treasure Coast are retirees. And I don't mean in the "Oh, it's Florida...of COURSE there are retired people there" sense. I mean that many of its communities were planned and built specifically for bluehairs. Port St. Lucie, for example, is just such a community.

Now as impossible as it may seem, octogenarians are not really up on the newest technological advances. The moment you say the words "landfill trash" to these people, the NIMBY (not in my backyard) impulse will dominate, and granny and gramps will be making phone calls, changing zoning rules, voting down money, and generally just making Geoplasma's job as difficult as possible. They're retired. If you thought they didn't have the time or inclination to do these kinds of things, then you're mistaken.

I know it makes no logical sense to want to make use of modern garbage disposal technology, and yet not want it anywhere within a million miles of you, but trust me, that is the mentality. The article characterizes this as a county-wide effort. I bet not. I bet the people who are slated to have this trash burning marvel right next to them will soon be mad as hell in 3...2...1...

Downsides

[Tablizer (95088)]

"Okay, who is the shit-head who threw away a barrel of sodium!"

Energy / time^2?

[Will_Malverson (105796)]

From the summary:

...generating about 120 megawatts of electricity per day

120 megawatts per day? So, after about 8 days, it'll be generating a gigawatt? In a year, will it be producing 43.8 gigawatts?

Probably not.

My first guess was that it's probably generating 120 megawatt-hours per day, or what those of us who know physics would call "5 megawatts".

They say that they'll use about 1/3 of the generated energy, and plan to sell the remainder back to the grid. Electricity is usually worth something like $20-$50 / MWh. If they're selling 3.3MW into the grid, they might be able to get $1600 - $4000 / day from this thing.

However, they also say that they can recoup their $425M investment in 20 years. Assuming a 4% interest rate (municipal borrowing is cheap!), they'd need to pay back a little over $2.5 million per month, or about $85,000 per day.

If the power plant is actually generating 120 megawatts, then they're looking at (80*24) megawatt-hours per day, or $38,400 - $96,000. They're also selling steam and sludge, and I don't know what the current market value of those is. Yes, I know that you pay $60 - $100 / megawatt-hour for your home electric service, but electricity on the bulk market (especially at night) is a lot cheaper.

Re:Energy / time^2?

[CaffeineJedi (643314)]

My first guess was that it's probably generating 120 megawatt-hours per day, or what those of us who know physics would call "5 megawatts".

Um... no. I think they actually meant 120 megawatts. Because you see:
120 megawatts * 24 hours = 2880 megawatt-hours.
If the price of a megawatt-hour is about $35 dollars (we'll just use the median value of your estimate), then they are making $100 800 a day .
Multiply that by 365, and you get: $36 792 000 dollars a year.
Which means... that if they sell back 2/3 of the energy over the course of 20 years, they will make: $490 560 000 dollars (gross, in today's dollars)

Just FYI, some of us also "know physics" and can actually use Google calculator to make an estimate ;)

120 MW a day ??

[Old Wolf (56093)]

It's not possible to have "120 megawatts per day". A watt is a RATE of energy usage (joules per second, in fact). It takes 120 MW to power a million 120W light bulbs -- for 5 seconds, or 5 hours, or a day, or a year -- how long you keep that rate up, has nothing to do with how fast the actual rate is !

Perhaps the article meant "120 megawatt-hours per day", although that would be a very strange unit of measurement (not as bad as Libraries of Congress, though).

Orange Juice?

[Skudd (770222)]

I'm sorry, but I highly doubt I'll be consuming any more Tropicana products if they're going to be made from steam of vaporized landfill waste... There's just something unsettling about that.

Am I the only one who sees a disconnect here?

[vrmlguy (120854)]

"County officials estimate their entire landfill -- 4.3 million tons of trash collected since 1978 -- will be gone in 18 years."

"Geoplasma expects to recoup its $425 million investment, funded by bonds, within 20 years through the sale of electricity and slag."

Does this mean that during the last two years, St. Lucie County will be importing trash from other counties? What if those counties also build these things? Will "trash pirates" be raiding nearby landfills for material to burn?

Re:Am I the only one who sees a disconnect here?

[drfireman (101623)]

during the last two years, they will vaporize the plant itself

Re:Am I the only one who sees a disconnect here?

[evilviper (135110)]

Does this mean that during the last two years, St. Lucie County will be importing trash from other counties?

No, that means they'll finally START burning the trash that has been collecting in the 18 years since the plant began operations.

When they say the "entire landfill" ... "will be gone in 18 years", they don't mean it's going to explode, or turn into a black hole. Trash will keep piling up, though, interestingly, not as fast as the plant can dispose of it.

Perhaps that will mean the cost of dumping will drop, and more trash trucks will divert to that dump, instead of going elsewhere.

That is the situation in the Puente Hills landfill (L.A.) as dumping fees are cheaper than elsewhere, in-part because they siphon off the methane, and run a large power plant off of it.

We may well be entering the age of fewer, larger, regional landfills, all making money off of the trash they collect in one way or another.

In Mickey Mouse Land

[rahvin112 (446269)]

I'm guessing the most optimistic person in the world wrote that. First they aren't generating much power, the waste steam is a huge maintenance hassle as steam pipes either need to be made of stainless steel or something else that isn't going to rust. Second, after building it they are going to discover that they need to spend millions every year on scrubbers just to keep themselves below the EPA limits on the pollution, heavy metals and other nasty stuff from getting into the air. After doing that they will find out that their garbage fees go up astronomically as a result of the number of shutdowns due to violating said EPA standards because half the residents are throwing away toxic materials in the trash (you can ask people not to throw mercury, batteries and toxic chemicals away but they will still do it) and as a result of the damage said materials do to the scrubbers, incinerator and geration systems. And finally they will be paying to dispose of the hazerdous sludge that contains the remainder of the heavy metals and other toxic chemicals (take two household chemicals toss in a plasma arc and what will you get? millions of cominations of nasty nasty substances that can't be predicted or accounted for) that weren't belched out of the smoke stack. And if they think for a minute any roadway designer or contractor is going to use that stuff without being mandated by law they need to lay off the crack.

The fact is that you don't build roads with materials that have unknown and extremely variable properties. 50 years ago they might have used the sludge in road construction (because they didn't know better) but not now, the chemical properties could be destructive/corrosive to the roadway, cause hazardous contamination in runoff and dust, and it could range from hard durable rock like material to a bad bit of clay. We don't build roads out of trash, unless someone is paying for you to take that trash, and it's a guaranteed uniform and chemically neutral substance, like glass. But this is what happens when you let the marketing department write your article.

Our county made the mistake of building an incinerator 20 years ago, it was the worst mistake they ever made and became the biggest money suction device that has kept the county broke for the length of the factility. I bet the total cost over 20 years not including interest was double the estimated price and it would have been cheaper to ship the garbage to China at the prices being paid per ton to incinerate the garbage.

Re:In Mickey Mouse Land

[dattaway (3088)]

The stainless steel pipes are what we use for steam, but its the gaskets that keep blowing. Its friction due to heat contraction cycles that wears them out and creating leaks all the time. The gaskets are made out of high temperature sythetic aramid fibers and have a limited lifetime due to this wear. I know, because I used to have to replace them. I won't mention maintenance due to hard water deposits, insulation problems, and the expansion due to long lengths of pipe. And these massively long schedule 80 pipes do expand great lengths. That fresh Tropicana Orange Juice had better be next door, because even a mile of pipes is going to require constant work.

The joys of working with 450F, 450psi steam. Ever seen pictures of someone who got exposed to something like that?

Napkin numbers

[gregor-e (136142)]

It takes 9000 tons [syr.edu] of coal per day to run a 1000 MWe generation plant. Geoplasma says they plan to consume 3000 tons of garbage per day to generate 120 MW. That'd give garbage about 1/3rd the energy density of coal using this process, which doesn't seem preposterous. They say the plasma will consume 1/3rd of the electricity, yielding 90 MW of marketable electricity. Florida commercial average is 5.86 cents/kWh, so 90 MW ought to go for about $126 thousand per day.

Their other products are chump change:

Quarried rock goes for about $3.75/ton. Of the 9000 tons of garbage they burn, they end up with 600 tons of slag, worth about $2000/day.

Steam is worth about $10/1000 lb. The 80000 lbs of steam they'll sell to Tropicana is worth about $800/day.

They don't mention it, but they are probably able to collect tipping fees from the sewage folks and, once this landfill is gone, dumping fees for future garbage.

Still, the bottom line is electricity. If their efficiencies are off or if the market for electricity gets cheap, they may have a hard time amortizing $425 million in debt, even at favorable bond rates. $425 Million at 4.5% over 30 years would require about $2 million/month to service. Their $126K/day income gives them a gross of $3.8 million/month. Enough to service the debt and have about $1.8 million/month for salaries and other recurring costs. It might fly. But if they rack up significant maintenance costs that amount to a significant fraction of their total $425 million plant cost over the 30-year lifetime, it probably won't.

Tipping Fees

[sgent (874402)]

The tipping fees are not insignificant.

In our local (Southeastern US) landfill, the tipping fee is $10.51/ton. At 3,000 tons / day, your looking at an extra 960k/month in revenue.

Pave it all

[ddt (14627)]

That's great, because nothing says "environmentally friendly" like spewing out miles of asphalt so that we can continue to pave the planet.

Re:Whence this vapor?

[Junior J. Junior III (192702)]

The summary also mentions processing 3000 tons of garbage a day, and yielding 600 tons of sludge. Unless they're converting mass directly into energy, a la nuclear fission, I'd say there's about 2400 tons of apparent gas that needs to be accounted for still.

Re:Whence this vapor?

[LWATCDR (28044)]

Well most of that will be water vapor. I think this is great and worth trying. I do think that my opinion of this counts a lot more than most of the people posting on slashdot.
I happen to live in Port Saint Lucie, FL. If this meet the emissions standards which the small plants in Japan do then it will beat the daylights out of an other coal fired plant and get ride of that huge landfill.

Re:Whence this vapor?

[Millenniumman (924859)]

"Tropicana, made from pure garbage."

Re:Whence this vapor?

[interiot (50685)]

"Plasma arc" = incinerator [no-burn.org]. No fancy chemical or nuclear processes happen, they still dump out a huge amount of CO2, just like normal incinerators. Sure, they scrub the exhaust for really harmful chemicals and particles, but they still release a lot of CO2.

Re:Whence this vapor?

[Skye16 (685048)]

As would the oil/coal/natural gas power plant that was burning afore mentioned fossil fuels, as well.

If we require a amount of energy and produce x amount of CO2 and y amount of trash, but have a way to reduce y without drastically increasing x, then I don't see why this is such a bad thing. If the exhaust is scrubbed, and the CO2 is nearly the same, then we've taken one little step toward a cleaner world.

Ideally, there may come a time when our cars don't produce CO2, industry produces minimal amounts, and our power plants are primarily green as well. In that case, dumping *some* CO2 into the atmosphere while reducing the amount of landfill we need for garbage is one hell of a bargain.

Re:

[alienw (585907)]

I think it said in the summary the gas would be burned and turned into electricity in a gas turbine. Less pollution than a coal plant, not using fossil fuels, removing trash from landfills. Not bad.

Re:

[jhealy1024 (234388)]

Hawaii does this with their H-Power [honoluluhpower.com] incinerator. It has a series of magnets to remove recyclable metals, and a series of filters to remove the most noxious substances. Yes, it does produce polution, but it's better to burn garbage than coal or oil. Also, it reduces landfill use, which is important in Hawaii, where land is at a premium.

Re:

[CosmeticLobotamy (155360)]

Someone didn't pay excessive amounts of attention in physics or chemistry class, it seems.

Supposedly...

[Mark_MF-WN (678030)]

Supposedly the temperatures are so high that everything is reduced to a plasma. That is, there can't BE any carcingonic fumes, toxins, or anything else, because all of those things are molecular. Plasmas are totally lacking in anything resembling an atomic bond. If one had an unlimited supply of energy available, reducing things to a plasma and then seperating the components would be the ideal way of recycling while simultaneously refining vast quanities of new feedstock for industrial purposes. It's ju

Re:

[Firehed (942385)]

Given how much we throw away each year, it sounds closer to a perpetual-motion device. Or more like one of those LEDs powering the solar panel that powers the LEDs scenarios.

Re:Indeed

[ozmanjusri (601766)]

can you conceive of how many cities are going to want one of these plants if it's for real?

If it's used effectively, a plant like this could clean up whole countries. In anticipation of it's availability, Australia has built a collection site for our most environmentally damaging garbage. Once this rubbish [aph.gov.au] has been fed through a white-hot plasma, our country will be much cleaner, and it's wonderful that we'll finally be benefiting from something which has long been little more than a toxic eyesore.

Re:Indeed

[c6gunner (950153)]

You'd be surprised. These plants exist in other parts of the world already, so it's a proven process. Toronto's been debating building one for a while (mainly for the garbage-disposal value since we now ship our trash to Michigan) but every time the environuts hear the word "incinerator", they get their collective panties in a collective bunch. Doesn't matter that the technology is proven, clean, and a damn sight better than wasting thousands of dollars and burning fossil fuels to ship our garbage to another country. Environutism has never been about being rational.

Re:Indeed

[Martin Blank (154261)]

That's thermal depolymerization. There are two plants right now, the larger one at the Butterball Turkey Plant in Carthage, MO, which is fed turkey offal. It had been shut down on several occasions due to complaints about odors coming from the plant, some of which were of dubious accuracy, but those concerns have been addresses now. The major end-product is roughly the equivalent of lightweight heating oil or diesel fuel, with some water, methane (which is used to power the process), carbon black, and minerals as additional byproduct. There was also an issue of cost of the petroleum product (about $80 per barrel) until Congress approved TDP for a $1 per gallon tax credit as a biofuel source.

However, TDP needs to be tweaked for each installation: what works for turkey offal will probably not work as well for sewage or tires. However, the final byproduct is arguably more useful than simply providing electricity, as it can be shipped up to New England for heating, used in transport, or (I think) further refined to extract other useful products. What you gain in flexibility of end-products, you lose in flexibility of initial installation.

Re:That's complete folly!

[Conspiracy_Of_Doves (236787)]

Yeah. When it returns in a thousand years, we can just deflect it with another trash ball. Of course the world will be completly clean by then, so we'll have to make more trash in a hurry.