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."

Megawatts per day

[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?

Could happen in the Toronto area soon as well

[ergo98]

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]

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.

Energy / time^2?

[Will_Malverson]

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:Whence this vapor?

[interiot]

"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.

120 MW a day ??

[Old Wolf]

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).

Re:Whence this vapor?

[alienw]

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:Mr. Fusion!

[tickbox]

88 miles per hour...

Re:Whence this vapor?

[jhealy1024]

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:Almost free energy?

[Firehed]

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.

Napkin numbers

[gregor-e]

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.

Re:It's a waste of valuable garbage

[lawpoop]

I think that the idea is that plastics in the ground aren't valuable /now/, but 100 years from now, when there's no more petroleum to pump out of the ground, it will be profitable to 'mine' plastics from old landfills.

Re:Orange Juice?

[ForestGrump]

In the article:
About 80,000 pounds of steam per day will be sold to a neighboring Tropicana Products Inc. facility to power the juice plant's turbines.

Grump

Old News

[fosensei]

They've been doing this in Hawaii for years... check this out: http://www.honoluluhpower.com/ [honoluluhpower.com]

Re:In Mickey Mouse Land

[dattaway]

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?

Re:How tested is this technology.

[pbettendorff]

I cannot tell about Japan, but in Zurich (Switzerland) two such plants are operating since 1969 (continously upgraded). A link (in german, unfortunately) to the technical description: http://www.stadt-zuerich.ch/internet/erz/home/khkw /technik.html [stadt-zuerich.ch]. The plants do not only generate electricity, but also heat, which in transported to industries and houses in the vicinity (a couple kilometers around the plants).
Most interesting, and answering a lot of the previous question is the PDF about the energy production:

• Electricity production: 91500 MWh
• Internal electricty consumption: 38000 MWh
• Net electricity production: 53500 MWh
• Heat production: 406000 MWh

A second PDF links to the emission statistics. For the non-german speakers: the red bars are the legal limits, which are quite strict compared to the US.

Re:How many AOL CD's?

[Z34107]

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:Whence this vapor?

[Timberwolf0122]

True they produce alot of CO2 but the majority of garbage is plant/animal or paper waste (I'm guessing that the old tin cans are removed?), essentialy the CO2 released will be re-absorbed by the planet to make new products for us to turn into garbage and re-vapourised.

Also CO2 is far less harmful than Methane and other gasses release though natural Biodegridation in landfills + no risk of ground water contamination.

Re:In Mickey Mouse Land

[Anonymous Coward]

Here are some facts to confound the very silly moderator who moderated you up despite your clear trolling; it took me only a few seconds with a search engine to find publications containing facts about heavy metal (mercury) pollution from waste incinerator flue gases:

1. "The PCO process for photochemical removal of mercury from flue gas", C.R.McLarnon, E.J.Granite,H.W.Pennline, Fuel Processing Technology 87(2005):85-89

"Preliminary testing showed [...] 91% oxidation and removal of elemental mercury"

The high mercury concentration (300 ppb) used in these experiments is representative of the levels found in some waste incinerator flue gases. "

However, scrubbers in current commercial power plants/waste incinerators in the USA typically achieve only 40% mercury removal. [pnwis.org] Even if the newest method were in widespread commercial use, you still get 9% * 300ppb = 27ppb leaked mercury emission into the atmosphere. Even at these reduced levels, the mercury and its compounds are still harmful, especially to kids, causing nerve/brain damage/lowered IQ, and bio-accumulating up to harmful concentrations through food-chain amplification as plants are eaten by fish/animals which are in turn eaten by higher predators and so on up to the top of the food chain to animals such as humans.

gasification

[coal_burner]

I seem to detect a distinct misunderstanding with how this technology works. Solid waste material is fed into a plasma arc chamber where there is very little oxygen present. The waste is converted into 2 separate streams. The gaseous stream is made mostly of carbon monoxide and hydrogen, the liquid stream is made up mostly of non combustables (ash). The gas is piped to a rather normal looking furnace and burned in a fashion similar to natural gas. The liquids pass over a heat exchanger to cool them down and allow them to solidify. The energy used to create the plasma arc is mostly recovered. The reason that this is more efficient than just incinerating the trash directly is because of the difference in excess air requirements. Gaseous fuels require about 5-10% above stoichiometric ratio of air to fuel. Incinerating trash in a retort style furnace requires 100-150% excess air. That is a huge volume of air that is being heated for no good reason.

Re:It is burning the waste.

[Anonymous Coward]

You should have more respect for these "bureaucrats", as you call them. Unlike you, they have devoted much of their time to dealing with issues like waste disposal. Unlike you, they have considered with great care and detail the environmental and economic impacts of the various methods of waste disposal. They know what they are talking about, you do not.

Maybe you took a chemistry course when you were in high school. That does not make you an expert at waste disposal methodology, Dennis Forbes! What it does come down to is that this method may prove to be environmentally harmful. It is the duty of that official to discount possibilities that will have an unsuitable level of harm.

I know you have a flagrant hatred for conservatives, libertarians, and those who wish to carefully consider their options, rather than acting on pure emotions and uneducated speculation. Those of us in the real world don't have time for your unjustified "it'll be safe!" nonsense, especially when studies have shown that incineration of garbage is one of the worst possible methods of disposal.

A liberal such as yourself might have a hard time considering the actual consequences of garbage incineration. So I'll lay it out plainly for you: burning garbage (by whatever means) causes airborne, waterborne and solid pollution. Much of the toxins released into the air, water and surrounding soils are carcinogens, causing horrible cancers and birth defects in humans. The surrounding areas will likely be heavily polluted for many decades. This in turn is very harmful to the economy, as the land may be unusable, but of great potential worth. In addition, workers being treated in a hospital for terminal cancer aren't producing, which further harms the economy.

So please, take your knee-jerk liberalism elsewhere. The official who eliminated this type of technology did the correct thing, and as such it is in the best interest of not only your community, but of all the communities downwind from yours.

Re:Could happen in the Toronto area soon as well

[Malc]

So easy to blame Toronto in all this, but what about the business in Michigan? Surely it's their fault? Of course, that would mean Michiganers blaming one of their own. The reality is, Toronto has to find the best deal to keep costs down for its tax payers. The site in Michigan is the cheapest site capable of handling Toronto's waste. And in all fairness to Toronto, the city has made massive strides to reduce the amount of rubbish [toronto.ca] it places in land fill sites.

BTW, less than 25% of the waste from Ontario that goes to Michigan comes from Toronto.

Re:How many AOL CD's?

[momerath2003]

It's called "backwork." Any power plant uses some fraction of the power it generates to power itself (pumps, compressors, etc.) It's no different with accelerator-driven plants or this concept, except they use more power.