PlascoEnergy to Build North America's First Waste Gasification Plant
by Jeremy Elton Jacquot, Los Angeles on 07. 2.08
The idea behind waste gasification is an attractive one: Take trash and subject it to extreme heat under anoxic conditions to produce syngas, a blend of carbon monoxide and hydrogen, which can be used as a fuel source. Despite its promise, its high operating costs and relative inefficiency had heretofore limited its applicability in most countries.
Yet, as reported by Technology Review's Peter Fairley, that is all set to change with the approval of North America's first gasification plant in Ottawa, Ontario. The inaugural plant, which will use electric-plasma torches to zap waste into syngas, will be built by Ottawa-based PlascoEnergy.
The plant is expected to be able to convert up to 400 metric tons of garbage a day into 21 megawatts of net electricity, which would be enough to power roughly 19,000 homes. Fairley describes how the process will work:
"First, bulk metals are removed, and the rest of the shredded waste is conveyed to a 700 ºC gasification chamber. Most of it volatilizes to a complex blend of gases and rises toward a plasma torch operating at 1200 ºC--well below the 3000 to 5000 ºC used with hazardous wastes. The plasma reduces the complex blend to a few simple gases, such as steam, carbon monoxide, and hydrogen, plus assorted contaminants such as mercury and sulfur; subsequent cleanup systems remove the steam and mercury and scrub out the soot before the syngas is sent to an internal combustion engine generator.The waste that doesn't volatilize forms a solid slag and drops to the bottom of the gasification chamber. The slag is then pushed to another plasma torch, which drives off remaining carbon in the slag before the slag is cooled and vitrifies. The resulting glass can be blended into asphalt road surfacing or cement."
The hefty upfront costs, about $125 million, in addition to the standard operating expenses (the process will cost the city $60 per ton) will likely keep this technology from becoming widely implemented in the near future. Once the plant is completed 3 years from now, the hope is that continuous improvements and economies of scale will quickly drive down the costs and make it a more appealing option for other communities.
Via ::Technology Review: Garbage In, Megawatts Out (magazine)
Other waste gasification projects
::Zapping Trash With Plasma Produces Clean Energy and Fuel
::Turning Radioactive Waste Into Clean Fuel
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This may be the first trash-to-energy gasification plant, but is definitely not the first trash-to-energy plant. Energy has been produced from burning trash in NA for decades, just not nearly as cleanly as a plant like this.
Meh. It seemed like an ok idea but then this turned me off.
"The resulting glass can be blended into asphalt road surfacing or cement."
Yay, more roads.
Actually, using the glass is a good thing. It doesn't necessarily indicate new roads - roads are continually being patched and resurfaced, so there's a good chance that this byproduct could end up replacing some tar, etc in road repair. "Glassphalt," as it's called, was used in Baltimore for a number of years and created a really cool, sparkly effect.
See good article here:
http://www.citypaper.com/news/story.asp?id=2494
And, of course, a Wiki:
http://en.wikipedia.org/wiki/Glassphalt
hey Anonymous, i'd rather have our roads and paved bike paths, whether the old ones that get redone or new ones, made from recycled waste slag than freshly mined gravel and/or raw asphalt (made from oil drilling).
this seems like a good bet to me. i just wonder what they do with the accumulated mercury.
I don't see the cost being prohibitive as is. At $0.11 per KWh, they can make about $55,000 per day from surplus electricity production, and about $24,000 per day from 'tipping' fees. This gives about $29 million income per year, so about a five-year payback, not counting operating costs.
They should also be able to sell the slag for roads and other construction processes. Other byproducts include salt, sulphur, and potable water, which might also be sold.
This certainly wouldn't be my vision for the future of trash, but it works and it is far better than landfilling.
Anyway, I would like to see communities implement curbside bins for compostables the way we have curbside recycling now.The vast majority of "garbage" nowadays is either recyclable or compostable. Most things that look like styrofoam (which most people, thinking it is styrofoam, throw out) are actually recyclable plastic if you look at the bottom. This would be another good way to get a second use out of garbage. since it is only organic matter that can be converted to energy through a plant like this.
@Anthony: How do you know it's only organic waste? No plastic?
Thermal Depolymerization (TDP) is cleaner, more energy efficient and produces a more flexible output with a higher value. The temp, pressure & time used can steer the output from methane for use in natural gas applications, though gasoline up to diesel weight.
It's also in use already.
http://en.wikipedia.org/wiki/Thermal_depolymerization
Whoops, this gasification plant was scooped by Edmonton's, announced on Treehugger a few days ago.
http://www.treehugger.com/files/2008/06/waste-to-energy-plant-first-edmonton.php
The Edmonton facility will gasify waste to produce methanol and ultimately ethanol.
Hi Buddy,
Are you sure the 21 MW are constant power output and not just the total amount of energy output of the 400 tons of MSW.
I"ve just made a small calculation, based on your calculations, I calculated that 1 ton of MSW gives about 10% of the energy of what a ton of Coal would give.
If that is true, I guess every city will soon be willing to buy such a system.
I don't know how much metals and stuff could be recycled out of the garbage, but with the current prices for aluminum, iron and so on it might even be a bigger bang for the buck.
I guess every city with an old landfill is going to build a second one, next to it, and harvest their own stored energy from the last 40 year or more.
According to Plasco's website ( http://www.plascoenergygroup.com/ ), from each tonne of waste they get:
1.2 MWh electricity
300 L potable water
5-10 Kg commercial salt
150 Kg aggregate
5 kg sulfur agricultural fertilizer
This gives 480 MWh per day, assuming 400 tonnes of waste processed.
If this process can actually produce a sustained power load of 21 MW, it's operating at 50% overall efficiency. Quite impossible to do.
The plasma unit uses the majority of its electrical output to ignite the trash - tha't why the lower 'effiiciency'. But it makes other byproducts for sale - so you can't judge on electrical output alone..
Keep watch for proposed plants in Texas, Maryland, or Florida which use a rotary kiln instead of plasma. The differences - greater efficiency, produces water as a byproduct, and potentially no emissions - all that is needed is a consumer for the gas byproducts including CO2. If CO2 can be used for such things as pellletized urea fertilizer production (safe,non-toxic), agricultural crop production (feed plants CO2), synthetic diesel or enhanced oil recovery, - little or no emissions.