June 6, 2007 4:00 AM PDT

Powering cities on landfill waste

(continued from previous page)

Other processes for converting waste to fuels include ethanol, methane from trash and manure, as well as biodiesel from animal fats. Many of these techniques are being tested to operate at a commercial scale, as part of the clean, or green tech, investment run-up.

Using municipal solid waste as a feedstock hasn't yet taken off because in the past there wasn't much interest in alternative fuels and people underestimated the material handling requirements, Ze-gen's Davis said.

A treatment center in New Bedford will pay Ze-gen a "tipping fee" to take its construction debris, which would otherwise have to be hauled somewhere else. But Davis said the process would be cost-effective even if a waste-to-energy facility operator wasn't paid. It's also conceivable that facilities would have to pay for waste in the future.

The process, if successful, could also qualify for renewable-energy credits or be used to sell carbon offsets, said Flagship Ventures' Matheson.

"Since we're reducing the carbon footprint of incineration and landfill quite dramatically, we think the (facility) should qualify for carbon offsets," he said.

By the end of the year, Ze-gen should have an idea of how its plant is performing, including the quality of the syngas, which varies depending on the process. The modular design of the plant means it can increase production quickly, assuming sufficient capital, and can be used with different types of garbage.

"Given that gasification is proven at a chemical level...it is going to be the next big thing (in waste to energy)," Davis said. "It's just a question of seeing who does it most efficiently."

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19 comments

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ass
wouldnt that smell like ass
Posted by mongoose13223 (2 comments )
Reply Link Flag
Quality reporting...
I find the otherwise quality of the c|net news to be degraded by the frequent misuse of English and no editing to catch it. "cites" or sites?
Posted by netman115167 (1 comment )
Reply Link Flag
Only Construction Waste?
Can other forms of waste (paper, plastic, other chemicals) be used in addition to wooden waste at construction sites?

Also, how does this lower the carbon foot print. The same amount of carbon in the waste goes into the gas which gets burned and goes into the air, so how is this cleaner that simply burning the waste?
Posted by cmk_78212 (9 comments )
Reply Link Flag
Other waste/ versus incineration
Other forms of waste can be done through this process, according to the CEO. They're initially testing it with construction debris, which includes wood but also other materials.
They claim the gasification process is cleaner because you're not creating a lot of carbon dioxide as you would if you just burned the trash. Of course, this type of plant also calls for burning the synthetic gas post gasification to make electricity. But the CEO and prospective investor told me that entire process is cleaner than just incineration.
Posted by mlamonica (330 comments )
Link Flag
Two possibilities jump to mind
There are two things I can think of that might reduce the carbon foot print:

1. It's possible that this process is more efficient than simple incineration. They're saying that they can produce 38MW of electricity for every 8MW used in the process, which is pretty good. I would guess that standard incinerators are less efficient, though I have no numbers.

2. The gas being burnt is syngas, which burns very cleanly and produces only CO2 as an output. While CO2 gets all the attention for carbon footprints, it's actually not a very strong greenhouse gas as compared to many others. Of particular interest would be methane, that has a solar forcing factor 21 times higher than that of CO2. Burning 1 methane molecule in air to make 1 CO2 molecule (plus 2 H2O) means you've reduced your "carbon foot print" to 1/21 of what it was, even though you still have the same number of carbon molecules.

Probably more important in my mind though is that this process should result in very little air pollution. The big problem with incinerators is not the carbon dioxide they spew but rather the other stuff, like NOx, SOx, carbon monoxide and particulate matter. By gasifying the waste and then burning the syngas you should (at least in theory) have most of your pollutants separated out as solid waste (ash) while the stuff coming out of your smoke stack will be mostly non-polluting CO2 and H2O.

Of course, how well this all works in practice remains to be seen. Also this should in no way supplant the basic reduce, reuse and recycle principles which are almost always much more efficient.
Posted by Hoser McMoose (182 comments )
Link Flag
PLASMA
what exactly is the point of this article? you talk about a company that is converting trash to energy but don't mention how it is doing it? shoddy reporting. it is PLASMA GASIFICATION technology that ATOMIZES the trash into the syngas which is then burned to spin turbines. this is state of the art technology that is only now being used in production environments, and which could one day soon eliminate all of the world's trash and nuclear waste (yes it can burn that too). CNET is about tech, so report about it!
Posted by chris cicc (1 comment )
Reply Link Flag
not yet?
Plasma arc technology wasn't considered viable on O'ahu, Hawaii
(where I live) in 2004:

www.honolulu.gov/refs/csd/publiccom/honnews04/
plasmaarcrecommendations.htm
Posted by sjkx (49 comments )
Link Flag
theoretically cleaner
Until they actually build the plant and get figures on energy
consumed to make the molten metal bath and on the contents
of the plant's exhaust and any ungassified waste stream, we
really won't know if it is cleaner. A lot of energy goes into
gassification, so you may not have that much power to sell
because you are using part of the power generated to heat the
molten metal. If you end up with emmisions and minimal power
for sale, it could wind up worse than a high temperature burn
with good furnace air flow control and lots of exhaust scrubbers.
Let's wait for the numbers to come in before we say this is
cleaner and better.
Posted by wylbur (110 comments )
Reply Link Flag
magma molten metal
wasn't there a company in MA in the 90s called Magma Molten
Metal that tried this and failed?
Posted by wylbur (110 comments )
Reply Link Flag
>>>"Powering cities on landfill waste"<<<
A very interesting article indeed; but, it would be good to see all the financial, economic and technical statements; also, the financial, economic and environmental impact on an international scale!
Posted by Commander_Spock (3123 comments )
Reply Link Flag
The toss up "question" is....
... just "how many" (individuals) worldwide can really and truly (all the talking aside) show us some "real" financial, (particularly the economic) and technical numbers/statements in as much as we now live in computer savvy world today!
Posted by Commander_Spock (3123 comments )
Link Flag
So,....
... when is there going to be the worldwide summit on -- "Powering cities on landfill waste"?
Posted by Commander_Spock (3123 comments )
Reply Link Flag
Or,...
... is it that the "big oil companies" are not going to be very happy by these developments worldwide. Huh!
Posted by Commander_Spock (3123 comments )
Link Flag
755
Interesting, cool article, made me chuckle.

<a class="jive-link-external" href="http://www.bestmobiletools.com/popular.html" target="_newWindow">http://www.bestmobiletools.com/popular.html</a>
Posted by shark12er (10 comments )
Reply Link Flag
What about thermophyllic digesters
<a class="jive-link-external" href="http://news.cbsi.com/Microgy+lands+deals+to+help+it+turn+cow+manure+into+natural+gas/2100-11395_3-6135099.html?tag=item" target="_newWindow">http://news.cbsi.com/Microgy+lands+deals+to+help+it+turn+cow+manure+into+natural+gas/2100-11395_3-6135099.html?tag=item</a>
Posted by jamie.p.walsh (288 comments )
Reply Link Flag
Net Carbon producer
The idea that gasification might lead to a net reduction in CO2 or CO emissions is wholly wrong. Almost no construction waste is incinerated, it just sits in the landfill. Biological breakdown of commercial timber is negligible, therefore the CO2/CO foot print of putting it in the landfill is essentially 0. Any emissions above 0 means this is a CO2/CO producing process, regardless of what it's proponents might say.
Posted by feliusrex (48 comments )
Reply Link Flag
Thermal Depolymerization
Close the CO2 loop.

<a class="jive-link-external" href="http://lists.envirolink.org/pipermail/ar-news/Week-of-Mon-20030804/004435.html" target="_newWindow">http://lists.envirolink.org/pipermail/ar-news/Week-of-Mon-20030804/004435.html</a>
Posted by shera89 (19 comments )
Reply Link Flag
There's a group that's building awareness to TVs polluting the world with an online graveyard called JUNKED TV at http://www.junkedtv.com

It's weird how tv's are now popping up on the sidewalks of the world as a common fixture - If you see a junked tv on the side of the road take a pic and email it to them to add it to the campaign.
Posted by petesamuels (2 comments )
Reply Link Flag
 

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