Comments on: Powering cities on landfill waste

A start-up is opening a plant that will convert municipal waste into electricity through a cleaner process than burning.
Photo: Turning waste into energy

[mongoose13223]

ass

wouldnt that smell like ass

[netman115167]

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?

[cmk_78212]

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?

[mlamonica]

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.

[Hoser McMoose]

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.

[chris cicc]

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!

[sjkx]

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

[wylbur]

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.

[wylbur]

magma molten metal

wasn't there a company in MA in the 90s called Magma Molten
Metal that tried this and failed?

[Commander_Spock]

>>>"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!

[Commander_Spock]

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!

[Commander_Spock]

So,....

... when is there going to be the worldwide summit on -- "Powering cities on landfill waste"?

[Commander_Spock]

Or,...

... is it that the "big oil companies" are not going to be very happy by these developments worldwide. Huh!

[shark12er]

755

Interesting, cool article, made me chuckle.

http://www.bestmobiletools.com/popular.html

[jamie.p.walsh]

What about thermophyllic digesters

http://news.com.com/Microgy+lands+deals+to+help+it+turn+cow+manure+into+natural+gas/2100-11395_3-6135099.html?tag=item

[feliusrex]

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.

[shera89]

Thermal Depolymerization

Close the CO2 loop.

http://lists.envirolink.org/pipermail/ar-news/Week-of-Mon-20030804/004435.html