FORT PIERCE, Florida -- A Florida county has grand plans to ditch its dump, generate electricity and help build roads -- all by vaporizing garbage at temperatures hotter than parts of the sun.The syngas can also, according to other companies, be used to make liquid fuels such as ethanol or diesel.
The $425 million facility expected to be built in St. Lucie County will use lightning-like plasma arcs to turn trash into gas and rock-like material. It will be the first such plant in the nation operating on such a massive scale and the largest in the world.
Supporters say the process is cleaner than traditional trash incineration, though skeptics question whether the technology can meet the lofty expectations.
The 100,000-square-foot plant, slated to be operational in two years, is expected to vaporize 3,000 tons of garbage a day. County officials estimate their entire landfill -- 4.3 million tons of trash collected since 1978 -- will be gone in 18 years....
Synthetic, combustible gas produced in the process will be used to run turbines to create electricity -- about 120 megawatts a day -- that will be sold back to the grid. The facility will operate on about a third of the power it generates, free from outside electricity.
Given that it's a form of waste disposal and electrical generation that doesn't require any kind of fossil-fuel inputs, I'm beginning to think that plasma incineration will play a pretty big role in the future. The one caveat here is that so long as all of our plastic junk is made from oil, any incineration of that stuff is, by necessity, going to create greenhouse gas emissions.
3 comments:
for more information on plasma system try reading this site
www.startech.net
They are decomposing garbage using electricity, then claiming the decoposition products will generate more electricity than it took to decompose the garbage.
This seems impossible, but I have not seen an energy balance.
Using the process to generate electricity does not seem like it will make as much economic sense as using the syngas to generate synthetic fuel for transportation.
If the syngas drives a combined cycle power plant, only at most 60% of the energy in the syngas comes out as electricity, and once you have that there is the plasma torch that will be gobbling its share of the juice.
Converting the syngas to high-value products (fuel oil, etc.) instead of electricity and heat makes more sense. The plasma-arc system in general seems best suited for hazardous waste such as PCBs, obsolete pesticides, chemical warfare agents, etc. Mass-burning incineration or - heaven forbid - SOURCE REDUCTION might just be the way to go for MSW.
The waste is decomposed - it is broken down into simple yet energy rich substances like carbon monoxide and hydrogen. It takes some energy to do that.
Incinerators, for example, first "char" the waste using a little bit of energy then produce flammable gases and carbon which are subsequently reacted with excess oxygen to release a whole lot more energy. It all happens in one shot. The plasma system separates the two steps and puts pollution controls in between them.
Post a Comment