Quote:
Originally Posted by efattah
Thanks to the Startech plasma converter ( http://www.startech.net/), which will soon see service in 16 countries (including my own country), all garbage including toxic waste can be converted into clean electricity. So stop worrying. |
The plasma technology is definitively interesting and progressive, but the articles about Startech Plasma Converter are highly idealized and extremely hyped. They do not address at all diverse problems occurring during the plasma conversion. I have to find yet an objective independent document analyzing the ecologic balance of the device. I think it will be positive, but still there are many problems involved.
Layman reading the description on Startech's website or in numerous popular science magazines, without the ability to read between the lines, may easily become under the impression that the device converts all matter into some kind of uniform gas (PCG) and solid matter (obsidian glass). Less educated persons could be even easily under the impression that the device converts waste (it means all type of molecules and atoms) into hydrogen or natural gas, and some kind of unspecified homogene harmless matter (obsidian glass).
That's, of course, quite a nonsense denying all physical and chemical laws. Its the same believe as the one that drove medieval alchemists in their attempts to convert diverse matters into gold. The only way to change atomic properties of a matter is nuclear fusion or fission, but that's quite a different category, that we are still pretty far from even experimenting with (even less mastering it), and has absolutely nothing to do with plasma gasification.
So what actually happens in a plasma converter? Well, in no way atoms change their properties. Hydrogen remains hydrogen, oxygen remains oxygen, iron remains iron, lead remains lead, mercury remains mercury, arsenic remains arsenic, etc, etc. Only molecular chemical bindings are disrupted, hence molecules (both organic and inorganic) cease to exist and break into the composing atoms. But still these atoms remain in the plasma; they do not disappear or convert into atoms of other elements.
Now, the plasma needs to be cooled - that happens by injecting big amounts of water, cooling down the plasma from ~16,000°C (30.000°F) to 50°C (122°F). Basically, the two mentioned waste products result from this process - the PCG gas and the obsidian glass. But amount of the waste matter is washed away with the cooling water too. Startech website claims that the pollution of the water is minimal, and that the PCG gas and the obsidian glass are non-toxic. That's really hard to believe. Better told, I think it is an outright lie. If you "burn" daily thousands of tons of waste, it necessarily contains kilograms of different heavy metals and other further nonbreakable (atomic) toxic or dangerous elements. The same amount of the toxins will necessarily remain on the output too. There is no way they could disappear. They do evaporate in the plasma, but the solidify back after cooling it down.
Furthermore, since there is no process in the device separating the resulting elements, they are all mixed together in the gas, in the cooling water, and in the obsidian-like stone, and hence they will necessarily chemically react and create possibly toxic molecules. Water need to be filtered (Startech claims it does not if the waste contains few heavy metals, but everything including plastics and practically any other material contains heavy metals), and the PCG gas needs to be filtered through carbon filters - that creates also a lot of quite toxic waste.
Startech claims that the obsidian-like byproduct is nontoxic and non-leachable, but in another article about Startech (quite positive) in Popular Science, the admit there are opponents of the technology pointing out the extreme toxicity of the obsidian byproduct and its water solubility and hence the danger of ground water contamination. And other experts warn about the chemical building of toxins in cooling plasma.
So yes, the technology seems to be better than landfills or traditional incineration, but still you should not expect from it any miracles and claiming that it turns sh!t into gold, or that the more waste the better. Also the final energy balance (including the energy needed for the production, distribution, and consumption the products creating the waste) will be always negative - if you know some basic physical laws, it is certainly clear enough. In other words, a better technology for compacting waste (and the plasma converter is not really much more than that) is certainly welcome, but is should be no excuse for unnecessary consumption and creation of waste!
