Plasma for Waste Disposal?

Plasma.  You’ve probably heard of it before (and hopefully somewhere outside of Best Buy).  It is the fourth state of matter (the first three being solid, liquid, and gas), in which molecules have been split apart into their most basic atomic form and ionized.  Accomplishing this splitting, or disassociation, requires huge amounts of energy.  So it’s not surprising that plasma plays a key role in a number of high-power applications including plasma cutters and fusion reactors.  Again, you’ve probably heard of those.  But I’ll bet you’ve never heard of dental plasma torches or plasma arc waste disposal.

Plasma Torch (Courtesy PyroGenesis via HSW)

So what’s the deal here?  Using plasma for waste disposal?  Sounds like overkill.  I mean, vaporizing trash with a torch that reaches temperatures of 25,000°F?  That’s more than twice the temperature at the surface of the sun.  Well, there actually are advantages to this.  For one thing, plasma torches can break down almost any material into its constituent atoms.  Plastics, metals, toxic compounds, medical waste, apple juice – basically anything except heavy radioactive materials (such as spent nuclear fuel rods) can be converted into gasses and slag (molten solid waste, shown below):

Plasma Furnace Slag Drain (Courtesy PyroGenesis via HSW)

As an added bonus, with plasma arc waste disposal, the byproduct gasses can actually be used as fuel.  In fact, these plasma converters, as they’re called, can generate more energy than they require for operation.  In other words, they convert waste into energy, similar to an old-fashioned incinerator.  But unlike incinerators, which burn waste in the presence of oxygen, plasma arc furnaces break apart waste using a process called pyrolysis, which can be done in an airtight container.  The result?  Fewer hazardous byproducts.

Anyway, I’ll stop here and refer you to HowStuffWorks for further information.  They’ve produced an excellent article on plasma converters which goes into more detail on how these systems work and where they’re currently being designed and used.

In other news, yes, this is my first post in three weeks.  My apologies for being so lazy, but I’ve been a little busy with moving from Troy, NY to Waterloo, IA for my new job with John Deere.  I’ve just wrapped up my second week of work and it’s been pretty exciting so far.  During my first week of orientation I toured a different Deere facility each day.  I saw some pretty amazing things there, including electrostatic painting robots, inductive heat treatment, and some pretty hefty robotic welding stations.  Perhaps in the future I’ll be able to write about some of these things (although the details of a lot of these systems are confidential).  Anyway, to my subscribers, thanks for sticking around!