Sound too good to be true? Well, it gets better. The amount of energy that can be generated from the fuel produced is actually greater than the amount of energy it takes for the machine to process the garbage. So, not only does this prevent waste from going into landfills, and provide fuel and raw materials for construction, if used to produce electricity, it generates more energy than the process uses.

The Process
The trash to be processed first processed to remove anything that can be easily recycled (e.g. cans and bottles). Things like batteries which have been thrown in the trash rather the recycled correctly, can also be removed at this stage by centrifuge sorting. The remainder is then shredded ready to be added to the plasma gasification system.

As it enters the first stage of the machine, the pre-gasifier, steam and oxygen are injected into the shredded waste resulting in some gasification. The partially processed waste then drops through to the next step: the plasma chamber. At the bottom of the plasma chamber is a molten glass bath. In the plasma chamber, the waste is heated by a plasma arc, which reach temperatures hotter than 10,000°C. At that temperature, the bonds between the molecules break and the elements can be recombined into useful materials. Inorganic compounds are dissolved into the glass bath; metals can be drained off at the bottom for recycling, the remainder stay in the glass, which is ejected from the machine slowly while it works and can be used to create a range of construction products.

Most of the material fed into the system though is converted into synthesis gas. That gas is cleaned and can then be converted to hydrogen, ethanol or other fuels.

Heavy Metals & Other Chemicals
What happens if heavy metals like mercury, or toxic chemicals are added to the machine in the mix of trash? Well, according to InEnTec, the high temperatures of the plasma arc are capable of breaking down the bonds in most harmful chemicals rendering them safe. The heavy metals, like cadmium and mercury, that might find their way into the system are drained off so that the glass ejected from the machine contains at most only traces of these elements.

Slate has more information about plasma gasification.

Is it safe?

I took a look at the containers I have here, both bought ones designed for the purpose, and ones I am reusing from my pantry & fridge. They are all made from the same plastic, labeled with recycling code 5, or the letters PP for polypropylene. Polypropylene has not been associated with any health concerns, and does not leach chemicals into the food stored within it. Whether reused or bought, make sure you wash them well between uses.

Even better, according to Recycle Now’s guide to plastic recycling codes, polypropylene is often not accepted by recycling centers, so reusing them is saving them from the landfill too. When it does come time to dispose of them, check with your local facility about recycling before throwing them out – ours here in Alameda does indeed take code 5 plastic.

What About Water Bottles?

There have been some questions about the safety of reusing bottles marked with code 1 – PETE. The American Chemical Council has a page talking about the safety of polyethylene terephthalate bottles. Their conclusion is that they are safe if well washed. The only exception they list is PET trays used for microwaveable food. Other sites seem to confirm this view that these bottles are safe to refill. Organic Picks has a list of safe and unsafe plastics that looks like this:

If you’re still worried, the good news is that they are easily recycled. Just remember to take the caps off before throwing them in the blue cart.

Of course, you’d be doing the environment (and your wallet) a bigger favour by not buying your water in bottles in the first place. A water filter and some reusable water bottles. Avoid the trendy clear plastic polycarbonate ones though as there is still a concern about chemicals leaching from those into the water, especially if it is hot water. There are plenty out there made from safe plastics, including the safe polypropylene (code 5) used for those storage containers, or you can opt for a cool stainless steel bottle. At home, think about using a glass.

Other Storage Jars

On the subject of glass, the other type of container from your pantry that you might want to think about keeping is glass jars; the kind that things like pasta sauces, pickles and salsa dip come in. These can be washed easily, and reused for storing your own sauces and other food items in the kitchen.