Turning PLASTIC back into the oil it came from

This must be a joke. There is no rational or saving to do this.

The process is well known. It is no joke, can't say much about that particular machine though.

I mean the idea must be a joke. Over here we either burn the plastic garbage for domestic heating and/or hot water (CO2), or we recycle it.

Adding heat to return it to oil takes energy (CO2) and then you burn the oil anyway (CO2).

Which means, the machine does nothing to reduce your carbon footprint, instead it makes you release even more. (Not that it matters, but this was the point made by the inventor).

Hi,

In Germany where re cycling and garbage separation is taken to an extremely hi level.

There are Bio Bins for all the things that rot down, there are blue bins for all things paper and cardboard related no waxed or plasticised materials allowed, there is another one for Restmull - all the other stuff EXCEPT for what goes into the Gelb Sack (Yellow Bag) This flimsy see through yellow hued plastic bag is the catch all for all things plastic, polystyrene, waxed cardboard, tin foil and foil food containers, plastic bottles with no deposit on them and the list goes on. It is collected every second week to be carefully aligned and thrown into the incinerator at the local Mulldepone ( Dump)

It is used to make heat for a number of other recycling processes that are carried on at the facility.

Glass is a whole different story where non Pfand ( deposit) bottles go to recycling depots with white in one and all colours in another. All bottles with Pfand on them go back to retailers where you get the money back either in cash or as credit against further purchases. The deposits can be substantial with Euro 25c being charged for 1 lt Volvic water bottles.

The Green Movement doesn't always reveal the absolute costs in a particular popular bandwagon if it helps to get their message across to the gullible.

As an old fella I knew once told me there are lies, lies and statistics.

I tend to think he was correct all those years ago.

The most likely location for plastic to oil conversion devices is at existing landfills where the plastic is available. Those landfills produce great volumes of methane which (in the US at least) is collected and used to drive onsite diesel or gas turbine powerplants.

The energy in the landfill gas can power the conversion process.

http://www.gizmag.com/envion-plastic-waste-to-oil-generator/12902/

There are several pilot plants operating now and it looks like more operational plants are permitted and going online at landfills around the country. Time will tell if the technology is as economical or beneficial as its promoters claim. Personally, I believe they are on to something.

You guys must have some amazing home heating devices if they can burn plastics and not poison everyone downwind for a thousand miles!

Already in the 1950:s we had a suction tube from the house to a central where all the garbage was burnt and returned as hot water.

Our next house in the 60:s was connected to a nuclear plant giving us hot water...

Wouldn't only a fraction be returned as oil? What happens to the rest of the gunk (sorry non-engineering term)?

Hey all...

I wrote this for another forum on the same topic and am posting it here at the request of one of your members.


A little basic chemistry to help this all make sense...

Pretty much all of this stuff starts out as crude oil. Crude is a mixture of a whole bunch of different hydrocarbons, loose carbon, nitrogen, sulfur compounds and various other crud. The hydrocarbons are the useful bits, so lets take a look at those.

A hydrocarbon is a molecule containing carbon and hydrogen atoms in various structures. The simplest is Methane, or natural gas, which has one carbon and four hydrogen atoms. Structurally, it looks like this:



From there, the hydrocarbons get bigger and bigger. For example, Propane has three carbon atoms and 8 hydrogen atoms and looks like this:



As ther molecules get bigger their properties change in predictable ways. Hydrocarbon molecules are often refereed to by how many carbon atoms they have, so methane might be referred to as C1 (One carbon) and Propane as C3. As a hydrocarbon gets larger (a higher C number) it tends to become less volatile and less combustible. Gasoline is usually in the C5-C8 range (but has a bunch of other stuff mixed in). Kerosene is usually C6-C16 and diesel fuel is in the range of C8-C21. The more carbon atoms in a molecule, the more energy it provides, but the harder it is to get it to burn.

When we talk about plastics we are talking about polymers. These are long chain molecules that can contain thousands of carbon atoms. These polymers are put together from monomers which are a single building block. The simplest plastic is polyethylene, for which the monomer is ethylene. Ethylene has a formula of C2H4 and looks like this...



Notice how the molecule has two attachment points between the carbon atoms instead of just one. You can break that bond to create an "open" molecule that looks like this:



You can then stick a whole series of those "broken" molecules together in a chain or arbitrary length like this:



This is essentially the same as a standard hydrocarbon molecule, except the C number can be in the millions.

Different monomers are used to get different physical properties. For example, if you replace one of the hydrogens in ethylene with a chlorine atom you get a monomer that looks like this:



Stick a bunch of those together and you get this...



This is Polyvinyl Chloride or PVC

There is an almost unlimited number of variations to this process which produces the wide variety of plastics we see today.

To convert these plastics to gasoline requires cutting the molecules down to the size we need. Practically what is needed is heat and a catalyst to break the C-millions polymers to the C5-C8 range for gas. By changing the temprature and pressure under which the reaction is taking place we can change the size of the output molecules. This works great for polyethylene which is basically just one big hydrocarbon molecule, but with other plastics and their different chemistries you will get all sorts of different, and potentially nasty, compounds.

Actually, burning it in the backyard usually doesn't get hot enough to break the C-C bonds and so while the hydrogen burns off to produce water, the carbon tends to clump into something like graphite, which is the black solid stuff you see coming from the fire. With PVC or Teflon the halogen atoms (chlorine and fluorine respectively) bind with the extra hydrogen to form hydrochloric and hydrofluoric acids, both of which are nasty things to be breathing. Some of the carbon atoms which are separated can bind with nitrogen to form cyanide and nitrous oxide compounds which are also pretty toxic. Finally, the carbon soot is a smog contributor.