Slashdot Mirror
Continuous System For Converting Waste Plastics Into Crude Oil
rtoz writes: A MIT spinout company aims to end the landfilling of plastic with a cost-effective system that breaks down nonrecycled plastics into oil, while reusing some of the gas it produces to operate. To convert the plastics into oil, this new system first shreds them. The shreds are then entered into a reactor — which runs at about 400 degrees Celsius — where a catalyst helps degrade the plastics' long carbon chains. This produces a vapor that runs through a condenser, where it's made into oil. Much of the system's innovation is in its continuous operation (video). This company aims to produce more refined fuel that recyclers can immediately pump back into their recycling trucks, without the need for oil refineries. Currently, 2 trillion tons of plastic waste is sitting in U.S. landfills, so there is a huge demand for this technology.
If this technology is so good like they said, and many companies (or better: governments) adopt such ways of transforming plastic into fuel, we can organize all the World plastic waste in to TWO recycle ways: produce FUEL and recycle PLASTIC. We don't need to transform all the plastic waste into fuel. The industry still needs plastic in their products so with a better equilibrium we can reduce the petroleum extraction (a.k.a.: dependency), try to utilize all the annual plastic waste, and (better) we can contribute with the environment with less pollution, in the air and in the ground (I think).
Why even bother with the landfills? There are massive garbage patches floating around in the oceans, the vast majority of which are plastics. If you can get a big enough tanker and implement this system on it, you could probably cut the amount of fuel needed even further - the tanker goes into a garbage patch, melts all the plastic down, keeps the oil, and uses some of it to get back to land. It would probably be more effective than loading fleets of trucks.
I don't know how they define "cost effective", but since the plastic mostly came from oil in the first place, any energy expenditure to recover it is a net minus overall.
For an individual organization that can get a hold of a lot of landfill plastic cheap, this may be a win, but overall it is a fuel source with an energy return on investment (EROI) less than 1.
We're in trouble if we have to start resorting to this as an energy source. Deep trouble.
Left MS Windows for Linux Mint and never looked back!
Vote for Bernie in 2016!
I'm all for eliminating waste, but if the net effect is that we're removing plastic from landfills and emitting it as CO2, that's not terribly different from digging up crude oil and emitting it as CO2.
Now, I'm sure there's some sort of multiplier here that makes it a bit better - perhaps the plastics are a cleaner source and less energy will be used to process it - but currently this carbon is sequestered in an inert if unattractive form whose dangers are mostly localized.
While this converts waste plastic to oil it does not however:
A.: complete this conversion at a less than or equal cost of energy generated by the oil. The shredder, crucible, and condenser arent powered by the mellow rock stylings of huey lewis and the news.
B.: Absolve us from researching alternatives to crude oil, a fossil fuel that is finite in supply and directly contributing to climate change.
Our lust for oil has become all but indistinguishable from a heroin addicts search for a fix.
Good people go to bed earlier.
From the article:
About 70 to 80 percent of the product comes out as oil. Roughly 10 to 20 percent becomes hydrocarbon gas that heats the system, while the remainder is char residue.
For every 10 units of plastic the system is fed, it generates 7-8 units of oil, 1-2 units of gas which powers the system, and 0-1 units of waste 'char residue'. So it produces quite a bit more fuel from the plastic than it consumes.
The statement that there is 2 trillion tons of plastic in land fills got me wondering how much oil actually goes into producing something. From what I can gather a barrel of oil weighs about 300 pounds so if there aren't any other external inputs into making plastics that would mean that about 13 trillion barrels of oil have been turned into plastic. This doesn't seem the least bit right given that under 2 trillion barrels of oil have been extracted and not all of that went into making plastic. So how much oil actually goes into making plastic and how much is other stuff is use?
This leads me to my next question which is how much of the weight of the plastic is turned into oil? If it is over 1/6 of it then we have the equivalent of more than all presently extracted oil in our land fills already.
Time to offend someone
Install on floatation device, Pacific Ocean garbage patch, lather, rinse, repeat.
Pyrolysis for "recycling" plastic waste into oil (or tire waste into oil) has been around since at least the 1990s. The main problems are 2: A) As Irate Engineer states, a polymer is an "added value" and deconstructing polymers back to oil always fails economically when actual recycling to like-polymers is available, and B) as Itzy says, the comparative value of returning it to fuel, vs. leaving it in an Municipal Solid Waste to energy facility and burning it, is small.
I read TFA and cannot figure out what differentiates this from the pyrolysis "waste investments" of the 1990s, none of which really sailed.
Gently reply