How to turn plastic waste into diesel fuel cheaply

[lowriderzzz]

PS not at 100%, but mixed for example with PE and PP in a 20%, otherwise it tends to return to its original composition and can make a block in the car tank and engine (very simple explanation, but it happens... )

you mean 20% PS and 80% PP or PE. That is still acceptable since I have plenty PS garbage around.

[Beyond Biodiesel]

I'm no chemist but I believe what happens is at high temperatures the nitrogen and carbon bonds break in the nylon and form into CN or HCN

No, you have to have cyanide (CN) not C-N) present for cyanide to be released from any reaction.

Nitrogen gas (N2) doesn't decompose at pyrolysis temperatures which makes it safe as an inert gas.

Correct. At Chevron research all of the labs had large liquid N2 cylinders that supplied each lab with N2 for purge gas, and we all used it. However, CO2 is cheaper, and should be just as effective.

I would strongly disagree that pyrolysis of plastics is one of the most toxic occupations. At their most basic, plastics are just hydrocarbon chains just like crude oil. Plastic pyrolysis of the right types of plastic is no more toxic than crude oil refining.

As long as you feed in some sort of PE, PP or PS you'll be fine. The danger lies in the contaminants that can be introduced. Even so, the contaminants can be avoided by bubblers, combustion and other processes which I have no knowledge in.

Agreed; however, avoiding the contaminants can be impossible.

I have no experience in WMO so I won't comment on that.

Even WMO has its toxic contaminants, which I recorded here almost a year ago. Those contaminants could have killed me if I did not have the experience to know that I had bumped into something very toxic (HCL).

Holy Dooly you guys are mad.

Burning plastic with/without oxygen is one thing, burning unknown plastics is another. Good God, who knows what is in it, or what it could form.

Be careful here guys, any disease caused from toxic fumes via these methods probably wont be acute until it is too late, make sure your exhausts are well away from you and everyone else.

If you don't know what the plastic is, exactly, don't burn it. Or at the very least buy a gas mask with those oxygen cylinders. There is a reason why it isn't done main stream and some of those research institutes that do it have safety methods in place.

I have been preaching this from the beginning of my presence here over a year ago. However, we are not burning plastics. We are pyrolyzing them in an inert environment in a controlled process, or should be.

[Toll]

Holy Dooly you guys are mad.

Burning plastic with/without oxygen is one thing, burning unknown plastics is another. Good God, who knows what is in it, or what it could form.

Be careful here guys, any disease caused from toxic fumes via these methods probably wont be acute until it is too late, make sure your exhausts are well away from you and everyone else.

If you don't know what the plastic is, exactly, don't burn it. Or at the very least buy a gas mask with those oxygen cylinders. There is a reason why it isn't done main stream and some of those research institutes that do it have safety methods in place.

[fibuslitero]

PS not at 100%, but mixed for example with PE and PP in a 20%, otherwise it tends to return to its original composition and can make a block in the car tank and engine (very simple explanation, but it happens... )

Do you think PS is OK as a feedstock. I think that I remember earlier on this thread to be said that PS is a No No. However i'm not quite sure of this.

[lowriderzzz]

As long as you feed in some sort of PE, PP or PS you'll be fine. .

Do you think PS is OK as a feedstock. I think that I remember earlier on this thread to be said that PS is a No No. However i'm not quite sure of this.

[mjohnson1]

I'm no chemist but I believe what happens is at high temperatures the nitrogen and carbon bonds break in the nylon and form into CN or HCN


Nitrogen gas (N2) doesn't decompose at pyrolysis temperatures which makes it safe as an inert gas.

I would strongly disagree that pyrolysis of plastics is one of the most toxic occupations. At their most basic, plastics are just hydrocarbon chains just like crude oil. Plastic pyrolysis of the right types of plastic is no more toxic than crude oil refining.

As long as you feed in some sort of PE, PP or PS you'll be fine. The danger lies in the contaminants that can be introduced. Even so, the contaminants can be avoided by bubblers, combustion and other processes which I have no knowledge in.

I have no experience in WMO so I won't comment on that.

[Beyond Biodiesel]

Here is bit of info taken from - Hydrogen Cyanide: New Concerns for Firefighting and Medical Tactics - Fire Engineering

"But the real offender is the combustion of manmade plastic and resins containing nitrogen, especially if the fire is hot and in an enclosed space. Common manmade materials that generate cyanide gas during combustion include nylon, polyurethane, melamine, and acrylonitrile."

Thanks, mjohnson1, that is very useful information. But, I do not see how Nitrogen in the hydrocarbon molecule leads to cyanide (CN) being there, but I can see how Nitrogen in the hydrocarbon molecule can lead to higher energy, which can translate into a hotter fire, which should not be a problem for controlled pyrolysis.

I find it curious that ABS is not mentioned in the fire fighting manual as having cyanide (CN), when it does have it. Also, polyurethane does not have cyanide (CN) in its formula.

The bottom line for me is the pyrolysis of plastics to turn them back into petroleum fractions has to be the most toxic occupation on the planet. There are much easier/less toxic ways to convert garbage into fuel. I plan to develop the device and get some experience with the practice, but I have no intention of long-term use of it.

The distillation of WMO is toxic enough, and way less toxic than the pyrolysis of plastics; however, I have no intention of long-term use of it either. My goal is to use these skills to extract fuel from trees, because it is far less toxic, and I live surrounded by forests.

[mjohnson1]

Here is bit of info taken from - Hydrogen Cyanide: New Concerns for Firefighting and Medical Tactics - Fire Engineering

"But the real offender is the combustion of manmade plastic and resins containing nitrogen, especially if the fire is hot and in an enclosed space. Common manmade materials that generate cyanide gas during combustion include nylon, polyurethane, melamine, and acrylonitrile."

[Beyond Biodiesel]

Your sample floats in water so its either PE or PP. Both are good for pyrolysis.
If it had sunk it would not be suitable. If it was nylon it would have sunk. Nylon is not suitable because pyrolysis would break it down and release nitrogen( result cyanide) and also oxygen ( result Boom!)

I checked the WIKI on nylon. See below:

Nylon is a generic designation for a family of synthetic polymers known generically as aliphatic polyamides, first produced on February 28, 1935, by Wallace Carothers at DuPont's research facility at the DuPont Experimental Station. Nylon is one of the most commonly used polymers.[1] Key representatives are nylon-6,6, nylon-6, nylon-6,9, nylon-6,12, nylon-11, nylon-12 and nylon-4,6.[1]
Incineration and recycling
Various nylons break down in fire and form hazardous smoke, and toxic fumes or ash, typically containing hydrogen cyanide. Incinerating nylons to recover the high energy used to create them is usually expensive, so most nylons reach the garbage dumps, decaying very slowly.[11] Some recycling is done on nylon, usually creating pellets for reuse in the industry.[12]

I do not happen to see how the thermal decomposition of any nylon results in releasing hydrogen cyanide, because the chemical formula for nylon does not include cyanide (CN). However, anyone doing pyrolysis of plastics to crack them back to petroleum fractions needs to accommodate for the unexpected release of toxic byproducts.

I feel that I should say that I am coming to the conclusion that I should withdraw from this discussion. There are many people who have begun to experiment with this technology who have only the vaguest idea of the risks. Sooner or later some one is going to be seriously injured or lose their life and while I feel that everyone is entitled to take risks with their own life and property I do not wish to be held even partly responsible. I have learned a great deal from my participation in this forum and I wish to thank everyone who has contributed over the last few years.

In concur fully with your feelings imakebiodiesel. I have been conflicted from the beginning of my participation here, because I knew then that cracking and fractionation of hydrocarbons is extremely dangerous, and I have since found that cracking plastics can release extremely toxic substances. However, I have remains on this forum for two reasons.
1) To learn how to simplify the cracking and fractionation of hydrocarbons and plastics in a safe manner.
2) To remind everyone interested in this process of three things:

Safety
Safety
Safety

So I encourage you to remain here to help remind people of the three most important things to keep in mind when engaged in the pyrolysis of hydrocarbons.

[mjohnson1]

which is good for using it as feedstock right ? Actually is nylon and plastic bags good for feedstock ?

Nylon - No
PVC - No
PET - No
ABS - No

Plastic bags - Most likely yes. I've only seen bags made from hdpe and ldpe and rarely pp.

Here in the US many plastic items have recycle codes. I'm not sure if this is the same in your area of the world. Recycle codes usually have the triangle and a number in them. This is the easiest way to identify plastics. If you have any doubts test to verify the composition of the plastic before using it.

[mjohnson1]

Your sample floats in water so its either PE or PP. Both are good for pyrolysis.
If it had sunk it would not be suitable. If it was nylon it would have sunk. Nylon is not suitable because pyrolysis would break it down and release nitrogen( result cyanide) and also oxygen ( result Boom!)

I feel that I should say that I am coming to the conclusion that I should withdraw from this discussion. There are many people who have begun to experiment with this technology who have only the vaguest idea of the risks. Sooner or later some one is going to be seriously injured or lose their life and while I feel that everyone is entitled to take risks with their own life and property I do not wish to be held even partly responsible. I have learned a great deal from my participation in this forum and I wish to thank everyone who has contributed over the last few years.

I really hope you'll stay as you have a lot of knowledge and real world experiences. Without someone to advise them many beginners would be at an even greater risk.

I think you're the farthest along in the plastic to fuel process especially in the catalyst area. I know your advice has helped me a lot and I thank you for all your contributions.

[imakebiodiesel]

Your sample floats in water so its either PE or PP. Both are good for pyrolysis.
If it had sunk it would not be suitable. If it was nylon it would have sunk. Nylon is not suitable because pyrolysis would break it down and release nitrogen( result cyanide) and also oxygen ( result Boom!)

I feel that I should say that I am coming to the conclusion that I should withdraw from this discussion. There are many people who have begun to experiment with this technology who have only the vaguest idea of the risks. Sooner or later some one is going to be seriously injured or lose their life and while I feel that everyone is entitled to take risks with their own life and property I do not wish to be held even partly responsible. I have learned a great deal from my participation in this forum and I wish to thank everyone who has contributed over the last few years.

[lowriderzzz]

If the object floats then its PE or PP, either way its good for pyrolysis. It look clean and uncoloured which makes it even better. It cant be nylon because the density of nylon ie 1.15 -1.41 so nylon would sink in water. If you want to distinguish between PE and PP try putting it into a container of clean vegetable oil. PE will sink in vegetable oil and PP will float.
This may not work with every vegetable oil, I use rapeseed ( canola) oil and it works a treat.

thanks I'll try that too

[lowriderzzz]

It is most probably either nylon or a polyethylene, and most probably not PVC, or PTFE, or ABS.

which is good for using it as feedstock right ? Actually is nylon and plastic bags good for feedstock ?

[imakebiodiesel]

If the object floats then its PE or PP, either way its good for pyrolysis. It look clean and uncoloured which makes it even better. It cant be nylon because the density of nylon ie 1.15 -1.41 so nylon would sink in water. If you want to distinguish between PE and PP try putting it into a container of clean vegetable oil. PE will sink in vegetable oil and PP will float.
This may not work with every vegetable oil, I use rapeseed ( canola) oil and it works a treat.