How to turn plastic waste into diesel fuel cheaply

[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.

[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]

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]

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]

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.

[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.

[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.

[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.

[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.

[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.

[mortimer.dan]

Regards to All

Well I for one am very sorry to see IMBD go from the forum, but respect his choice. I would like to thank all here esp IMBD for providing such rich information. I am but a lowly junior member but have read all through the post taking notes as i went. I remain very interested and convinced this type of technology will / is starting to filter in to the mainstream. Albeit at very high prices. I am in email contact with old member Asad now and he is doing well I think selling Pyrolysis machines. Safety really is number 1 in this game, i have learn't that so the forum is working not everyone is trying this stuff without proper knowledge. And it is not the responsibility of IMBD or anyone to feel guilty or be conflicted with the knowledge provided, however I can see why it is an issue. People will try this stuff regardless and probably get hurt because they didnt read the whole thread first. Youtube is full of people doing this now. Beyond biodiesel if you would be willing to share you experiences or plans for pyrolysis with wood and or plant matter I for one would be happy to listen. Youtube has a guy called Mr Teslonian who does this very well, and gets syngas, a form of crude, uses different catalysts and runs a generator, a propane fridge, heats water all form a single fire, its worth a watch if your interested in this type of thing.

It seems to me that with all the knowledge on here it would be a good idea to band together and plan or build a universal up to date schematic of a complete system, a bit like jetsis did at the start. Things are so much more complex now, anyway probably just thinking out loud ( or on screen ). The link to the plant mentioned is here.

https://www.youtube.com/watch?v=arbXj9R6ZXw

Sorry for the long post.

[Mechanical Enginerd]

Summary thus far...

Hello Everyone,

First, I'd like to thank everyone who has contributed information to this subject. So far I've read through post 705.

I was wondering whether someone could kindly summarize the findings thus far. What works and what doesn't work primarily from a catalyst standpoint.

By trade I'm a test engineer specializing in control systems. I've been interested in developing a reactor for several years now but have up until now not had the funds nor time to begin this particular endeavor. That being said I have given it much thought. One primary aspect being a method to precisely control conditions in the reactor to optimize output of desired fractions from the reaction.

A simple and relatively inexpensive method would be the utilization of a PLC (programmable logic controller) in conjunction with thermocouples in the condensors that would optimistically be temperature controlled via a heat exchanger and pump controls. Parameters can be very easily dictated through the PLC for different stages in the operating process (i.e. startup, mid range production, tail off assuming a batch reactor configuration), in which valves can be opened and closed from the reflux tower as needed based on operating conditions. The control system setup would not differ much from those used in industrial beer brewing operations.

Sorry to make this so lengthy. If there is interest in this feel free to respond and we can discuss further.

Thanks

[Excalibur]

Hello Everyone,

First, I'd like to thank everyone who has contributed information to this subject. So far I've read through post 705.

I was wondering whether someone could kindly summarize the findings thus far. What works and what doesn't work primarily from a catalyst standpoint.

By trade I'm a test engineer specializing in control systems. I've been interested in developing a reactor for several years now but have up until now not had the funds nor time to begin this particular endeavor. That being said I have given it much thought. One primary aspect being a method to precisely control conditions in the reactor to optimize output of desired fractions from the reaction.

A simple and relatively inexpensive method would be the utilization of a PLC (programmable logic controller) in conjunction with thermocouples in the condensors that would optimistically be temperature controlled via a heat exchanger and pump controls. Parameters can be very easily dictated through the PLC for different stages in the operating process (i.e. startup, mid range production, tail off assuming a batch reactor configuration), in which valves can be opened and closed from the reflux tower as needed based on operating conditions. The control system setup would not differ much from those used in industrial beer brewing operations.

Sorry to make this so lengthy. If there is interest in this feel free to respond and we can discuss further.

Thanks

Welcome Mechanical Enginerd.
Thanks for making the effort in the marathon read to post 705. Forum members appreciate it. This project is a joint effort with many contributors sharing a vast wealth of knowledge and experience.

I'm interested in the PLC approach to plant management as I've just put together an Arduino microcontroller set up for gas control from thermocouple signal in the retort of my latest prototype. The plan is to use non-condensable and surplus gases as heat for the retort.

Please tell us more. What would a basic PLC cost and how difficult is the programming?

[mercedes 308]

I can understand Imakebiodiesel's reservations about posting further in this thread. But I think the more well established developers willingness to give advise, has probably saved the less experienced members from tragic mistakes.
This subject is so widespread that without this thread many would have attempted this on their own, with disastrous results. His observations, and input will be sorely missed.

[Beyond Biodiesel]

Well I for one am very sorry to see IMBD go from the forum, but respect his choice.

I too will miss IMBD, but I respect his choices, and understand the conflict, because every time I read someone on here firing up they pyrolysis unit for the first time, and find that all it was was a barrel, and no condenser, I think I should not be on this forum.

Beyond biodiesel if you would be willing to share you experiences or plans for pyrolysis with wood and or plant matter I for one would be happy to listen. Youtube has a guy called Mr Teslonian who does this very well, and gets syngas, a form of crude, uses different catalysts and runs a generator, a propane fridge, heats water all form a single fire, its worth a watch if your interested in this type of thing.

It seems to me that with all the knowledge on here it would be a good idea to band together and plan or build a universal up to date schematic of a complete system, a bit like jetsis did at the start. Things are so much more complex now, anyway probably just thinking out loud ( or on screen ). The link to the plant mentioned is here.

https://www.youtube.com/watch?v=arbXj9R6ZXw

Sorry for the long post.

Thanks for your interest mortimer.dan in my approach to bio-gas production. I have been interested in bio-gas and cracking plastics back to petroleum for about 40 years, so I have given these processes a great deal of thought, and research, but not much bench level research until a year and a half ago.

What I see wrong with most of the bio-gas production units that I see is they lack a decent cracking front end, and fractionation back-end, so they are throwing out most of the fuel they make.

What I see here in plastic cracking is typically an inadequate fractionation back-end.

The only difference between what I have and what I will have when I add bio-gas production to my pyrolysis, cracking and fractionation unit is a bio-gas production front end. I plan to just build a bio-gas production unit and pipe it right into my cracking unit. That is the only difference that will take place in my unit.

Welcome Mechanical Enginerd, Excalibur and I are working independently on Arduino controllers for our respective pyrolysis units. I think one of the things that is missing from this thread is a discussion of PLC (programmable logic controller), and Arduinos as PLC (programmable logic controller). So, I look forward to your contribution on this subject.