How to turn plastic waste into diesel fuel cheaply

[Excalibur]

Sorry if i am not being clear, i intend to house a reactor inside a drum as jetijs did, i am trying to source a good option for a reactor & am in contact with a compressor service enginneer i know who may be able to get me a 50litre cylinder.

What would you guys think about using a truck fuel tank?

I don't think this would be heavy enough gauge in the wall thickness for the reactor. This would not be much thicker than some panel steel. A LPG cylinder or compressor cylinder would be much more suitable. Thinking safety here.

[Beyond Biodiesel]

Sorry if i am not being clear, i intend to house a reactor inside a drum as jetijs did, i am trying to source a good option for a reactor & am in contact with a compressor service enginneer i know who may be able to get me a 50litre cylinder.

I know all of the compressor repair shops in Tucson, AZ, USA have yards full of compressor tanks. And, every propane supplier seems to have a yard full of dead tanks, so those are good places to look for a tank. Then you have to find someone who is good at welding to cut and weld the tank into something you can use as a retort.

The lid is the big problem. A homemade flange, such as jetiji used, seems problematic unless you have a machinist working for you.

A 4" tapered thread, or a 4"-6" steam flange might be best. These flanges are off-the-shelf at commercial plumbing houses in most big cities, and can be welded, and seals found for them.

If you are going to stay under 500F (260c), then simple teflon tape can be used to seal a tapered thread fitting. Otherwise I have used anti-gal compound to successfully seal tapered thread fittings that operated up to 1200F (650c).

I made a teflon seal for my pressure cooker the other day. Here are the steps:






After three attempts I discovered that the teflon seal stretches during the process of forcing it into the pressure cooker lid, so I had to taper the outer edge, and make it 1/2" smaller in diameter, and 1/8" wider.

[thissideup]

I know all of the compressor repair shops in Tucson, AZ, USA have yards full of compressor tanks. And, every propane supplier seems to have a yard full of dead tanks, so those are good places to look for a tank. Then you have to find someone who is good at welding to cut and weld the tank into something you can use as a retort.

The lid is the big problem. A homemade flange, such as jetiji used, seems problematic unless you have a machinist working for you.

A 4" tapered thread, or a 4"-6" steam flange might be best. These flanges are off-the-shelf at commercial plumbing houses in most big cities, and can be welded, and seals found for them.

If you are going to stay under 500F (260c), then simple teflon tape can be used to seal a tapered thread fitting. Otherwise I have used anti-gal compound to successfully seal tapered thread fittings that operated up to 1200F (650c).

I made a teflon seal for my pressure cooker the other day. Here are the steps:






After three attempts I discovered that the teflon seal stretches during the process of forcing it into the pressure cooker lid, so I had to taper the outer edge, and make it 1/2" smaller in diameter, and 1/8" wider.

you can also use braided graphite rope, good to over 500c, just need to be dilligent at making a tight fit when the two ends meet, beter if can make it wrap around a couple times to cover the joint.

[Jetijs]

this does not work for plastics and tires, been there and done that. If possible, stick with the metal to metal groove seals, this is a proven method and works every time and at any temperature. Those ropes will soak through with condensed light fractions like when solvents soak through cloth. It will drip everywhere and possibly catch on fire. Don't make the same mistakes!!!!

[Beyond Biodiesel]

Thanks, thissideup, it looks like Graphite Packing might be the solution to my sealing problems if I find I need to go over 500F (260c)

Graphite Packing
Temperature:1000°F(540°C) pH:0-14
Pressure:600 PSI (41 bar)
YC Industries Inc. Graphite Packing

this does not work for plastics and tires, been there and done that. If possible, stick with the metal to metal groove seals, this is a proven method and works every time and at any temperature. Those ropes will soak through with condensed light fractions like when solvents soak through cloth. It will drip everywhere and possibly catch on fire. Don't make the same mistakes!!!!

According to the specs Graphite Packing can do it, so it appears one just has to learn how to use it properly. I also noticed that the people who supply Graphite Packing, also have graphite sheet seals as well.

[imakebiodiesel]

Somebody is going to get killed if they follow the advice being given out on this thread. Beyond Biodiesel is confidently advising other people on how to pyrolyse waste plastics despite the fact he has never done it and seems to have no intention of doing it. People who have a lot of experience in this area have tried to warn of the dangers but are being ignored. So by all means follow his advice but dont say you were not warned.

[thissideup]

this does not work for plastics and tires, been there and done that. If possible, stick with the metal to metal groove seals, this is a proven method and works every time and at any temperature. Those ropes will soak through with condensed light fractions like when solvents soak through cloth. It will drip everywhere and possibly catch on fire. Don't make the same mistakes!!!!

I've been using it for years as pump packing in my tanker truck, i haul condensate, crude, xylene... never had an issue, but then again it's under considerable pressure inside the packing nut. I will heed your advice.

[Uncorruptable]

Good to hear people advise to be cautious here, my intention once i have sourced a suitable tank is to have an enginneer make a suitable sealed gasket head as advised, metal against metal.

[Beyond Biodiesel]

Somebody is going to get killed if they follow the advice being given out on this thread. Beyond Biodiesel is confidently advising other people on how to pyrolyse waste plastics despite the fact he has never done it and seems to have no intention of doing it. People who have a lot of experience in this area have tried to warn of the dangers but are being ignored. So by all means follow his advice but dont say you were not warned.

While I have not done pyrolysis of plastics, I am apparently the only one on this thread who has actually worked for a petroleum refinery, designed, built and operated cracking units and distillation towers; and I have posted a lengthy cautionary note that should be at the head of this thread. And, certainly no one else on this thread represents anyone with "a lot of experience in this area."

I have already recommended a number of seal designs that are well established systems, such as the ConFlat Flange copper seal system. I have used those flanges for years in a number of applications from 1.8 Kelvin to 922K (1200F) without a failure. Graphite packing and seals seem like an excellent solution to this problem, over some bogus one of a kind flange seal system made by someone with no experience in either flange design or pyrolysis of plastics.

By the way some of you might find this link useful when designing flange-seal systems;
- Mercer Gasket & Shim

[Marso Green]

By the way some of you might find this link useful when designing flange-seal systems;
- Mercer Gasket & Shim

Thank you for the material reference. According to the table, Aluminum is an adequate material for diesel fuel and aromatic hydrocrabons. Barring any boiling point or temeprature control issues, does this mean that condensers can be made out of aluminum when pyrolizing tires/plastics/WMO? I recall reading in this thread somewhere (sorry was unable to find the actual post number) that Aluminum was not recommended

Can anyone shed light on this issue?

Thank you

Marso Green

[Beyond Biodiesel]

Thank you for the material reference. According to the table, Aluminum is an adequate material for diesel fuel and aromatic hydrocrabons. Barring any boiling point or temeprature control issues, does this mean that condensers can be made out of aluminum when pyrolizing tires/plastics/WMO? I recall reading in this thread somewhere (sorry was unable to find the actual post number) that Aluminum was not recommended

Can anyone shed light on this issue?

Thank you

Marso Green

Stainless steel is the most common material of choice when designing cracking units and distillation towers. However, copper and brass are even more resistant to corrosion than Stainless steel, and are highly conductive, so they are useful for distillation columns.

Aluminum is adequate, but it has a low melting point (933.47 K, 660.32 °C, 1220.58 °F), so it is marginal for cracking but not for O2 regeneration cycles.

My prime focus at the present is distillation of WMO, not cracking anything, and I have no plan to implement O2 regeneration cycles, so it is not a problem for my application.

Also, I believe the use of graphite seal is used as a Spiral Wound Gasket, not as Braided Packing.

Most probably the reason why Jetijs had the leak problem when he tried using graphite Braided Packing was he most probably is not getting enough compression pressure in his homemade seal, which suggests that he is most probably not getting enough compression pressure in his homemade seal to properly seal against a copper gasket either.

The Conflat flange requires intense torque pressures, which requires special high tinsel strength bolts. The intense pressures I had to apply to tighten Conflat flanges in the lab for years ended up ruining my hands.

[Patrick]

The costs that I mentioned include the consumed electric energy. For example, I can get shredded plastic from recycling plants for about 50$ a ton, that means about 5 cents per kilogram. Our device converts around 25 kg of plastic into 24 litrers of diesel in 4 hours, consuming around 3kw average power all the time, this means about 12kWh of power is used to get 24 liters of diesel. Our energy costs for a kilowathour is about 8 cents, that means that for 24 lieters of produced diesel we have used up 96 cents worth of electricity and 1,25$ worth of plastic. That is 2,21$ for 24 liters of diesel or 9.2 cents per liter. Do you know how much diesel costs now in our country? It costs around 1.35$ per liter. If you can make your own for only 9.2 cents a liter, then you are almost independant of oil companies, you are making your own energy and save a huge amount of money

Hy! New guy here . I have been reading this thread for a while now (read it all twice) and i would like to thank you for the good job u are doing. Have some question for you:
1. Jetis where did u find the plastic at 50$/ton? because in my country they want 500$/ton and i even if my math is a little bit off but i get some 1,25-1,5$/L of diesel made and its like i would buy it from the pomp.
2. Can anyone tell me if it would be better to use a catalyst to get the wax out of the final product?
In august i am going to build my on device and then i would be helping more even some desings.
Thankyou.

[CRMoore]

Don't think you'd get enough waste plastic from volunteer groups, friends & neighbors? I certainly should like to see my waste plastic turn into fuel but don't have the equipment (yet). I echo the fear that many such homemade units will be dangerous & would like to promote the non-profit distribution of professionally built units/kits for the cautious pyrolysist. Does anyone else feel that viable market exists for 5-10 kg batch processors (other than the scamsters at ERM)
I see by your commas that you aren't from the US (for here we put (.)s where others put(,)s-UK perhaps?

[Patrick]

Don't think you'd get enough waste plastic from volunteer groups, friends & neighbors? I certainly should like to see my waste plastic turn into fuel but don't have the equipment (yet). I echo the fear that many such homemade units will be dangerous & would like to promote the non-profit distribution of professionally built units/kits for the cautious pyrolysist. Does anyone else feel that viable market exists for 5-10 kg batch processors (other than the scamsters at ERM)
I see by your commas that you aren't from the US (for here we put (.)s where others put(,)s-UK perhaps?

I am from Romania and that's why! I hear your need for caution but i will build it whit all the precaution instruments needed. I have to say that i will use all the fuel made for my own purpose. I want to start my own business in agriculture am i wouldn't have much use for the 5-10kg machine. As for gathering from friends and relatives the same story, they can't supply the much needed material so that's why i was asking.
Thankyou.

[Mark Bruhn]

Stainless steel is the most common material of choice when designing cracking units and distillation towers. However, copper and brass are even more resistant to corrosion than Stainless steel, and are highly conductive, so they are useful for distillation columns.

Aluminum is adequate, but it has a low melting point (933.47 K, 660.32 °C, 1220.58 °F), so it is marginal for cracking but not for O2 regeneration cycles.

My prime focus at the present is distillation of WMO, not cracking anything, and I have no plan to implement O2 regeneration cycles, so it is not a problem for my application.

Also, I believe the use of graphite seal is used as a Spiral Wound Gasket, not as Braided Packing.

Most probably the reason why Jetijs had the leak problem when he tried using graphite Braided Packing was he most probably is not getting enough compression pressure in his homemade seal, which suggests that he is most probably not getting enough compression pressure in his homemade seal to properly seal against a copper gasket either.

The Conflat flange requires intense torque pressures, which requires special high tinsel strength bolts. The intense pressures I had to apply to tighten Conflat flanges in the lab for years ended up ruining my hands.

This is a thread about thermal cracking of plastic into hydrocarbons.
People posting here have cracked or intend to crack hydrocarbons.
Presumably a whole range of hydrocarbons. Before recommending or using copper anywhere in these home made setups, consider this:-

quote from Wikipedia Copper(I) acetylide - Wikipedia, the free encyclopedia
"Copper acetylide can form inside pipes made of copper or an alloy with high copper content, which may result in violent explosion.[1] This was found to be the cause of explosions in acetylene plants, and led to abandonment of copper as a construction material in such plants.[2] Copper catalysts used in petrochemistry can also possess a degree of risk under certain conditions.[3]"