How to turn plastic waste into diesel fuel cheaply

[wheels]

I am using flame arrestor to prevent flashback. The flame arrestor consist partly of a non-return valve and partly a flame filter that stops and extinguishes any flashback.

Use with caution. I am not saying it won't work, but I also am thinking that the flame filter inside may clog up and I am not sure what will happen over time with hot Acids. These units are brass and likely to corrode.

[sunilkm153]

The only important thing to remember, is that you are playing with mostly Hydrogen Gas and Hydrogen is the most explosive and volatile Gas you can get. But then, any flamable gas is still dangerous, just take precautions. You still need Oxygen to make it Burn, so you have to be absolutely sure you have no oxygen in whatever you store it in. Some have made large PVC bags and stored it that way. You could use it directly as you produce it of course, but if you run an engine, you need to be able to provide enough for the engine to run and if you produce more, then you need to regulate it somehow.
By returning the Gas to the Retort burner, you are basically getting rid of any possible nasty by products that could have come through with the Gas. But you also need to ensure that there is no way that the Gas can "flashback" via the supply pipe into your plant. It can leave a nasty ringing in your ears.

With the design of my plant, we are going to be using the Gas to fuel a completely different process, that at the moment I can not talk about. But I have not gotten to the storage of it part yet. Probably an early next year project.

I am using flame arrestor to prevent flashback. The flame arrestor consist partly of a non-return valve and partly a flame filter that stops and extinguishes any flashback.

[Excalibur]

Recently rebuilt the plant that produced wax problems in the past.
Now have a plant that runs like a DREAM.
Some of the biggest changes are as follows.
1.Firebox wall or pass diameter increased to 40mm all round.
2.Firebox chamber under retort doubled in size.
3.stainless steel deflection plate installed in firebox chamber.
4. increased distillation tower size.
We now able to run the system were the temperature figures from the exhaust system almost match the distillation tower figures.The firebox internal temps are approx. 25*c higher.
No super heating chamber at the firebox which caused high temps and produced the wax.
We have had excellent runs and produce approximately 40lt/hr at 0.84 on hydrometer.Product very clear with the catalyst added.

[jonathan]

pyrolysis

thanks rozier56 for photo keep it up...if you can tell us your tempretures of retort,reflux and condensors...thanks

[rozier56]

new changes to plant work well

Recently rebuilt the plant that produced wax problems in the past.
Now have a plant that runs like a DREAM.
Some of the biggest changes are as follows.
1.Firebox wall or pass diameter increased to 40mm all round.
2.Firebox chamber under retort doubled in size.
3.stainless steel deflection plate installed in firebox chamber.
4. increased distillation tower size.
We now able to run the system were the temperature figures from the exhaust system almost match the distillation tower figures.The firebox internal temps are approx. 25*c higher.
No super heating chamber at the firebox which caused high temps and produced the wax.
We have had excellent runs and produce approximately 40lt/hr at 0.84 on hydrometer.Product very clear with the catalyst added.

[wheels]

Ok, it has been a long time coming, but in 15mins I am getting the angle grinder out and preparing the bits and pieces I have accumulated for this project. The retort will be made from an air compressor tank. I presume it was MIG welded at time of manufacture (can you tell just by sight?). Going off Wheel's comment above I should grind that MIG weld away and have it re-welded using mild steel electrodes. Has anyone had issues with MIG welded seams?
Thanks.
Excited to be getting into it finally!
Col

No you should be fine with a small tank like that. Plus the Air tanks are often made from a slightly higher grade steel than just mild and so much more like the MIG metal it was welded with.
My original comment was referring to a much much bigger Retort. I am using an Air tank and so far there have been no problems and intend to simply change the tank when it gets too worn. It's easy to have a quick look at the tank between uses and make sure everything is OK. Plus I am playing with Plastics that produce a lot of Acids and nasties.

[Col]

MIG v TIG Welding and longevity of weld seams

Mild steel withstands the heating and cooling cycles far better than most other metals. If the seams have been welded with mild steel electrodes, the welds behave just like the rest of the vessel metal. But if it has been MIG welded, MIG weld is hard low Hydrogen and will present a "different metal"composition at the weld interface. Two different metals, even though they are both steel, can cause a galvanic action with the Acids and heat. So the Welds need to be inspected regularly.

Ok, it has been a long time coming, but in 15mins I am getting the angle grinder out and preparing the bits and pieces I have accumulated for this project. The retort will be made from an air compressor tank. I presume it was MIG welded at time of manufacture (can you tell just by sight?). Going off Wheel's comment above I should grind that MIG weld away and have it re-welded using mild steel electrodes. Has anyone had issues with MIG welded seams?
Thanks.
Excited to be getting into it finally!
Col

[wheels]

The only important thing to remember, is that you are playing with mostly Hydrogen Gas and Hydrogen is the most explosive and volatile Gas you can get. But then, any flamable gas is still dangerous, just take precautions. You still need Oxygen to make it Burn, so you have to be absolutely sure you have no oxygen in whatever you store it in. Some have made large PVC bags and stored it that way. You could use it directly as you produce it of course, but if you run an engine, you need to be able to provide enough for the engine to run and if you produce more, then you need to regulate it somehow.
By returning the Gas to the Retort burner, you are basically getting rid of any possible nasty by products that could have come through with the Gas. But you also need to ensure that there is no way that the Gas can "flashback" via the supply pipe into your plant. It can leave a nasty ringing in your ears.

With the design of my plant, we are going to be using the Gas to fuel a completely different process, that at the moment I can not talk about. But I have not gotten to the storage of it part yet. Probably an early next year project.

[rozier56]

important to note the burner head Excalibur posted! it's a high pressure head burner,not the normal low pressure associated with burners.We use the same ones here.

[Excalibur]

As a novelty I used the gas in one of these:

[rozier56]

gases

My idea is to use the gas as plastic melting process.Then you can melt the 25lt etc cans and bulky items.We are currently building one which will make up brick size blocks which are easy to load into retort.

[sunilkm153]

Dear friends

is any one utilizing uncondensed (remaining) gases in a diffferent manner that means other then heating the retort like to produce electricity or any other novel idea



all in advance

[Excalibur]

[wheels]

Early on, Jetijs discovered that waxing occurred when the reflux temperature was allowed to run too high. The retort temperature should be at a point where the contents is simmering in a controlled fashion and not too vigorous. The reflux should be at a point below

I am doing a bit of guessing here, but wax may possibly be the wrong description. It is possible that another thing is taking place causing the liquid to solidify. This idea came about from Excalibur and I discussing a slightly different situation and he discovered that a particular Hydrocarbon when at room temperature, existed in a solid crystal form. It did not melt to a liquid till 70degC. I made a comment then, "I wonder what that does to the other liquids once the temperature drops below 70Deg". I am sorry I have forgotten the name of the Hydrocarbon, so Excalibur, can you remind me again please?
Anyway, what surprised me was that this Hydrocarbon is a short chain one. These very short chains can be formed by the types of Plastic's and to high a temperature causing over cracking. Cracking is caused by anyone or a combination of.... Heat, Time in the Retort, what weights are cycled back from reflux and Catalyst. So if the desired end product is wanted as a Diesel weight Fuel, then it is quite possible that the Plastics are being "overcooked" in the process. Hence jetji's comment about having a waxing problem at high temps. It is possible that a high proportion of this crystal form of Hydrocarbon is causing the liquid to solidify to a consistency of wax.
A lot of trial and error maybe required, but I suggest changing a few of the processes. Firstly, as it is desirable to have the process go as fast and efficiently as possible, plus we don't all have perfect heat control, I suggest that perhaps the removal of the catalyst (if one is used) be tried first. Second, the temperature of the reflux vessel is possibly more important than the Retort temp. But it is possible the temperature may need to be varied either up or down. That is going to be a little trial and error. Temperature of reflux will affect the weight of fractions sent back to retort as well as what continues on through the system, as well as time the Hydrocarbons remain within the Reflux vessel. Any vessel that is heated will affect Hydrocarbons that have a Boiling point below that heated Vessel temp. Once Fractions are heated to above boiling point, they can under go cracking. Obviously the hotter the temp, the more likely a chain will crack.
This is however, just an idea. I could be wrong, but most certainly if you are having a waxing problem, then try changing a few of the suggestions and report back on what was found.

[Excalibur]

Can anybody tell me at what temperature wax is made and and what temperature diesel is made either in the retort or reflux.
Thanks, Piet.

Early on, Jetijs discovered that waxing occurred when the reflux temperature was allowed to run too high. The retort temperature should be at a point where the contents is simmering in a controlled fashion and not too vigorous. The reflux should be at a point below