How to turn plastic waste into diesel fuel cheaply

[black]

V-groove

Hi guys could you advise me on the v-groove seal.
Does it seal on the sharp points were the two v`s meet or on the side, kind of like a hydraulic bullnose fitting?
This part makes me nerves and I am scared of a leak and then a explosion.

[black]

How tight do you guys torque the bolts at the v-groove and how much pressure (bar or psi) will a v-groove seal take.
I know its all at atmospheric pressure but am only trying to understand this seal better.

[Excalibur]

It is hard to tell from the photo, but that TC does not leak like it is sheathed. If it is not sheathed, then how are you going to seal it so that it does not leak. or are you planning on placing this TC outside of your pyrolysis unit?

It's a 3mm stainless sheath, non grounded. I think I'll simply insert this into a 8mm (5/16") tube from the top flange. Probably 1.2m ~ 1.3m long though the shed roof height does restrict the length I can fit. I think that even 350mm (14") off the bottom is fine because when the level falls below that, it'll be because I'm finishing a run and boiling the retort down to dry carbon. I'm confident that the probe inside a tube will give satisfactory results because temperature changes don't have to be registered instantly.

Hi guys could you advise me on the v-groove seal.
Does it seal on the sharp points were the two v`s meet or on the side, kind of like a hydraulic bullnose fitting?
This part makes me nerves and I am scared of a leak and then a explosion.

It seals on the tapered sides of the v. When you make the tapers, use "engineers blue" to show how good the fit is.

How tight do you guys torque the bolts at the v-groove and how much pressure (bar or psi) will a v-groove seal take.
I know its all at atmospheric pressure but am only trying to understand this seal better.

I don't torque the bolts but I'm careful to tighten evenly with only moderate tension. I use high tensile bolts and apply nickel-anti-seize. Ordinarily I'd expect a taper seal to take very high pressure but I don't ever plan to test it. Jetijs flange leaked when his pipework plugged with solid plastic.

[wheels]

Hi guys could you advise me on the v-groove seal.
Does it seal on the sharp points were the two v`s meet or on the side, kind of like a hydraulic bullnose fitting?
This part makes me nerves and I am scared of a leak and then a explosion.

While we always need to ensure safety working with these things, at the same time, they are reasonably safe, even if you get a leak. There must be oxygen inside the tank for combustion. No oxygen, no combustion, no bang. However, any leak will lead to a terrible smell, depending on what type of plastic you are heating.
To add to excalibur,
The V, so one plate will have that V as a ridge and the other plate will have the V as a Slot. The ridge fits into the slot. The design can be varied, just like the Hydraulic fittings, there are many designs that work. The V tends to be a fairly easy shape to machine and make work.
The problem you may have is machining which ever one is welded to the Vessel. It can be difficult to get the Vessel into a Lathe. But if you machine the Collar as a separate unit and then weld it to the vessel, you can end up distorting the Collar and not have the V seal correctly. I made the Collar separately and welded it afterward and then I spent hrs lapping the V's with Valve grinding paste till I could ensure I had a perfect seal.

[fox32]

It is hard to tell from the photo, but that TC does not leak like it is sheathed. If it is not sheathed, then how are you going to seal it so that it does not leak. or are you planning on placing this TC outside of your pyrolysis unit?

Beyond Biodiesel, if i remember corectly, i guess you were using a long sheated probe for your pyrolisis unit. By any chance you still have the link from were you bought yours? cheers!

[Beyond Biodiesel]

Beyond Biodiesel, if i remember corectly, i guess you were using a long sheated probe for your pyrolisis unit. By any chance you still have the link from were you bought yours? cheers!

I buy them on eBay. Here is one that is still listed:
Type K Thermocouple w Plug | eBay

[Excalibur]

My thermocouple turned up. It checks out, right part number, mineral insulated, K-type, 1.5m, un-grounded etc so all seems good to go.



BB, that Ebay link of yours come up as expected if I click on it. But if I try to search for it using the title or even view items by the seller, no items can be found. If that wasn't bazaar enough, if I click "buy it now" on the auction, the following message appears: Sorry, this seller is on vacation, so this item is unavailable for purchase.
Even if I wanted the item, the listed $42 shipping would totally ruin it for me.

[Excalibur]

I got thinking about the upcoming changes to my plant so I'm speculating on what I'll discover.
I think the new k-type thermocouple fitted which extents down into the liquid will show a noteable difference in temperature readings compared to the current TC at the top of the retort. There must be a number of variables like specific liquid level height which would affect the figures.
In any case I'll be recording temperatures from the old and new TC throughout the next run so hopefully we can learn some useful information.

New refit details..
The new TC will be monitored by a PID temperature controller. It will signal a 240v/28w solenoid which actuates the throttle arm on the injector pump. The parts are here except the PID.

[sunilkm153]

What You say is absolutely right . One can think of 2" retort size for continuous pyrolysis . This depends on the capacity of pyrolysis per minute , heat input .
I have designed 5 M.T / 24 HOUR CAPACITY continuous plant . and my retort size of dia. 300 mm . I am going for direct dual gas/oil fired burner and avoiding hot air generator . The best way is going for microwave heating but the cost of system is very high .

dear ndsunil
what is the length of your reactor and what about feeding rate to acheive 5 mt per day capacity what type of plastic are you using finally what is residence time for your process

[fox32]

I got thinking about the upcoming changes to my plant so I'm speculating on what I'll discover.
I think the new k-type thermocouple fitted which extents down into the liquid will show a noteable difference in temperature readings compared to the current TC at the top of the retort. There must be a number of variables like specific liquid level height which would affect the figures.
In any case I'll be recording temperatures from the old and new TC throughout the next run so hopefully we can learn some useful information.

New refit details..
The new TC will be monitored by a PID temperature controller. It will signal a 240v/28w solenoid which actuates the throttle arm on the injector pump. The parts are here except the PID.

Nice progress, you are on way to fully automize the plant. I was also thinking how liquid level will affect the temperature reading. Keep us posted with your progress!

[piu.iuu]

This is an area where none of us have much experience. The plastics that easily pyrolyse into relatively simple fuels are polythene. polypropylene. and polystyrene. I have attempted to pyrolize a mixture containing PET and it was a disaster. Only a small proportion of the plastic converted into fuel.. The fuel was black and acidic, and therefore useless and the residue was also black, sticky and very acidic. My mild steel retort was damaged, as was my condenser. If I had used a scrubber containing a strong solution of sodium hydroxide I might have been able to reduce the acidity of the uncondensable gases but that would not have helped the quality of the fuel.
My advice, for what its worth, is to gain experience with the three plastics PE, PP and PS that pyrolize easily before trying to tackle the two more difficult and dangerous plastics PETE and PVC.

Hi there

I have seen a vid: on youtube which a guy makes Benzene from PET and NaOH. Source ( https://www.youtube.com/watch?v=JhUxaNesnxs )

Any thoughts?

Thank you.

[wheels]

Hi there

I have seen a vid: on youtube which a guy makes Benzene from PET and NaOH. Source ( https://www.youtube.com/watch?v=JhUxaNesnxs )

Any thoughts?

Thank you.

I don't really think he knows what he has got. It's a bit of a stretch for him to be calling it Benzene with no testing and if he did test it, he would find it probably isn't Benzene at all. He has no temperature probe to know just what Temp he really has and he has a yellowish residue in the end tube, which is anybodies guess to what it really is. But even if it was Benzene, it is very little for the amount of PET he Pyrolysed. He may have moisture in the tube and that may have reacted to form something
PET ( Polyethylene Teraphthalate, or commonly known as Polyester, C10-H8-O4) Note the 4 oxygen molecules!! That is not good to have in the Retort.
PET is made in two ways. Hydroxyterephthalate and Ethylene Glycol via an Esterfication reaction, or Dimethylterephthalate and Ethylene Glycol via an Transesterification reaction.
You have to be extremely cautious pyrolysing PET. As you notice in the Video, it goes from a Solid to a Gas with no real liquid stage. It's melting point is about 260degC. Then you will notice it suddenly produces a large volume of Gas. That point is where the Acid decomposes at about 350DegC. The Gas is Terephthalic Acid and the danger with it is that as soon as the temperature of the gas cools below the 280degC point, it turns back to solid Terephthalic Acid which is a Whote Crystal. If that happens in any of the Pipe work or Vessels, it will simply block it all up with a White powdery material, being the Terephthalic Acid.
I guess in some countries, PET may be easy to come by, but in many Countries, PET plastics are sort after to make Polyester fibers and it is worth quite a lot of money.

[piu.iuu]

I don't really think he knows what he has got. It's a bit of a stretch for him to be calling it Benzene with no testing and if he did test it, he would find it probably isn't Benzene at all. He has no temperature probe to know just what Temp he really has and he has a yellowish residue in the end tube, which is anybodies guess to what it really is. But even if it was Benzene, it is very little for the amount of PET he Pyrolysed. He may have moisture in the tube and that may have reacted to form something
PET ( Polyethylene Teraphthalate, or commonly known as Polyester, C10-H8-O4) Note the 4 oxygen molecules!! That is not good to have in the Retort.
PET is made in two ways. Hydroxyterephthalate and Ethylene Glycol via an Esterfication reaction, or Dimethylterephthalate and Ethylene Glycol via an Transesterification reaction.
You have to be extremely cautious pyrolysing PET. As you notice in the Video, it goes from a Solid to a Gas with no real liquid stage. It's melting point is about 260degC. Then you will notice it suddenly produces a large volume of Gas. That point is where the Acid decomposes at about 350DegC. The Gas is Terephthalic Acid and the danger with it is that as soon as the temperature of the gas cools below the 280degC point, it turns back to solid Terephthalic Acid which is a Whote Crystal. If that happens in any of the Pipe work or Vessels, it will simply block it all up with a White powdery material, being the Terephthalic Acid.
I guess in some countries, PET may be easy to come by, but in many Countries, PET plastics are sort after to make Polyester fibers and it is worth quite a lot of money.

Hi wheels thank you 4u reply.

I have also seen a vid at "https://www.youtube.com/watch?v=APlczT3YJ2I" biomass to liquid or fuel using microwaves. By the way what kind of fuel "oil" is that? Can that be converted to diesel? Or is it more like heating oil?

excuse my ignorance

Thank you.

[wheels]

Hi wheels thank you 4u reply.

I have also seen a vid at "https://www.youtube.com/watch?v=APlczT3YJ2I" biomass to liquid or fuel using microwaves. By the way what kind of fuel "oil" is that? Can that be converted to diesel? Or is it more like heating oil?

excuse my ignorance

Thank you.

While we are on the subject of Plastics not to Pyrolyse, there is of course the PVC materials which we have discussed here before. But another rather obscure material, which is not really plastic, but could be considered as such, is Polyurethane. This is a difficult one to identify and there are several stocks of which it can come from and you can not tell by eye. The Polyurethanes that are bad are the ones that have had an Isocyanate Curative. When you melt Iso based Polyurathanes, they release vast amounts of Isocyanate and it can not be easily removed in any of the Backyard type Pyrolysis units. You need very specialised Filtering to remove it. Isocyanate is very Toxic and will make you very very sick, sometimes for the rest of your life. Even a small dose of it can cause severe Skin and Lung problems.

I will make another post about the Microwave system.

[wheels]

Hi wheels thank you 4u reply.

I have also seen a vid at "https://www.youtube.com/watch?v=APlczT3YJ2I" biomass to liquid or fuel using microwaves. By the way what kind of fuel "oil" is that? Can that be converted to diesel? Or is it more like heating oil?

excuse my ignorance

Thank you.

Microwave is just one of several ways you can Pyrolyze. There are many ideas and systems built to melt plastics. But you can Pyrolyze all sorts of things and Biowaste is one. Microwave energy flip/flops Molecules at extremely high frequencies (i.e. very fast) and this creates friction. A Domestic Microwave Oven is tuned to use a frequency that is resonant to Water Molecules and heating the water in food is what cooks it. Microwaves for heating plastic is tuned to do just that. So instead of having a large Retort, they focus high energy Microwave at a small space and pass the Plastic or Biowastes through that Focus point and the energy instantly heats and vaporizes the material. The Hydrocarbon Products produced depends on what is processed. it doesn't make anything different to what a Retort vessel would with the same material. However, you can get slightly different cracking, because the Heating is for a very short time. So thus it can be more controlled.
Another principle is using Plasma. Basically an Electric Arc in an inert Gas, much like a Welding Arc. It produces intense heat and once again, a very small focal point that the Material is passed through and instantly vaporized. Both Microwave and Plasma are specialized expensive machines and you will find them in large scale commercial installations.
Other methods more similar to what we are playing with, use various ideas to solve issues, like making a process continuous and not having Carbon build up in the bottom of the Retort. But each method comes with it's own negatives as well, being mostly complexity and thus scale. For instance, Fluidized Bed reactors use Super Heated Sand and the Gas produced is blown back into the bottom of the Vessel and "fluidizes" the sand. The Plastic is introduced as granules and the hot sand melts it quickly. The gas boiling the sand like a liquid is blown up through the top of the reactor vessel and cyclones separate the sand from the gas and the Carbon from the Gas. The Sand is super heated again and dropped back into the bottom of the Resort to continue the process.
The big advantage of any of these commercial practices is speed and because the Hydrocarbons are heated quickly and for a very short duration, the type of Fraction can be controlled and this can be a big benefit to stability of the Hydrocarbon. Or in other words, it doesn't oxidize. They then use specialized Distillation processes, just like an Oil Refinery, to crack the Hydrocarbons into what is wanted and maintain the stability.