How to turn plastic waste into diesel fuel cheaply

[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!

[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

[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.

[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.

[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

[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!

[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.

[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.

[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.

[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.

[Beyond Biodiesel]

I just today ordered a new mineral insulated k-type TC and a PID controller

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?

[wheels]

Excalibur, thks for your response, i had a lesson on control of my duel burner and found out it was set at max output{65Kw/hr}. far too hot,reset to 40Kw great temp control.Great info on your blog site,have a few questions.
What is the volume of your retort?
At what reflux temp do you get best diesel production?
Are you happy with the ungrounded K-type thermocouple?
If one produces waxing material is this too high temp or too low temp?
Most info shows best diesel production at 280*c? in the distillation column.
My raw material is ldp plastic.Thanks.
Anybody can please respond to these queries.

260-280 degC is the condensing point of fractions that give a specific weight equal to Diesel. That does not mean you should operate the Reactor at 280degC. You will need a temperature in the range of 400-500, 460 being optimum. Then you need a catalyst and reflux vessel with a temperature of either that 260-280 to capture the Diesel fuel, or 350-400degC(optimum temp if you are using a Catalyst), but will need further distilling. Heavy fractions, which include the Paraffin (wax) are in the temperatures of 300deg and upwards. These need to be dropped back to the Reactor vessel to be cracked further and eventually they will pass the 350degC reflux/cat and flow on through. You need another distilling vessel at a temp of around 160deg to remove the very light fractions from your Diesel. It depends on how much of the Benzene and lighter fractions you want in your Diesel.
Please note that all the temperatures I have listed above, are approximate as each and every set up is going to differ for people. That is where a lot of practice and patience will come in to see what you produce.

[Excalibur]

Excalibur,looking at you web site i seem to notice you have a long pipe between your reflux area and your condenser?Also i assume the condenser is slightly pointed down?
Reason for the above questions is because we ran the wmo/plastic run and got good results for diesel at temp 289-350*c.We made wax when we ran higher temp.The higher temp produced good liquid product when extracted but waxed on cooling to room temp.Produced good quality rate at higher temp not at lower temps 280-350*c.
Do you reflux any of your product after condenser back to retort during a run?
If that pipe i mentioned above does exist then that will act as a reflux return.trying to figure out your production rates?
Derek.

Yes, the long pipe is several meters long and runs downhill. The condenser also runs downhill. There is a smaller pipe which is coolant for the condenser.
If you are getting wax, then uncracked hydrocarbon is getting past the reflux. You don't say whether it's retort or reflux temperature that you are quoting but I believe it's the latter? The fact that wax is coming points to either the retort and/or the reflux being too high in temperature.
When both retort and reflux are in harmony for temperature balance, hydrocarbons will automatically recycle until they fail to condense in the reflux and subsequently are allowed to escape downstream.
I do not need to return any product for re-cracking because once it exits my reflux it's already no.2 diesel by weight. If yours is not, most likely it's a temperature problem.
I suggest a thermocouple for the retort (in the liquid) and another for the reflux (near the exit). Start heating and hold retort at about 400°C. Then observe the reflux. If it's too high, remove some insulation or apply some other method of cooling.

[Beyond Biodiesel]

Hello all, I want to ask this Can I put food oils used in the pyrolysis retort? And What do I get? Thank you

There are a number of ways to convert vegetable oils to diesel fuel, which are a lot simpler than distilling and cracking them. Also, cracked vegetable oils tend to produce profoundly toxic byproducts, so it is generally frowned upon.

[rozier56]

Excalibur,looking at you web site i seem to notice you have a long pipe between your reflux area and your condenser?Also i assume the condenser is slightly pointed down?
Reason for the above questions is because we ran the wmo/plastic run and got good results for diesel at temp 289-350*c.We made wax when we ran higher temp.The higher temp produced good liquid product when extracted but waxed on cooling to room temp.Produced good quality rate at higher temp not at lower temps 280-350*c.
Do you reflux any of your product after condenser back to retort during a run?
If that pipe i mentioned above does exist then that will act as a reflux return.trying to figure out your production rates?
Derek.