How to turn plastic waste into diesel fuel cheaply

[Col]

The vertical pipes from the condenser are just drain lines.

I was referring to the ones on the side of the condensers, not directly off the bottom. You may answer my question in your response to Excalibur's comment.
All the best,
Col

[Excalibur]

chipsnpips

A few constructive thoughts...

I made 2 prototypes using the level equilibrium idea. The first was a very small retort and I noticed a reluctance for oil to flow toward the hot zone, almost as if the heat created a kind of pressure barrier. The very small size of piping may have distorted the effect though.
The second prototype showed how sensitive the levels were to pressure differences. In your case, the bubbler water height is going to create back pressure. A possible or partial solution could be to reduce the effective bubbler water level to 50mm (2"). Also I speculate that because you are incinerating the non-condensable gases, the second bubbler is unnecessary. I think I'm right in saying that eliminating the 2nd bubbler will halve the back pressure.

The non-condensable gas feed to the burner needs a method of diverting gas when/if the volume becomes excessive, otherwise you risk a runaway retort situation. More gas = more heat = more gas = more heat... you get the picture? Think safety! You cannot simply close off the feed dead as there will be major pressure build up. A gas-jar or a way to flare off the surplus could be the answer.

Are those level sight glasses on the condensers? If yes, then they need to be vented at their tops, back to the vessel itself. You can't vent to atmosphere otherwise gases or distillate will escape and they won't work without any vent.

BTW, what burner head are you planning use? I see you have a blower

I'm excited to see how you progress and hoping my ramblings are helpful

[chipsnpips]

Hi chipsnpips, and others

Great drawing - what are the vertical pipes coming from the base of the condensers? Would a simple non-sprung, steel check valve do the job to ensure the (minimal) pressure and vapours from the retort do not flow back toward the feedstock? Looks like the cups at the bottom of the drain cocks from the condensers are there to provide a liquid seal against air entering the condensers as the fuel automatically drains out? So you're not letting any liquid build up in the condensers, just in the cups? Is the dotted line running down the condensers is a baffle to direct the incoming vapours down through packing on one side and up through more packing on the other side? Do you think this has an advantage over the vapours entering at the bottom of the condensers because the vapours then have to pass through twice as much distance of packing? Perhaps you could get a pocket of light vapours stuck at the entrance point, not condensing downward?

I am also in the early stages (still) of putting together a continuous, WMO-fed distiller / cracker. My thought for the retort is to use a heavy section of rectangular tube (C-channel with a long lid welded on after initial works are done) on a 20 degree (or so) slope with a gradient of heat ranging from 150C at the high end where the oil drips in, to 450C at the down hill end. The oil runs down the slope until it comes to a temperature hot enough to distil or crack it. I expect there will be a lot of distilling up to 380-425C, and cracking just at the far end of the heat bed. This ensures the lowest amount of heat is used for the shortest period of time (Asad recommended this) to distil each molecule of hydrocarbon, and therefore reduces the chance of degradation. I will pre-treat the feed oil by heating it to and holding at 120C to ensure all the water is removed and also hopefully the light ends with low auto ignition temperatures. Has any one had any advice / experience with auto ignition temperatures being a potential problem at temperatures up to 450-500C? I spoke to a guy who commercially distilled paint thinners and he said to be very careful you do not reach the auto ignition temperature of the feed stock or it will combust even without oxygen present. The square tube will basically be a flat heating bed which I can bracket hot plates to. Each hotplate will have its own thermostat positioned 5mm away from it on the inside of the square tube. I'm thinking of using 5 hotplates to form a steady gradient. I guess I would have to heat the top of the square tube too to prevent vapours condensing on it. Now I think about it I'm not sure a flat bed to bracket hot plates to is better than using band heaters on round pipe (a band heater will heat the floor, ceiling and walls of the round pipe, but a hot plate does one side only).

Good luck to everyone.
Col

Cheers Excalibur and BB

Col,
Regarding the fill line, I don't believe a check valve will be necessary as the fluid level will always be maintained above the inlet, thus preventing any vapours returning to the supply tank. The vapours should only rise. The feed line will have minimal flow, the flow should only be equal to what is being sent to the condensers. and this will be matched with an orifice/needle valve once I know what the rate is. I will also be incorporation another float valve into the inlet tank for safety to prevent low levels of WMO.

The vertical pipes from the condenser are just drain lines. The little cup your referring too is a standard drawing reference of a tank. I will need to adjust my bleed rate once the process is in full swing to keep the condenser level steady. Keeping a level will ensure the system is enclosed. These valves will just be needle valves.
Yes the dotted lines in the condensers are baffles. If the temperatures of the process are correct and the variables are removed from the system then I wouldn't think I'd have a problem with this set up(I hope)

Your continuous feed set up sounds interesting, I hope it works for you

Thanks for your reply, your comments are well received.

[Col]

Continous cracking

Hi chipsnpips, and others

Great drawing - what are the vertical pipes coming from the base of the condensers? Would a simple non-sprung, steel check valve do the job to ensure the (minimal) pressure and vapours from the retort do not flow back toward the feedstock? Looks like the cups at the bottom of the drain cocks from the condensers are there to provide a liquid seal against air entering the condensers as the fuel automatically drains out? So you're not letting any liquid build up in the condensers, just in the cups? Is the dotted line running down the condensers is a baffle to direct the incoming vapours down through packing on one side and up through more packing on the other side? Do you think this has an advantage over the vapours entering at the bottom of the condensers because the vapours then have to pass through twice as much distance of packing? Perhaps you could get a pocket of light vapours stuck at the entrance point, not condensing downward?

I am also in the early stages (still) of putting together a continuous, WMO-fed distiller / cracker. My thought for the retort is to use a heavy section of rectangular tube (C-channel with a long lid welded on after initial works are done) on a 20 degree (or so) slope with a gradient of heat ranging from 150C at the high end where the oil drips in, to 450C at the down hill end. The oil runs down the slope until it comes to a temperature hot enough to distil or crack it. I expect there will be a lot of distilling up to 380-425C, and cracking just at the far end of the heat bed. This ensures the lowest amount of heat is used for the shortest period of time (Asad recommended this) to distil each molecule of hydrocarbon, and therefore reduces the chance of degradation. I will pre-treat the feed oil by heating it to and holding at 120C to ensure all the water is removed and also hopefully the light ends with low auto ignition temperatures. Has any one had any advice / experience with auto ignition temperatures being a potential problem at temperatures up to 450-500C? I spoke to a guy who commercially distilled paint thinners and he said to be very careful you do not reach the auto ignition temperature of the feed stock or it will combust even without oxygen present. The square tube will basically be a flat heating bed which I can bracket hot plates to. Each hotplate will have its own thermostat positioned 5mm away from it on the inside of the square tube. I'm thinking of using 5 hotplates to form a steady gradient. I guess I would have to heat the top of the square tube too to prevent vapours condensing on it. Now I think about it I'm not sure a flat bed to bracket hot plates to is better than using band heaters on round pipe (a band heater will heat the floor, ceiling and walls of the round pipe, but a hot plate does one side only).

Good luck to everyone.
Col

[Beyond Biodiesel]

Hello guys,
Well I just read every post and have slowly designed my unit and taken many notes along the way ...
So.... My question for you long time buffs that have some knowledge in WMO cracking and distilling is

1) Optimum Cracker/retort temperature range
2) Optimum Reflux temperature range
3) Optimum 1st condenser temperature range to fraction off anything lighter then Diesel

Welcome, chipsnpips, good to know you read through the thread. Nice drawing. I have been working on distilling WMO for about 1.5 years.

My answers:
1) Regardless of what hydrocarbon, hydrocarbon cracking temperature is generally considered to be 800F (425c). My last batch of PID controllers were C only and 400c max, but they cracked and evaporated all of my WMO batches.
2) I keep the retort reflux at cracking temperature (400-425c).
3) I keep the first condenser at 300c and drop in 100c stages down to 0c.

On your plan for continuous feed:
You just want to make sure your flow goes away from your feed and toward your bubbler, and you will be OK.

[Excalibur]

Nice design, thanks for posting and welcome.

1) Optimum Cracker/retort temperature range
I just completed a run of WMO and found I was getting good results up to 405*C. I didn't experiment with any higher temps on this run with this retort. I would say aim at the 400*C mark and tweak from there. Too much temperature will risk boil over while too low is slow. Note also that my retort is tall and skinny so that amongst other things will create variables. Feedstock will have a bearing on the target temps too, for example my current lot has some white spirits mixed in so this boils off early.

2) Optimum Reflux temperature range
Ok, I was aiming at 300*C and in doing so I made winter diesel of .83 SG. In other words it was a little on the light side. I'll be aiming at slightly higher temp next time perhaps 320*C. It's early days but I'm going to remove the reflux swarf packing and improve the insulation. There was no catalyst.

3) Optimum 1st condenser temperature range to fraction off anything lighter then Diesel
This was talked about only a few weeks ago. I was aiming at 80 -100*C but my set up was struggling to reach the mark. Still the diesel was OK so I'm not sure what to recommend. You could choose a relatively low temp and simply expose the diesel to that temp for a longer duration, which would achieve the same result.

Hope this helps...

[chipsnpips]

Praise, suggestions and info ;-)

Hello guys,
Well I just read every post and have slowly designed my unit and taken many notes along the way thanks to all your trials and tribulations! Like everyone on this forum I would like to thank the guys who began this topic some years ago. Polymer cracking was rather interesting but as I found waste oil was far easier to get hold of, I soon turned to distillation process of WMO.(for now)

I have a few questions which perhaps you seasoned vets may be able to answer. While taking notes I have found there to be many differences in cracking and distillation process, temperatures and possible catalysts.

First of all some information, my proposed unit is an "on the fly" continuous feed process with a goal of producing Diesel fuel.

My plan is to have a rather shallow retort level with large diameter and feed the retort via float traps. This will keep the unit sealed and provide a constant level in my retort/reactor which I can monitor externally by simply looking at my external tank level. My drawing may explain this better. This will be experimental so I won't get upset if it doesn't work.

The heat source will be LPG at this point until my system is proven, then I will switch to a liquor burner. Everything insulated as required, I have an abundence of insulation and materials at work at which I can acquire to construct my unit. Please keep in mind this is a sketch, not an outright design and not to scale.

As this is planned to be a continuous feed process I would surmise that once I reach and hold cracking temperature in the retort my plant temperatures, feed rate, condensable and non condensable should remain rather steady. For this reason I am going to try and achieve reflux and condenser temperatures by modifying the distance between them. Thus there will be no reason for axcillary heating or cooling on said equipment. (again this is an experiment)

So.... My question for you long time buffs that have some knowledge in WMO cracking and distilling is

1) Optimum Cracker/retort temperature range
2) Optimum Reflux temperature range
3) Optimum 1st condenser temperature range to fraction off anything lighter then Diesel

I will be experimenting with my plant but a temperature goal would be nice to work towards. I've noticed through out the 101 pages the temps have ranged quite a bit so it's hard to get a handle on what top aim for. Keep in mind I want diesel

Once again, to all the long time forum members that went through hell to get to this point Awesome!

[Beyond Biodiesel]

Has anybody tried using one of these cheap Stainless Steel Electric Band Heater from ebay for their retort?


Just making concept design. For WMO feedstock only...


AC 220V 220 Voltage 2300W Ceramic Plug Stainless Band Heater 140mmx180mm | eBay

I did notice Jetijs used one in an earlier design of his, although it was around 3.8kw from memory.

Thanks

I use two band heaters on my retort,

along with a linewrap heater,

and a hot plate made from a stove heating element.

They heat my retort fairly rapidly,

and I control them with PID controllers, and variacs.

Hi guy's,just been contemplating the idea of using halogen lamp principal as a heat source?Instant,quick and same cost as elect elements.What do you think?

Heating a retort with halogen lamps is using radiant heat to heat with. Just as heating a retort with resistance wires that are not in physical contact with the retort is still just radiant heating.

It is good to keep the laws of thermodynamics in mind when designing a pyrolysis unit. The laws of thermodynamics show that conduction is the most efficient way to heat something. Convection is the next most efficient way to heat something. Radiation is the least effective way to heat something.

Thus a hot plate, band heaters, and line wrap are the most efficient ways to heat a retort electrically.

[rozier56]

derek

Hi guy's,just been contemplating the idea of using halogen lamp principal as a heat source?Instant,quick and same cost as elect elements.What do you think?

[southoz]

ceramic band heater question

Has anybody tried using one of these cheap Stainless Steel Electric Band Heater from ebay for their retort?


Just making concept design. For WMO feedstock only...


AC 220V 220 Voltage 2300W Ceramic Plug Stainless Band Heater 140mmx180mm | eBay

I did notice Jetijs used one in an earlier design of his, although it was around 3.8kw from memory.

Thanks

[lowriderzzz]

My cuestion is if is posible put the resistance inside the reactor in contact with the waste?

Thank you.

Search through the thread, there is discussed a way that you put your catalyst in the form of powered straight with the retort.

* use the advanced thread search with the words and their variations (catalyst in retort / reactor)

** Question - correct spelling

[imanes]

Resistance inside the reactor

My cuestion is if is posible put the resistance inside the reactor in contact with the waste?

Thank you.

[Ron Hammar]

Welcome southoz

There is a huge wealth of knowledge and experience on this forum. It now has 100 pages so finding the required info can be difficult. I suggest taking notes is an excellent idea.
As is normal, opinions vary. So does the design of each ones' pyro-machine. No two are alike. This makes it not only interesting but also allows opportunity to learn and to have access to a range of ideas.
I would suggest you start small with perhaps a 20 liter reactor. Get that working as a first step, then evaluate and plan the direction for a bigger build.
Hope this helps.

What I have done is open a word doc and copy and paste it for taking notes.

[southoz]

Thanks Excalibur.
I am pleased to see your current success with your MK6 turk retort. That is an impressive setup!! with great yield capabilities.

[Excalibur]

Welcome southoz

There is a huge wealth of knowledge and experience on this forum. It now has 100 pages so finding the required info can be difficult. I suggest taking notes is an excellent idea.
As is normal, opinions vary. So does the design of each ones' pyro-machine. No two are alike. This makes it not only interesting but also allows opportunity to learn and to have access to a range of ideas.
I would suggest you start small with perhaps a 20 liter reactor. Get that working as a first step, then evaluate and plan the direction for a bigger build.
Hope this helps.