How to turn plastic waste into diesel fuel cheaply

[Beyond Biodiesel]

Welcome wheels, it sounds like you could make a valuable contribution here. I look forward to what you have to offer us. By the way, Excalibur is a fellow Kiwi, so maybe you 2 will do some real time show and tell.

[wheels]

Intro

Hi guy's, this is my first post here. I have been working through all the thread and am upto page 61. Very interesting seeing the progression. A little info about me. I have three trades qualifications. One Electronics, another Engineering and the third not relevant to this topic. I have spent several years designing and building equipment for Lipid Oil extraction. During that time I had to learn a lot of Chemistry and Physics, which are both still ongoing educations. The knowledge has gone a long way toward understanding Pyrolysis. What I am now involved in is actually the back end of what you guys are doing. We haven't really been interested in making the Fuels as such. Well not till now anyway. After reading here, I am kind of keen in playing with that. But what we actually do is reduce what you guy's would call Toxic Plastics. Mainly the ABS plastics from Ewaste. Ewaste recycling is part of what we do and the disposal of the Plastics is expensive here in NZ. We also break down PVC from Electrical cable. Our Machine is small, at least at the moment. Not any bigger than most of the ones here. But a little more sophisticated in the end filtering stages. We have been carrying out a lot of research and testing in taking care of all the Toxins and noxious byproducts from the processes.
Regards.

[fox32]

suddenly lose strength once the melting point is reached. A good reminder and warning for the unwary!!

Yes, that is correct, it is solder.Thnaks for clearing that up!

I was searching for some pirolysis unit for sale under 10.000 euros, and got across this interesting article from Japan... https://staff.aist.go.jp/tohru-kamo/...SFR99/DE-3.pdf

Btw are there any companies that manufacture and sell pyrolisis plants? for under 10k E.

[Excalibur]

?fludor(the stuff electronists use),

suddenly lose strength once the melting point is reached. A good reminder and warning for the unwary!!
Thanks for bringing it up.

[fox32]

Quote:

I was thinking of oil cooled heat ctor/retort, electrically heated with band heaters... I could run another pipe up inside it, the full length of it, and have the
flame at the bottom going up this tube ? (or the heat from the flame anyway)

This way i created my sistem inspired by a wood fired water heater. Now i would do it different, with the exhaust coming out on one side of the reactor so i could put another door next to my reflux, for feeding cleaning and maintaining so i won't have to get my reflux down(is very heavy), but there are advantages, the flue can be directed to the reflux to heat it. Still youl need some baffle, or corkscrew inside the heat exchanger to be more efficient. And the welds should be extra strong.


About the condenser, you should not use anything that is glued with ?fludor(the stuff electronists use), because it will melt at high temperatures. And copper from what i understand affects the quality of the final product.

[Excalibur]

knighty
The dual heat reactor/retort idea reminds me of the gas water heaters with the central flue. The one I saw had a neat looking baffle in the flue pipe. The object seems to be to slow the exhaust down for better heat exchanging. I got that baffle before the rest was sent out for scrap metal .I'm going to test it next week in my new feedstock preheater.

The plumbers delight would be fine for cooling the vapor stream assuming it had adequate capacity. One means of control you'll have is the speed of the water flow. A variant I once used for condensing petrol vapor, I set the flow to 'minimum to achieve the temperature target' as a means only to save water.

about 5litres/hour

A reasonable 1st target. You've clearly been thinking a lot about details and that's a good thing. Getting a working machine is more difficult than it looks.
Step by step. Get a small prototype running as a 1st step.

[knighty]

the reason I was thinking of oil cooled heat exchangers over water cooled is because I was worried about water boiling off when cooling the diesel to @120'C (I'm assuming this is why other people are doing / thinking about the same thing ?)

but... now I think about it some more... I could either run with salt water, or with some antifreeze mixed in to raise the boiling point... or even run at pressure ? (if the water is pumped, this would be easy to do with a pressure release valve on the return to your water storage tank set to the desired pressure)

I guess another option is less efficient heat exchangers ? if they're not as efficient, there can be a larger gap between the hot side and cold side temperatures ?

I was thinking about using a "plumbers delight" heat exchanger, the same as the bio diesel guys use to condense methanol out of there bio diesel when they're bubbling it / after reacting it

Plumbers delight condenser - Biopowered

and/or using some flat plate heat exchangers


anyone know how much vapour to expect from 1 litre of WMO ?


for the dual electric and gas heating...

I was thinking of a tall 8inch pipe for a dual reactor/retort, electrically heated with band heaters... I could run another pipe up inside it, the full length of it, and have the flame at the bottom going up this tube ? (or the heat from the flame anyway)

if I use a venturi to run a vacuum, I could make it dual purpose if instead of pumping water I pumped the final stage / anything that condensed out after the diesel... sucking in through the venturi and mixing with the pumping liquid should be enough to condense anything out of the vapour (I'm half tempted to try condensing the diesel out like this too)

the vent from the tank for that would be the gas supply to the burner (with a mains gas pilot light/flame)

the venturi would also mean I could have a bit of positive pressure for the burner, which would mean I could use an off the shelf burner (probably with a bit of modification)

I'd be happy with about 5litres/hour, 10 would be better

[jonathan]

retort problem

thanks a lot excalibur next time l will try to heat my reflux with electric heater and try to heat my retort 380-425 degrees c. and see what happened.

[Excalibur]

as l say before my retort tempreture was 316 degrees c and reflux 90 degrees c know i open my retort and find about 6 inch like carbon but not solid from 30 litres waste oil. l am asking this because l like to learn.l was thinking because reflux tempreture is to low and waste oil comes out as gas.

Greetings.... So i was surfing mr Excalibur's website(wich i recommend to all), i was looking at the turk design, when i had an ideea. What if we could use the same sistem, but to pulverize wmo (preheted) on a 400c hot plate, or heat exchanger of some sort. I have made a diagram to better explain my ideea. My main concern is that the wmo will jam the injectors, but maybe if is hot enough it will be thin enough. And if the injectors run on turns, the plate will never lose the temperature. Theoretically...

Spray onto a hot plate idea has been chewed over and over. It has some really good things going for it. One thought is that any condensate refluxing back to the hot plate will need heat compensation. The injector pump shut-off valve could be wired so to cut feed and allow the hotplate heat to recover. It could be a job for an Arduino microcontroller and a MAX31875 breakout board to monitor the thermocouple on the hotplate. The Arduino is infinitely programmable,,,setpoints, time delays, you name it.
BTW, my injectors seized last run. I guess I found their limit. I did manage to fix them but one spring was looking decidedly collapsed.

Has anyone tried running bubbles up through the condensing vessel? I am interested to know what kind of extra pressure it creates.

Not tried but studied the prospect after seeing a diagram of an alcohol still which used the principle. According to the Engineering Toolbox, fluid head pressure calculation is 27.7 inches of water equals 1 psi.

[Col]

cooling condensate and bubbling vapours through condensate

oil has less heat capacity than water, so you will need to increase the surface area of your heat exchangers.

every inch of head increases the upstream pressure, this is why bubble caps are very low profile.

I was considering what material to use to make a shell and tube heat exchanger, like the one Excalibur has made. I figured because standard stainless steel has poor heat transfer properties it would not be the material of choice, and that carbon steel would be better. If you were to use carbon steel, and water to cool the condensate, you would also need to give consideration to water treatment, as for a boiler, to prevent corrosion and other related issues. I expect making the heat exchanger larger and using oil to cool it would require less maintenance. But what about if the feedstock is not pre-heated and you have water in it - will that lead to corrosion in the carbon steel heat exchanger? Any oxygen in the water in the feedstock will pass through the system first, followed by water, followed by hydrocarbons. Perhaps the pipes will not have time to rust before they are coated in hydrocarbon?? I understand there is little to no oxygen content in water above a certain temperature but if you start from ambient temperature then the oxygen has to pass through the system at some point. Does it present a problem?
Does anyone have any experience / feedback on this? I expect the condition of pipes running from vessel to vessel will be in the same condition as pipes in a heat exchanger.

Has anyone tried running bubbles up through the condensing vessel? I am interested to know what kind of extra pressure it creates.

Thanks
Col

[fox32]

Greetings.... So i was surfing mr Excalibur's website(wich i recommend to all), i was looking at the turk design, when i had an ideea. What if we could use the same sistem, but to pulverize wmo (preheted) on a 400c hot plate, or heat exchanger of some sort. I have made a diagram to better explain my ideea. My main concern is that the wmo will jam the injectors, but maybe if is hot enough it will be thin enough. And if the injectors run on turns, the plate will never lose the temperature. Theoretically...

[jonathan]

pyrolysis proplem

as l say before my retort tempreture was 316 degrees c and reflux 90 degrees c know i open my retort and find about 6 inch like carbon but not solid from 30 litres waste oil. l am asking this because l like to learn.l was thinking because reflux tempreture is to low and waste oil comes out as gas.

[Beyond Biodiesel]

Hi, Over the last week I've read this thread from start to finish, but I apologise if I'm asking questions which have already been asked, it was a lot of information to take in! I really appreciate all the work you guys have done, all the tiem you've spent posting about it here, and all the help you've given to other people (which helped me too)

Good work, reading the forum helps reduce mistakes.

I'm thinking of building a system for WMO only (continuous feed system),

Yes, some of us are focused on WMO distallation, because we have access to enough to make it work, and 5-gallons (20L) in is almost 5-gallons (20L) out.

I'm only interested in the diesel output,

OK, so how about blending light fractions with heavy fractions to make a middle (diesel) fraction? This practice is called "blending" and I have been doing it successfully for 7 years.

I plan to heat electrically (have 415v 3 phase available)

3 phase power is the ay to go, but it might be more power than you need. How much WMO are you planning on processing per unit time?

but I guess I might as well interoperate gas heating too, to take advantage of the excess gas/vapours

Sounds like a good idea, but difficult to implement. I would be interested in observing how you accomplish it.

I've read that reactor and retort temperatures should be the same (or close)

It depends upon what your object is. If all you want to do is remove dissolved solids from WMO, which is my focus, then cracking is not needed. ON the other hand, if you are interested in cracking all your WMO to diesel, then the first reflux should be lower, as Excalibur does; however, thermal cracking alone takes a lot of energy and thus time.

what about instead of having one stacked on top of the other, I used a long (say 16foot?) length of 8 inch pipe, used the bottom as the reactor and filled the top with wire wool to work as a retort ?

I am not sure if you are talking about it being horizontal or vertical; however, in either case 16ft (4.9m) is a long retort to have to heat. On the other hand, if you gradually increased the heat along the pipe so that at the bottom it was only 100C and at the top it was 425c, then the bottom of your pipe becomes a pre-heater, and the top of the fluid is your retort, with about 3 feet (1m) for your reflux.

8inches should be wide enough if it's a continuous system ?

Sure, it should be fine. It just depends upon your throughput.

I could pre-heat the oil to about 200'C (or see what works) before it's fed in, to stop it cooling the reactor too much.

Seems reasonable

I could also stop the feed every few hours and check how long it takes the reactor to run out of oil, to give me an idea of the oil level in it and let me adjust the feed rate

I believe a continuous feed WMO pyrolysis unit is going to work best by keeping the contents of the retort low, so matching feed to output will be important.

for the condenser, I was thinking of making an oil cooled condenser, because I could pre-heat the cooling oil before I ran the system, and then later on cool it as needed....

It should work, but oil has less heat capacity than water, so you will need to increase the surface area of your heat exchangers.

but I'm also wondering why I can't bubble the vapours from the reactor through the output liquids, if I hold them at the right temperature ?

so I could first bubble through oil held at 150'C
then though diesel held at 120'C
then finally either through whatever at room temperature to catch any liquids, or feed it straight into a burner

This is what the bubble caps do in a commercial refinery. It improves condensation of the vapor stream, and it acts as additional barriers to the migration of oxygen up stream; however, it does not eliminate the need for a water bubbler at the end of your processing system, which acts as a flash-back arrester, oxygen barrier, and most importantly as a toxic gas absorber/neutralizer.

I would need the collection vessels to be tall, and to make sure I had small bubbles passing through the liquids, but that shouldn't be too hard ?

every inch of head increases the upstream pressure, this is why bubble caps are very low profile.

I also read that lower temperatures give a better final product, but I don't see many people running under a vacuum...

I employ vacuum distillation. It works for me, but it reduces cracking while increasing throughput and it is an excellent way to reduce the danger of oxygen migration into the hot zone.

I could easily use a pump and a venturi to create a good, constant vacuum without much extra work/fuss... is a vacuum a good idea or has it been dismissed for some reason ?

I see a number of problems with a venturi to produce a vacuum, most notably, the vacuum one can get from a venturi is not very good, and if you use water to make the venturi, then you will have water migrating up-stream, aside from a venturi representing a profound waste of resources.

I made a very rough, very basic diagram, just to give a rough idea of what I'm thinking of
imgur: the simple image sharer
(electric heating the full length of the reactor/retort)

I do not think tall is going to work, unless you want that first tall pipe/retort to be a fractionation tower.

[Excalibur]

Way-to-go! You read the forum in a week. That must be some kind of record. Thanks for doing that and helping yourself. (Hint for others to do same). Yes, the systems are complicated so no-one would be expected to achieve success with 1st attempt. Everyones got to start somewhere...

3 phase plus gases for heat. All possible with enough thought. Yeah, why not.

I've read that reactor and retort temperatures should be the same (or close)

8inches should be wide enough if it's a continuous system ?

Yes, absolutely. (Mine happens to be 8").

I could pre-heat the oil to about 200'C (or see what works) before it's fed in, to stop it cooling the reactor too much. I could also stop the feed every few hours and check how long it takes the reactor to run out of oil, to give me an idea of the oil level in it and let me adjust the feed rate

Preheating is a good idea. I suggest a few batch runs 1st, then look at preheat. You'll have enough to worry about without the complication! Knowing how fill or empty the reactor is at any one time is a key part of the puzzle. Currently a good method is needed for level monitoring.

for the condenser, I was thinking of making an oil cooled condenser, because I could pre-heat the cooling oil before I ran the system, and then later on cool it as needed....

My system uses oil heat exchanged against the vapour stream going counter-current. It's proving to be not enough heat exchanged onto ingoing oil but it's a start.

but I'm also wondering why I can't bubble the vapours from the reactor through the output liquids, if I hold them at the right temperature ?

I've seen alcohol stills set up like that. Watch out for liquids being sucked back upstream as the reactor cools after shutdown.

is a vacuum a good idea or has it been dismissed for some reason ?

[knighty]

Hi, Over the last week I've read this thread from start to finish, but I apologise if I'm asking questions which have already been asked, it was a lot of information to take in! I really appreciate all the work you guys have done, all the tiem you've spent posting about it here, and all the help you've given to other people (which helped me too)

I'm thinking of building a system for WMO only (continuous feed system), I'm only interested in the diesel output, I plan to heat electrically (have 415v 3 phase available) but I guess I might as well interoperate gas heating too, to take advantage of the excess gas/vapours

I've read that reactor and retort temperatures should be the same (or close)

what about instead of having one stacked on top of the other, I used a long (say 16foot?) length of 8 inch pipe, used the bottom as the reactor and filled the top with wire wool to work as a retort ?

8inches should be wide enough if it's a continuous system ?

I could pre-heat the oil to about 200'C (or see what works) before it's fed in, to stop it cooling the reactor too much. I could also stop the feed every few hours and check how long it takes the reactor to run out of oil, to give me an idea of the oil level in it and let me adjust the feed rate

for the condenser, I was thinking of making an oil cooled condenser, because I could pre-heat the cooling oil before I ran the system, and then later on cool it as needed....

but I'm also wondering why I can't bubble the vapours from the reactor through the output liquids, if I hold them at the right temperature ?

so I could first bubble through oil held at 150'C
then though diesel held at 120'C
then finally either through whatever at room temperature to catch any liquids, or feed it straight into a burner

I would need the collection vessels to be tall, and to make sure I had small bubbles passing through the liquids, but that shouldn't be too hard ?


I also read that lower temperatures give a better final product, but I don't see many people running under a vacuum...

I could easily use a pump and a venturi to create a good, constant vacuum without much extra work/fuss... is a vacuum a good idea or has it been dismissed for some reason ?


I made a very rough, very basic diagram, just to give a rough idea of what I'm thinking of
imgur: the simple image sharer
(electric heating the full length of the reactor/retort)