How to turn plastic waste into diesel fuel cheaply

[mjohnson1]

If I carry the pyrolysis process to the very end, with catalyst, I am left with 8 grams of char per kilo of plastic. I have has this analysed by mass spectrometry and gas chromatograph and it is 98% carbon, so yes it is carbon black. However I have found that it is much more energy efficient to extract only 1.1 litres of fuel from each kilo and the residue is a quantity of soft black wax. This wax can be mixed with waste wood shavings and sawdust. When molded into blocks it burns cleanly and without smell in a wood stove.

The idea of pyrolyzing veg oil seems a strange one. The esters in most veg oils are of roughly the same molecule length, average C17, as diesel fuel so cracking, either thermal or catalytic, will not achieve anything useful. The problem with veg oil as a motor fuel is the presence of glycerol but pyrolysing will not eliminate this. Esters will gasify at 400C before the glycerol 750C leaving behind the stinking tarry mess mentioned above.

Are you using your catalyst during the liquid or gas phase?

[Marso Green]

It seems to me that if you can guarantee liquid phase at all times within the auger pipe, you don't need to purge any trapped O2.

But if you can't fully control the liquifying in the auger tube, I suggest placing the CO2 and O2 purge ports somewhere high in a sealed double-lid (double chamber) hopper and a pressure blow-off valve as an O2 (air) purge port. Basically you would open the first lid, place shredded plastic, close the lid, push CO2 or N2 until blow-off valve is activated, then you're ready to open the second lid through an adequately sealed (graphite seal) external handle for plastic to fall in the reactor area.

Can anyone help me out with devising an auger feed system that would work with purge gasses?

I have a 1 1/2 inch auger and a steel pipe to house it. It works fine but I can't connect it to the reactor until I can figure out a purge system. I plan on using CO2 for the purge gas but N2 can also be used.

I have seen systems with an open hopper that still purges the oxygen i'm just not sure how to design it.

I'm thinking a premelt system would be the solution with electric/gas heating that just gets the plastic to liquid form.

The plastic would not have empty space then like in solid form.

Can anyone think of another way of going about this? Any advice would be appreciated.

Here's a diagram of my idea:

[Marso Green]

IMB,

Do you know if Copper Nickel pipe would be adequate to use? Particularly CuNi90/10 or CuNi70/30?

Thank You

I have found that the best pipe for our purposes is plain steel threaded pipe with steel threaded fittings sealed with high temperature silicone mastic. Stainless steel is good but not any better. Avoid copper or galvanized pipe. Obviously plastic pipe is not suitable anywhere on the system.

[Marso Green]

Jetijs,

It's all the result of inspiration and encouragement from you in the first place! And we owe you all the support we can muster... And hopefully less in the form of defense and more in the form of successful pyrolysis systems in our backyards :-)

I think you'll agree that many are already stepping up their efforts and there are a handful of us who are approaching the big day when the success story and results are revealed

Marso Green, I like you!

[imakebiodiesel]

Well done mjohnson1, there may have been some luck involved in your early success but I find that the more you research and learn, the luckier you get.

The glass bulb would indeed have acted as a reflux but I think if you want to have more control over how it functions you may have to change it for a cylindrical column. Some sort of packing material to slow down the gas flow and increase the surface area will increase the efficiency and a heating device will give you fine control of the top exit temperature.
I have not done much work with continuous feed but one problem is that plastics do not melt down into a homogenous liquid. Shredded plastic melts down into a sticky paste full of small air bubbles. These bubbles are difficult to purge and although that small amount of air is probably not dangerous it will certainly contribute to the oxidation of the fuel.
Marso green, I would avoid any form of copper in your system. Copper causes rapid oxidation of conventional fuels (mostly very stable alkanes) Our fuel contains higher than normal levels of unstable alkenes and will oxidize in the presence of copper in a matter of hours.

[teegoenergy]

please can i use analog thermostart instead of digital..?
thanks i wait your soonest response
Forward Message

[teegoenergy]

jegins

please can i use analog thermostart instead of digital..?
thanks i wait your soonest response
Forward Message

[imakebiodiesel]

I missed your earlier question mjohnson1. I do use a catalyst of my own formulation. It is used in the gas phase.
1 kg of mostly PE with up to 20% PP and PS will yield 1.1 litres of liquid fuel and a small residue of wax in the retort and some gas. If I push the fuel yield up to 1.2 litres I get no residual wax, just a few grams of carbon powder.
My crude fuel is made up of 75% kerosene and 25% petrol ( gasoline). I deliberately avoid producing any diesel fraction although I can if I modify the catalyst.

[Beyond Biodiesel]

Can anyone help me out with devising an auger feed system that would work with purge gasses?

I have a 1 1/2 inch auger and a steel pipe to house it. It works fine but I can't connect it to the reactor until I can figure out a purge system. I plan on using CO2 for the purge gas but N2 can also be used.

I have seen systems with an open hopper that still purges the oxygen i'm just not sure how to design it.

I'm thinking a premelt system would be the solution with electric/gas heating that just gets the plastic to liquid form.

The plastic would not have empty space then like in solid form.

Can anyone think of another way of going about this? Any advice would be appreciated.

Here's a diagram of my idea:

To me the problem with an augur system for continuous feed of plastics into a retort has the basic problem of assuring a proper purge, and without a reliable purge, then there will eventually be a very costly accident.

Thus, I am looking at a pre-melt system, as you suggested. Most plastics have a melting point that is about 100-200c, so a vat with an open lid to a hopper could be used to continuously feed plastic into, which is melted, then perhaps augured into a retort, as long as the plastics are fully melted, which would eliminate air trapped in the plastics. So, one would just have to assure a proper melt of the plastics before they reach the augur.

[Beyond Biodiesel]

Most of you know that I have started my pyrolysis experiments with distilling WMO, and my progress has been slow due to lack of funding, but I finally got a 6-gallon (23L) retort up and running, which is electrically heated with just a hot plate, a band heater, and a line heater to 400c (750F). So far it looks like 1 gallon/hr product rate, and yesterday I poured some of the heavier distillate into my crankcase and noticed that a glob slithered out, so I screened it through a coarse kitchen screen and this is what I got.

[CRMoore]

Plungers anyone?

[QUOTE=mjohnson1;218142]Can anyone help me out with devising an auger feed system that would work with purge gasses?

I have a 1 1/2 inch auger and a steel pipe to house it. It works fine but I can't connect it to the reactor until I can figure out a purge system. I plan on using CO2 for the purge gas but N2 can also be used.

I have seen systems with an open hopper that still purges the oxygen i'm just not sure how to design it.

I'm thinking a premelt system would be the solution with electric/gas heating that just gets the plastic to liquid form.

The plastic would not have empty space then like in solid form.

Can anyone think of another way of going about this? Any advice would be appreciated.

In the Blest B-240 they use worm gears like augers. However these wear out somewhat quickly so they might be replaced with plungers.

[seetniex]

buy

Hey guys.

I have a question for you - I'd really like to buy such a pyrolysis reactor to make my own fuel from plastic waste( i wouldn`t have time or pateience to build it myself)

Any ideas where to look or even how to look?

[kamal11]

Jetijs. I really appreciate the effort of patiently explaining details that for you are too obvious.

How do you get a non oxygen environment?

I would like to know in detail the dimensions.

Could you tell me (please think in a 2kW macihne so I guess it would be 1/3 high) the height and diameter of the external tank.

The internal diameter of the white inner rings? What are the dimension of the bricks?
Could you tell us the dimensions of the internal cage?

Can you show us the holes and bolts (or whatever you use) for the thermocouple and for the coils?

The cage you have showed us it doesn't have solid walls so the plastic will fall down to the bottom of the tank. How do you keep then the reactor container apart from the bricks and coils?

Can you show us the inside of the condensing containers?

This is going to sound silly but could you show us a pic of the shredded plastic so I have a good idea when I try to buy it?

Do you mean the external tank is a 50 liter one?
What are the dimensions of both grooves? How do you make them?
Could you please, show us more photos of the upper lid?


I would like to replicate first this machine and then when you have the one burning the fule to heat the plastic I would like to replicate it also.

Thank you very much for your help.

This project sounds really interesting. What a shame that the Japanese sell them so expensive. There is a market for cheaper ones.

(talking about Japanese it reminds me of a Pink Floyd song: YouTube - Pink Floyd Final Cut (12) - Not Now John )

This is the best process to get fuel from waste plastic.

[imakebiodiesel]

My apologies to both mjohnson1 and drgoldsmith. I got you mixed up in a recent post.
drgoldsmith, in your experiments with glassware does the molten plastic foam up as it approaches the cracking temperature? In my steel retort I only put 1kg of plastic into a retort that could hold 6 or 7 kilos. My fear is the the molten would foam up and possibly block the upper outlet. Of course I cant see what is going on inside my retort so I have to be extra cautious.
Over the holidays I will be testing my larger retort. Its maximum capactiy is about 75kg but i will only half fill it for the first few batches.

[mjohnson1]

Hey guys.

I have a question for you - I'd really like to buy such a pyrolysis reactor to make my own fuel from plastic waste( i wouldn`t have time or pateience to build it myself)

Any ideas where to look or even how to look?

The only small scale ones for sale that I know of are the Blest systems. Very pricey from what I hear.

Blest.co.Ltd., "Question & Answer"

I don't believe the Blest desktop systems allow the use of catalyst in gas phase without modification.

If you are looking for a commercial system they are available through Chinese companies.