How to turn plastic waste into diesel fuel cheaply

[Francisco Mora]

Hi all.
I got some PET pellets and put them through my unit today to see why no one uses it and now I certainly can see why. First of all your output liquid will be very dark and at least 4/5 of it will be black water. A bit brighter fuel floats on top of it, but still very dark, only with a very bright light you can see somewhat through the fuel and see the proportions of fuel/water. It stinks very bad, almost as bad as when rubber is used in the pyrolysis process. It stinks all over the place and the smell may be very toxic, so never use PET. And the worst part is that it makes all your refluctors, reactors and condensers dirty and black. Very much cleaning is needed to get rid of that stuff. Also it leaves very much dry stuff behing, almost 20% of the PET volume and this stuff is hard like asfalt and is very hard to remove. So I learned my lesson - DON'T USE PET!!!!!
Thanks,
Jetijs

jetijs hello Thank you for reporting your experiments, you are helpful, you wonder how it is used as the catalyst?, what with the plastic tank, and what amount is used?, please help me greetings
: Notworthy:

[kaguar]

jetijs,
PET is the dirty one, yes. It could be used in minute quantities together with PE, PP or wmo, something around 0.5-1%. What you got in your system is terephthalic acid - a solid stuff. It sublimates at 400C, no liquid phase.
However, PET could be turned into useful liquids if heated to 700C in presence of Ca(OH)2. What you get is BTX mixture which can be used as high octane petrol.
I`ve tried it and it works but it`s a painful process.

[ABO]

Hi AOB. I have been searching too, proving difficult so far. The only company I came accross so far are tyretooil, I would not thrust them by the emails I revieved back form them. If I do come accross something I will post it here.

Hi diesel. I've got the same feeling from one of the Chinese sites.
I'll be posting anything I find here also, this is a great site.

[extraloud]

thoughts on condenser

this condenser design is often used in industry - i thihk it is more efficient at cooling than shell and tube.

it uses a quench loop to self cool the incoming vapors -

you pump the liquid to a spray nozzle. and it is also pumped through a heat exchange to either cool or heat the spray fluid. in steady operation you could - in theory control the temperature of the loop.

you could also pump it through a filter as well. The pump is sensitive because it is a hot / acidic / messy fluid with particles in it.

i do not know if i will implement this design or not - sorry for crude drawing

[fibuslitero]

Hi:
I have found this videos, basically the are using HDPE: gasification, obtaining wax, reflux, etc, etc...
A basic setup but very interesting imho:

‪Plastic into fuel.wmv‬‏ - YouTube

‪Plastic into fuel #2‬‏ - YouTube

‪Plastic into fuel #3.wmv‬‏ - YouTube

Hi jetijs, Is it possible to fraction off the wax with a high temperature condenser? what is the operating temperature of your kerosene condenser and do you have a higher temperature condenser?

I posted this before "Cracking PE will give mainly paraffins (Kerosene is a paraffin).... The paraffin wax can be separated out by cooling and straining though it is not absolutely required. (meting point is 60c, boiling point is 370C)

Maybe the best compromise is a two stage cracking process with three fractioning vessels.

That is the product of the first vessel, held at a temperature of 275c be fed back into the reactor (or collected), the second vessel is held at 100c to produce kerosene and the third at room temperature will collect petroleum distillates in the gasoline region.

I hope I got all these figures right hehe, it came from wikipedia. I’m sure someone in the petroleum industry could give us better info."

I know that holding a condensation vessel at 275 will be a little more difficult but not impossible. The liquid waxes could be used to heat the reactor or first condenser using a paraffin burner.

Your PE experiments are very interesting to me here, scrap PE is about 10cents per kilo and there is lots of it.

[mbrownn]

Interesting. this confirms what I believe about the system I looked at some years ago. It consisted of a reactor vessel, a cyclone type filter and three fractionating vessels all with feedback loops going back to the reactor. Its all in my earlier posts. It was obviously a self-made device but big enough to make several drums of fuel at a time.

Reading the posts about the darkening of the fuel suggests that the oil drums that I could see could have contained fuel that was obtained during the warm up process. Thinking about it, I believe that these drums that had "lumpy" dark oil in them, would be fed back into the reactor at a later date. If the feed to the reactor is broken down into smaller molecules by hitting a high temperature it would make sense to get the reactor up to temperature and pump this waxy stuff in at a rate that would not cause the vessel to cool unduly. I cannot remember everything about it but there were more pipes and tanks around the reactor than I described in my earlier posts. Unfortunately I cannot remember what exactly they connected to.

The unit was on a plastic recycling company's site, they shredded plastic using diesel powers shredders they also recycled oil. I believe that much of the plastic that was unsuitable for recycling was cracked into paraffin and used to power the diesel engines. The usable plastic was made into garbage bins and the recycled oil was sold to DanOil for blending and processing. The owner bragged that he had no electricity supply to his site and it was self-sustaining. People paid him to take the plastic and old oil and then he sold all the products from the recycling to other companies and made millions. Then he was bought out by one of the big recycling companies for an untold sum and retired to the tropics, what a success story.

I never was able to see the system operating and at the time didn't know what its function was but recognized the fractionating vessels. Only when reading this thread did all the pieces fall into place. Thanks guys, If I remember anything else I will post it.

[Jetijs]

Hi all.
Today's experiment was very interesting. I learned another thing that you shouldn't do

I got some packing film, it is the one that is very thin and sticks to everything. Farmers use it to pack green feedstock in big rolls. Anyway, I used a hydraylic cylinder press to compress large amounts of that film into the reactor. I managed to densly pack about 1.5 kg of this plastic into the reactor. But I had a bad feeling about this from the beginning. Because the compressed plastic still has much air bubbles trapped between the plastic layers and the plastic was also a bit wet. So I turned the heat on and the fun begins. When the temperatures reached around 250 degree celsius, the gas stopped in the bubbler. That was strange so I turned the heat off. But it does not cool instantly. Nothing happened for a while and then there was this huge release of gas and smoke from the bubbler, it blew the bubbler vessel away. After that nothing for a while till I saw that smoke starts to come from the V shaped seal on the reactor, this is bad, this means that there is a blockage of the gas flow. The pressure dropped a bit and the smoke stopped. When this thing cooled down, I opened it up and was amazed at the results. The molten plastic along with superheated steam filled all the refluctor vessel shut, the connecting pipe that connects the reactor with the refluctor was also full with molten plastic. And the pipe going from the refluctor to the condenser was coated with about 1-2mm thick layer of partly cracked plastic with the consistency of candle wax. Here are the funny pictures:



This is the reactor:


The reactor lid:


The refluctor with removed lid:


The inside coating of the tubes:


This is what came out of the refluctor:




This is the inside coating in the tube connecting the refluctor lid to the condenser:

The other side of that pipe:


Lots of fun
Hope nobody will make this mistake again

[Francisco Mora]

hello all, I've been doing my first experiments with PP and PE, using sodium bentonite as catalyst 10 wt% hydrated lime and 1% by weight, giving me results in a very clear diesel, the commercial diesel mix with 50/50 and no change of color.

[Asad Farooqui]

sodium bentonite

hello all, I've been doing my first experiments with PP and PE, using sodium bentonite as catalyst 10 wt% hydrated lime and 1% by weight, no change of color.

Hello Francisco Mora ;
Very good . Let us know You added 10% sodium bentonite and 01% CaOH2 with PP/PE in your reactor and the resultant fuel has a light yellow color & what about the SMELL ?? has it gone , I've heard bentonites are also used as deodorants ???

[imakebiodiesel]

The three videos above are great, real backyard science. The two guys were more interested originally in a gasifying unit to run an engine on, until they realized they could make liquid fuel. The have done in one operation what Jetijs has been saying all along. If you crack PE twice you will get a stable liquid fuel. With their very primitive outfit it is not possible to know exactly what temperatures were involved but my guess would be just over 400C for the first cracking unit and 6-700C for the second.
Francisco Mora, sounds like your experiments are going well, when you say PE and PP do you mean a mixture of the two or did you process them separately?

In the early days of petroleum cracking, Eugene Houdry, the grandad of modern catalytic science, discovered by using Fullers Earth ( bentonite) he could obtain much better high octane fuel. The hi-tech zeolites used by the oil industry today are just highly refined synthetic versions of the clay used by Houdry. Bentonite is commomly available as cat litter.

[abdullah khan]

hi jetijs.... plz tell me the reactions take place in the reactor with chemical equations........ plz m waiting

[islander]

Hi jetijs

Obviously the water inside the layers was the problem. Violent steam production when the molten plastic released water onto very hot surfaces, blowing all the molten stuff out. Possibly this could be avoided if your device was pre-pressured.

[kaguar]

Yeap, had the same problem some years ago. The water being heavier than molten plastic sinks to the bottom and when heated steam pushes the upper layer of lighter material. The feedstock must be well dried before entering batch reactor.
Another point Jetijs. Cling film is usually made of LDPE but there are some sorts made of PVC which could be a complete disaster for your equipment.

[oldguy]

Water in Reactor

Hi Jetis,
Finished my reactor, trying some space age gaskets and have made allowances to hook in a vacuum pump to counter the problem you had. Since LDPE melts a a temp so close to water boiling, don't you think putting a partial vacuum will get the water to boil off at say 60 degrees, eliminating the problem? One drawback would be the necessity for valves on your piping.

[kaguar]

oldguy,
I`ve done it with the vacuum pump and it doesn`t help because by lowering the boiling point of water you lower it for the plastic as well. In my experience vacuum makes it only happen more violently. What I found out is when your feed is wet you need to heat it slowly to about 110C so long as you can hear it bubbling inside. When the boiling stops you are safe to increase the temperature further. Again, this is all out of my experience. Nowadays I use only dry feed.