How to turn plastic waste into diesel fuel cheaply

[ashiki]

Kaowool is good to 1200'c or so.

Thanks excaliber,infact it was a misunderstanding and what we bought was not glass wool but something else(a small scale insulator),and im gonna get wool immedietly.

[lowriderzzz]

lowriderzzz

The purge gas is put into the retort by going from a high pressure to a low pressure. You use a tank filled with nitrogen or co2 and hook a hose up to the gas inlet to your retort. If you want to use a rubber gas hose make sure you have an extension pipe coming off of your retort otherwise the rubber will melt.

The oxygen may flow out naturally but that isn't something you want to take a chance with.

Yes water would evacuate any air in any close container once it's heated to 100c or above and turned into steam.

Continuous feed is tricky and I would suggest you start out with a batch reactor.

I noticed in your picture that you don't have a way for the off gases to be vented. I could be wrong and it's just not visible in the picture. You need a way for the gases generated from your retort to be released. Otherwise you're going to have a big pipe bomb on your hands.

I don't wish to reveal the catalyst I use. It has taken me months of research and testing to get to where i'm at. I would suggest using some perlite or broken clay pots for your catalyst.

Yes I'll take care for the off gases as well. I still don't have the bubbler ready, but I'm working on it.

Perhaps will start with batch type as you recommend. How much time you think it will take to convert 5 kg feedstock into fuel. I mean how long the whole process should be ?

Thanks.

[lowriderzzz]

I think you should start with insulation on the reflux. As temps come up to target, then progressively remove the insulation. It may be on the large side but try it first.


380 - 420'c for the retort, don't rush it. About 300'c for diesel at the reflux and tweak from there.


Yes, I used 6mm blind tube and slipped in the tiny thermocouples. Worked well.


I worry about the small pipe size.

Best to fit the reflux directly overhead of the retort with a single pipe. This will ensure the reflux can work correctly and so distillate doesn't pool in the bottom of the reflux.

Threaded pipe joins at retort/reflux will need a high temperature sealant. Thread tape etc will burn out and leak!.

Thank you for the feedback. I'll take into consideration all of what you say and do the necessary modifications.

[mjohnson1]

Yes I'll take care for the off gases as well. I still don't have the bubbler ready, but I'm working on it.

Perhaps will start with batch type as you recommend. How much time you think it will take to convert 5 kg feedstock into fuel. I mean how long the whole process should be ?

Thanks.

If you are using a purge gas and aren't burning your off gases you don't need a bubbler.

It will take ~3 hours to convert 5kg feedstock into fuel once the retort is up to temperature. I run mine at 450C.

[lowriderzzz]

If you are using a purge gas and aren't burning your off gases you don't need a bubbler.

It will take ~3 hours to convert 5kg feedstock into fuel once the retort is up to temperature. I run mine at 450C.

thanks one more time. How big is your unit btw? Do you have an image online of it ?

[mjohnson1]

This is my catalyst testing setup as of now. Very simple and made out of pipe fittings with a few welded additions.

Testing reactor used for 100 gram plastic samples-




Outlet pipe for fuel to come out of. Has a steel box welded on the outside that is water tight and I fill it full of ice water. Also has a piece of stainless wool in there to make sure things condense.



Plastic shredder with temporary wood hopper. Works great for HDPE/PP.



Here's the shredder I purchased-

[lowriderzzz]

nice pictures

@ mjohnson1

nice pictures (pretty large though). So your experimental unit is way smaller.

[mortimer.dan]

Hello All

Dear All,

Great information all 92 pages of it, what a marathon read yet so informative. I miss assads input, he was/is wise and very clever. I see via the Aston links that this technology is becoming more widespread and the fact the military are interested means to me that its going to be become the norm in many respects for the future. It seems to me that collectively this forum holds knowledge that most people can only hope to gain by going to university to study. Myself I have decided to try and get the local recycling company to make a unit instead of shipping the local plastic waste to china via container. I am also very interested in cow manure and possibly pine needles/cones and woodchips as New Zealand where I live has lots of these. The Cow crap is a really bad polluter of the countries water ways, dairy farming is huge and big business out here. It seem that a continuous feed system is the way to go. I have a lot of questions but I will post them slowly. The first simple question is, to ask anyone with a working pyrolysis machine/system if they would be prepared to have a go with cow manure only?.

My gratitude regards this forum extends to jetsis of course and all senior and junior members for the wealth of knowledge and information, safety measures and down right common sense approach to a simple yet difficult process. Thanks Dan

[imakebiodiesel]

Cow manure will contain a high percentage of water(80-90%) which will use a lot of energy to boil off. The manure itself will yield a very small amount of pyrolysis oil (10-20% of dry weight) and some syngas. Im afraid pyrolysing cow manure will use up a lot of good quality energy and yield a small amount of low grade fuel. Composting or a methane digester are better low energy options.
Pyrolysis is only going to be viable with feedstocks that contain very high hydrocarbon content, plastics, waste oils etc.

[fibuslitero]

Thanks for sharing Mjohnson1, you are working hard with your setup.
Did you buy online that shredder?.
I saw it on youtube, can be very useful but please be extremely careful specially when unblocking.
Regards.

[wrtner]

I am not follwing this thread closely and so, this may be redundant but....

The pics make it look as if you are runnng equipment indoors. If the gear leaks, possibly as a result of a gap caused by thermal expansion, you may get gases which are :

1. deadly poisonous and/or

2. highly inflammable or explosive.

If you must function indoors, it would be good to have a couple of those 15" office fans blowing air from inside, through the room, to outside.

[mjohnson1]

fibuslitero

I did buy the shredder online from a gentleman named Marcus. He's from germany. If you search for mini shredder or diy shredder on Google you'll be able to find his Facebook page. I hooked it up to a 3 phase motor and had to use a phase converter for the 220V single phase power in the garage.

I always feed plastic using a pair of plastic tongs and unplug/shut off the breaker when removing stuck plastic.

wrtner

I don't run this indoors always outside a minimum of 30 feet away from any flammable objects with water and a fire extinguisher nearby.

[Col]

Cyclone

Is the jury back on the cyclone concept? Is anyone actually using a cyclone currently?

[lowriderzzz]

fibuslitero



I always feed plastic using a pair of plastic tongs and unplug/shut off the breaker when removing stuck plastic.

How big the shredder pieces come out with this type of shredder. We had those in much bigger scale in the incinerator at cruise ships I used to work on, however it didn't cut the waste to small pieces but just sort of smash and compressing it, making it less bulky.

Do you this one will be suitable for cutting flexible plastic into small pieces that could be further used for continuous feeding?

[imakebiodiesel]

The cyclone separator is for removing dust particles and is used in syngas generators because there is a considerable amount of ash and dust carried along in the gas. When pyrolysing plastic the feedstock is liquid and little or no ash or dust is produced. I have never needed to clean out the top of my retort or pipework after more than 70 batches of plastic.
I dont know if this is the same for WMO as I have only done a couple of small batches but Im sure BB or someone else can comment on that.

Ive come across a book that will be of interest to anyone considering building a granulator/shredder for waste plastics. Its called Small Scale Waste Plastic Recycling by Jon Vogler. It it aimed at projects in the developing world and takes a very low tech approach. There is a chapter on building your own granulator/shredder with drawings and text. Two models are explained and could be constructed by a workshop with basic welding and fabrication facilities.
The book is available on line, do a search for Pla-vogler_ebook.pdf and you should find it.