How to turn plastic waste into diesel fuel cheaply

[WALMAR]

Tar problem

Hi
I must say thanks to Jetijs , for his video on youtube that brouht me here to all the "experts" on diesel !!

I' am making +- 200 liter of fuel a day with all your plans , and using it my
self with my courier company.

The question I've got , is there a way to reduce black tar like compound in fuel?
Fuel is bright yellow when coming out of condensor , but when it goes through
centrifuge turns dark, because of reacting with oxygen.
Is the colour in the fuel darkening because of tar?
Is the centrifuge making more tar in the fuel?

[toomuch]

Too much diesel!

WALMAR, Great! Awesome to hear, that is more the scale I would consider building. There has been much progress in the direction discussed throughout the event of this tread, I feel I would need to take thorough notes throughout a study of the last six months experiments undertaken here, and this over whelms me. I have spent about 12 hours reading the computer screen here and am very great-full for all the shearing of this simple yet revolutionary technology, it is as if characters here have become people I am familiar with as friends. Some of you guys have put so much of your time throughout the course in-to helping others openly in this humain direction via this thread, this is notably noble. It is known, the best way to attaining knowledge is from a person who already has an understanding in the desired topic, and further to this, one may progress in the given direction by entering at any level with-out necessity of study through the trials of their teachers. I hereby submit a humble request for a summary from somebody who is successfully producing meaningful amounts of fuel per day. Perhaps a clear photo or two with a simple explanation of the process would be fine? It may appear that I am trying to get a diploma without the study, however I intend to keep up the study on the above topic. I am eager to start on a pyrolysis project as soon as I feel confidant enough in my direction. What I don not wish to do is overlook design aspects to find my self tracing footsteps. Would a master in this please kindly post here or e-mail me pics and any detail you care to share, I am happy to make a call if I have a phone number area/country code etc, to discuss. A summary of the best found things to do. A diagram plan would be a great way to pass on this information and would be much appreciated. God bless.

[blackchisel97]

If you melt your sample with a soldering iron, if it has a sharp smell and leaves black residue, it is most probably PVC - do NOT use that. If it has a terible smell and tends to bubble a lot when melting, it is most probably PETE - also NOT good. If it does not bubble, leave black residue where it was heated and does not have a too sharp or terrible smell, it is probably PP or PE and is good for making a good quality fuel.

In fact I have made a basic presentation with all the basic info needed about the material types, pros and cons and yield numbers. Here is a link:
. File Upload, sharing and hosting. Serviss failu, foto un bilžu glabāšanai vai apmaiņai

it will be active for two weeks only

Thank you Jetijs, very nice presentation . I'm gathering parts and hopefully will get my unit done soon. I was going to use custom made propane burner which will have 4 vertical elements as well as bottom part. The idea was to distribute heat all around the reactor vessel not just the bottom. There is a second idea to use modified oil furnace to heat vessel. I have thick wall steel tank, approx 100 L capacity and oil furnace. I think the oil furnace with its burner would make such unit self sufficient since it can run on the product.
I was thinking to have an outlet from the reactor coming near the top but off its side. This would save the trouble with uncoupling pipes every time to load the substrate in.

Cheers
Vtech

[WeirdoC]

I just joined the forum last night when I found this thread. I was up until 3am trying to power through all 44 pages of material on this thread, but had to give up and go to bed somewhere around page 32. I logged back on around 1 this afternoon to finish it up.

Of course, I have LOTS of questions, but I have also learned a tremendous amount, especially from Jetijs and imakebiodiesel. My first question is directed toward the latter.

160 degrees C is a good divider between diesel and kerosene. It produces a slightly "heavy" diesel with good lubrication qualities. My crude fuel contains only 5% petrol/ white spirit etc so I dont separate it from the kerosene. Asad could help with the figures for these volatiles.

We know from readily available literature that the diesel fraction produced by industrial fractional distillation is precipitated in the range of about 200 to 300 degrees Celsius. You have mentioned before that you maintain your head temperature on your catalysis/reflux chamber between 180 C and 220 C. So, your widest possible temperature range for diesel condensation is 160-220 C. it would seem that this should be producing an exceptionally light diesel/kerosene/naphtha, rather than a heavy diesel as your are actually getting.

Could this apparent discrepancy have something to do with the relatively low retention time and limited recirculation of hydrocarbons in the condenser system? That is, perhaps the system requires lower condensation temperatures because it does not produce the level of stratification and constant re-evaporation that is achieved in an industrial fractionating column?

[Excalibur]

Hi, I joined the group a while ago and have been reading, learning and gathering parts. Also acquired some polyethylene granules.

The materials cost nothing so I assembled a simple test rig to prove the theory to myself and just to make a start.



Inside the 200L drum is a 9KG lpg propane cylinder which is the sealed reactor while exiting gases are forced to bubble through water in the 20L plastic container.
So to the experiment. My thermocouple started out reading OK, then decided to get eratic so I continued without.
At first regular bubbles appeared though I had to get the fire quite hot. I ran for over an hour, though toward the end the bubbling stopped. I decided to stop in case there was a blockage. I expected more oil to come out but am not sure if what I'm seeing is the residue from the container. I know I should have cleaned it out but I expected more gas and oil condensing.
Looking back, I'm thinking the drum should have some insulation and I need a replacement thermocouple.
Any thoughts please? Should this have worked?
Thanks

[imakebiodiesel]

Its impossible to give exact temperatures that will work for every situation and mix of plastics so dont follow my advice blindly, just use it as a guide. I use a lower temperature at the column head because I find it prevents the formation of waxes but that may not work with a different size and shape of reflux column. The temp of 170C at the first condenser is to separate the diesel from the kerosene.
The diesel produced is actually quite heavy and has an oily feel between the fingers. When changing between my diesel and ordinary low sulphur diesel you can hear the engine running quieter and smoother. I recently had my car tested for exhaust smoke content and found that my diesel produced marginally less smoke than ordinary diesel.
My son Ruairi who has been working with me on the project, entered our small reactor into the Isef science competition and made it through to the finals. We travelled from Ireland to Pittsburgh USA to compete in the finals and he won a second place in his section. We and his school are very pleased with this result.
The apparatus above, although crude, should work. How much plastic did you put in and how much wax/oil did you get out?

[Excalibur]

Thanks for the reply.
As you say it's crude though I was only wanting to prove the concept at this early stage. The reactor vessel itself is about 15liter and I filled it two thirds.
I got no oil out, though there was a reasonable amount of bubbling through the water in the condensing cubie.
This morning after it had cooled off overnight, I noticed all the water in the condensing bubbler had been drawn into the reactor vessel. I suppose the contraction caused that. The plastic inside the vessel had gone from granules to a solid mass. So I'm guessing that the temp wasn't high enough and/or long enough. Sadly the thermocouple stopped working so I don't know much about the range it was in. The flue could have been bigger for more draw on the fire. For all the smoke and flame, I didn't think the horizontal pipe leading to the condensor was hot enough. Indeed on the far end it was cool-ish to the touch. I want to get a probe thermocouple this time instead of the tiny sensor type. Then I'll drill and mount the probe to monitor internal temps. Is that recommended?
Thanks
I have 8-9years+ experience will vege oil and other oil types as alternative diesel fuels.

[farmerboy]

mixing of various types of plastics

Halloevery one
I intend to collect used plasptic at the local land fill site. However this is normaly not very clean and also a mixture of different types of plastic. I think the PVC and PET might not be too difficult to seperate, but will the soiled plastic be OK to use in my reactor?
Secondly, I would like to use a waste oil burner instead of electric elements. Any one with ideas how to achieve this? (temp controle and placement of the burners)
I would greately appretiate any help.

[Excalibur]

use a waste oil burner

Yes, that's what I was looking at doing too. My first thought is to use some of the fuel made and squirt it through fuel injector nozzles. Most cars these days have such nozzles and can open/close on electrical signal. I have a number of these in the shed even now. In addition the pressure, often 40psi can be varied to suit. All this controlled by a thermostat of some kind, perhaps as simple as bimetallic contacts. No doubt there's modern electronics available off the shelf nowadays, perhaps look at furnace thermostat controls?
Using a variable fan to blow air into the hearth would seem a good step to increase efficiency.
Just a few thoughts...

[imakebiodiesel]

You almost certainly did not get it hot enough. You must get the reactor up to 385 degrees C. A good temperature sensor is essential. There is a very good stainless steel probe about 6 inches long with a 3/8 npt thread for sale on ebay for about 5 euro and you can also buy a K type digital thermometer from hong kong for about 5 euro. Although ridiculously cheap these are accurate and reliable.
A larger flue, perhaps with a damper fitted would be better and replace the bend above the water container with a tee and a valve. That way when you are finished you can open the valve a crack to prevent the water being sucked back into the reactor. This is potentially very dangerous because if the reactor had been at full temp it would have exploded when the water was drawn in.

There is no problem with the plastic being dirty or wet. Any water will boil at 100 degrees C and will purge air out of the system. It may collect in your condenser but it is easy to separate from the fuel with a water block filter. Dirt will simply carbonise and add to the char that is left behind in the reactor at the end of processing.
Using waste motor oil to power a reactor is feasible if a little difficult to control. Have a look at an oil burner under the name of Ozzirt Waste oil Burner on U tube.

[quintusk]

http://www.fao.org/docrep/010/ah810e/AH810E119.gif

If larger diametre pyro chamber is used this problem will not occur, or using less of plastic in it.

WMO may help too by lowering the viscosity of the molten mix, i guess. It will be more liquid than cream/honey like, and will stay on the bottom.

[Excalibur]

You almost certainly did not get it hot enough. You must get the reactor up to 385 degrees C. A good temperature sensor is essential. There is a very good stainless steel probe about 6 inches long with a 3/8 npt thread for sale on ebay for about 5 euro and you can also buy a K type digital thermometer from hong kong for about 5 euro. Although ridiculously cheap these are accurate and reliable.
A larger flue, perhaps with a damper fitted would be better and replace the bend above the water container with a tee and a valve. That way when you are finished you can open the valve a crack to prevent the water being sucked back into the reactor. This is potentially very dangerous because if the reactor had been at full temp it would have exploded when the water was drawn in

Thanks. I agree it can't have been hot enough and temp sensor is a key to knowing what is really going on. I have a new replacement k type sensor on the way from Hong Kong which should be here by next week. A larger flue with damper will be made. I should have a 4inch pipe for this in the steel rack. The valve idea to vent after finishing is an interesting idea and easy enough to implement. I hadn't thought of the danger aspect in quite that way.
All good thoughts, thanks.

[WeirdoC]

I think the PVC and PET might not be too difficult to seperate, but will the soiled plastic be OK to use in my reactor?

To add a little to what imakebiodiesel said, any carbon-based material you place in the reactor should pyrolyze. Most organic (carbon-based) materials are high in carbohydrates, and will break down into several basic components when they are pyrolyzed: H2 (diatomic hydrogen), CO (carbon monoxide, which is highly toxic to humans), carbon char, and a small amount of CH4 (methane).

The H2, CO, and CH4 will all be flammable, non-condensable gasses. Any gasses that come out of your bubbler will include the flammable byproducts of any contaminants that were included with your plastic feedstock. You should either be flaring off any byproduct gasses after your bubbler to keep them from entering the atmosphere; or, better yet, you should be burning the gasses in your combustion chamber to help increase the overall efficiency of the system if you can build the system to do so safely.

Also note: I am speaking theoretically from my understanding of the process, not from actual experience.

[Excalibur]

The H2, CO, and CH4 will all be flammable, non-condensable gasses. Any gasses that come out of your bubbler will include the flammable byproducts of any contaminants that were included with your plastic feedstock. You should either be flaring off any byproduct gasses after your bubbler to keep them from entering the atmosphere; or, better yet, you should be burning the gasses in your combustion chamber to help increase the overall efficiency of the system if you can build the system to do so safely.

Also note: I am speaking theoretically from my understanding of the process, not from actual experience.

Thanks for bringing this aspect up about burning off the gases. Given the flammable/explosiveness of these, is any flame trap set up required?
The burning off of gases as recycled heat for the reactor is such a good idea.
I've wanted to do this but was cautious about flame travelling up pipework.
Part of me says there's not the oxygen to burn the gases in the pipes and it needs to exit in order to do so. Please advise of any general/special precautions. Thanks.

[blackchisel97]

Thanks for bringing this aspect up about burning off the gases. Given the flammable/explosiveness of these, is any flame trap set up required?
The burning off of gases as recycled heat for the reactor is such a good idea.
I've wanted to do this but was cautious about flame travelling up pipework.
Part of me says there's not the oxygen to burn the gases in the pipes and it needs to exit in order to do so. Please advise of any general/special precautions. Thanks.

Simple spark arrester made with steel wool inside the pipe is the cheapest option but to be 100% safe I would make a bubbler, where non soluble gasses enter through the pipe immersed in water. Output collector pipe needs to be above the water surface.
An old water filter could be modified for such -

Vtech