How to turn plastic waste into diesel fuel cheaply

[rozier56]

rozier56

Excalibur, your reflux vessel! Have you completely filled that chamber with your packaging?
Is that the same one you will use on your new retort chamber as well?
What was the volume of your old retort?
What volume will the new one be at?

[Excalibur]

Excalibur, your reflux vessel! Have you completely filled that chamber with your packaging?
Is that the same one you will use on your new retort chamber as well?
What was the volume of your old retort?
What volume will the new one be at?

The retort and reflux vessels are the same except retort is shortened about 150mm. It has only lost 2 or 3 liters. I think volume was 47L (but only filled to about 80% max capacity). The packing is a job still to be done, probably I'll use light gauge stainless.

[rozier56]

rozier56

Thanks,
So the stainless will be filled in the reflux/distillation column up to 80%?

[rozier56]

rozier56

Has anybody measured the back pressure in their system?Trying to establish residence time required!
Also would like to know the exhaust gas outlet proportion in case we are not liquefying all the diesel we should be and driving some to atmosphere.

[Excalibur]

Thanks,
So the stainless will be filled in the reflux/distillation column up to 80%?

It might just happen to turn out to be 80% because inside the reflux chamber, I want a small gap at the bottom and top.

The 80% figure I was earlier referring to is the retort maximum fill capacity, for safety reasons.

[wheels]

Has anybody measured the back pressure in their system?Trying to establish residence time required!
Also would like to know the exhaust gas outlet proportion in case we are not liquefying all the diesel we should be and driving some to atmosphere.

Back pressure, are you meaning the pressure required to overcome the water bubbler? It depends on the depth the pipe is down in the water. Lets say for instance, the end of the pipe is down at a depth of 4 or 100mm. So the gas has to push that water back out of the pipe and that is the same as if it was 4" / 100mm head of water pressure. That's a mere 0.000145037738 PSI or 1 Pa.

The Residence time... are you heating Plastic or WMO?

Exhaust Gas. In basic, the Hotter you heat the Vessel, the more Gas that tends to be produced. But it does also vary between WMO or Plastic and the WMO depends on what is in the WMO mix. So unless it is just plain Sump oil, then it does become very difficult to know exactly what is going to come out. If the WMO has come from a Vehicle Service facility, then there is a chance that the mix could have Cleaners/ Solvents, Petrol, Transmission fluid and Brake fluid along with the Sump Oil. You do need to very careful with this stuff. It can be highly Toxic depending on what has been dumped. Getting back to the Gas, well as you can imagine, it can become difficult to low and vary between batches, depending on what is in it. With Plastic, it is mostly temperature related. The higher the Temperature, the more non condensable Gases are created. It has been established temperature of around 460 DegC is a Balance point between best quantity of Liquid to Gas and coupled to time of process. Temperatures below 450, the more liquid, the longer the process time and thus more heating energy used. Temperatures above 450, more Gas, less processing time, maybe more energy used to gain the heat, less liquid, so the process is inefficient. Unless of course the aim is to produce Gas.
Did that help?

[rozier56]

rozier

Thanks folks,
When i asked about back pressure measurement, i was wondering if some of you have tested your own system and what sort of levels are out there?
My new system has one way valves and flow meter , no water system anymore due to irregular pressure flows and difficult to control production flows.
My current back pressure related after the condenser is 0.4bar.I intend to vary this with steam pressure valves that are adjustable on the run to determine the best back pressure to achieve max diesel condensation in condenser.Thereby maximizing output in this area.
All my production is done with mixed ldpe/hdpe and polypropylene.

[wheels]

Thanks folks,
When i asked about back pressure measurement, i was wondering if some of you have tested your own system and what sort of levels are out there?
My new system has one way valves and flow meter , no water system anymore due to irregular pressure flows and difficult to control production flows.
My current back pressure related after the condenser is 0.4bar.I intend to vary this with steam pressure valves that are adjustable on the run to determine the best back pressure to achieve max diesel condensation in condenser.Thereby maximizing output in this area.
All my production is done with mixed ldpe/hdpe and polypropylene.

0.4 bar????? !!!!! You sure? That is nearly 6 PSI and that is far too high. Should that figure be millibar?? The pressure should be virtually unmeasurable if you are using "bar" scale. Perhaps your pipe size is far too small or you have a restriction in a valve or a connection that is causing back pressure. As I have stated in my last post, the water allows a backpressure of just a fraction of a PSI.
Pressure needs to be as close to zero as is possible. By increasing pressure, you increase the temperature needed to cause the plastic to vaporize. This slows down the process because you need a higher temp for the plastic to start to release vapor, which means more energy and it takes more time to get to the higher vaporization temp. The cracking also changes. Although just how will be hard to know as it's different due to many variables. But chances are, you will get more Gas and more lighter fractions.
The water also acts as the very last means of trapping condensable liquids, leaving you with a "Clean" Gas discharge.

[Excalibur]

Rozier
Without pics or diagrams it becomes difficult to understand your exact situation so I hope my comments are helpful...
I think a better plan would be to make the diesel condenser much longer. In this way the vapor can be subjected to longer resident times because of the sheer length of travel. In addition use coolant in counter-current style if not already doing so.
My plant runs at up to 1 psi at a guess but only because of the attached gas-jar. Even then the backpressure is relative to the amount of gas in storage. I consider the 1 psi max back pressure a compromise and I'd rather have 0 psi.

BTW, if you run with some means of vapor stream restriction and thereby create back pressure, I think a pressure alarm warning system would be prudent. Should the alarm sound off, at least you'd have an opportunity to remedy and stabilize the situation.

[alejandroramallo]

Hello everyone. Although long ago that I have been following the Forum, and conducting experiments on the subject, my results are not as advanced as many of you. However I wanted to provide a picture and a video of what I have achieved so far. If my English is not good, I ask forgiveness. I am using a translator to write. My language is Spanish.
[VIDEO]https://www.youtube.com/watch?v=0c_zMXGcYyw[/VIDEO]

[alejandroramallo]

This is the picture, which appears to have been no previously uploaded.
Let me clarify that this is the fraction of gasoline, which is where I get higher

[Excalibur]

Hello everyone. Although long ago that I have been following the Forum, and conducting experiments on the subject, my results are not as advanced as many of you. However I wanted to provide a picture and a video of what I have achieved so far. If my English is not good, I ask forgiveness. I am using a translator to write. My language is Spanish.

Great fun. I once run my lawnmower on homemade fuel. It ran well enough to mow the entire lawn however the next time I went to start the engine I discovered the carburetor had gummed up. I hope you don't suffer the same fate.

BTW, it looks like you tried to post a picture, perhaps of your fuel?? The picture is not showing. Please remedy.

[alejandroramallo]

I hope it does not happen that Excalibur. I uploaded a single photo. In the second post, since at first I could not. On my computer, I can see it, you do not?

[wheels]

I hope it does not happen that Excalibur. I uploaded a single photo. In the second post, since at first I could not. On my computer, I can see it, you do not?

No I can't see your Picture either

[Excalibur]

I hope it does not happen that Excalibur. I uploaded a single photo. In the second post, since at first I could not. On my computer, I can see it, you do not?

Only the video is showing. If I extract and follow the picture link, it gives the message: "Invalid Attachment specified. If you followed a valid link, please notify the administrator"
The solution could be to upload the picture to a image hosting site and paste the link in your forum post with [IMG] [/IMG] tags.
See this tutorial