How to turn plastic waste into diesel fuel cheaply

[mindxploration]

There is only one valve in vapor stream just before bubbler. Other valves only close off condenser tanks from vapor stream. Also pressure guages double as vacuum guage and are safety features not requirements, although I think all safety parameters should be considered required. I have two 75 psi blow off valves with sintered flame arrestors, one on retort and second on first condenser tank. These are adjustable blow off valves set at 75 from factory.

[Excalibur]

There is only one valve in vapor stream just before bubbler. Other valves only close off condenser tanks from vapor stream. Also pressure guages double as vacuum guage and are safety features not requirements, although I think all safety parameters should be considered required. I have two 75 psi blow off valves with sintered flame arrestors, one on retort and second on first condenser tank. These are adjustable blow off valves set at 75 from factory.

Nice work! You've always gotta be thinking, what if.. what if, and have a plan.

[wheels]

There is only one valve in vapor stream just before bubbler. Other valves only close off condenser tanks from vapor stream. Also pressure guages double as vacuum guage and are safety features not requirements, although I think all safety parameters should be considered required. I have two 75 psi blow off valves with sintered flame arrestors, one on retort and second on first condenser tank. These are adjustable blow off valves set at 75 from factory.

It's looking flash. I hope you haven't spent too much on it though. While the pressure sensors are nice, they are way over the top for what is really needed. But if they don't cost you much, then it is nice to have as much info of what is happening as possible.
The only thing that concerns me though, are the pressure reliefs settings 75PSI is a lot. Can you turn them down to a much lower setting. You only really need say 10PSI max. or even less. The Retort Vessel will have a significant reduction of it's pressure rating at the temperatures it will be operating at. 75PSI will be pushing it's limit somewhat. Plus Vapor escaping at 75PSI will be dangerous as it will jet a long way and will be at a high temperature. That makes it extremely dangerous to be around.

[sunilkm153]

It's looking flash. I hope you haven't spent too much on it though. While the pressure sensors are nice, they are way over the top for what is really needed. But if they don't cost you much, then it is nice to have as much info of what is happening as possible.
The only thing that concerns me though, are the pressure reliefs settings 75PSI is a lot. Can you turn them down to a much lower setting. You only really need say 10PSI max. or even less. The Retort Vessel will have a significant reduction of it's pressure rating at the temperatures it will be operating at. 75PSI will be pushing it's limit somewhat. Plus Vapor escaping at 75PSI will be dangerous as it will jet a long way and will be at a high temperature. That makes it extremely dangerous to be around.

exactly 10 / 11 psi pressure is more then sufficient actually 300 mm water column ( 11 psi ) is the recommended pressure limit for commercial plants wheels is right it is extremely dangerous to release petrochemical vapour at 75 psi

[Excalibur]

As far as pressure sensors go, I thought a buzzer/alarm on pressure above say couple psi would be effective. Usually I'm too busy to notice a gauge needle. If pressure was as high as that I'd be wanting to investigate because it must equate to some kind of restriction.

[mindxploration]

Thanks guys. I figured 75 psi was bit much that's why I went with adjustable ones. Just set them for 10psi. Also I scored the pair of wika vacuum/pressure guages for 50 Usd shipped and were brand new. Ebay has some amazing scores on industrial parts if you search around.
My retort ran 500 shipped. Thought I'd mention a product I found at local auto parts store, blue magic brand extreme quik steel. Good to 1300c and strength improves with heat. States welds cracks and holes in iron and steel. Can be machined , drilled etc after curing.

[Excalibur]

Wishing everyone best wishes for Christmas and New Year!

I've been encouraged to create a short tutorial video showing in simple steps, posting of photos onto a forum using Photobucket as host. I made this in the hope it would help those struggling with the process. If it helps, here it is:
How to post photos to a forum with Photobucket

[sunilkm153]

: A very happy new year and happy experimenting to all energetic forum members

[rozier56]

rozier56

The diesel we are making from ldpe/hdpe plastics is light yellow in colour when produced.
The product darkens to a dark brown colour very quickly. I think this has to do with sucking up oxygen?. Are there ways to stop this,and will it reduce the diesel performance?

[Excalibur]

Your fuel will be oxidizing and the formation of gum may be noticeable.
Butylated Hydroxytoluene is at least one antioxidant believed to work.
I'm not aware of any power loss however if gum restricts vehicle fuel flow then of course some power loss will result.
IIRC, petrol/gasoline is more likely to suffer from oxidization and gum. Good distillation practices are said to keep gum to a minimum. The fuel should be stored in cool environment (and it might be darkness was desirable to).

[rozier56]

rozier56

Thks Excalibur.
Some plants are producing product that sits at 0.78-0.79 on the hydrometer reading.When you increase the temp range very slightly you start to produce wax. This is confusing as when you look at normal crude oil distillation plants the process shows production as diesel[heavy molecule] first ,then parrafin and petrol later at cooler temps?Any reason way we different?

[Excalibur]

rozier56,
The wax is a clear sign that uncracked hydrocarbon is passing through the reflux. Ordinarily, heavier weight hydrocarbon will condense in the reflux and run back to the retort. In this way light and heavy is automatically separated.
There could be a combination of factors causing wax. You should consider all the plant parameters as a fine balance, vessel size, applied heat, temperatures etc.
Possible causes: reflux not effective enough to deal with the volume of vapor. Reflux temperature too high. Retort temperature too high or too much applied heat causing the reflux to be overwhelmed.
Crude oil and plastic are both hydrocarbons so the same laws of physics apply.
If your burner has just one power setting, I suggest work out a way where the flame temperature can be turned down once the retort reaches target temp. In this way you can match the flame temp to actual retort requirement.

[rozier56]

rozier56

Thanks for your response.
I think my problem could be my reflux column."Beyond" once suggested the reflux should be approx 70% of the retort size. My current plant has capacity 250 lt in volume and the reflux has only 30lt by volume. I think i need to make the reflux volume around 90lt/volume. This will create less forces/gas been passed through and make the system easier to control.
Excalibur, out of interest ,what sort of capacity volumes do you have when comparing retort and reflux?

[Excalibur]

The exact vessel sizes are quoted on the respective pages of my DIYDiesel blog. I think they are within the region of about 1/4 to 1/5. Yours is closer to 1/8 which is a size I've not tested. You could also try separating the two vessels with a short length of pipe, I used 3"( see blog pics).
You could also try bringing the retort temperature up in stages. On my rig cracking WMO I start by bringing the temperature up to 380° then reducing the flame heat so as just to tickle the vessel contents. If I get product flow I hold the temperature there for a while. Then I increase a few degrees and reduce the flame again to tickle the contents at the higher temperature. Then I go higher, step by step. In this way the lighter fractions are lifted off progressively. This avoids boil-over.
It's normal for the reflux to lag behind retort in temperature because it requires flow of vapor to raise its' temperature. I add or remove insulation to/from the reflux to help control its' temperature however I keep the retort pinned at its' own temperature target irrespective of what the reflux is doing.
So at the beginning I might have the reflux fully wrapped with insulation but at the end I may have removed some/most.

[rozier56]

rozier56

Thks Excalibur,will make the changes and observe.
How long does it normally take you to get to your desired temps in your retort?