How to turn plastic waste into diesel fuel cheaply

[rozier56]

rozier56

The retort temp's sit at 325*C to 330*c.
The plastic is ldpe and hdpe pellets and shredded.
We test samples from beginning of production for flammability as we work. paraffin and petrol produced will flame when ignited. Diesel wont burn, so when we achieve this we check hydrometer at 20*c sample and waxing.
My retort size is 310 lt and the reflux 96 lt.
The burner is a 28 kW/HR. This burner is auto controlled to switch on and off at desired temp, either at retort or reflux settings.
It takes me 2,5 hrs to reach desired temps, ie,280*c in reflux column measured at top of column.

[wheels]

I have a machine burning waste plastic shreds.When we reach temp of 285*c we produce product of 0.78 on hydrometer.
We increase temp by 1*c and it starts to wax when cooled too 20*c.
Just cant get to the 0.80 on hydrometer to clear as diesel.
Any idea's?

What temperature are you testing the Fuel at?
I am not sure why you want to test SG. It tells you very little, if anything at all. But SG of Fuel and Oils is measured at a Temperature of 60degF/15.6degC. What will probably be more important to you is the Viscosity.
What Plastic stock are you using? That is more important re what range of Hydrocarbons are produced. Also making the Retort hotter is going to produce lighter weight fractions, thus the SG is going to be lighter, not heavier. You probably want to decrease the temperature and see what you get, rather than increase it.
What size is your reflux vessel and are you using any form or Catalyst? You need to play with both those area's. If the heavy chains stay too long in the reflux, or cycle too much, they may break down too much.

[Excalibur]

Is the 285°C temperature recorded at the reflux tower? If yes, then what is the simultaneous retort temperature?

How many KW is the burner? or liters per hour?

[rozier56]

rozier56

I have a machine burning waste plastic shreds.When we reach temp of 285*c we produce product of 0.78 on hydrometer.
We increase temp by 1*c and it starts to wax when cooled too 20*c.
Just cant get to the 0.80 on hydrometer to clear as diesel.
Any idea's?

[Excalibur]

Excalibur,
Do you control your burner switching on/off from your retort temp controller,or from your distillation control?
Is your retort temp probe measuring liquid content or the gas above the liquid?
Thks.

The burner switches according to retort temperature. The burner does not switch off completely, it toggles between power mode and idle mode in response to settings of the controller. Both power mode and idle mode set points are individually adjustable with a screw stop on the burner itself.
Retort probe measures the liquid temperature. There is an additional probe at the top of retort in the flange but it only monitors temperature on a display for the operators' information.

[rozier56]

rozier56

Excalibur,
Do you control your burner switching on/off from your retort temp controller,or from your distillation control?
Is your retort temp probe measuring liquid content or the gas above the liquid?
Thks.

[rozier56]

rozier56

Hi Excalibur,are you available on skype?
My SKYPE is derek.cornish2.

[Excalibur]

I'm still here..
Waiting for diesel prices to go astronomical again. It's the calm before the storm.

Ha! I've always wanted to use this smilie

[rozier56]

rozier56

Hi FOLKS,
Are you guys still out there?
No query's or responses for a long period.

[Excalibur]

with the chemical mixture, is there a formula similar to diesel fuel?

Diesel does not have a specific formula because it is not a single compound. Instead, diesel is made of a mix of saturated hydrocarbons and aromatic hydrocarbons.
Diesel is about 75% saturated hydrocarbon and 25% aromatic hydrocarbon. The average chemical formula for common diesel is C12H23, ranging approximately from C10H20 to C15H28.
Hope this helps else rephrase or elaborate the question.

[kedigen]

hi everyone

with the chemical mixture, is there a formula similar to diesel fuel?

[wheels]

Yep, will light it up (heavily diffused if I remember correctly).
I have a lead on some oil I can get (will find out more info tomorrow). It has ammonia in it. Sometimes enough to hit you in the face when you take the lid off, sometimes not so strong. Are there any issues with ammonia in fuel? Any issues with ammonia at high temperatures in a retort? Maybe I should just blend it?
Col

BE CAREFUL!!!!
Ammonia is an interesting compound. The number of other Chemicals it will react with is vast. Because Waste Oils can contain all sorts of things, you never really no what possible reactions and by products could be produced. Leaving aside the fact that Ammonia itself is deadly, many of the resulting Chemicals that can be created can range from Nitric Acid through to many other toxic gasses.
Interestingly Ammonia is used in the Oil refining industry. But that doesn't make it useful for us as it is used in a very specific and controlled way that we can not duplicate.
It's toxicity to us is interesting. Our body actually produces ammonia, so it is not specifically poisonous to us. However, it is still highly Toxic to us. It quickly accumulates in our Blood and only a very very tiny amount can cause us to lose consciousness, enter into a Comma and even death.

[Excalibur]

Sounds like refrigerant waste oil. I've had ammonia in oils in the past. I'd try venting it off before doing anything else. It has a boiling point of -33.34 °C so should lift off at ambient temperature.
Another thought is I've had situations where the same oil was holding water in suspension. I thought the oil may be engineered with water absorbing additive. Not sure. If it's the case it wouldn't suitable for constant feeding a retort until the water was removed.

[Col]

Ammonia in fuel

Yep, will light it up (heavily diffused if I remember correctly).
I have a lead on some oil I can get (will find out more info tomorrow). It has ammonia in it. Sometimes enough to hit you in the face when you take the lid off, sometimes not so strong. Are there any issues with ammonia in fuel? Any issues with ammonia at high temperatures in a retort? Maybe I should just blend it?
Col

[Excalibur]

Yep. Good work.

Because the glass needs to be removed from time to time for cleaning, one other thing I did was to fit short lengths of hose over the bolt shanks adjacent to the glass. This helped centralize the window and made nipping the bolts up easier. Just a thought that might help..

Recently I fitted a LED light to outside of one sight glass. The effect was great, especially after dark. I'm a great believer in observing the quality and quantity of the condensate stream as a live indicator of plant health.