How to turn plastic waste into diesel fuel cheaply

[Beyond Biodiesel]

I dont know the Mypin controller but is it possible that it has an AC signal output? I see that all of your ssrs are DC signal inputs.

Thanks, I tried both AC and DC SSRs, neither worked, but it is a good call.

I happen to be running everything off solar panels and a modified sine wave inverter, so maybe it is the inverter that is the problem for the Mypin controller. So far, if that is my only problem, then I can do without the Mypin controller, because a true sine wave inverter of 3 KW is lots of $$$.

[waterboost]

Reflux Column

Hello Everyone, I've read all the posts and I am eager to make a some oil from plastic, specifically diesel. I was going to start my 'research' by playing with oil drums so I bought two off ebay locally.

When I went to collect them I fell in love with a Nitrator. After much research and haggling I found my own Nitrator, probably 60 years old but stainless steel and beautiful.

I day of cleaning and I'm just waiting for the paint on the legs to dry...

It will soon have a manifold to bring the two flu pipes into one and inside it will have the sealed chamber (10" x 21") with access from the top using a 5" stainless boss with the rubber seal removed and replaced with glass fibre fire rope.

The exterior of the Nitrator has a sealed pipe going inside to monitor internal boiler temperature.

I was going to run it on waste oil but after reading the posts on this forum I have opted for propane for controllability.

The Nitrator is also jacketed giving me the option of hot water in abundance

The main issue now is deciding how to approach the reflux column, cooling and collection. I have clay balls and zeolite for inside the column and I plan to have two temp gauges, one at the top of the column and one at the bottom. Is it correct that if I want Diesel I need the top of the column to be no more than 200 degrees?

If the reactor is 350 degrees C and the column is 200 C where will the wax condense?

If these arent the right questions please could someone advise?

[waterboost]

Reflux Column

I've done a sketch of my reflux column design.

I thought the catalyst should be inside the retort where it is hot

sorry about the sketch, I prefer the back of a beer mat

[waterboost]

Other bits

I thought I would include a few more bits... keep them all together

The pyrolysis chamber bolts onto the Nitrator (see below)

The 3" pipe will go directly to the high pressure filter trap (see below) and then any remaining gasses will be condensed through the 100+ litre indirect heat exchange coil in the copper cylinder shown below...

I havent chosen my final collection vessel... and then any remaining gases go back to the fire....

[imakebiodiesel]

Your reflux looks about right, I would move the catalyst up to the middle of the column, the zeolite will be very prone to coking that low in the column. Cracking of pe and pp starts around 385C so you will want higher temps in your retort. To get full conversion I find I have to push the temp up to 410 towards the end of the batch. 200C is way too low for the top of your reflux. If you set it at 260 you will get only middle distillate ( kerosene). I would try about 330C to begin with and adjust it from there as you need to.
the idea of the reflux is that uncracked ( or not fully cracked) hydrocarbons will condense in the column, flow down back into the retort and be cracked again. That way there should be no waxes.

[Heartburn]

Yes, I found out first hand how dangerous/toxic HCL gas is, and how effective a bubbler is at handling it. I just direct the water from my water jacketed condensers to the bubbler so that it has a steady flow of water, the water flowing out of the bubbler goes right to the sewer. i figure it cannot be any different than the chlorinated water that the municipality feeds us.

Well it is acidic where as chlorinated water is not, and it is hard to know how the HCL will react if at all in the sewage.

It might be worth looking at recycling the HCL to compliment the process, but I am also all for keeping my system simple and reducing its toxicity and corrosives.

If your already burning the uncondensed gasses your half way there.

[Beyond Biodiesel]

It will soon have a manifold to bring the two flu pipes into one and inside it will have the sealed chamber (10" x 21") with access from the top using a 5" stainless boss with the rubber seal removed and replaced with glass fibre fire rope.

It all looks good waterboost, but glass fibre fire rope will not work as a seal. Do look into Garlock Metallic Gaskets, or graphite gaskets for your retort, because they are designed for sealing flanges for high temperature applications.

Well it is acidic where as chlorinated water is not, and it is hard to know how the HCL will react if at all in the sewage.

The HCL will be heavily diluted as it leaves the bubbler, as long as the bubbler has a steady flow of water, so it is not likely to pose an environmental hazard.

If your already burning the uncondensed gasses your half way there.

I have a burner, but nothing seems to burn in my exhaust. It could be because I have an ice trap, which traps out the light fractions.

[Beyond Biodiesel]

Seals and gaskets for high temperature applications

For those who are interested I just started a thread on my forum for Seals and gaskets for high temperature applications to make it easier to find information on this important subject, which comes up regularly on this subject.

[Heartburn]

The HCL will be heavily diluted as it leaves the bubbler, as long as the bubbler has a steady flow of water, so it is not likely to pose an environmental hazard.

I agree

I have a burner, but nothing seems to burn in my exhaust. It could be because I have an ice trap, which traps out the light fractions.

Even with an ice trap you have butane, propane and such but if your craking just right you would not have much.

the simplest way to use the HCL is to supplement the burner with hydrogen.

No need to say this is highly explosive gas so much care is needed and a check valve close to the burner and a screen is a good idea to reduce risk of accident.

Anyway, by adding aluminum to your bubbler the HCl will react with it and release hydrogen. This is important, if you put aluminum is hydrochloric acid, it is slow to start, but reacts violently. So make sure you have fresh cut aluminum in there to give the reaction a clean start point. As the HCL is diluted in the water it will slowly react and keep the reaction low. As for the water input, you only need to keep the level high enough to keep the gasses bubbling.

If you just want to reduce the water waist you can add baking soda to the bubbler (NaHCO3). It will neutralize the HCL and release CO2

[Heartburn]

I was wondering if anyone processed "dirty" plastics. Basically strait from the garbage bin to the retort without cleaning.

How about WMO contaminated with antifreeze ?

[mjohnson1]

I was wondering if anyone processed "dirty" plastics. Basically strait from the garbage bin to the retort without cleaning.

How about WMO contaminated with antifreeze ?

I've processed dirty plastics before without any problems. Labels, residue, food etc not really a problem. It just leads to more coke.

I don't process dirty plastic containing chemicals like bleach, detergent, etc though I always wash those out.

[Heartburn]

I've processed dirty plastics before without any problems. Labels, residue, food etc not really a problem. It just leads to more coke.

I don't process dirty plastic containing chemicals like bleach, detergent, etc though I always wash those out.

Have you ever run a batch that was not cleaned out of chemicals ? I knew that you can run organic matter through but residual chemicals can have serious side effects. Some contaminants will exhaust with the uncondensables, but will the rest contaminate the fuels ?

Humm kinda answered my self there didn't I

Maybe a better question is can we detect a contaminated batch of diesel or gas and avoid running it in the car/truck ?

[imakebiodiesel]

If you are going to use your fuel in a vehicle, especially a modern common rail diesel, then you would be well advised to test each batch of fuel before you put it into your tank. A replacement injection pump can cost the same as a years fuel so its not wise to take risks. There are several tests that you can carry out with only minimal equipment.

Water content test.
To measure water content accurately in fuel you will need to assemble a Carbide manometer. About 30 euro will cover the parts. I invented this device about 4 years ago and Im pleased to say that it has become the standard test used by biodiesel makers all over the world. See the video below to see how it works.
carbide manometer video.wmv - YouTube

Specific gravity.
Low sulphur diesel has a specific gravity of 0.845. Pyrolysis diesel is lighter because of the lack of aromatics but should still measure above 0.800. A lower figure would indicate a greater than normal light fraction. Too much light fraction can cause damage to injectors by pre-ignition and also lack of lubrication leading to excessive wear in the injection system.
To test specific gravity simple accurately weigh ( in grams) exactly one litre of the fuel and divide by 1000.

Flash point test.
Half fill a tin can with fuel. Measure the temp with a thermometer. Pass a blow torch flame quickly over the top of the can. If the fuel does not ignite heat the fuel up by 10 degrees with the blow torch and repeat the flame test. Continue until the fuel ignites. To put the flame out place a plate on top of the can. Diesel should not ignite until it is in the 80 - 90C range. A lower flash point will indicate too much light fraction.

Acid number. PH strips and PH meters only work in aqueous solutions. Hydrocarbons will give a faulty reading. To measure the acidity of a fuel it is necessary to perform a simple titration. You will need a small amount of isopropyl alcohol with a pinch of tumeric dissolved in it as an indicator and a some solution of potassium hydroxide dissolved in distilled water. Exactly one gram in exactly one litre.
Half fill a small shot glass with the indicator and using a syringe add exactly 1ml of your fuel. Stir with a plastic stick, an old pen will do. Now fill another clean syringe with the potassium hydroxide solution and add it drop by drop stirring all the time. Stop when the yellow colour turns red. note the number of ml you have used. this is the acid number. A result of more than 1.5 would be of concern. If the fuel is acidic it may be contaminated by chlorine or florine or sulphurous compounds.

Copper strip test. Bring a small pan of fuel up to 100C. Hang a strip of polished copper on the rim of the pan so that a part of it is submerged in the fuel. Maintain the temp for 3 hours. Remove the strip and compare the discolouration with a strip tested in normal diesel. Greater discolouration indicated more contamination. Different colours of corrosion indicated different types of contamination.

[jonathan]

plastic to oil

thanks everyone good information keep it up

[waterboost]

Suitable Feedstock

Can we start a list of plastics and their suitability?

ABS - ?
Perspex - ?
Polycarbonate - ?
Polyester - NO
PET - NO (Oxygen)
PVC - CHLORINE (Dioxins)
Polyethylene - OK but Waxy
Polypropylene - Excellent
Polystyrene - Excellent